LTC1645CS8 Linear Technology, LTC1645CS8 Datasheet - Page 6

• Manufacturer Part Number: LTC1645CS8
• Description: IC CTRLR SEQ HOTSWAP DUAL 8SOIC
• Manufacturer: Linear Technology
• Type: Hot-Swap Controllerr

Specifications of LTC1645CS8

• Applications: General Purpose
• Internal Switch(s): No
• Voltage - Supply: 1.2 V ~ 12 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Linear Misc Type: Positive Low Voltage
• Family Name: LTC1645
• Package Type: SOIC N
• Operating Supply Voltage (min): 1.2V
• Operating Supply Voltage (max): 12V
• Operating Temperature (min): 0C
• Operating Temperature (max): 70C
• Operating Temperature Classification: Commercial
• Product Depth (mm): 3.99mm
• Product Height (mm): 1.5mm
• Product Length (mm): 5mm
• Mounting: Surface Mount
• Pin Count: 8
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

BLOCK DIAGRA
LTC1645
PI FU CTIO S
Whenever the timer is inactive, an internal N-channel FET
shorts the TIMER pin to ground. Activating the timer
connects a 2 A current source from V
and the voltage starts to ramp up with a slope dv/dt = 2 A/
C
the timer is reset by pulling the TIMER pin back to ground.
The timer period is (1.23V • C
GATE1 (Pin 12/Pin 6): Channel 1 High Side Gate Drive.
Connect to the gate of an external N-channel MOSFET. An
internal charge pump guarantees at least 4.5V of gate
drive. The charge pump is powered by the higher of V
and V
on by connecting a 10 A current source from the charge
pump output to the GATE1 pin and the voltage starts to
ramp up with a slope dv/dt = 10 A/C
pin is below 0.8V but above 0.4V, a 40 A current source
pulls GATE1 toward ground. If the ON pin is below 0.4V,
6
TIMER 11
FAULT 4
TIMER
U
ON
CC2
10
. When the voltage reaches the trip point (1.23V),
. When the ON pin exceeds 0.8V, GATE1 is turned
U
2 A
0.4V
0.8V
REF
2V
U
+
–
+
–
+
–
+
–
W
(14-Lead Package/8-Lead Package)
TIMER
)/2 A.
2.23V
V
UVL
14
CC1
GATE1
CC1
to the TIMER pin
. While the ON
FILTER
+
1.5 s
SENSE1
13
–
+
–
50mV
LOGIC
1.12V
V
UVL
CC2
1
CC1
FILTER
+
1.5 s
SENSE2
the circuit breaker trips or the undervoltage lockout circuit
trips, the GATE1 pin is immediately pulled to ground with
a 12mA (typ) current source.
SENSE1 (Pin 13/Pin 7): V
a sense resistor placed in the supply path between V
and SENSE1, the circuit breaker trips when the voltage
across the resistor exceeds 50mV for more than 1.5 s. If
the circuit breaker trip current is set to twice the normal
operating current, only 25mV is dropped across the sense
resistor during normal operation. To disable the circuit
breaker, short V
V
from 2.375V to 12V for normal operation. I
1mA. An undervoltage lockout circuit disables the chip
whenever the voltage at V
logic is powered by V
–
+
CC1
2
–
50mV
(Pin 14/Pin 8): Positive Supply Input. V
GLITCH
FILTER
CC1
GATE1
REFERENCE
4 CHARGE
12
1.238V
PUMP
and SENSE1 together.
CC1
GATE2
3
CC1
.
CC1
–
+
–
+
is less than 2.23V. All internal
Circuit Breaker Set Pin. With
REF
REF
1645 BD
CC1
CC1
6
5
7
8
9
FB
RESET
GND
COMP
COMPOUT
is typically
can range
+
1645fa
CC1