LTC2924 Linear Technology, LTC2924 Datasheet
LTC2924
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LTC2924 Summary of contents
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... Errors in power supply sequencing and the control input are detected and reported at the F A U L T output. The LTC2924 features pre- cision input comparators which can provide 1% accuracy in monitoring power supply voltages. ...
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... F A U L D O N E .............................. –0. Output Voltages (OUT1 - OUT4) (Note 5) .............. –0. 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 ...
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... ON and IN1-IN4 pins OUT(EN) OUT ONE OUTPUT DRIVING CURRENT (µA) OUT LTC2924 www.DataSheet4U.com MIN TYP MAX ● 0.93 1 1.07 ≤ 0. ● PGT 0.93 1 1.07 100 ● 15 ● 400 ● 2 ● 1.6 ● ...
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... LTC2924 TYPICAL PERFOR A CE CHARACTERISTICS DONE (V) CC OUTn (Off Temperature SAT –60 –40 – TEMPERATURE (° 200 180 160 140 120 100 2924 G04 ...
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... F A U L T (Pin 9): Fault Pin. Pull this pin high with an external 10k resistor. The LTC2924 will pull this pin low if a fault condition is detected (see Applications Information for details). Pulling this pin low externally causes a simulta- neous unsequenced Power Off. ...
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... 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 – 0.61V I H HYS/CFG FIRST 15 DETECT 5µA + – 1V TMR 0.61V 1V INTERNAL REFERENCE 0.5V UVLO CLOCK CHARGE PUMP ...
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... Power Off sequencing. A second capacitor can be added to enable a power good timer which detects the failure of any power supply to turn on within the set time. The ON pin signal is used to command the LTC2924 to start the Power On and Power Down sequences. To command the Power On sequence, the ON pin is pulled above 0 ...
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... Power On sequence. OUT4 is turned off first. The timer function is used between each supply being sequenced down. The PGT is not used. The end of the Power Off sequence is indicated by the LTC2924 floating the D O N E pin. ON TMR OUT4 ...
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... 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 sup- plies two through five are enabled by the OUT1 through OUT4 pins, and their turn on sensed by the IN1 through IN4 pins respectively. The last power supply is enabled by the ...
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... HYS For this example HYS which is greater than 4mV. 3.3V SHDN 5V SHDN 1.6V SHDN 2.5V SHDN V CC OUT1 IN1 LTC2924 10k OUT2 IN2 OUT3 IN3 OUT4 IN4 ON DONE FAULT TMR HYS/CFG PGT GND 150nF 150nF Figure 6. Typical Power Supply Sequencer www.DataSheet4U.com Ω ...
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... As a practical matter, lay out these resistors as close to the LTC2924 as possible. Details of Resistor Calculations In this example, the voltage at the IN pins is 0.61V when the LTC2924 detects that the power supply is On during a Power On sequence or Off during a Power Off sequence. The delta voltage, ΔV, represents the difference: ΔV = 2.2V – 1.2V ...
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... Figure 8 and add more LTC2924s in the middle. Notice that the last LTC2924 in the cascade string must have a pull-up resistor on the D O N E pin. Any LTC2924 that is not the first in the cascade string should have the hysteresis current setting resistor, R instead of ground. The value of the R unchanged. The ...
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... Fault Condition Indicator If the LTC2924 receives a commanded fault (a cascaded LTC2924 or an external source pulls down on the F A U L T pin) the LTC2924 will pull the TMR pin low. If the LTC2924 has detected the fault itself (from its internal fault detec- ...
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... OUT pins will be pulled low. After sensing the Externally Commanded Fault, the LTC2924 will also pull down on the F A U L T pin until the conditions for clearing the fault condition exist (see Clear- ing the Fault Condition). ...
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... OUT3 IN3 10k OUT4 IN4 ON LTC2924 11.8k DONE FAULT TMR HYS/CFG PGT GND 49.9k 150nF 150nF 5V 3.3V 2V/DIV 1V 10V/DIV DONE ON 2V/DIV 2V/DIV TMR 2924 TA02b LTC2924 www.DataSheet4U.com V = 0.93V 0.91V OFF V = 2.79V 2.73V OFF V = 4.21V 3.76V OFF V = 3.32V 2.80V OFF 45.3k 6.04k 1 ...
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... Power On Sequence Timer Delay Longer than Power Off Sequence Timer Delay IN1 OUT1 IN2 OUT2 IN3 OUT3 LTC2924 IN4 OUT4 ON PGT TMR FAULT 150nF DONE GND 150nF 2924 TA04 2N7002 POWER ON TIMER DELAY = 30ms POWER OFF TIMER DELAY = 15ms www ...
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... IN4 OUT2 IN3 OUT1 IN2 LTC2924 ON IN1 FAULT PGT DONE HYS 49.9k TMR GND 150nF 5V 3.3V 2V/DIV DONE ON 1V/DIV 1V/DIV TMR 2924 TA05b LTC2924 www.DataSheet4U.com PARASITIC RESISTANCE V V ≥ 4.64V OUT ≤ 4V OFF V ≥ 2.98V V ON OUT V ≤ 2.65V 3.3V OFF 64.9k 33.2k 150nF 9.83k 8 ...
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... Precision Negative Rail Sequencer Q1 10k 1.36k 1M – LM321 + 2N3906 SOT- 0.1µF Q4 52. OUT1 IN1 OUT2 IN2 OUT3 IN3 10k OUT4 IN4 ON LTC2924 11.8k DONE FAULT TMR HYS/CFG PGT GND 49.9k 150nF 150nF 5V 3.3V 5V/DIV –5V 5V/DIV DONE 2V/DIV TMR ON 2V/DIV 2924 TA07b www.DataSheet4U.com V – 4. – ...
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... TYP .008 – .012 (0.203 – 0.305) TYP INCHES LTC2924 www.DataSheet4U.com .189 – .196* (4.801 – 4.978) .009 (0.229 REF .150 – .157** (3.810 – 3.988) ...
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... LTC2924 TYPICAL APPLICATIO U 12V 3-Supply Sequencer with LTC2924 Power Supplied by a Zener Shunt Regulator 12V SYSTEM 12V SUPPLY 49.9k 1.5k 2.94k 5.1V 0.1µF ZENER BZX84C5V1 49.9k 150nF RELATED PARTS PART NUMBER DESCRIPTION LTC2920-1/ LTC2920-2 Single/Dual Power Supply Margining Controller LTC2921/LTC2922 Power Supply Tracker with Input Monitors ...