LTC2924CGN#TRPBF Linear Technology, LTC2924CGN#TRPBF Datasheet
LTC2924CGN#TRPBF
Specifications of LTC2924CGN#TRPBF
Available stocks
Related parts for LTC2924CGN#TRPBF
LTC2924CGN#TRPBF Summary of contents
Page 1
... F A U L T output. The LTC2924 features pre- cision input comparators which can provide 1% accuracy in monitoring power supply voltages. Multiple LTC2924s may be easily cascaded to sequence a virtually unlimited number of power supplies. , LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners 2.64V ...
Page 2
LTC2924 ABSOLUTE AXI U RATI (Note 1) Supply Voltage (V ) ................................ –0.3V to 6.5V CC Input Voltages ON, IN1-IN4 ............................... –0. PGT, TMR, HYS/CFG .................. –0. Open-Drain Output Voltages F ...
Page 3
ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER TMR Characteristics I Timer Pin Output Current TMR V Timer High Voltage Threshold TH(HI) PGT Characteristics I Power Good Timer Pin Output Current PGT V Power Good Timer Fault ...
Page 4
LTC2924 TYPICAL PERFOR A CE CHARACTERISTICS DONE (V) CC OUTn (Off Temperature SAT ...
Page 5
PI FU CTIO IN1-IN4 (Pins 4): Sequenced Power Supply Moni- tor Input. Connect this pin to an external resistive divider between each sequenced power supply and GND. During Power On sequencing, 0.61V (typ) ...
Page 6
LTC2924 FU CTIO AL DIAGRA – 0.61V I H IN1 + 1 – 0.61V I H IN2 + 2 – 0.61V I H IN3 + 3 – 0.61V I H IN4 + 4 ...
Page 7
OPERATIO U V PS1(ON) V PS2(ON) 0V TMR* ON DONE *TMR IS CAPACITOR ADJUSTABLE Figure 1. Power On and Power Off Sequence for Four Supplies The LTC2924 is a power supply sequencer designed for use with external N-channel MOSFETs or ...
Page 8
LTC2924 OPERATIO U logic, which starts the charge pump and enables OUT1 to turn on the first power supply. The power good timer circuit is also enabled by turning off the switch that is shorting the external capacitor to ground ...
Page 9
APPLICATIO S I FOR ATIO five supplies can be sequenced to a sixth master supply by a single LTC2924 (Figure 4). The turn on of the first power supply is sensed by the ON pin. Power ...
Page 10
LTC2924 APPLICATIO S I FOR ATIO Power On sequence (V ) and Off during a Power Off ON sequence (V ). OFF Referring to Figures 5 and 6, each set of resistors can then be calculated by: ...
Page 11
APPLICATIO S I FOR ATIO U U Minimize stray capacitance on the ON and IN1-IN4 pins practical matter, lay out these resistors as close to the LTC2924 as possible. Details of Resistor Calculations In this example, the voltage ...
Page 12
LTC2924 APPLICATIO S I FOR ATIO HYS Figure 7. Cascading Two LTC2924s to Fully Sequence Up to Eight Power Supplies TMR HYS/CFG LTC2924 HYS IN1 IN2 IN3 IN4 FAULT Figure 8. Cascading Three ...
Page 13
APPLICATIO S I FOR ATIO U U PS1 PS2 Connecting Unused OUT and IN Pins Figure 9 shows how to connect unused OUT and IN pins on the LTC2924. Unused OUT-IN pairs must be connected together to ensure proper operation. ...
Page 14
LTC2924 APPLICATIO S I FOR ATIO U U Note that the TMR pin may take a while to reach the V voltage. The pin is pulled to V with the same 5µA current CC source used for the TMR function. ...
Page 15
TYPICAL APPLICATIO 0.1µF 3.3V 0.1µF 5V 0.1µF 5V EARLY 0.1µF 10k SYSTEM CONTROLLER Power-Up Sequence 2V/DIV 10V/DIV 2V/DIV 2V/DIV 25ms/DIV Series MOSFET Power Supply Sequencer 0.1µF Q4 52. OUT1 IN1 OUT2 IN2 ...
Page 16
LTC2924 TYPICAL APPLICATIO S U POWER SUPPLY 1 POWER SUPPLY 2 POWER SUPPLY 3 POWER SUPPLY 4 5V EARLY* 10k SYSTEM CONTROLLER *5V EARLY MUST BE ON BEFORE SEQUENCING SUPPLIES 16 Shutdown Pin Power Supply Sequencer 3.3V SHDN 5V SHDN ...
Page 17
TYPICAL APPLICATIO S U 2-Supply Sequencer with Delayed Sense Pin, One Channel Unused + OUT MODULE + SENSE 5V DC/DC 3.3V SHDN 10k 10k SYSTEM CONTROLLER D1: 1N5711 Q1, Q2: IRL3714S Power-On REMOTE SENSE ENABLE 2V/DIV 1V/DIV 1V/DIV 25ms/DIV Q1 ...
Page 18
LTC2924 TYPICAL APPLICATIO S U –5V 0.1µF 100k 3V 0.1µF 5V 0.1µF 5V EARLY 0.1µF 10k SYSTEM CONTROLLER Power-Up Sequence 5V/DIV 5V/DIV 2V/DIV 2V/DIV 10ms/DIV 18 Precision Negative Rail Sequencer Q1 10k 1.36k 1M – LM321 + 2N3906 SOT-23 Q2 ...
Page 19
... FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. ...
Page 20
... Closed Loop (Feedback) Tracking for 3 Supplies For Point of Load or Distributed Applications www.linear.com ● µC V CC1 V CC2 1k RESET_B 1.24k FPGA V CC1 V CC2 20k 5.11k ASIC V CC1 V CC2 10k 10k 2924 TA08 LT/LT 1005 REV A • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 2005 2924fa ...