 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| Freescale Semiconductor Advance Information Document Number: MC34675 Rev. 3.0, 4/2008 28V-Input-Voltage Single-Cell Li-Ion Battery Charger with 10mA Regulator The 34675 is a high-input-voltage Li-Ion battery charger with a 4.85V/10mA linear regulator. The high input voltage, up to 28V, eliminates the input over-voltage protection circuit required in handheld devices such as cell phones, Bluetooth accessories, and portable media players. The 4.85V linear regulator is capable of 10mA output current and can be used to directly power a sub-system such as a USB transceiver. The charge cycle of the 34675 includes trickle, constant-current (CC) and constant-voltage (CV) charge modes. The CC mode current is programmable up to 1A, with an external resistor. The voltage across the external resistor is also used to monitor the actual charge current. The constant voltage is fixed at 4.2V with 0.7% accuracy over the -40C to 85C temperature range. The trickle-mode current is pre-set to 20% of the CC mode current when the battery voltage is lower than the trickle-mode threshold. The end-of-charge (EOC) current threshold is pre-set to 10% of the CC mode current, to save board space and cost. A charge current thermal foldback feature limits the charge current when the IC internal temperature rises to the preset threshold of 120C. The 34675 also protects the system with its input overvoltage protection (OVP) feature. Two indication pins (PPR and CHG) can be simply interfaced to a microprocessor or LEDs. When no power supply is connected, or when disabled, the charger draws less than 1.0A leakage current from the battery. Features * * * * * * * * * * 34675 POWER MANAGEMENT IC EP SUFFIX (PB-FREE) 98ASA10774D 8-PIN UDFN ORDERING INFORMATION Device MC34675AEP/R2 Temperature Range (TA) -40C to 85C Package 8-UDFN No external MOSFET, reverse-blocking diode, or current-sense resistor is required Guaranteed maximum 1A programmable CC mode current 0.7% voltage accuracy over -40C to 85C 6% current accuracy over -40C to 85C 4.85V/10mA linear regulator with a 6.8V input over-voltage protection threshold 28V maximum voltage for the power input with a 6.8V over-voltage protection threshold Trickle charge for fully discharged batteries Charge current monitor Charge current thermal foldback Pb-free packaging designated by suffix code EP VIN CIN 34675 VIN GND BAT COUT ISET CHG PPR OFF EN ON DET CDET RISET TO SYSTEM TO BATTERY Figure 1. 34675 Simplified Application Diagram * This document contains certain information on a new product. Specifications and information herein are subject to change without notice. (c) Freescale Semiconductor, Inc., 2008. All rights reserved. INTERNAL BLOCK DIAGRAM INTERNAL BLOCK DIAGRAM VIN BAT VIN Monitor Internal Supply Linear Reg REF - + VREF Charge Control - + ISET DET VIN + - BAT CHG EN Logic Control VOS + - - + IREF Die Temp 120C PPR + - IEOC GND Figure 2. 34675 Simplified Internal Block Diagram 34675 2 Analog Integrated Circuit Device Data Freescale Semiconductor PIN CONNECTIONS PIN CONNECTIONS VIN Transparent Top View PPR CHG EN 1 2 EPAD 3 4 8 7 6 5 BAT ISET DET GND Figure 3. 34675 Pin Connections Table 1. 34675 Pin Definitions A functional description of each pin can be found in the Functional Pin Description section beginning on page 12. Pin Number 1 2 3 4 5 6 7 Pin Name VIN PPR CHG EN GND DET ISET Pin Function Input Output Output Input Ground Output Output Formal Name Input supply Power present indicator Charge indicator Enable Ground Regulator output CC mode current setting and charge current monitor Charger output Exposed pad The power supply input. Indication of the input power status. Open drain output. Indication of the charge status. Open drain output. Enable logic input. Ground. The 4.85V/10mA linear regulator output. CC mode current setting and charge current monitoring pin. Definition 8 EPAD BAT EPAD Output N/A The charger output pin. Connect this pin to the Li-Ion battery. The exposed pad for thermal dissipation enhancement. It must be soldered on the large ground plane on the PCB to increase the thermal dissipation. The pad must be connected to GND electrically 34675 Analog Integrated Circuit Device Data Freescale Semiconductor 3 ELECTRICAL CHARACTERISTICS MAXIMUM RATINGS ELECTRICAL CHARACTERISTICS MAXIMUM RATINGS Table 2. Maximum Ratings All voltages are with respect to ground unless otherwise noted. Exceeding these ratings may cause a malfunction or permanent damage to the device. Ratings ELECTRICAL RATINGS Input Voltage Range VIN Pin PPR and CHG Pins EN, BAT, ISET and DET Pins ESD Voltage(1) Human Body Model (HBM) Machine Model (MM) THERMAL RATINGS Operating Temperature Ambient Junction Storage Temperature Thermal Resistance(2) RJC RJA Reflow(3),(4) TPPRT 10 70 Note 4 C TA TJ TSTG -40 to +85 -40 to 150 -65 to +150 C C/W C VESD VIN VPPR, VCHG VEN, VBAT, VISET, VDET -0.3 to 28 -0.3 to 12 -0.3 to 5.5 V V Symbol Value Unit 2000 200 Junction-to-Case Junction-to-Ambient Peak Package Reflow Temperature During Notes 1. ESD testing is performed in accordance with the Human Body Model (HBM) (CZAP = 100pF, RZAP = 1500), and the Machine Model (MM) (CZAP = 200pF, RZAP = 0). 2. 3. 4. Device mounted on the Freescale EVB test board per JEDEC DESD51-2. Pin soldering temperature limit is for 10 seconds maximum duration. Not designed for immersion soldering. Exceeding these limits may cause malfunction or permanent damage to the device. Freescale's Package Reflow capability meets Pb-free requirements for JEDEC standard J-STD-020C. For Peak Package Reflow Temperature and Moisture Sensitivity Levels (MSL), Go to www.freescale.com, search by part number [e.g. remove prefixes/suffixes and enter the core ID to view all orderable parts. (i.e. MC33xxxD enter 33xxx), and review parametrics. 34675 4 Analog Integrated Circuit Device Data Freescale Semiconductor ELECTRICAL CHARACTERISTICS STATIC ELECTRICAL CHARACTERISTICS STATIC ELECTRICAL CHARACTERISTICS Table 3. Static Electrical Characteristics Characteristics noted under conditions VIN = 5V, -40C TA 85C, CIN = 1.0F, COUT = 2.2F, CDET = 0.22F (see Figure 1), unless otherwise noted. Typical values noted reflect the approximate parameter means at VIN = 5V and TA = 25C under nominal conditions, unless otherwise noted. Characteristic POWER INPUT VIN Pin Normal Operation Input Voltage Range(5) VIN Pin Supply Current Charger enabled(6) Charger disabled Regulated Output Voltage VIN = 5.0V; IBAT = 10mA; TA = 25C VIN = 5.0V; IBAT = 10mA; TA = -40 to 85C Power MOSFET On Resistance VBAT = 4.0V; IBAT = 400mA; ICHG = 500mA BAT Pin Standby Current VIN not powered or charger disabled Power On Reset Rising VIN threshold Falling VIN threshold VIN-BAT Offset Voltage Rising threshold Falling threshold Over-voltage Protection Rising Threshold Over-voltage Protection Threshold Hysteresis CHARGE CURRENT Constant Current Mode Charge Current Range(7) ICHG Accuracy For ICHG between 300mA to 1000mA (tested at 450mA) For ICHG between 50mA to 300mA(7) Trickle-Mode Charge Current End-of-Charge (EOC) Threshold When ICHG >300mA (tested at ICHG=450mA) When ICHG <300mA(7) ISET-Pin Voltage for ICHG Reference VISET ITRKL IEOC 8.5% 8.0% 10% 10% 1.0 11.5% 12% V ICHG ICHG 94% 90% 18% 100% 100% 20% 106% 110% 22% ICHG ICHG 0.05 1.0 A ICHG VOVP VOVPHYS VOS 1.0 6.6 6.8 200 60 22 7.0 V mV VPOR 3.5 2.4 3.6 2.5 3.7 2.6 mV ISTDBY 1.0 V RDS(ON) 330 475 A VBAT 4.185 4.170 4.20 4.20 4.215 4.230 m VIN IIN 1400 360 2000 450 V 2.6 6.6 V A Symbol Min Typ Max Unit Notes 5. Refer to the Power-on-Reset parameter for VIN turn on and turn off values. 6. 7. Supply current does not include the current delivered to the battery through the BAT pin. Not tested. The accuracy is guaranteed by design. 34675 Analog Integrated Circuit Device Data Freescale Semiconductor 5 ELECTRICAL CHARACTERISTICS STATIC ELECTRICAL CHARACTERISTICS Table 3. Static Electrical Characteristics (continued) Characteristics noted under conditions VIN = 5V, -40C TA 85C, CIN = 1.0F, COUT = 2.2F, CDET = 0.22F (see Figure 1), unless otherwise noted. Typical values noted reflect the approximate parameter means at VIN = 5V and TA = 25C under nominal conditions, unless otherwise noted. Characteristic CHARGE THRESHOLDS Trickle Mode Rising Threshold Voltage Trickle Mode Threshold Voltage Hysteresis Recharge Threshold Voltage Recharge Falling Threshold Voltage Hysteresis LINEAR REGULATOR Output Voltage VIN = 5.2V, Output Current < 10mA, IBAT = 0mA Dropout Voltage VIN = 4.7V, Output Current = 10mA, IBAT = 0mA Output Current Limit Output Pull-down Resistance 2.0V < VIN < VPOR or VIN > VOVP LOGIC INPUT AND OUTPUT EN Input High Threshold Voltage EN Input Low Threshold Voltage EN Input Pull-down Current VEN = 3V PPR and CHG Sink Current when the Output is Low VCHG = VPPR = 0.6V PPR and CHG Leakage Current When the Output is High-impedance VCHG = VPPR = 5.0V CHARGE CURRENT THERMAL FOLDBACK Current Foldback Die Temperature Limit TLIMIT 100 120 140 C IPCLEAKH 1.0 IPCSINKL 9.0 15 A VIH VIL IEN 2.0 7.5 mA 1.5 0.5 V V A IREGLMT RREGPD 200 VDO 10 90 13 150 16 mA k VLR 4.6 4.85 5.0 mV V VTRKL VTRKLHYS VRECH VRECHHYS 2.6 40 4.075 2.7 100 4.100 25 2.8 150 4.125 50 V mV V mV Symbol Min Typ Max Unit 34675 6 Analog Integrated Circuit Device Data Freescale Semiconductor ELECTRICAL CHARACTERISTICS DYNAMIC ELECTRICAL CHARACTERISTICS DYNAMIC ELECTRICAL CHARACTERISTICS Table 4. Dynamic Electrical Characteristics Characteristics noted under conditions VIN = 5V, -40C TA 85C, CIN = 1F, COUT = 2.2F, CDET = 0.22F (see Figure 1), unless otherwise noted. Typical values noted reflect the approximate parameter means at VIN = 5V and TA = 25C under nominal conditions, unless otherwise noted. Characteristic END OF CHARGE EOC Filter Time OSCILLATOR Oscillation Frequency fOSC 40.0 50.0 60.0 kHz tEOC 6.0 8.0 12 ms Symbol Min Typ Max Unit 34675 Analog Integrated Circuit Device Data Freescale Semiconductor 7 ELECTRICAL CHARACTERISTICS ELECTRICAL PERFORMANCE CURVES ELECTRICAL PERFORMANCE CURVES 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 0 30 60 450 400 Battery Voltage 350 300 250 200 Charge Current 150 100 50 0 90 120 150 180 210 240 Time (min) 16 Charge Current (mA) Battery Voltage (V) 12 IBAT (A) 8 4 0 -4 0 1 2 3 VBAT (V) 4 5 Figure 4. Complete Charge Cycle VIN = 5.0V, ICHG=400mA, 740mAh Li-Ion Battery, TA=25C Figure 7. BAT Pin Current vs Battery Voltage in OVP VIN = 7.0V, TA = 25C BAT Pin Output Voltage (V) 4.3 4.2 4.1 4.0 3.9 3.8 3.7 3.6 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 Constant Charge Current (mA) 1200 1000 800 600 400 200 0 3.5 4.0 4.5 5.0 5.5 6.0 Input Voltage (V) 6.5 7.0 RISET=7.9 k RISET=3.95 k RISET=15.8 k Input Voltage (V) Figure 5. Charger Output Voltage vs VIN IBAT = 0mA, TA = 25C Figure 8. Constant Charge Current vs VIN VBAT = 3.7V, TA = 25C Trickle Charge Current (mA) VIN Pin Supply Current (A) 2100 1800 1500 1200 900 600 300 0 3 4 5 6 Input Voltage (V) 7 Charger Disabled Charger Enabled 250 RISET=3.95 k 200 150 RISET=7.9 k 100 RISET=15.8 k 50 0 3 4 5 6 Input Voltage (V) 7 Figure 6. VIN Pin Supply Current vs VIN IBAT = 0mA, TA = 25C Figure 9. Trickle Charge Current vs VIN VBAT = 2.0V, TA = 25C 34675 8 Analog Integrated Circuit Device Data Freescale Semiconductor ELECTRICAL CHARACTERISTICS ELECTRICAL PERFORMANCE CURVES Charge Current (mA) 1000 800 600 400 200 0 0 1 2 RISET=3.95 k DET Pin Output Voltage (V) 1200 5 4 3 2 VIN Falling VIN Rising RISET=7.9 k RISET=15.8 k 1 0 0 1 2 3 4 5 Input Voltage (V) 6 7 3 4 5 Battery Voltage (V) Figure 10. Charge Current vs Battery Voltage VIN = 5.0V, TA = 25C Figure 13. DET Pin Output Voltage vs Input Voltage RDET = 470, IBAT = 0mA, TA = 25C 1.2 1.0 VISET (V) 5.00 4.95 VDET (V) 4.5 5.0 5.5 6.0 VIN (V) 6.5 7.0 0.8 0.6 0.4 0.2 0.0 4.0 4.90 4.85 4.80 4.75 4.70 0 200 400 600 IBAT (mA) 800 1000 Figure 11. VISET vs VIN VBAT = 3.7V, TA = 25C Figure 14. DET Pin Output Voltage vs Charge Current VIN = 5.2V, IDET = 10mA, TA = 25C 1.2 1.0 VISET (V) 0.8 0.6 0.4 0.2 0.0 0 200 400 600 800 1000 1200 Charge Current (mA) RISET=15.8k RISET=7.9k RISET=3.95 k 5.00 4.95 VDET (V) 4.90 4.85 4.80 4.75 4.70 0 2 4 6 8 IDET (mA) 10 12 14 Figure 12. VISET vs Charge Current VIN = 5.0V, TA = 25C Figure 15. DET Pin Output Voltage vs Output Current VIN = 5.2V, IBAT = 0mA, TA = 25C 34675 Analog Integrated Circuit Device Data Freescale Semiconductor 9 ELECTRICAL CHARACTERISTICS ELECTRICAL PERFORMANCE CURVES 85C 25C Trickle Charge Current (mA) DET Dropout Voltage (mV) 160 120 250 200 150 RISET=7.9k RISET=3.95k -40C 80 40 0 0 100 50 0 -40 -20 RISET=15.8k 2 4 6 8 10 DET Pin Output Current (mA) 12 0 20 40 60 Temperature (C) 80 Figure 16. DET Dropout Voltage vs Output Current VIN = 4.7V, IBAT = 0mA Figure 19. Trickle Charge Current vs Temperature VIN = 5.0V, VBAT = 2.0V BAT Pin Output Voltage (V) 4.210 4.205 1.10 1.05 VISET (V) 4.200 4.195 4.190 1.00 0.95 4.185 4.180 -40 -20 0 20 40 60 Temperature (C) 80 0.90 -40 -20 0 20 40 60 Temperature (C) 80 Figure 17. Charger Output Voltage vs Temperature VIN = 5.0V, IBAT = 0mA Figure 20. VISET vs Temperature VIN = 5.0V, VBAT = 3.7V Constant Charge Current (mA) 1200 1000 800 600 400 200 0 -40 -20 0 20 40 60 Temperature (C) 80 RISET=7.9k RISET=3.95k 450 400 RDS(ON) (m) 350 300 250 200 -40 -20 0 20 40 60 Temperature (C) 80 RISET=15.8k Figure 18. Constant Charge Current vs Temperature VIN = 5.0V, VBAT = 3.7V Figure 21. RDS(ON) vs Temperature VBAT = 4.0V, ICHG = 500mA, IBAT = 400mA 34675 10 Analog Integrated Circuit Device Data Freescale Semiconductor ELECTRICAL CHARACTERISTICS ELECTRICAL PERFORMANCE CURVES Recharge Voltage Threshold (V) 4.15 4.10 4.05 4.00 3.95 -40 -20 0 20 40 60 Temperature (C) 80 VIN Pin Supply Current (A) 4.20 2500 2000 1500 1000 500 0 -40 -20 Charger Disabled Charger Enabled 0 20 40 60 Temperature (C) 80 Figure 22. Recharge Voltage Threshold vs Temperature RISET = 7.9k, VIN = 5.0V Figure 24. VIN Pin Supply Current vs Temperature VIN = 5.0V BAT Pin Supply Current (A) DET Pin Output Voltage (V) -20 0 20 40 60 Temperature (C) 80 1.00 0.75 0.50 0.25 0.00 -0.25 -0.50 -40 5.00 4.95 4.90 4.85 4.80 4.75 4.70 -40 -20 0 20 40 60 Temperature (C) 80 Figure 23. BAT Pin Supply Current vs Temperature VBAT = 4.2V, VIN Pin Not Powered or Charger Disabled Figure 25. DET Pin Output Voltage vs Temperature VIN = 5.2V, IDET = 10mA, IBAT = 0mA 34675 Analog Integrated Circuit Device Data Freescale Semiconductor 11 FUNCTIONAL DESCRIPTION INTRODUCTION FUNCTIONAL DESCRIPTION INTRODUCTION The 34675 is a fully-integrated Li-Ion and Li-Polymer battery charger, with a 4.85V/10mA linear regulator in a tiny package. It uses current, voltage, and temperature control loops to regulate the charge current. It has up to a 28V input voltage rating, which makes the handheld device safe even when connected to a wrong AC adapter. In addition, it provides a 4.85V/10mA linear regulator. The 34675 requires only two external capacitors and one resistor to build a fully functional charger for space-limited applications such as cell phones, Bluetooth accessories and MP3 players. Its ultra high accuracy voltage (0.7%) and temperature limited charging current, offer additional battery safety during charging. The CC current can be programmed with an external resistor (RISET). The voltage across this resistor is proportional to the charge current, so the system can monitor the charge current during the whole charge cycle. The EOC threshold is preset to 10% of the CC mode current. For a deeply discharged battery with a voltage lower than 2.7V, the 34675 charges the battery with a trickle-mode current, which is 20% of the CC mode current. The linear regulator provides 4.85V with 10mA capability. The output is turned on when the input voltage is above the POR threshold, but lower than the OVP threshold. The Linear regulator is independent. It is not related to any signals of the charger, including the enable input pin. Two indication outputs make it easy to report the input power status and the charge status to MCUs, or users via LEDs. FUNCTIONAL PIN DESCRIPTION INPUT SUPPLY (VIN) The supply input. This pin should be bypassed to ground with a 1.0F capacitor. LINEAR REGULATOR OUTPUT (DET) The linear regulator output. The output voltage is typically 4.85V. The output current capability is 10mA. Bypass this pin to ground with a ceramic capacitor between 0.1F and 1.0F. POWER PRESENT INDICATOR (PPR) Open-drain logic output to indicate the status of the supply input voltage. The PPR pin output is singularly determined by the input voltage.The output is pulled low if VIN is higher than VPOR. This pin is capable of sinking at least 9.0mA of current to drive an LED indicator. CHARGE INDICATOR (CHG) Open-drain logic output to indicate the charge status. The output is low when the 34675 is charging, until the EOC conditions are reached. This pin is capable of sinking at least 9.0mA of current to drive a LED indicator. CC MODE CURRENT SETTING AND CHARGE CURRENT MONITOR (ISET) The CC mode current, ICHG, is programmed by connecting a resistor, RISET, between this pin and ground. When charging in the CC mode, the voltage at this pin is 1.0V. The voltage reduces proportionally as the charge current reduces in the CV mode. During the whole charge cycle, the voltage at this pin can be used to monitor the charge current, using the following equation: V ISET I BAT = -------------- I CHG 1.0V where IBAT is the actual charge current, ICHG is the programmed CC mode current, and VISET is the voltage of the ISET pin during the whole charge cycle. ENABLE (EN) Active low enable logic Input. This pin is internally pulled to ground by a weak current source. When left floating, the charger is enabled. Pulling this pin to a high voltage externally disables the charger. CHARGER OUTPUT (BAT) Charger output pin. Connect this pin to the battery being charged. Bypass to ground with a 2.2F or higher capacitor. GROUND (GND) Ground. EXPOSED PAD (EPAD) Exposed pad. This must be soldered to the large ground plane on the PCB to enhance the thermal conductivity. The pad must be connected to GND electrically. 34675 12 Analog Integrated Circuit Device Data Freescale Semiconductor FUNCTIONAL DESCRIPTION FUNCTIONAL INTERNAL BLOCK DESCRIPTION FUNCTIONAL INTERNAL BLOCK DESCRIPTION MC34675 - Functional Block Diagram Integrated Supply Internal Supply & Reference Sensing & Control VIN Monitor Charge Control Current Setting Current Monitor End of Charge VIN - BAT Comparator Die Temperature Feedback Logic Logic Control Status Indication Integrated Supply Sensing & Control Logic Outputs Outputs Power MOSFET Linear Regulator Figure 26. 34675 Functional Internal Block Diagram INTEGRATED SUPPLY Internal Supply and Reference This block steps down the high input voltage to a lower voltage which powers all the internal blocks. In addition, this block generates the reference voltage for the charge-control block. Charge Control The charge control block controls the gate voltage of the power MOSFET to regulate the charge current, the battery voltage, or the die temperature. It can also completely turn off the power MOSFET, to stop the current flow between the input and the battery. Additionally, monitoring of the charge current and the charger output voltage determines the tricklecharge mode and the recharge cycle. EOC (End of Charge) The EOC block monitors the charge current and the battery voltage for the EOC conditions. Once the EOC conditions are reached, this block outputs a logic signal to indicate the end of the charge. VIN-BAT Comparator The VIN-BAT comparator monitors the voltage difference between the input voltage and the battery voltage. The input voltage has to be higher than the battery voltage for the charger to be enabled. If the input voltage falls below the battery voltage, this block outputs a signal to disable the charger to prevent the leakage current from the battery to the input. SENSING & CONTROL VIN (Input Voltage) Monitor The input voltage monitor block monitors the input voltage for two thresholds, power-on-reset (POR) and over-voltage protection (OVP). If the input is lower than the POR or higher than the OVP threshold, this block outputs a logic signal to disable the charger and the linear regulator. Current Setting & Monitor This block sets the charge current in the constant-current mode, and monitors the actual charge current during the whole charge cycle. 34675 Analog Integrated Circuit Device Data Freescale Semiconductor 13 FUNCTIONAL DESCRIPTION FUNCTIONAL INTERNAL BLOCK DESCRIPTION Die-Temperature feedback The die temperature feedback block monitors the die temperature. Once the die temperature reaches the threshold temperature, this charge control block can reduce the charge current to prevent further die temperature rise. OUTPUTS Power MOSFET The power MOSFET passes the charging current from the input to the output. Linear Regulator The linear regulator outputs a regulated 4.85V from the input voltage with 10mA current capability. If the Input Voltage Monitor detects that the input voltage is lower than the POR or higher than the OVP threshold, the linear regulator is disabled. No other signal can control the linear regulator. LOGIC Logic Control and Status Indication The logic control block determines the on and off of the charger and indicates the charger status. It takes the signals from the input voltage monitor, VIN-BAT comparator, EOC, and the external enable signal, and determines the on and off states as well as the charge status indication outputs of the charger (CHG and PPR). 34675 14 Analog Integrated Circuit Device Data Freescale Semiconductor FUNCTIONAL DEVICE OPERATION OPERATIONAL MODES FUNCTIONAL DEVICE OPERATION OPERATIONAL MODES CHARGE CYCLE The 34675 uses the standard charge profile with trickle, constant-current (CC), and constant-voltage (CV) charge modes, as shown in Figure 27. Both the CC and the CV charge modes are also called fast-charge mode. When the input voltage rises above an internal power-on-reset threshold, the PPR pin outputs a low voltage to indicate the power-supply presence. The charger starts with the tricklecharge mode until the battery voltage is above 2.7V. The CHG pin outputs logic low voltage at the beginning of the trickle-charge mode. If the battery voltage is unable to rise due to a battery failure, charging will remain in the tricklecharge mode. When the battery voltage reaches the 2.7V threshold, the 34675 softly changes to the CC mode. The soft transition minimizes the input-voltage drop and reduces the requirement of the input decoupling capacitance. When the battery voltage reaches 4.2V, the 34675 enters the CV mode and regulates the output voltage at 4.2V. The charge current decreases gradually in the CV mode. When the current drops to the EOC current threshold, the 34675 outputs logic high level at the CHG pin to indicate that the charging is completed. After the charge cycle is completed, the 34675 continues to regulate and monitor the output to 4.2V. If a load is connected in parallel with the battery, the 34675 will ensure that the charger continues to supply the charge current, even if the charge cycle is completed. If the load current exceeds the preprogrammed CC mode current, the battery will supply the additional current to the load, thereby reducing the battery voltage. Once the battery voltage drops below the recharge voltage, the 34675 returns to the fast charge mode and indicates a logic low at the CHG pin. When one of the following three conditions happens, the 34675 stops charging and enters disable mode. 1. VIN > VOVP 2. VIN-VBAT < VOS 3. EN pin is high where VOS is the offset voltage for the comparator that monitors the input and the battery voltages Figure 29 shows the complete charge cycle state diagram. Trickle Constant Current Constant Voltage ILOAD >ICHG 4.2V ICHG Battery Voltage 100mV 2.7V ITRKL Charge Current IEOC TIME CHG TIME Figure 27. Charge Profile CHARGE CURRENT SETTING An external resistor between the ISET pin and ground sets the CC mode current with the following equation: 4000I CHG = ------------R ISET where RISET is the resistor between the ISET pin and ground in . ICHG is in Amps. In addition, the current out of the ISET pin is proportional to the charge current. The system may measure the ISET pin voltage to monitor the actual charge current during the whole charging cycle, using the following equation: 34675 Analog Integrated Circuit Device Data Freescale Semiconductor 15 FUNCTIONAL DEVICE OPERATION OPERATIONAL MODES INPUT POWER PRESENCE INDICATOR V ISET I BAT = -------------- I CHG 1.0V CHARGE CURRENT LIMITATION The charge current is limited by multiple factors. When the voltage difference between the input and the battery (VIN-VBAT) is low, (VIN - VBAT) / RDS(ON), where RDS(ON) is the on resistance of the power MOSFET, may be less than the programmed CC mode current ICHG. In this case, the charge current is limited by (VIN - VBAT) / RDS(ON). When the voltage difference between the input and the battery is too high, the large power dissipation may lead to the charge current thermal foldback operation, due to the die temperature regulation. The charge current is reduced to prevent further temperature rise (See Charge Current Thermal Foldback section for more information). When VIN is applied and the voltage is above the poweron-reset voltage threshold (VPOR), the PPR pin outputs a low voltage to indicate the input-power presence. The PPR output is only controlled by the input voltage. All other functions, such as the EN pin, the over-voltage protection, and the VIN-BAT comparator, do not affect the PPR output. The PPR pin is capable of sinking at least 9.0mA of current when outputting a low voltage to drive an external LED. CHARGE STATUS INDICATORS The 34675 has one charge-status indicator, CHG. CHG outputs a low voltage when the charger is enabled and the charging is in progress. When the charge cycle completes, CHG outputs high-impedance. If the charger is disabled or the input voltage is out of the power-good range, the CHG pin outputs a high-impedance as well. The CHG pin has at least 9.0mA current-sinking capability to drive an external LED, the same as the PPR pin. DC INPUT VOLTAGE The 34675 accepts up to a 28V DC input. When all of the following conditions are satisfied, the input is in a power-good range for the charger to start charging. The conditions include: 1. VIN > VPOR 2. VIN -VBAT > VOS 3. VIN < VOVP where VOS is the offset voltage for the comparator that monitors the input and the battery voltages. The VOS is for preventing the reverse leakage current from the battery when the external power supply is off. VOVP is the over-voltage protection threshold. When the DC input voltage is above the over-voltage protection threshold, the charger is disabled internally. The 28V input voltage rating eliminates the need of any additional input over-voltage protection circuitry. CHARGE CURRENT THERMAL FOLDBACK An internal thermal feedback loop begins to reduce the charge current, when the die temperature reaches 120C, to prevent further temperature rise. This feature protects the 34675 from over-temperature failure, and allows the user to push the limits of the power-handling capability of a given circuit board, without the risk of damaging the 34675. The charge current can be programmed according to the typical (not the worst case) ambient temperature, with the assurance that the charger will automatically reduce the current in worst case conditions. LINEAR REGULATOR The linear regulator provides a 4.85V output with 10mA current capability. The output is turned on when the input voltage is above the POR threshold but lower than the OVP threshold. The output is independent of any other signals in the charger, such as the enable (EN) input. When the input reaches the rising POR threshold, the DET output starts to output a voltage, but is in the dropout mode. The output voltage is determined by the dropout voltage. As the input voltage rises above the regulation voltage, the output is regulated at 4.85V. When the input voltage further rises above the OVP rising threshold, the linear regulator is turned off, and the output voltage drops to zero with an internal 200k pull-down resistor. The output voltage resumes to 4.85V when the input voltage falls below the OVP falling threshold. The output voltage versus the input voltage is shown in Figure 28, where the VPORR and VPORF are the POR rising and falling threshold. The VOVPR and VOVPF are the OVP rising and falling threshold. An output decoupling capacitor of 0.1F to 1.0F is required between the DET pin and ground for the stability of the linear regulator. CHARGE-ENABLE INPUT The charge-enable input, EN, has a weak internal pulldown current. Driving it to a low voltage, leaving it float, or shorting it to ground, will enable the charger if the input voltage is in the power-good range. Whenever the EN pin is driven to a high voltage, the charger is disabled. When the charger is disabled, the BAT pin does not output voltage and current, the leakage current into the BAT pin is less than 1.0A, the output of the CHG pin is high, and the voltage at the ISET pin is zero. If the input voltage is in the power-good range when the charger is disabled, the output of the PPR is still low to indicate the input voltage status and the DET pin outputs voltage as well. 34675 16 Analog Integrated Circuit Device Data Freescale Semiconductor FUNCTIONAL DEVICE OPERATION CHARGE STATE DIAGRAM VIN VOVPR VPORR VDET VOVPF 4.85V VPORF Figure 28. DET Pin Output Voltage vs Input Voltage CHARGE STATE DIAGRAM PWR OFF Charger: OFF VIN>VPOR EN=high or VIN>VOVP or VIN Charger: OFF VBAT < 2.7V EN=low and VIN TRICKLE CHARGE VBAT > 2.7V Charger: ON VBAT < 2.7V FAST CHARGE Charger: ON VBAT=4.2V and IBAT < IEOC VBAT<4.10V CHARGE COMPLETE Charger: ON Figure 29. Charge Cycle State Diagram 34675 Analog Integrated Circuit Device Data Freescale Semiconductor 17 TYPICAL APPLICATIONS APPLICATION INFORMATION TYPICAL APPLICATIONS APPLICATION INFORMATION INPUT CAPACITOR The input capacitor is used to reduce the input voltage transient, which may cause instability when the input voltage is near VBAT+VOS. A 1.0F, X5R, 16V rated ceramic capacitor is recommended for most applications. the power MOSFET. The worst case of the RDS(ON) is 475m. The input voltage should be at least higher than VBAT + ICHG x 475m, to guarantee the programmed CC mode current. USE DET AS POWER PRESENCE INTERRUPT OUTPUT CAPACITOR For stable operation, an X5R ceramic capacitor with a minimum 2.2F nominal value is recommended at the charger output. Depending on the load transient current, a larger capacitance may be required. The linear regulator is designed to be stable with a ceramic capacitor of 0.1F through 1.0F. An X5R ceramic capacitor of 0.22F is recommended for the application. Some cell phone designs require an active-high power presence indication signal, to turn on an originally-off phone, when an ac/dc adapter is plugged in. The DET output can be used for such a purpose, instead of the PPR pin. THERMAL CONSIDERATIONS The 34675 is available in a tiny 2x3 thermally-enhanced UDFN package. A careful thermal design must be considered. The exposed pad needs to be well soldered to a large copper ground plane on the component layer. If the component layer is space limited and does not allow for a large copper plane, the thermal pad must be connected to other ground layers through a via array. This allows the 34675 to charge the battery with the maximum current, while minimizing the die temperature. CC MODE CURRENT SETTING The CC mode current can be programmed by the external resistor, RISET. A 1% accuracy resistor is recommended to guarantee 6% current accuracy. DROPOUT VOLTAGE If the DC input voltage is too low, it may not maintain the programmed charge current due to the voltage dropout over TYPICAL APPLICATIONS CHARGER IN THE HANDHELD SYSTEM When the charger is used in handheld systems with MCU control, the 34675 uses PPR to report the DC input status to the MCU. After the MCU pulls the EN pin to a low logic level to start charging, the 34675 reports the charge status through the CHG pin to the MCU. The MCU can also monitor the charge current by measuring the voltage at the ISET pin. The linear regulator powers subsystems, such as a USB transceiver, that require a voltage higher than 4.5V. Figure 30 is the typical application circuit. DC Input 1.0F VIN BAT 2.2F Li+ VIO 100K 100K GND MC34675 ISET 8.06K CHG PPR EN OFF ON MCU DET 0.22F USB Xcvr Figure 30. Li+ Battery Charger in Handheld System 34675 18 Analog Integrated Circuit Device Data Freescale Semiconductor PACKAGING PACKAGE DIMENSIONS PACKAGING PACKAGE DIMENSIONS For the most current package revision, visit www.freescale.com and perform a keyword search using the "98A" listed below. EP SUFFIX 8-PIN 98ASA10774D REVISION 0 34675 Analog Integrated Circuit Device Data Freescale Semiconductor 19 PACKAGING PACKAGING DIMENSIONS (CONTINUED) PACKAGING DIMENSIONS (CONTINUED) EP SUFFIX 8-PIN 98ASA10774D REVISION 0 34675 20 Analog Integrated Circuit Device Data Freescale Semiconductor PACKAGING PACKAGING DIMENSIONS (CONTINUED PACKAGING DIMENSIONS (CONTINUED EP SUFFIX 8-PIN 98ASA10774D REVISION 0 34675 Analog Integrated Circuit Device Data Freescale Semiconductor 21 PACKAGING 34675 22 Analog Integrated Circuit Device Data Freescale Semiconductor REVISION HISTORY REVISION HISTORY REVISION 1.0 2.0 3.0 DATE 4/2008 4/2008 4/2008 DESCRIPTION OF CHANGES * * * Initial Release Added Tape & Reel positioning drawing Deleted Tape & Reel positioning drawing 34675 Analog Integrated Circuit Device Data Freescale Semiconductor 23 How to Reach Us: Home Page: www.freescale.com Web Support: http://www.freescale.com/support USA/Europe or Locations Not Listed: Freescale Semiconductor, Inc. Technical Information Center, EL516 2100 East Elliot Road Tempe, Arizona 85284 +1-800-521-6274 or +1-480-768-2130 www.freescale.com/support Europe, Middle East, and Africa: Freescale Halbleiter Deutschland GmbH Technical Information Center Schatzbogen 7 81829 Muenchen, Germany +44 1296 380 456 (English) +46 8 52200080 (English) +49 89 92103 559 (German) +33 1 69 35 48 48 (French) www.freescale.com/support Japan: Freescale Semiconductor Japan Ltd. Headquarters ARCO Tower 15F 1-8-1, Shimo-Meguro, Meguro-ku, Tokyo 153-0064 Japan 0120 191014 or +81 3 5437 9125 support.japan@freescale.com Asia/Pacific: Freescale Semiconductor Hong Kong Ltd. Technical Information Center 2 Dai King Street Tai Po Industrial Estate Tai Po, N.T., Hong Kong +800 2666 8080 support.asia@freescale.com For Literature Requests Only: Freescale Semiconductor Literature Distribution Center P.O. Box 5405 Denver, Colorado 80217 1-800-441-2447 or 303-675-2140 Fax: 303-675-2150 LDCForFreescaleSemiconductor@hibbertgroup.com Information in this document is provided solely to enable system and software implementers to use Freescale Semiconductor products. There are no express or implied copyright licenses granted hereunder to design or fabricate any integrated circuits or integrated circuits based on the information in this document. Freescale Semiconductor reserves the right to make changes without further notice to any products herein. Freescale Semiconductor makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Freescale Semiconductor assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. "Typical" parameters that may be provided in Freescale Semiconductor data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including "Typicals", must be validated for each customer application by customer's technical experts. Freescale Semiconductor does not convey any license under its patent rights nor the rights of others. Freescale Semiconductor products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Freescale Semiconductor product could create a situation where personal injury or death may occur. Should Buyer purchase or use Freescale Semiconductor products for any such unintended or unauthorized application, Buyer shall indemnify and hold Freescale Semiconductor and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that Freescale Semiconductor was negligent regarding the design or manufacture of the part. FreescaleTM and the Freescale logo are trademarks of Freescale Semiconductor, Inc. All other product or service names are the property of their respective owners. (c) Freescale Semiconductor, Inc., 2008. All rights reserved. MC34675 Rev. 3.0 4/2008 |
Price & Availability of MC34675AEPR2
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |