LTC2954 Linear Technology, LTC2954 Datasheet
LTC2954
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LTC2954 Summary of contents
Page 1
... Independently ad- justable On and Off timers allow dependable push button control of the enable output and resistance to accidental toggling of system power. The LTC2954 operates over a wide 2.7V to 26.4V input Packages TM voltage range to accommodate a wide variety of input power supplies. Very low quiescent current (6µA typical) makes the LTC2954 ideally suited for battery powered applications ...
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... U Operating Temperature Range LTC2954C-1 .............................................. 0°C to 70°C LTC2954C-2 .............................................. 0°C to 70°C LTC2954I-1 .......................................... – 40°C to 85°C LTC2954I-2 .......................................... – 40°C to 85°C Storage Temperature Range DFN Package ..................................... – 65°C to 125°C TSOT-23 ............................................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec) .................. 300°C ...
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... Note 5: The enable lock out time is designed to allow an application to properly power down such that the next power up sequence starts from a consistent powered down configuration. P ignored during this lock out time. This time delay does not include t LTC2954 MIN TYP MAX UNITS ± ...
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... LTC2954 TYPICAL PERFOR A CE CHARACTERISTICS W Supply Current vs Temperature 26 www.DataSheet4U.com 0 – –25 TEMPERATURE (°C) Turn On Debounce Time (t DB ONT External Capacitance ONT 10000 T = 25° 3.3V IN 1000 100 100 ONT EXTERNAL CAPACITANCE (nF) Internal Default ...
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... T = 100°C A 150 T = 25° –45°C A 100 EXTERNAL PB RESISTANCE TO GROUND (kΩ) 2954 G10 E N (LTC2954-2) Voltage 25°C A 100k PULL-UP FROM 2954 G12 IN IN ...
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... P pressed and held low (t operating range for this low leakage pin 26.4V. E N (LTC2954-2, Pin 6/Pin 7): Open Drain Enable Bar Output. This pin is intended to enable system power. E asserted low after a valid P B turn-on event (t ...
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... BLOCK DIAGRA W 1. 2.7V TO 26.4V 29V 2.4V ZENER 100k PB www.DataSheet4U.com 0.8V GND DIAGRA REGULATOR 2.4V OSCILLATOR 10µS DEBOUNCE FILTER ONT t KILL(PW) KILL t KILL(PD) EN/EN LTC2954 HIGH VOLTAGE LOGIC OSCILLATOR PDT 2954 TD01 EN (–1) EN (–2) KILL 0.6V INT 2954 BD 2954f 7 ...
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... PB PDT INT Off Interrupt Timing, P B Pressed and Released, Enable Remains Active PB PDT INT EN (LTC2954-1) Forced Off, Power Down Timing, P B Pressed and Held Low for t > & KILL IGNORED DB, ON ONT KILL, ON BLANK 16 CYCLES ...
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... PDT timer expires. Turn On When power is first applied to the LTC2954, the part ini- tializes the output pins. Any DC/DC converters connected to the EN/ E N pin will therefore be held off. To assert the enable output, P B must be held low for a minimum of ...
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... PB t DB, ON ONT PDT www.DataSheet4U.com INT KILL XXX DON'T CARE EN Figure 1. Simplified Power On/Off Sequence for LTC2954-1. μP Asserts K I L L after an Interrupt Figure 2. K I L L Remaining Low Aborts Power On Sequence for LTC2954 ...
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... XXX DON’T CARE Figure 3. µP Turns Off Power (LTC2954- system is now in its reset state where the LTC2954 is in low power mode (6µA) and P monitored for a high to low transition. Aborted Power On Sequence The power on sequence is aborted when the K I L L remains low at the end of the 512ms blanking time. Figure simplifi ...
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... V IN switch is physically located far from the LTC2954 P B pin, parasitic capacitances may couple onto the high imped- ance P B input. Additionally, parasitic series inductance may cause unpredictable ringing at the P B pin. Placing a 5.1k resistor from the ...
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... P B pin can withstand ESD HBM strikes up to ±10kV. In order to keep external noise from coupling inside the LTC2954, place an R-C network close to the P B pin. A 5.1k resistor and a 0.1µF capacitor should suffice for most noisy applications (see Figure 8). ...
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... P B voltage may fall close to the threshold window. To mitigate the effect of the board leakage, a 10k resistor recommended (see Figure 9). IN www.DataSheet4U.com 14 U Reverse Battery Protection To protect the LTC2954 from a reverse battery connec- tion, place a 1k resistor in series with the V Figure 10). LTC2954-1/ LTC2954 ...
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... PACKAGE OUTLINE 0.200 REF TS8 Package 8-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1637) 0.65 REF 1.22 REF 1.50 – 1.75 2.80 BSC 1.4 MIN (NOTE 4) 0.80 – 0.90 1.00 MAX 0.09 – 0.20 (NOTE 3) LTC2954 R = 0.115 TYP R = 0.05 5 TYP 2.00 ±0.10 (2 SIDES) 0.56 ± 0.05 (2 SIDES) 4 0.25 ± 0.05 0.75 ±0.05 2.15 ±0.05 (2 SIDES) 0 – 0.05 BOTTOM VIEW—EXPOSED PAD 2 ...
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... McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● 910k 0.1µF LTC2954-1 INT PB KILL GND ONT PDT ONT PDT 0.033µF 1µF Figure 10. Reverse Battery Protection COMMENTS Adjustable R E S E 10-Lead MSOP and 3mm x 3mm DFN Packages 6 ...