LTC1642ACGN Linear Technology, LTC1642ACGN Datasheet - Page 7

• Manufacturer Part Number: LTC1642ACGN
• Description: IC,Electronic Circuit Breaker,CMOS,SSOP,16PIN,PLASTIC
• Manufacturer: Linear Technology

Specifications of LTC1642ACGN

• Linear Misc Type: Positive Low Voltage
• Family Name: LTC1642A
• Package Type: SSOP N
• Operating Supply Voltage (min): 2.97V
• Operating Supply Voltage (max): 16.5V
• Operating Temperature (min): 0C
• Operating Temperature (max): 70C
• Operating Temperature Classification: Commercial
• Product Depth (mm): 3.99mm
• Product Height (mm): 1.5mm
• Mounting: Surface Mount
• Pin Count: 16
• Lead Free Status / Rohs Status: Not Compliant

PI FU CTIO S
OV (Pin 9): Overvoltage Input. When the voltage on OV
exceeds its trip point the GATE pin is pulled low immedi-
ately and the CRWBR timer starts. If OV remains above its
trip point (minus 3mV of hysteresis) long enough for
CRWBR to reach its trip point, then the part turns off until
reset by pulsing the ON pin low. Otherwise, the GATE pin
begins ramping up one RST TMR timing cycle after OV
goes below its trip point. Ground the OV pin to disable
overvoltage protection.
COMPOUT (Pin 10): Uncommitted Comparator’s Open
Drain Output.
COMP
ing Input.
COMP
Input.
REF (Pin 13): Reference Voltage Output. The 1.22V ±1%
reference should be bypassed with a 0.1µF compensation
capacitor. For V
GATE (Pin 14): Gate Drive for the External N-Channel
MOSFET. An internal charge pump provides at least 4.5V
of gate drive and sources 25µA. The pin requires an
external series RC network to ground to compensate the
current limit loop and to limit the ramp rate. A resistor of
100Ω is also recommended in series with the MOSFET
gate to suppress high frequency oscillations. GATE is
U
+
–
(Pin 11): Uncommitted Comparator’s Noninvert-
(Pin 12): Uncommitted Comparator’s Inverting
U
CC
= 5V it can source 1mA.
U
immediately pulled to ground when the overvoltage com-
parator trips or the input supply is below the undervoltage
lockout trip point. During current limit the GATE voltage is
adjusted to maintain constant load current until the circuit
breaker timer trips. At that point GATE is pulled to ground
until the chip is reset. Clamp the GATE pin with a zener
diode to ground if the supply is 8V or higher. For the 8V to
12V range use an 18V zener (1N4705), and for supplies
exceeding 12V use a 20V zener (TOSHIBA 02DZ20Y).
SENSE (Pin 15): Current Sense Input. To use the current
limit place a sense resistor in the supply path between V
and SENSE. When the drop across the resistor exceeds a
threshold voltage, the GATE pin is adjusted to maintain a
constant load current and the circuit breaker timer is
started. A foldback feature reduces the current limit as the
voltage at FB approaches ground. Short SENSE to V
disable the current limiting.
V
voltage lockout circuit holds the GATE pin at ground until
V
regulator protects the chip from V
voltages up to 33V. In this case the GATE pin voltage will
usually be low but this is not guaranteed; use the OV pin
to ensure that the pass device is off. The V
provides a high side connection to the SENSE resistor.
CC
CC
exceeds 2.73V. If V
(Pin 16): Positive Supply Voltage. An internal under-
CC
exceeds 16.5V an internal shunt
LTC1642A
CC
and SENSE pin
CC
pin also
CC
1642af
7
CC
to