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Dual, USB 2.0 Full/Standby Power Controller with Supply Steering Preliminary Technical Data ADM1072
GENERAL DESCRIPTION
FEATURES 500mA Load Current (100mA in Standby Mode) 135m On Resistance Switchable Current Limit 50A Typical Quiescent Current 10nA Typical Shutdown Current 40nA Typical Switch Off Leakage Short-Circuit Protection Thermal Shutdown FLT Outputs Small, 16-Pin QSOP Package APPLICATIONS Desktop Computers Palmtop Computers Notebook Computers Hand-Held Instruments Universal Serial Bus (USB)
1A MAIN FET
The ADM1072 is a logic controlled, dual P-channel switch with low on resistance and a built-in current limiter, capable of sourcing up to 1A from supply voltages between 2.7V and 5.5V. In addition to logic inputs that switch each channel on and off, the device has a standby input that switches the output current limit, making it ideal for use with USB peripherals. In normal operating mode and Standby mode the output current is typically limited to 500mA and 100mA respectively, as outlined by the USB2.0 Specification. This allows the system power supply to be protected against short-circuits and surge currents in peripheral USB devices powered via the ADM1072. Over-current and over-temperature conditions are signalled by a fault output (FLT) for each channel. The ADM1072 also offers low quiescent current of typically 50A and shutdown current of typically 10nA.
MAIN_IN (2.7V TO 5.5V)
22F
2
3
14
15
1A MIRROR FET
STBY_IN (2.7V TO 5.5V)
0.2A MAIN FET
5
12
1
OP1
4.7F
TO CHANNEL 2
0.2A MIRROR FET MIRROR AMPLIFIER
4
120F
O N 1 11
CONTROL LOGIC
VPULLUP 0 TO 5.5V
CURRENT LIMIT AMPLIFIER
1.24V BANDGAP REFERENCE
FLT1
6
RPULLUP 10k TO 100k
STBY 9
UNDERVOLTAGE SENSOR
ADM1072
CURRENT SETTING RESISTOR
VPULLUP 0 TO 5.5V
TEMPERATURE SENSOR
OVERTEMP
8
GND
10k
FLT2
RPULLUP TO 100k
7
TO CHANNEL 2 TO CHANNEL 2
TO CHANNEL 2
13
16
OP2
O N 2 10
CHANNEL 2 IS IDENTICAL TO CHANNEL 1
120F
FUNCTIONAL BLOCK DIAGRAM
Rev. PrE 1/02
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 World Wide Web Site: http://www.analog.com Fax: 781/326-8703 (c) Analog Devices, Inc., 2002
ADM1072-SPECIFICATIONS
(Specification for either channel 1 or channel 2, VIN = +5.0V, TA = -40 to +85oC, unless otherwise noted.)
Parameter Operating Voltage Range Quiescent Current (Total Device) Shutdown Supply Current (Total Device) Undervoltage Lockout On Resistance NOMINAL CURRENT-LIMIT Full Power Mode Standby Mode ON1,ON2, STBY Input Low Voltage, VIL ON1,ON2, STBY Input High Voltage, VIH ON1,ON2, STBY Input Leakage FLT1,FLT2 Logic Output Low Voltage FLT1,FLT2 Output High Leakage Current Turn-On Time Turn-Off Time ? ? 0.05 2.4 0.01 1 0.4 1 4 4 20 2.0 Min +2.7 50 0.01 2.3 ? ? 0.8 160 1.0 200 2 2.6 135 ? 1.2 240 0.8 Typ Max +5.5 Units Volts A A V m m A mA V V A V A ms ms s VIN = 5V, ON1,ON2 = GND, IOUT = 0A ON1,ON2 = VIN = 5.5V, VOUT = 0V VSTBY_IN, Rising Edge, 1% Hysteresis VIN = 4.75V VIN = 3.0V STBY Low Note 1 STBY High Note 1 VIN = 2.7V to 5.5V VIN = 2.7V to 5.5V VON, VSTBY = 5.5V ISINK = 1mA VFAULT = 5.5V VIN = 5V, IOUT = 500mA VIN = 3V, IOUT = 500mA VIN = 5V, IOUT = 500mA Test Conditions/Comments
Notes 1 Current limit is specified with VOUT = 4.5V. 2 Guaranteed by design. Derived from the ISET current ratio, current-limit amplifier and internal set resistor accuraciues. 3 Tested with IOUT = 200mA and VSET adjusted until (VIN - VOUT) 0.8V. 4 Specifications to -40oC are guaranteed by design, not tested.
-2-
Rev. PrE 1/02
ADM1072
ABSOLUTE MAXIMUM RATINGS*
(TA = +25C unless otherwise noted)
O P1 M AIN _IN M AIN _IN O P1 S T BY _IN F LT 1 F LT 2 G ND 1 2 3 4 5 6 7 8 16 O P2 15 M AIN _IN 14 M AIN _IN
MAIN_IN to GND . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6V ON1,ON1,FLT1, FLT2 to GND . . . . . . . . . . . -0.3V to +6V OP1,OP2 to GND . . . . . . . . . . . . . . . . +0.3 V to (VIN + 0.3V) Maximum Switch Current Full Power Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1A Standby Power Mode . . . . . . . . . . . . . . . . . . . . . . . . 200mA Continuous Power Dissipation (TA = +70oC) . . . . . 667mW QSOP (derate 8.3mW/oC above +70oC) Operating Temperature Range Industrial (A Version) . . . . . . . . . . . . . . . -40C to +85C Storage Temperature Range . . . . . . . . . . . -65C to +150C Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . +300C
*This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability.
AD M 10 72
T O P V IE W (No t to S cale)
13 O P2 12 S T BY _IN 11 O N 1 10 O N 2 9 S T BY
Pin Configuration
THERMAL CHARACTERISTICS
16-Pin QSOP Package: qJA = 105C/Watt, qJC = 40C/Watt ORDERING GUIDE
Model ADM1072ARQ Temperature Range -40C to +85C Package Description 16-Pin QSOP Package Option RQ-16 Package
PIN FUNCTION DESCRIPTION
Pin 2, 3, 14, 15 5, 12 1, 4 13, 16 6
Mnemonic MAIN_IN STBY_IN OP1 OP2 FLT1
Function Input to MAIN P-channel MOSFET source (both channels). Bypass MAIN_IN with a 22F capacitor to ground. Input to Standby P-channel MOSFET source (both channels) and supply to chip circuitry. Bypass STBY_IN with a 4.7F capacitor to ground. Output from channel 1, P-channel MOSFET drains. Bypass OP1 with a 120F capacitor to ground. Output from channel 2, P-channel MOSFET drains. Bypass OP2 with a 120F capacitor to ground. Open-Drain Digital Output. FLT1 goes low when the channel 1 current limit is exceeded for 10mS or the die temperature exceeds +150oC. During startup, FLT1 remains low for the turn-on time. Open-Drain Digital Output. FLT2 goes low when the channel 2 current limit is exceeded for 10mS or the die temperature exceeds +150oC. During startup, FLT2 remains low for the turn-on time. Ground pin for all chip circuits. Digital Input. Active high standby mode input. STBY = 0 sets normal operating mode with 500mA current limit. STBY = 1 sets standby mode with 100mA current limit. Digital Input. Active-low switch enable for channel 2 (logic 0 turns the switch on). Digital Input. Active-low switch enable for channel 1 (logic 0 turns the switch on).
7
FLT2
8 9 10 11
GND STBY ON2 ON1
Rev. PrE 1/02
-3-
ADM1072
Typical Performance Curves
IN G A IT AW TA DA
Figure 1. Quiescent Current vs. Input Voltage
IN G A IT AW TA DA
Figure 4. Off-Switch Current vs. Temperature
IN G A IT AW TA DA
Figure 2. Quiescent Current vs. Temperature
IN G A IT AW TA DA
Figure 5. Normalized On Resistance vs. Temperature
IN G A IT AW TA DA
Figure 3. Off-Supply Current vs. Temperature
IN G A IT AW TA DA
Figure 6. IOUT/ISET Ratio vs Switch Current
-4-
Rev. PrE 1/02
ADM1072
Typical Performance Curves
IN G A IT AW TA DA
Figure 7. Normalized Output Current vs. Output Voltage
IN G A IT AW TA DA
Figure 10. Fast Current-Limit Response
IN G A IT AW TA DA
Figure 8. Turn-On Time vs. Temperature
IN G A IT AW TA DA
Figure 11. Slow Current-Limit Response
IN G A IT AW TA DA
Figure 9. Turn-Off Time vs. Temperature
IN G A IT AW TA DA
Figure 12. Load Transient Response
Rev. PrE 1/02
-5-
ADM1072
Typical Performance Curves
IN G A IT AW TA DA
Figure 13. Switch Turn-On Time
IN G A IT AW TA DA
Figure 15. USB Circuit Output Rise Time
IN G A IT AW TA DA
Figure 14. Switch Turn-Off Time
IN G A IT AW TA DA
Figure 16 USB Circuit output Fall Time
-6-
Rev. PrE 1/02
ADM1072
FUNCTIONAL DESCRIPTION SHORT-CIRCUIT PROTECTION
The ADM1072 is a dual, logic-controlled P-channel switch. Each channel of the ADM1072 comprises two P-channel switches. The source of one switch is connected to the "MAIN_IN" input pins and can switch up to 1A. The second switch is conected to the "STBY_IN" pins and can switch up to 200mA. The device is rated to provide 500mA continuously in full power mode and 100mA continuously in STBY mode. The STBY_IN inputs also provide the power for the chip circuitry and so must be connected to a supply at all times. When STBY is low the MAIN switch is active and when STBY is high the Standby switch is active. Each channel is individually controlled by an active-low logic input ON1 (pin 11) and ON2 (pin 10). When either ON1 or ON2 is low, the internal circuitry of the ADM1072 is powered up and the output of the corresponding current-limit amplifier is low, providing gate drive to the switching FET, thus turning it on. When both ON inputs are high, the internal circuitry is powered down and the current consumption is typically 10nA. It should be noted that the ADM1072 is not a bi-directional switch, so VIN must always be higher than VOUT. TABLE 1. Truth Table for ON1, ON2 and STBY ON1 0 0 0 0 1 1 1 ON2 0 0 1 1 0 0 1 STBY 0 1 0 1 0 1 X Channel 1 500mA 100mA 500mA 100mA OFF OFF Channel 2 500mA 100mA OFF OFF 500mA 100mA
The proportional relationship between the main FET and the mirror FET is only maintained down to an output voltage of about 1.6V. Below this voltage the output current is limited to approximately 1.2 x ILIMIT. In the event of a high dV/dt across the switching FET during a short-circuit, the switch will turn off and disconnect the input from the output. The switch is then turned on slowly with the current limited to the short-circuit value.
THERMAL SHUTDOWN
The thermal shutdown operates when the die temperature exceeds +150oC, turning off both channels. The thermal shutdown circuit has built-in hysteresis of 10oC, so the switch will not turn on again until the die temperature falls to +140oC. If the fault condition is not removed, the switch will pulse on and off as the temperature cycles between these limits.
UNDERVOLTAGE LOCKOUT
The undervoltage sensor monitors the input supply voltage (ie) the voltage on STBY_IN. The outputs will not turn on until the supply voltage is sufficient for the chip circuits to operate reliably. Undervoltage lockout occurs at between 2.0 and 2.6V.
FLT OUTPUTS
The ADM1072 has active-low fault outputs for each channel, FLT1 (pin 6) and FLT2 (pin 7). If the current limit is exceeded for greater than 10mS, the corresponding FLT output will pull low. If the thermal shutdown is activated, both FLT outputs will pull low. The FLT outputs are open-drain and require a pullup resistor of between 10k and 100k . Several FLT outputs may be wire-OR'd to form a common interrupt line, as shown in Figure 17 or FLT outputs may be wire-OR'd to an existing interrupt line that has a resistive pullup.
V P U L LU P
BOTH SHUT DOWN
RP ULL UP
X = don't care
IN T
CURRENT LIMIT
When either the Main or Standby switch is turned on a smaller mirror switch passes a proportionate current equal to IOUT/ 1000. The mirror amplifier maintains this relationship by keeping the drain of the mirror FET at the same voltage as the main FET, and drives the mirror current through an internal current-limit resistor, which is connected between the noninverting input of the current limit amplifier and ground. An on-chip bandgap reference of 1.24V is connected to the inverting input of the current-limit amplifier. When the load current exceeds the preset limit, the voltage across the currentlimit resistor exceeds 1.24V and the output voltage of the current-limit amplifier rises, reducing the gate drive to the FETs. By selecting between the Standby and Main FETs and their associated mirror FETs, the STBY input allows the two different values of current limit specified by USB2.0 to be selected. This feature is particularly useful when driving USB peripherals from a host system such as a PC that can go into a powersaving mode, since it limits the current that the peripherals can attempt to draw from the host power supply. Rev. PrE 1/02 -7-
F LT 1 AD M 1 072 F LT 2
F LT 1 AD M 1 072 F LT 2
F LT 1 AD M 1072 F LT 2
Figure 17. Wire Or'ing FAULT Outputs
During startup, the FLT output goes low for the turn-on time.
ADM1072
APPLICATIONS INFORMATION INPUT FILTERING
To prevent the input voltage being pulled below the minimum operating voltage under transient short-circuit conditions, before the current limit has had time to operate, a reservoir capacitor should be connected from MAIN_IN to GND. This does not need to be large, but should have a low ESR. A value of around 10 - 22F is suitable. Larger values will reduce the voltage drop still further. The STBY_IN input requires a proportionately smaller value, typically 2.2 to 4.7F.
OUTPUT CAPACITANCE
120F capacitors should be connected between OP1 and OP2 and GND to prevent the back e.m.f. of parasitic inductance from pulling OP1 and OP2 below ground during turn-off and to provide adequate turn- on current for Universal Serial Bus (USB) applications that are hot plugged to OP! or OP2. This causes the output rise and fall times to be longer, as shown in the typical operating characteristics, but does not affect the turn-off time of the ADM1072 itself.
LAYOUT CONSIDERATIONS
Printed circuit board tracks to and from the ADM1072 should be as thick and as short as possible to minimise parasitic inductance and take full advantage of the fast response time of the switch. Input and output capacitors should be placed as close to the device as possible (less than 5mm).
THERMAL CONSIDERATIONS
Under normal operating conditions, the worst-case power dissipation will be 135mW with the 135m on resistance and 3V supply (W = (1A)2 0.135 ). The package is capable of handling and dissipating this power, but heat dissipation can further be improved by providing a large area of copper in contact with the device pins, particularly MAIN_IN and OP1,OP2.
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
16-Pin QSOP Package (RQ-16)
0.197 (5.00) 0.189 (4.80)
16
9
0.157 (3.99) 0.150 (3.81)
1 8
0.244 (6.20) 0.228 (5.79)
P IN 1 0.059 (1.50) M AX 0.069 (1.75) 0.053 (1.35)
0.010 (0.25) 0.004 (0.10)
0.025 (0.64) BS C
0.012 (0.30) 0.008 (0.20)
S EAT ING P LAN E
0.010 (0.20) 0.007 (0.18)
8& 0&
0.050 (1.27) 0.016 (0.41)
-8-
Rev. PrE 1/02

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