LTC1422 Linear Technology, LTC1422 Datasheet
LTC1422
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LTC1422 Summary of contents
Page 1
... The ON pin can be used to cycle the board power or to generate a soft reset. The LTC1422 is available in 8-pin PDIP and SO packages. , LTC and LT are registered trademarks of Linear Technology Corporation. Hot Swap is a trademark of Linear Technology Corporation. ...
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... Input Voltage (FB, ON) ........................... – 0.3V to 13.2V Output Voltage (RESET) ........................ – 0.3V to 13.2V Output Voltage (GATE) ............................. – 0.3V to 20V Operating Temperature Range LTC1422C ............................................... LTC1422I ........................................... – Storage Temperature Range ................ – 150 C Lead Temperature (Soldering, 10 sec)................. 300 C ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T ...
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... Temperature 1.237 1.236 HIGH THRESHOLD 1.235 1.234 1.233 LOW THRESHOLD 1.232 1.231 1.230 1.229 1.228 14 – 55 – 35 – TEMPERATURE ( C) LTC1422 Gate Voltage vs Supply Voltage 105 125 SUPPLY VOLTAGE (V) 1422 G02 Gate Current vs Temperature 10 ...
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... LTC1422 W U TYPICAL PERFORMANCE CHARACTERISTICS TIMER Threshold Voltage vs Supply Voltage 1.244 1.242 1.240 1.238 1.236 1.234 1.232 SUPPLY VOLTAGE (V) 1422 G10 TIMER Current vs Temperature 2. 2.40 2.35 2.30 2.25 2.20 2.15 2.10 2.05 2.00 – 55 – 35 – 105 TEMPERATURE ( C) 1422 G13 Current Limit Threshold ...
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... RESET pin will be pulled low. An internal filter helps prevent negative voltage glitches from triggering a reset. When the voltage on the FB pin rises above the trip point, the RESET pin will go high after one timing cycle. LTC1422 ON Pin Pulse (Soft Reset) Time vs Temperature V ...
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... LTC1422 PIN FUNCTIONS GATE (Pin 6): The high side gate drive for the external N-Channel. An internal charge pump guarantees at least 10V of gate drive. The slope of the voltage rise or fall at the GATE is set by an external capacitor connected between GATE and GND, and the 10 A charge pump output cur- rent ...
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... The LTC1422 is designed to turn a board’s supply voltage on and off in a controlled manner, allowing the board to be safely inserted or removed from a live backplane. The chip also provides a system reset signal to indicate when board supply voltage drops below a programmable voltage ...
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... RESET pin will eventually go low (time points 4, 5 and 6). Timer The system timing for the LTC1422 is generated by the circuitry shown in Figure 6. The timer is used to set the turn-on delay after the ON pin goes high and the delay before the RESET pin goes high after the output supply voltage is good as sensed by the FB pin ...
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... C2)/2 A. For a 200ms delay, use a 0.33 F capacitor. Electronic Circuit Breaker The LTC1422 features an electronic circuit breaker func- tion that protects against short circuits or excessive cur- rents on the supply. By placing a sense resistor between the supply input and SENSE pin, the circuit breaker will be tripped whenever the voltage across the sense resistor is greater than 50mV for more than 10 s ...
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... LTC1422 to sit at the negative terminal of the 48V input. The clamp circuit of R5 and D1 provides power to the LTC1422. The resistive divider R1 and R2 at the ON pin monitors the input supply. The switching FET Q1 is prevented from turning on until the input supply is at least 38V ...
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... Figure 15 shows how to Hot Swap a controller’s 5V supply and a 48V module using two LTC1422s. Assuming the 5V supply comes up first, the controller waits for a power good signal from the 48V circuit. Once it receives the right signals the controller activates the GATE IN pin of the Vicor power module ...
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... LTC1422 U U APPLICATIONS INFORMATION Power N-Channel and Sense Resistor Selection The decision of which external power N-Channel to use is dependent on its maximum current rating and the maxi- mum allowed current times R DS(ON) transistor. Table 1 lists some transistors that are available. Table 1. N-Channel Selection Guide ...
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... R5 10k 5% LTC1422 1 8 RESET SENSE 3 6 TIMER GATE GND 25V D1 7.5V 1N755A > 38V IN Figure 13. Switching 48V to a Vicor Module LTC1422 AT&T JW050A1-E 50W + + OUT + C3 + SENSE 100 F – SENSE 100V – – OUT ON/OFF ...
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... LTC1422 R9 0 RESET V 5% R10 SENSE TIMER GATE 4 5 GND FB C5 0.33 F 16V R5 6.2k 5% LTC1422 1 8 RESET SENSE 3 6 TIMER GATE GND 25V C1 D1 0.1 F 7.5V 25V 1N755A CIRCUIT TURNS ON WHEN V > 38V IN CIRCUIT FOR ACTIVE HIGH TURN-ON MODULES ...
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... BSC S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 0.053 – 0.069 (1.346 – 1.752) 0.004 – 0.010 (0.101 – 0.254) 0.014 – 0.019 0.050 (0.355 – 0.483) (1.270) BSC TYP LTC1422 V OUT 3. 1/2 MBRS120T3 MMDF 2N02E V OUT ...
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... LTC1422 U TYPICAL APPLICATION Current Sensing with 48V Applications In the LTC1422, the SENSE pin threshold is 50mV below the V pin. Typically, the current sense resistor is con- CC nected to the V pin, but in 48V applications the sense CC resistor is connected to the negative terminal of the 48V supply. The circuit in Figure 17 translates the current in the sense resistor to a resistor connected to the LTC1422 SENSE pin ...