LTC2924IGN#PBF

LTC2924 Quad Power Supply Sequencer Description Features Fully Sequence and Monitor Four Supplies nn Six with Minimal External Circuitry nn Cascadable for Additional Supplies nn Power Off in Reverse Order or Simultaneously nn Charge Pump Drives External MOSFETs nn Drives Power Supply Shutdown Pins with No External Pull-Up Resistors nn 10µA Output Current Allows Soft-Starting of Supplies nn Done Indicator for Both Power On and Power Off nn Adjustable Time Delay Between Power Supplies nn Power Good Timer nn Power Supply Voltage Monitoring and Power Sequence Error Detection and Reporting nn Available in a 16-Lead Narrow SSOP Package The LTC®2924 is a power supply sequencer designed for use with external N-channel MOSFETs or power supplies with shutdown pins. Four power supplies can be fully sequenced by a single LTC2924 and up to five supplies can be sequenced to a sixth master supply. The LTC2924 requires a minimum of external components, using only two feedback resistors per sequenced power supply and a single resistor to set hysteresis. nn An internally regulated charge pump provides gate drive voltages for external logic and sub-logic-level MOSFETs. Adding a single capacitor enables an adjustable time delay between power supplies during both Power On and Power Off sequencing. A second capacitor can be added to enable a power good timer for detecting the failure of any power supply to turn on within the selected time. Errors in power supply sequencing and the control input are detected and reported at the FAULT output. The LTC2924 features pre­ cision input comparators which can provide 1% accuracy in monitoring power supply voltages. Applications Sequenced Power Supplies for ASICs with Multiple I/O and Core Voltages nn Latch-Up Prevention in Systems with Multiple Power Supplies nn Multiple LTC2924s may be easily cascaded to sequence a virtually unlimited number of power supplies. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Typical Application Power-Up Sequence VON = 2.64V VOFF = 1.98V 3.3V SHDN Q2 1V VON = 0.93V VOFF = 0.915V 5V SHDN 5V VON = 3.97V VOFF = 2.97V 0.1µF Q1 3V VON = 2.79V VOFF = 2.73V 6.04k VCC 5V EARLY 10k 10k OUT1 IN1 OUT2 IN2 OUT3 IN3 OUT4 IN4 ON LTC2924 SYSTEM CONTROLLER 100k 1.62k 5V 3.3V 3V 2V/DIV 1V 5V/DIV DONE 2V/DIV TMR ON 5V/DIV 10ms/DIV 66.5k 2924 TA01b Power-Down Sequence 5V 3.3V 3V 2V/DIV 1.69k 18.2k 3.09k 1V 20k DONE DONE FAULT TMR 150nF 150nF PGT 5V/DIV HYS/CFG GND 49.9k Q1-Q4: IRL3714S ALL RESISTORS 1% TMR 2V/DIV ON 5V/DIV 2924 TA01a 10ms/DIV 2924 TA01c 2924fc For more information www.linear.com/LTC2924 1 LTC2924 Absolute Maximum Ratings Pin Configuration (Note 1) TOP VIEW Supply Voltage (VCC)................................. –0.3V to 6.5V Input Voltages ON, IN1-IN4..................................–0.3V to VCC + 0.3V PGT, TMR, HYS/CFG.....................–0.3V to VCC + 0.3V Open-Drain Output Voltages FAULT, DONE................................–0.3V to VCC + 0.3V Output Voltages (OUT1 - OUT4) (Note 5)............... –0.3V to VCC + 4.5V Operating Temperature Range LTC2924C................................................. 0°C to 70°C LTC2924I..............................................–40°C to 85°C Storage Temperature Range................... –65°C to 150°C Lead Temperature (Soldering, 10 sec).................... 300°C IN1 1 16 ON IN2 2 15 HYS/CFG IN3 3 14 TMR IN4 4 13 GND OUT1 5 12 PGT OUT2 6 11 VCC OUT3 7 10 DONE OUT4 8 9 FAULT GN PACKAGE 16-LEAD PLASTIC SSOP TJMAX = 125°C, θJA = 130°C/W Order Information (http://www.linear.com/product/LTC2924#orderinfo) Lead Free Finish TUBE TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC2924CGN#PBF LTC2924CGN#TRPBF 2924 16-Lead Plastic SSOP 0°C to 70°C LTC2924IGN#PBF LTC2924IGN#TRPBF 2924I 16-Lead Plastic SSOP –40°C to 85°C Consult LTC Marketing for parts specified with wider operating temperature ranges. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix. 2 2924fc For more information www.linear.com/LTC2924 LTC2924 Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VCC = 3V to 6V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Supply VCC Input Supply Range l ICC Input Supply Current l VON(TH) ON, Low to High Threshold l VOFF(TH) ON, High to Low Threshold l 3 6 V 1.5 3 mA 0.6000 0.6060 0.6121 V 0.6014 0.6074 0.6135 V ON Threshold IN1-IN4 Threshold VON(TH) IN1-IN4 Low to High Threshold l 0.6020 0.6081 0.6142 V VOFF(TH) IN1-IN4 High to Low Threshold l 0.6026 0.6087 0.6148 V l 0.33 0.4 0.48 V 0.5 50 µA ±22 ±10 % % ±100 nA ON, IN1-IN4 Characteristics VFAULT ON, IN1-IN4 High Speed Low Fault Threshold ION(HYS) ON, IN1-IN4 Hysteresis Current Range VON ≥ VON(TH) (Note 2) l ION(ERROR) ON, IN1-IN4 Hysteresis Current Error 1 – (ION(HYS)/(0.5/RHYS)), VON(TH) = 1V 0.5µA ≤ ION < 25µA 25µA ≤ ION ≤ 50µA l l ILEAK ON, IN1-IN4 Leakage (Below Threshold) VON(TH) = 0.5V l VON(HYS) ON, IN1-IN4 Minimum Hysteresis Voltage IHYS • RIN (Note 6) l 2 4 mV OUT1-OUT4 Characteristics VOUT(EN) OUT1-OUT4 Gate Drive Voltage IOUTn = 0 VCC + 4.5 IOUT(EN) OUT1-OUT4 On Current OUTn On, VOUT = (VCC + 4V) l ROUT(OFF) OUT1-OUT4 Off Resistance to GND OUTn ­Off, IOUT = 2mA l 8.6 10 VCC + 6 V 11.2 µA 240 Ω 1M Ω HYS Characteristics RHYS HYS Current Programming Resistor Range (Notes 2, 3) VHYS HYS Programming Voltage RHYS Tied to GND RHYS Tied to VCC 10k 0.5 VCC – 0.5 V V TMR Characteristics ITMR Timer Pin Output Current Timer On, VTMR ≤ 0.9V VTH(HI) Timer High Voltage Threshold VCC = 5V l 4 5 6 µA 0.93 1 1.07 V PGT Characteristics IPGT Power Good Timer Pin Output Current Power Good Timer On, VPGT ≤ 0.9V VPGT Power Good Timer Fault Detected Voltage Threshold VCC = 5V l 4 5 6 µA 0.93 1 1.07 V 2924fc For more information www.linear.com/LTC2924 3 LTC2924 Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VCC = 3V to 6V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS DONE Characteristics RD(LO) DONE Pin Pull-Down Resistance to GND DONE = Low, I = 2mA l 100 Ω ID(HI) DONE Pin Off Leakage Current DONE = High l 15 µA FAULT Characteristics RFAULT (LO) FAULT Pin Pull-Down Resistance to GND FAULT Being Pulled Low Internally, I = 2mA l 400 Ω IFAULT(HI) FAULT Pin Off Leakage Current FAULT High l 2 µA VFAULT(HI) Voltage Above Which an Externally Generated FAULT Condition Will Not be Detected l VFAULT(LO) Voltage Below Which an Externally Generated l 1.6 V 0.6 V FAULT Condition Will be Detected RF(EXT) External Pull-Up Resistance l tFAULT Externally Commanded FAULT Below VFAULT(LO) to OUT1-OUT4 Pull-Down On Delay l tFAULT(MIN) Externally Commanded FAULT Minimum Time Below VFAULT(LO) (Note 4) Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: Hysteresis current must be 500nA minimum. Hysteresis current may exceed 50µA, but accuracy is not guaranteed. Note 3: HYS/CFG pin must be pulled to GND or VCC with an external resistor. See Applications Information for details. 4 10 kΩ 1 1 µs µs Note 4: Determined by design, not production tested. External circuits pulling down on the FAULT pin must maintain the signal below VFAULT(LO) for ≥1µs. Note 5: Internal circuits may drive the OUTn pins higher than the Absolute Maximum Ratings. Note 6: RIN is the parallel combination of the two resistors forming the resistive divider connected to the ON and IN1-IN4 pins. 2924fc For more information www.linear.com/LTC2924 LTC2924 Typical Performance Characteristics ICC vs VCC 14 IOUT1-4 = –10µA RHYS = 51k 2.1 VCC = 6V IOUT1-4 < 1µA 11 10 ON HIGH 1.5 VCC = 3V 8 VOUT (V) 1.7 6 1.3 10 9 4 ON LOW 1.1 4 4.5 VCC (V) 5 8 2 5.5 0 6 ONE OUTPUT DRIVING CURRENT 0 2 2924 G01 4 6 IOUT (µA) 8 RDONE vs VCC 6 2924 G03 180 RFAULT AT 2mA (Ω) 45 40 35 160 140 120 100 3 5 4 80 6 VCC (V) 5 4 3 6 VCC (V) 2924 G04 2924 G05 OUTn (Off) ISAT vs Temperature 35 VOUT = 5V 40 35 5 VCC (V) 200 50 45 4 3 2 RFAULT vs VCC 55 30 7 12 10 2924 G02 OUTn (Off) ISAT vs VCC VOUT = 5V 30 VCC = 6V ISAT (mA) 3.5 RDONE AT 2mA (Ω) 3 ISAT (mA) ICC (mA) VOUT(EN) vs VCC 12 12 1.9 0.9 VOUT(EN) vs IOUT VOUT (V) 2.3 30 25 25 20 20 15 VCC = 3V 15 10 20 40 60 –60 –40 –20 0 TEMPERATURE (°C) 80 100 10 2.5 3 3.5 4 4.5 5 5.5 6 6.5 VCC (V) 2924 G06 2924 G07 2924fc For more information www.linear.com/LTC2924 5 LTC2924 Pin Functions IN1-IN4 (Pins 1, 2, 3, 4): Sequenced Power Supply Monitor Input. Connect this pin to an external resistive divider between each sequenced power supply and GND. During Power On sequencing, 0.61V (typ) at this pin indicates that the sequenced power supply (enabled with each of the OUT1-OUT4 pins) has reached the desired Power On sequence voltage. A hysteresis current (programmed by the HYS pin) is sourced out of each of the IN1-IN4 pins after the 0.61V threshold is detected. During the Power Off sequence, 0.61V at this pin indicates that the sequenced power supply has reached the desired Power Off voltage. The hysteresis current is removed after the 0.61V thresh­ old is detected. OUT1-OUT4 (Pins 5, 6, 7, 8): Sequenced Power Supply Enable. Connect this pin to the shutdown pin or an external series N-channel MOSFET gate for each power supply being sequenced. (A low at this pin means the sequenced power supply is commanded to turn off.) When disabled, each output is connected to GND with a resistance of