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| PRELIMINARY CM9112 Dual Inputs Dual Outputs High Accurate Fast Charger Features * * * * * * * * * * * * * * * Monolithic linear charger requires no inductors, external sense resistors or blocking diodes 4.75V to 6.50V operating input voltage range It can support up to 30V on Adaptor input and 7V on USB input Up to 1.5A total system and charging current Provides power to the host system and charges the battery at the same time Supports AC wall adapter and USB input 4.2V/450mA, available for host system under Adapter input It provides 0.5% accuracy of CV mode for 4.2V An optional 0.1F cap on CT pin programs 30 min./ 60 min. timeout for Precharge/Termination. Two Thermal limits controls chip temperature and prevents overheating Remote sensing pin for Battery voltage Pin to pin shortage protection Maximum of 1A battery drain current Optional Battery thermistor (NTC) interface TQFN-16, RoHS compliant lead-free package Product Description The CM9112 is an integrated linear-mode charger for a single-cell, Lithium-ion battery. It provides both charg ing current for the battery and power for the host sys tem. It can deliver charging current up to 1A and system current up to 450mA at the same time. It takes power either from AC Adapter or USB Adapter. When both are present it automatically chooses AC Adapter as input. It requires no external blocking diodes or current sense resistors and uses 2 external resistors to program dif ferent charging current under AC Adapter or USB inputs. The CM9112 provides Precharge Mode, Constant Cur rent Mode (Fast-charge), Constant Voltage Mode and Termination by low current detection. Programmable timeout for Precharge and Termination and Thermistor interface to check Battery Temperature are optional available to the users. The CM9112 is protected against the use of a wrong high voltage Adapter up to 30V. An antiringing protec tion on Adaptor input allows the use of a cheaper adap tor without need of a shock inductor. Pin to pin shortage protection makes it friendly to the users against accidental handling during mounting or checking. The CM9112 is packaged into a miniature 16-pin TQFN package and operates between -40C and 85C ambient. Applications * * * Cellular phones and smart phones Pocket computers and PDAs Digital Still Camera Typical Application AD (AC Adapter ) Q1 10k 1k 1k VIN GAD 33 STAT1 STAT2 VSYS VREF VOUT 4k Q2 0.1u 4.2V/450mA 4.7u VAD USB USB GND ENA ISET1 5k CM9112 Li-ion Battery BSEN THERM ISET2 2.5k CT NTC 0.1u (c) 2006 California Micro Devices Corp. All rights reserved. 07/06/06 SYSTEM 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 1 PRELIMINARY CM9112 Package Pinout PACKAGE / PINOUT DIAGRAM TOP VIEW (Pins Down View) Pin 1 Marking VSYS GAD VAD VIN BOTTOM VIEW (Pins Up View) 13 14 15 16 15 14 13 USB GND ISET1 VREF 1 2 3 4 12 BSEN 11 VOUT 10 THERM 9 STAT1 12 11 10 9 16 1 CM9112 CT 7 STAT2 8 8 7 6 ISET2 5 ENA 6 CM9112-00QE 16-Lead TQFN Package (4mm x 4mm) Note: This drawing is not to scale. PIN DESCRIPTIONS LEAD(s) NAME DESCRIPTION 1 2 USB GND ISET1 USB compliant power input pin. Ground pin. Pin to set the maximum USB input current; Also, reflects actual charging current. A resistor between this pin and ground sets the charge current, ICH, RISET1 = 1000 x 2.5V ----------------------------I CC 3 4 VREF ISET2 4.2V, 2mA reference output pin. Pin to set the maximum charging current in the Fast charge (CC) mode. Also, reflects actual charging current. A resistor between this pin and ground sets the charge current, ICH, 1000 x 2.5V RISET2 = ----------------------------ICC 5 6 ENA CT Enable pin. Logic high (default value) enables charging. Logic low disables charg ing. ENA does not effect the VSYS output. Pin for capacitor, CT, for programming the Precharge and Termination timeout period. Timeout1[min]=300 x CT[F] Timeout2[min]=600 x CT[F] Charging status indicator 2 pin (open-drain output). Charging status indicator 1 pin (open-drain output). Thermistor input pin from battery monitoring circuit. 7 8 9 10 STAT2 STAT1 THERM (c) 2006 California Micro Devices Corp. All rights reserved. 2 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 5 00QE GND PAD 2 3 4 l www.cmd.com 07/06/06 PRELIMINARY CM9112 Ordering Information PIN DESCRIPTIONS 11 12 13 14 15 16 VOUT BSEN VSYS GAD VAD VIN Charger output pin (Battery/RF High Power). Battery voltage remote sense pin. Power output pin to the host system 4.2V/450mA. Gate drive to external P-MOSFET for adapter input pin. Adapter input voltage pin. Positive input supply voltage pin, which powers the charger. PART NUMBERING INFORMATION Lead Free Finish Pins 16 Package TQFN Ordering Part Number1 CM9112-00QE Part Marking CM9112 00QE Note 1: Parts are shipped in Tape & Reel form unless otherwise specified. Specifications ABSOLUTE MAXIMUM RATINGS PARAMETER ESD Protection (HBM) VIN to GND Pin Voltages VAD, GND to GND VOUT, VSYS, USB to GND ENA, ISET1, ISET2 to GND STAT1, STAT2 to GND BSEN, VREF, CT, THERM to GND Storage Temperature Range Operating Temperature Range (Ambient) Lead Temperature (Soldering, 10sec) RATING 1 [GND - 0.3] to +6.5 [GND - 0.3] to +30 [GND - 0.3] to +7.0 [GND - 0.3] to +6.5 [GND - 0.3] to +6.5 [GND - 0.3] to +6.5 -65 to +150 -40 to +85 300 UNITS kV V V V V V V C C C ELECTRICAL OPERATING CHARACTERISTICS (SEE NOTE 1) SYMBOL VAD VUSB IQ PARAMETER VAD Operation range USB Operation range Quiescent Current Charging modes, exclud ing current to and STAT1, STAT2 and THERM pins. CONDITIONS MIN 4.75 4.50 2 TYP 5.0 MAX 6.50 5.25 UNITS V V mA (c) 2006 California Micro Devices Corp. All rights reserved. 07/06/06 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 3 PRELIMINARY CM9112 Specifications (cont'd) ELECTRICAL OPERATING CHARACTERISTICS (SEE NOTE 1) SYMBOL ISHDN PARAMETER Shutdown Supply Current CONDITIONS ENA = "LOW", excluding current to STAT1, STAT2 and THERM pins. Both AC Adapter and USB removed MIN TYP 50 MAX 100 UNITS A IREV Battery Reverse Current 0.5 1 A VAD/USB Supply Voltage UVLOVAD UVLO threshold for VAD OVPVAD OVP threshold for VAD UVLOHYS_VAD UVLO,OVP Hysterezis for VAD Total input current under IIN_AD Adaptor input IIN_USB 4.75 6.2 4.8 6.4 300 4.85 6.5 V V mV VIN=5.0V; Adaptor in IIN_AD = ISYS + IVOUT 1700 IIN_USB = 2500 --------------------------------R SET1(k) mA mA Total input current with USB VIN=5.0V; USB in, Adap plugged-in and Adapter out tor out USB switch Rds(on) Charger Function IPR Precharge Mode Current IIN_USB = 500mA VOUT < 3.2V; Adaptor in 0.85 x IPR 150 IVOUT = 250 IPR = -------------------------R SET2 ( k ) 200 1.14 x IPR m mA VOUT < 3.2V; USB in, Adaptor out VCC ICC CC Mode Voltage Threshold CC Mode Charging Current VOUT > 3.5V; Adaptor in 0.85 x IPR IPR 3.20 0.92 x ICC ICC IVOUT = 250 = -------------------------R SET1 ( k ) 3.30 IVOUT = 2500 = -------------------------R SET2 ( k ) IVOUT = 2500 ICC = -------------------------R SET1 ( k ) 1.14 x IPR mA 3.40 1.08 x ICC 1.08 x ICC V mA VOUT > 3.5V; USB in, Adaptor out 0.92 x ICC mA VCV ITERM CV Mode Voltage Threshold Charging Termination Cur rent VOUT > 4.190V; Adapter in 4.190 0.8 x ITERM 4.200 IVOUT = 25 ITERM = -------------------------R SET2 ( k ) IVOUT = 25 I TERM = -------------------------RSET1(k) 4.100 4.210 1.2 x ITERM V mA VOUT > 4.190V; USB in, Adapter out 0.8 x ITERM 1.2 x ITERM mA VRCH Recharge Mode Threshold 4.090 4.110 V (c) 2006 California Micro Devices Corp. All rights reserved. 4 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 07/06/06 PRELIMINARY CM9112 Specifications (cont'd) ELECTRICAL OPERATING CHARACTERISTICS (SEE NOTE 1) SYMBOL CT OTP OCP RDSON TPR TTER VREF VREF PARAMETER Constant-temperature Mode, Limit Over-temperature Protec tion, Limit Over-Current Charging (OCP), Limit RDSON of Charger MOSFET Precharge Timeout (Note 4) Termination Timeout (Note 4) Regulated Voltage VREF CONDITIONS (Note 2) (Note 3) MIN 95 130 1.5 ICC = 500mA Adaptor in; BSEN < 3.2V, CT=0.1F, 1% Adaptor in; BSEN > 4.19V, CT=0.1F, 1% IREF < 1mA 100 27 54 TYP 105 140 1.7 120 30 60 MAX 125 150 1.8 150 33 66 UNITS C C A m Min. Min. 4.190 4.200 0.25 4.210 V VSYS (Available only with Adapter plugged-in) (Note 5) MOSFET RON RDSON VSYS ISYS ILIMIT Output Voltage Load Regu IOUT = 10mA to 300mA lation IOUT = 10mA to 450mA Output Current available 3.9V 4.3 4.1 450 V V mA mA Over-Current Shut-down (Note 6) Threshold Control Function BSEN Pin Leakage Current VIN = 0 IBSEN VSTAT1 VSTAT2 VIH EN VIL EN STAT1, STAT2 (Open Drain) ISINK = 5mA Output Low Voltage ISINK = 20mA ENA Input High Level ENA Input Low Level VIN = 5.0V (Note 9) VIN = 5.0V (Note 9) 0.2 1.0 0.1 0.5 A V V V 1.5 0.4 0.9 x VBH 0.9 x VBC 80 VBH = 0.5 x VIN VBC = 7/8 x VIN 100 1.1 x VBH 1.1 x VBC 120 V V V mV Thermistor Function (Note 7, 8) VBH Battery HOT Voltage Threshold (THERM Pin) VBC Battery COLD Voltage Threshold (THERM Pin) Hysterezis of VBH, VBC Note 1: TA = 25C unless otherwise specified. Note 2: When chip temperature reaches 105C, the IC's internal thermal limit will maintain this temperature by decreasing the pro grammed charge current. Note 3: When chip temperature reaches 140C, the IC goes into a latched shutdown mode. It stops charging, stops supplying VSYS with current from Adapter/USB, and switches VSYS (Baseband) to VOUT(Battery). To resume the charging function, a tog gle of VAD/USB is required. Note 4: The timeout can be disabled by connecting the CT pin to VIN. When enabled, both Timeout1 and 2 are proportional to the value of the capacitor connected on the pin CT. However, the ratio Timeout2/Timeout1 is constant and equal to two. The tim ing periods are digital, internally generated, based on a clock rate programmable by an external capacitor connected in the CT pin. Timeout feature is available only with AC Adaptor plugged in. Under USB input, both timeout are disabled to allow longer charging time due to low input current available. Note 5: When both the Adapter and USB are removed, VSYS is switched over to battery, through an external MOSFET, Q2. Note 6: When the VSYS maximum current limit is reached, LDO1 regulates this current by decreasing VSYS. However, VSYS can not go below VOUT (battery) by more than one diode's forward voltage (Vfwd) due to the body diode of the external MOS (c) 2006 California Micro Devices Corp. All rights reserved. 07/06/06 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 5 PRELIMINARY CM9112 Specifications (cont'd) FET, Q2. When this condition occurs, the battery will provide extra current to keep VSYS constant at Vbatt-Vfwd. This lasts until the power dissipated in LDO1 triggers the OTP. As a result, there will be no input current to supply either charging or LDO1. Current will still be available from battery to supply VSYS, through the external Q2. To resume charging (after the chip temperature drop bellow 120C), the VAD/USB inputs must be toggled. Note 7: This feature can be disabled by connecting the THERM pin to GND. Note 8: This function requires that Battery Thermistor should be connected between the THERM pin and GND. Another resistor connected between THERM pin and VIN is required, its value should equal the Thermistor Hot Value (at 50C). In order to catch both the 0C and 50C thresholds (typical range for Li-ion battery) use Thermistors following 7/1 ratio (Thermistor COLD/Thermistor HOT=7). Note 9: If the battery HOT/COLD detection identifies a condition outside the thresholds, the IC stops charging the battery and waits for the temperature to return to the normal value. During this event, VSYS will continue to be supplied with the required cur rent. Functional Block Diagram GAD USB VIN Qb VAD OVP & ADOK 0.03 LDO1 450mA OCP S/D LDO2 2mA 4.2V Qc / 1000 OTP VSYS Adapter Current Limit VREF ISET2 Over-Temp Limit Qc VOUT Current Mirror GND BSEN CT Timer Charger Control ENA ISET1 THERM CM9112 STAT2 STAT1 (c) 2006 California Micro Devices Corp. All rights reserved. 6 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 07/06/06 PRELIMINARY CM9112 Flow Chart No No Sleep mode Yes ADOK=1 VIN < BSEN Yes Shut down LDO1 , VREF, Stop Charging Connect VSYS with Battery through external Q2 Iin > 1.5A Tj > 150 oC OCP OTP Precharge Mode CHARGE STATE Precharge in progress Fast charge in progress Charge done Timer fault Sleep mode STAT1 ON ON OFF OFF OFF STAT2 ON OFF ON OFF OFF 4.75V USB > 4.5V ENA = High Yes Set Precharge Mode STAT1=STAT2=ON Start Timeout 1 No Stop charging Set STAT1=OFF, STAT2=OFF ENA has no effects of VSYS output Shut down LDO, VREF, Stop charging and Latch ; Set STAT1=STAT2=OFF Connect VSYS with Battery through external Q 2 Shutdown mode ADOK=1 Yes No Battery hot , cold or removed 2500 RISET2 Stop Charging Set STAT1=STAT2=OFF No 2.5V IVOUT 2500 RISET1 Yes BSEN < 4.200V-100mV Battery Temperature Checking No BSEN > 3.3V CC Mode Yes No ADOK=1 Yes Charge time > Timeout 1 Yes Standby Mode No Charge Done or Battery is not present Timer Fault Stop charging Stop Timeout 2; Set STAT1=OFF STAT2=ON Set CC mode STAT1=ON, STAT2=OFF ADOK=1 Yes Stop charging and Latch. Set STAT1=STAT2=OFF No IVOUT 2500 R ISET1 Yes No Yes Reset Timeout 2 Yes Charge time > No Timeout 2 Yes No IVOUT 2500 R ISET2 IVOUT <= 120 R ISET1 CV Mode No No BSEN >= 4.200V Yes Set CV Mode ADOK=1 Yes Start Timeout 2 IVOUT<= 120 R ISET2 Note: If Therm is used, during any charging mode removing a battery will cause the CV mode then termination, the equivalent , , to charge done. Until the battery is returned, the charger will cycle between standby mode and recharge cycle. - (c) 2006 California Micro Devices Corp. All rights reserved. 07/06/06 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 7 PRELIMINARY CM9112 Application Information The CM9112 is an integrated charger with a charging profile tailored for single-cell graphite electrode (anode) Li-ion batteries. This linear charger can be powered from either an AC voltage-source adapter or a USB port. When both are applied it will automatically select the AC Adaptor source. The charger features the three modes required for a safe and reliable Li-ion charging profile; Precharge, Fast-charge, and Termination charge. Extensive safety features include battery temperature monitoring, volt age and current monitoring and charging time limits. Two charging status indicators provide charge state information. Two different external resistors Riset1,Riset2 allow two different charging current to be programmed for either USB adaptor or AC Adaptor. This method allows an accurate control of USB input current. Under AC Adaptor input both VSYS (host system) and VOUT (battery) are simultaneously supplied with the current required by each oh them, independently. When the absolute over current limit protection is reached (1.5A), CM9112 goes into shutdown, latched mode. Under USB supply, with AC Adaptor out, CM9112 pro vide power only to VOUT. The total current available for VOUT is externally programmed by Riset1. why, under USB input, timeout for charger are disabled. When using AC Adaptor power, CM9112 will automati cally select the resistor Riset2 for charging current. In addition of this it will provide a free current to VSYS directly from Adaptor input through a power LDO. This will be limited to 450mA either by power dissipated on the chip, or absolute current limit. When using a constant-voltage, 5VDC nominal, AC adapter, the semi-regulated voltage to the charger, after accounting for the conduction losses through the power cord and connector contacts, is a voltage in the range of 5.0V to 6.0V. When a valid AC adapter voltage between 4.75V and 6.5V is detected on the VAD pin, an external MOSFET, Q1 is turn ON and VAD and VIN are connected together. An internal power MOSFET used for USB supply, is turned OFF, so there is no residual voltage on USB pin due to VAD supply. The same, when USB is used as input. No residual voltage in VAD pin. Charging Li-ion Batteries Once the CM9112 detects the presence of either a valid AC adapter or USB input voltage, and checks that the battery voltage at BSEN is less then VIN and that the battery temperature is within the correct range, it is ready to charge the Li-ion battery. The controller's internal counter is reset. If the battery voltage is deeply discharged (less than 3.2V), the CM9112 will start in the Precharge mode, charging at 10% of the programmed Fast-charge cur rent level. See Figure 1. While the battery is charging, the status pins will be set to STAT1=0 and STAT2=0. The Precharge current will gradually bring the battery voltage to above 3.2V. If the battery does not reach the 3.2V level, indicative of a defective Li-ion cell, the CM9112 will turn off the charging process after a Precharge timeout period (Timeout1, 30 minutes per 0.1F of CT capacitance). In this case, the status pins will be set to STAT1=VIN and STAT2=VIN. USB/AC adapter dual input The CM9112 can support inputs from either a USB bus or a 5V AC wall adapter. The USB standard specifies a 5.0V +/-5% bus voltage, capable of 500mA (High Power peripheral configura tion) of current. Since desktop and mobile PCs are equipped with USB or USB2 connectors for interfacing with peripherals and digital consumer electronics, it is advantageous to tap the USB's power to charge porta ble devices such as cell phones. When using USB input power, the CM9112 will auto matically select external resistor Riset1 to fix the total input current. This goes only into VOUT pin and is intended to charge the battery. However, the system is connected to the battery through a Schottky diode. This makes possible some current flowing into VOUT pin to go not only into Battery but into System too. A longer charging time will be the result of this. That's (c) 2006 California Micro Devices Corp. All rights reserved. 8 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 07/06/06 PRELIMINARY CM9112 Application Information (cont'd) PreCondition Constant Current Termination CV Current Charging Voltage Charging Current 4.0V (4.20V - VOC) and the internal impedance, Rinternal, of the Li-ion battery-pack. When it reaches termination current limit, stop charging is triggered and the Battery is fully charged. Following the Termination mode, the charger will enter the Standby mode. The status pins will be set to STAT1=VIN and STAT2=0. If the wall adapter or USB input is left plugged-in while in the Standby mode, the charger will continue to mon itor the battery voltage. It automatically re-charges the battery when the battery voltage drops below the re charge threshold. When the adapter is removed, the CM9112 will drain less than 1A from the battery. VIN VOUT I SYS I CH System VBAT 3.0V 2.0V Figure 1. Typical Li-ion Battery Charging Process Once the battery voltage exceeds the 3.3V threshold, the CM9112 enters the Fast-charge, constant-current (CC) mode. The status pins will be set to STAT1=0 and STAT2=VIN. During the CC mode, the charging current is limited by the maximum charging current, pro grammed with a single resistor between ISET1 for USB and ISET2 for adaptor: 2.5V x 1000 IFASTCHG (max) = ------------------------------ RISET1, 2 Conventional Floating Charger Most battery manufactures recommend an optimal charging current for their battery. This is typically a time ratio related to the battery capacity, with a value of .7C to 1C, once the battery is above the Precharge voltage level. For example, a 750mAh capacity battery with recommended charge of .7C could have ICC set for about 525mA, with RISET2 equal to 4.75k, 1%. The actual Fast-charge current might be further limited by the maximum chip temperature limit, determined by the power dissipation on the CM9112 chip, the ambient temperature (TA), and the junction-to-ambient thermal resistance, Rth(JA). The current requested by System, ISYS, might have a significant contribution to the power dissipated on the chip and reduction of the charging current. So, it is recommended to reduce as much as possible the ISYS current during charging. However, there is not timeout for fast charge period. So, there is no risk to stop the charging, just delay of it. When the battery voltage reaches 4.200V it goes into CV mode and CM9112 turn from a constant current source to a constant voltage source. As a result, the charging current start dropping. The actual charging current is now determined by the differential voltage (c) 2006 California Micro Devices Corp. All rights reserved. 07/06/06 Figure 2. Conventional Charger Limitations of Conventional Chargers In a conventional floating charging architecture, the system load is always tied directly to the battery, as shown in Figure 2. If the adapter is charging a deeply discharged battery in the Precharge mode, the system input voltage will be held below 3.2V, the same voltage as the battery voltage. This charger output voltage may be too low to allow a user to use the system, even for non-transmitting (low power) tasks, such as composing emails. Further, in the Precharge mode, the battery charge current is typically limited to 100mA or less. If the system is trying to power up, it may draw more cur rent than the Precharge current limit allows. In this con dition, the system will continue to drain power from the battery, potentially causing the battery charger to remain stuck in a Precharge mode indefinitely. After the Precharge timeout expires, the charger, thinking it has a defective battery, will shut down, and the battery is never charged beyond the Precharge mode. Fax: 408.263.7846 www.cmd.com 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l l 9 PRELIMINARY CM9112 Application Information (cont'd) When using conventional floating charger with the sys tem load connected directly to the battery, and in the CC mode, where a higher current limit is available, for example, the system can draw a continuous load cur rent of 300mA. However, since the system is always tied to the battery, the charger IC has no way to differ entiate the system power demand from the battery charging demand. The charger will limit the total output current to 300mA for the system and 1A for charging the battery. If the battery voltage is low, 3.2V for exam ple, the charger IC power dissipation will be at its worst case, or 3.6W. The charger's junction temperature rises quickly, triggering the over-temperature (OT) cur rent foldback. If the system continues to draw a large current, the battery will then be supplying part of that load current; putting the battery is in a discharge mode, rather than in a charge mode. The battery voltage will continue to drop, potentially falling back into a Precharge mode condition, and upsetting the charging sequence or forcing the charger to shut down. Even the charger power dissipation due to the system load alone: PD1 = 1.0A x (5V - 3.2V)= 1.8W VIN LDO1 VSYS 4.2V I SYS VREF System CM9112 VOUT Charger BSEN ICH VBAT Figure 3. Dual Outputs Charger Since the CM9112 provides an independent power path to the system, as soon as an adapter is pluggedin, the user can use the system power, even if the bat tery is dead or in the Precharge mode. Charging Current Foldback in the Overtemperature Condition A limitation of linear chargers is that they are vulnera ble to over-temperature conditions. The CM9112 will throttle down the charging current when the chip junc tion temperature reaches 105C (with 10C of hys terezis). This protects the charger IC and its nearby external components from excessive temperature. The Charger IC junction temperature is determined by several factors in the following equation: TJ = TA + PD + Rth(JA) (1) may already exceed the chip's thermal limit and cause OTP to trigger. The CM9112 Dual Outputs Charge Advantage To overcome these issues, the CM9112's Fast-charge architecture separates the system power output (LDO1) from the battery charging power output. See Figure 3. With a separate output, the power dissipation contributed by LDO1 in a condition similar to the one above is now only: PD1 = 1.0A x (5V - 4.2V)= 0.8W In other words, the LDO1 can support the system load, free from the hindrance of the charger, regardless of the battery voltage level. The user can continue use the host system, even when the battery charge voltage is very low, when there is a defective battery, or there is no battery present. The Rth(JA) is usually determined by the IC package and the thermal resistance between the package and the PC board. In particular, a SMD IC package relies on the underlying PC board copper to move the heat away from the junction. The key to reducing the ther mal resistance between the IC package and the under lying PC board is using a large copper (Cu) area for solder attach and a large ground plane underneath the charger IC to conduct the heat away. The power dissipation (PD in equation 1) of a linear charger is the product of input-output voltage differen tial and output current. (c) 2006 California Micro Devices Corp. All rights reserved. 10 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 07/06/06 PRELIMINARY CM9112 Application Information (cont'd) PD = (V IN - V OUT ) x IOUT The Need for OVP There are two primary reasons for adding an input OVP feature to the CM9112 charger. One is to protect the charger and the host system when an adapter with the wrong output voltage is plugged-in. The other is to protect the charger IC and the system against input surge voltage resulting from the ringing due to the input capacitor and an inductive adapter power cord. Almost all computer peripherals and consumer elec tronics use AC adapters. It is common to use an LCD monitor, a printer, a laptop computer, an ADSL or cable modem, a cell phone, an MP3 player, with all their indi vidual AC adapters clustered around a power strip. The output voltages of these adapters vary, yet most of these use a similar cylindrical style connector at the device interface. Thus, the chance that a user might plug-in a wrong adapter should not be taken lightly. The CM9112 provides over-voltage protection (OVP) against the plug-in of a wrong adapter, up to an output voltage of 30V. The CM9112 drives a 30V P-type power MOSFET as a disconnect switch. The propri etary OVP design of the CM9112 protects itself and the host system against the intermittent connection of a wrong adapter. Another source of over-voltage comes from voltage ringing that occurs when an adapter is first plugged-in, as shown in Figure 4. A long power cord from the adapter output can have an inductance of several H, and the input capacitor of a cell phone is typically a 10F to 100F ceramic, with very low ESR. Unfortu nately, the low resistance in the power cord and the low ESR of the input capacitor provide little dampening to this LC circuit, resulting in strong ringing, with input voltage overshoot, when the adapter is first plugged-in. The ringing could apply a peak voltage twice that of the nominal adapter output voltage at the input capacitor point. The CM9112 can withstand several forms of OVP con ditions; DC, DC with ringing, or intermittent contact of any frequency. In most cases, VIN is fixed at about 5.0V (either the AC adapter or the USB power input). The CM9112 has two outputs; one for the charger and one for the system from LDO1. The total power dissipation is: PD = (5V - 4.2V) x ISYS + (5V - V BAT ) x I FASTCHG Highest power dissipation occurs when the battery at its lowest level (3.2V), when it just starts in the Fastcharge (CC) mode. Assuming VIN = 5.0V, VBAT = 3.2V, ICC = 1A, the PD = (5V-3.2V) x 1A = 1.8W. Assuming Rth(JA) = 50C/W, then T = 1.8W x 50C/W = 90C. If the ambient temperature (TA) is 35C, then the junction temperature (TJ) could reach 125C without over-tem perature current foldback. With over-temperature (OT) current foldback, the CM9112 will throttle down the charging current, allow ing the junction temperature will reach steady-state equilibrium of 105C, which translates into 1.4W of power dissipation, or 0.78A of charge current. As the battery voltage rises during charging, the allowable PD dissipation is increased. When the battery voltage reaches 3.6V, a full 1.0A of charging current is allowed. Dual-Level OTP and OCP In addition to chip temperature regulation at 105C, the CM9112 provides absolute over-temperature shutdown protection. In the case of a malfunctioning charger con trol, high ambient temperature or an unexpectedly high IC thermal resistance, Rth(JA) (for example; due to faulty soldering of the charger IC chip), the power dissi pation from LDO1 alone could over-heat the device. The CM9112 provides an absolute OTP shutdown at junction temperature of 150C. Similarly, each output, LDO1 and VOUT (ISET2), has its own current limit. ISET1 provides the total adapter current limit for adaptive charging current control. How ever, in case of an inoperative ISET2 setting (for exam ple; RISET2 becomes shorted to ground), ISET1 will function as backup over-current protection. Combining the dual-level OTP and the dual-level OCP, the CM9112 in effect provides four layers of protection against charger or VSYS over-load faults. (c) 2006 California Micro Devices Corp. All rights reserved. 07/06/06 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 11 PRELIMINARY CM9112 Application Information (cont'd) reaches the normal operating temperature range. Charging below freezing must be avoided because plating of lithium metal could occur. Battery capacity will be reduced if charged between 0C and +10C due to the inefficient charging process at low temperatures. The CM9112 has incorporated a thermistor interface, responsible for the temperature control of the batterypack through a negative temperature coefficient (NTC) thermistor attached near the battery-pack. The inter face surveys the voltage on the THERM pin, which an input to a window comparator with thresholds associ ated with two battery-pack fault conditions: Vtherm<1/2 x VIN for Battery Hot Vtherm>7/8 x VIN for Battery Cold To avoid oscillation near the Vtherm thresholds, both windows have an associated hysteresis of 200mV. Rc(28K) 30K 20K 10K 0 COLD 7/8*Vin Thermistor Resistance Q1 Gate Drive Vdc Figure 4. Q1 Response to Undamped Ringing at the Input Charging status CM9112 provides two charging status indicator pins: STAT1 and STAT2. These are open-drain outputs, which can drive LEDs directly, with up to 20mA of cur rent sinking capability. Alternatively, the system super visory microprocessor can monitor the battery charging status by interfacing with these two pins, using a 100k pull-up resistor for each pin. See Table 1. CHARGE STATUS Precharge in progress Fast-charge in progress Charge completed Charge suspended (including thermistor fault, Precharge or Termination timeout, OTP, OCP and ENA pulled low) STAT1 Low Low High STAT2 Low High Low - + Vtherm OK Rh(4K) 1/2*Vin HOT 0oC 20oC 40oC 60oC High - High - Figure 5. Vtherm Windows Table 1: Charge Status for STAT1, STAT2 Thermistor Interface Li-ion batteries are prone to overheating when exposed to excess current or voltage. High heat, combined with the volatile chemical properties of lithium, can cause fire in some cases. The CM9112 provides a thermal interface for over-temperature protection, allowing safe charging of Li-ion cells. For safety, manufacturers suggest suspending any charging above 45C and below 10C until the battery (c) 2006 California Micro Devices Corp. All rights reserved. If the voltage on the THERM pin either exceeds 7/8 x VIN, or goes below 1/2 x VIN, the CM9112 stops charg ing and STAT1, STAT2 signal a fault condition (both go high). LDO1 remains fully functional and continues to provide the necessarily current to VSYS (the Base band load). The charging resumes only when the volt age on the THERM pin returns to within the window of 1/2 x VIN to 7/8 x VIN. Figure 5 illustrates these win dows. The thermistor interface consists of a thermistor con nected between THERM pin and ground, and a resis tor, Rtherm, connected between the THERM pin and 12 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 07/06/06 PRELIMINARY CM9112 Application Information (cont'd) VIN, as shown in Figure 6. To determine the proper value for Rtherm, the thermistor used in the batterypack should follow the 7:1 ratio on the Resistance vs. Temperature curve (for example, Vishay Dale's R-T Curve 2): * R cold (at 0C) --------------------------------------- = 7 Rhot (at 50C) Because the thermistor is typically located on the bat tery-pack, removal of the battery-pack will remove the thermistor, and cause value of voltage at the THERM pin to go above the window and thus stop charging. This allows the THERM interface to function also as a battery present detector. When using the CM9112 with a dummy battery, without a thermistor attached, this function can be disabled by connecting the THERM pin to GND. In this case, the THERM interface will never provide a fault condition to stop charge. If there is no need for the thermistor interface, the THERM pin could be used as a second ENABLE pin for charging control. If the system has an additional control condition for stop charge, then the THERM pin could be used as a second control input. Connecting the THERM pin to VIN will stop charging, while pulling to GND will resume charging. A thermistor with a room temperature value of about 10k, or higher, will keep the interface current drain from VIN low. Choose the Rtherm value equal to Rhot, with a 0.5% tolerance. A metal film resistor is best for temperature stability. For example, a typically used thermistor for this appli cation is Vishay Dale's NTHS0603N02N1002J. This thermistor has a Rhot (50C) = 4k and Rcold (0C) = 28k. The thermistor interface will work properly if Rtherm is 4.02k, 0.5%. At 25C the thermistor value is 10k. Therefore, a value of voltage at the THERM pin will be: 10k Vtherm= x5V = 3.57V 25o C 14k Vtherm= 4k x5V = 2.5V 50o C 8k 28k x5V = 4.375V 0o C 32k Timeout Intervals A programmable timer is used to terminate the Precharge and Termination charge modes. There are three modes in a normal charging procedure; Precharge, Fast-charge (or CC Mode), and Termination (or CV Mode). Because the first and the third modes take place at low currents, any failure of the battery (for example, excessive leakage current) could cause these modes to continue indefinitely if there was not a Timeout limit. CM9112 provides two Timeout intervals: Timeout1, which limits Precharge time and Timeout2, which limits the Termination time. These intervals are digitally pro duced based on an internal clock signal. Timeout1 counts 131072 (217) clock cycles and Timeout2 counts 262144 (218) clock cycles. The ratio of Timeout2/ Timeout1 = 2 is fixed by the design, but the absolute Timeout values are programmable by an external capacitor, Ct, connected between the CT pin and GND. This capacitor is responsible for the clock cycle rate. Timeout1 time can be calculated as: Vtherm= VIN Rtherm (4k) THERM NTC VOUT Battery Pack Vishay NTHS0603N02N1002 J Thermistor Interface CM9112 Charger BSEN Timeout 1 = 217 x Figure 6. NTC Thermistor Interface 13.6ms Ct (in minutes) 0.1uF 60 (c) 2006 California Micro Devices Corp. All rights reserved. 07/06/06 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 13 PRELIMINARY CM9112 Application Information (cont'd) A value of 0.1F provides a 13.6ms clock cycle period, producing 30 minutes for Timeout1 (Precharge) and 60 minutes for Timeout2 (Termination),. When VIN is applied to a fully discharged battery (VBAT<3.0V), the internal counter starts counting clock cycles for Timeout1. A constant Precharge current (10% of the programmed Fast-charging current) then charges the battery. If Timeout1 elapses before the battery reaches the 3.3V threshold of the Fast-charge (CC) mode, charging stops and a Charge Suspended fault is signaled by the status pins (STAT1=STAT2=VIN). This is a latched status and charging can only resume by toggling VIN. If the battery voltage attains 3.3V before Timeout1 elapses, the internal counter is reset without any action from the charging algorithm and the battery goes into the Fast-charge mode. During the Fast-charge mode, there is no Timeout counting, and, in theory, this mode can last indefinitely. During Fast-charge, the battery could be providing cur rent to a load. With only part of the available charging current going into the battery, the charging time will increase and becomes unpredictable. Thus, a Timeout interval during this mode is not used, allowing greater application flexibility. Once the battery reaches the 4.20V threshold, the Ter mination (CV) mode begins and the charging current starts to decrease. At the same time, the internal clock starts counting again. If Timeout2 elapsed before the Termination current threshold is reached, charging stops in a latched status (STAT1=STAT2=VIN). It can resume only by toggling VIN. If the Termination thresh old is reached before Timeout2 has elapsed, the counter resets and the charger enters into the Standby mode. If a stop charge to the battery is triggered by Timeout1/ Timeout2, it should be noted that VSYS would continue to provide power to the Baseband load. tion. The charging algorithm then will be controlled only by voltage on the BSENS pin (Battery Sense Voltage). Mode Summary Precharge mode is the typical charge starting mode for pre-conditioning a deeply discharged battery (<3.3V). A constant current of 10% of the programmed Fast-charge current is applied to raise the voltage safely above 3.3V. The maximum charge time is limited to the programmed Timeout1 period. Fast-charge mode is the constant current charging mode that applies most of the battery charge. A pro grammed constant current is applied to bring the bat tery voltage to 4.2V. Termination mode is the final charging mode, where a constant voltage of 4.2V is applied to the battery until the charge current drops below 5% or the programmed Fast-charge current. The charging time is limited by the programmed Timeout2. Standby mode is entered after a successful Termina tion mode and charging is done. Charging stops but VSYS continue to be supplied by AC Adaptor input. In this mode, the battery is monitored, and when its volt age drops below the re-charge threshold (4.100v), a new charge cycle begins. Shutdown- not latched mode is triggered by a charg ing fault. These include THERM pin voltage outside the window (battery is too hot, too cold, or removed), or pulling ENA pin low. The charging resumes if the failure condition is removed. VSYS is still alive and supply SYSTEM with current. Shutdown- latched mode Disabling the Timeouts To allow design flexibility for many different applica tions, the CM9112 allows disabling the Timeout inter vals as an option. If the application does not require Timeout Intervals to control Precharge and Termina tion, connecting the CT pin to VIN will disable the func If input current, sensed internally, exceeds 1.5A (OCP), or the IC junction temperature exceeds 150C (OTP). The shutdown happens again but this time it is latched. Only by toggling VAD/USB and removing the failure condition the CM9112 could resume the function. VSYS is no more supplied with current and an external Q2 MOSFET connect VSYS with the Battery which become the system power supplier. Timer-fault mode is entered when a Timeout ends without the battery reaching the proper threshold. Charging stops and remains stopped until VIN is tog gled. VSYS will continue to receive power through LDO1. (c) 2006 California Micro Devices Corp. All rights reserved. 07/06/06 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 14 PRELIMINARY CM9112 Application Information (cont'd) Sleep mode is entered when the Adapter or USB is removed (or is the wrong voltage). Charging stops and VSYS is connected to the battery through Q2. In this mode, the CM9112 draws less than 1A of current from the battery. Smartphones are available in the two leading cell phone topologies, CDMA and GSM. They each have unique power demands. The GSM is a TDMA (Time Division Multiple Access) system where up to eight users share a transmitting frequency channel. During transmitting, a GSM phone can draw up to 2.0A of pulse current from the battery (588 s pulse width, at a duty cycle of 1/8). When charging the cell phone battery and using the cell phone at the same time, the power amplifier still needs to draw 2A pulse current, which cannot be met with an adapter having less than 2A of rated output current capacity. Most adapters are rated at only 1A. In order to charge the battery and use the phone at the same time, the high-power section (mainly the RF power amplifier), has to be supported by the battery at all times, even when the adapter is plugged-in. See the typical configuration in Figure 7. With a discharged battery, the charger begins in the Precharge mode, which will only supply 100mA or less of charging current. In the case of very low battery volt age (typically below 3.2V), the cell phone is prohibited from transmitting and drawing large current from the battery. The CM9112, with its integrated 4.2V, 450mA LDO out put, can support the low-power section of a cell phone, such as the system microprocessor, LCD display and LED backlight for the user interface. In addition, the CM9112 can supply power to the system for non-trans mitting application such as reading and composing email messages, or synchronizing data transfers between a cell phone and a PC. The CDMA phone demands lower peak current during transmitting, typically 600mA peak. All the system power can be supplied by LDO1 when configured as shown in Figure 8. Typical Smartphone Applications A Smartphone is a cellular or mobile phone with special computer-enabled features not previously associated with telephones, such as advanced data functions. Most mobile phone includes some amount of memory uses such as storing a phone directory, and most can send and receive text messages, but a smartphone can perform many more functions, including PDA, an internet browser, a TV receiver, a multi-pixel camera, or an MP3 player. Compared to standard cell phones, smartphones usually have larger, more colorful displays, contain processors that are more powerful, and typically run operating system software. These features are all packed into a smaller box. This sophistication requires more battery power than a simple cell phone. 1. In normal battery operation Q2 is turned , on, the battery supplies power to both the RF and Baseband loads . 2. GSM transmitter requires up to 2.0A of pulse current. In the charging phase both , the battery and adapter supply current for the RF load. GAD VIN Baseband Load 33u VREF 0.1u VOUT Adapter Q1 10u 100 LDO1 VAD 0.1u VSYS Q2 LDO2 Charger RF Load BSEN CM9112 GSM Phone Figure 7. GSM phone application (c) 2006 California Micro Devices Corp. All rights reserved. 07/06/06 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 15 PRELIMINARY CM9112 Application Information (cont'd) 1. In normal battery operation Q2 is , turned on, the battery supplies power to the system load. 2. CDMA transmitter requires less than 500mA current. In the charging phase the , adapter alone can supply enough power for the CDMA system load. GAD VIN VSYS System Load 33u VAD 0.1u Adapter 5V Adapter Q1 10u 100 Q1 GAD VIN IIN < ISET 1 = LDO1 LDO2 VREF 0.1u VOUT USB LDO1 Q2 VSYS 0.03 Qb 4.2V LDO2 2mA VREF I SYS Q2 Charger CM9112 BSEN VOUT CDMA Phone CM9112 Qc GND VBAT I CH Figure 8. CDMA phone application Component Selection The constant voltage AC Adapter must be selected carefully to minimize power losses and heat dissipation in the charger. The input supply should be between 5.0 and 6.0V. The lowest allowable input voltage will mini mize heat dissipation and simplify the thermal design. An Adapter rated at 5.0V, 5% at the required input cur rent will provide adequate voltage for the VAD ADOK window. The output of LDO1, VSYS, requires a 33F or larger capacitor for good stability and minimum voltage droop during the battery switchover to VSYS at the end of charge. A low-ESR type capacitor will improve system response to load transients. The output of VREF (LDO2), the Q2 gate drive, requires a .1F ceramic capacitor for stability. The CM9112 drives two external P-channel MOSFETs (PMOS) to control the charging and system currents. Refer to Figure 9. The most important specifications for the pass PMOS transistors are current rating, RDS and package power dissipation. Figure 9. Current paths In normal operation, Q1 is a fully turned-on switch when an AC adapter is used. The worse-case power dissipation for the input PMOS, Q1, is: PQ1 = ISET1 RDS The MOSFET Q1 and PCB heatsink must be rated for this power. Q1 functions as a clamp to limit input volt age transients, and should be selected to handle the worst-case Drain-to-Source voltage, 30V is suggested. The RDS of Q1 should be low enough so that the volt age drop across it will not cause VIN to drop below the minimum of 4.5V when the adapter is at its lowest out put. For example, if the adapter is 4.75V minimum at a load of 1.0A and ISET1 is programmed to 1.0A: R DS (4.75 V 4 .5 V ) = 250 m 1 .0 A 2 Q2 is used to supply power to the system from the bat tery when not charging (adapter removed, end-of charge, OCP, OTP, etc.). This current passed through Q2. The worse case power dissipation for Q2 would (c) 2006 California Micro Devices Corp. All rights reserved. 07/06/06 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 16 PRELIMINARY CM9112 Application Information (cont'd) occur when LDO1 is disabled and the battery must supply full system load. PQ2 = Isys RDS The Q2 and PCB heatsink must be rated for this power. 2 Layout Considerations Because the internal thermal foldback circuit will limit the current when the IC reaches 105C it is important to keep a good thermal interface between the IC and the PC board. It is critical that the exposed metal on the backside of the CM9112 be soldered to the PCB ground. The Cu pad should is large and thick enough to provided good thermal spreading. Thermal vias to other Cu layers provide improved thermal perfor mance. VIN, VSYS and VOUT are high current paths and the traces should be sized appropriately for the maximum current to avoid voltage drops. BSEN is the battery feedback voltage and should be connected with its trace as close to the battery as possible. (c) 2006 California Micro Devices Corp. All rights reserved. 07/06/06 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 17 PRELIMINARY CM9112 Mechanical Details TQFN-16 Mechanical Specifications The CM9112-00QE is supplied in a 16-lead, 4.0mm x 4.0mm TQFN package. Dimensions are presented below. For complete information on the TQFN16, see the Cal ifornia Micro Devices TQFN Package Information doc ument. Mechanical Package Diagrams D PACKAGE DIMENSIONS Package Leads Dim. A A1 A3 b D D1 D2 E E1 E2 e L # per tape and reel 0.45 2.00 2.00 3.90 0.25 3.90 Millimeters Min 0.07 0.00 0.20 REF 0.30 4.00 1.95 REF 2.10 4.00 1.95 REF 2.10 0.65 TYP. 0.55 0.65 0.018 3000 pieces E2 TQFN-16 (4x4) 16 Inches Max 0.80 0.05 0.35 4.10 2.20 4.10 2.20 Min 0.28 0.00 .008 0.010 0.154 0.079 0.154 0.079 0.012 0.157 0.077 0.083 0.157 0.077 0.083 0.026 0.022 0.026 0.087 D1 E Pin 1 Marking Nom 0.030 Max 0.031 0.002 0.014 0.161 0.08 C 0.10 C Nom 0.75 0.15 C 0.15 C TOP VIEW 0.087 0.161 SIDE VIEW A3 A1 A Controlling dimension: millimeters E1 D2 L DAP SIZE 1.8 X 1.8 e b 16X 0.10 M CAB BOTTOM VIEW Package Dimensions for 16-Lead TQFN (c) 2006 California Micro Devices Corp. All rights reserved. 07/06/06 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: 408.263.3214 l Fax: 408.263.7846 l www.cmd.com 18 |
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