LTC1647-1IS8#TR Linear Technology, LTC1647-1IS8#TR Datasheet - Page 10

• Manufacturer Part Number: LTC1647-1IS8#TR
• Description: IC CONTROLLER HOTSWAP DUAL 8SOIC
• Manufacturer: Linear Technology
• Type: Hot-Swap Controllerr

Specifications of LTC1647-1IS8#TR

• Applications: General Purpose
• Internal Switch(s): No
• Voltage - Supply: 2.7 V ~ 16.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Linear Misc Type: Positive Low Voltage
• Family Name: LTC1647-1
• Package Type: SOIC N
• Operating Supply Voltage (min): 2.7V
• Operating Supply Voltage (max): 16.5V
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• 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

LTC1647-1/
LTC1647-2/LTC1647-3
BLOCK DIAGRAMS
APPLICATIONS INFORMATION
V
The LTC1647-3 features separate supply inputs (V
and V
pump circuit draw supply current from the higher of the
two supplies. An internal V
makes the power connection automatically. This allows
a 3V channel to have standard MOSFET gate overdrive
when the other channel is 5V. An internal Zener clamps
GATE about 15V above V
If both supplies are connected together (internally for
LTC1647-1 and LTC1647-2 or externally for LTC1647-3),
the reference and charge pump circuit draw equal current
from both pins.
10
CC
Selection Circuit
CC2
) for each channel. The reference and charge
SENSE1
SENSE2
FAULT1
FAULT2
V
V
GND
ON1
ON2
CC1
CC2
15
16
14
1
2
3
8
4
5
CC
CC
+
–
.
1.21V
50mV
selection circuit detects and
REFERENCE
–
–
+
+
2.45V
UVL
1.21V
FILTER
50μs
(DUPLICATE OF CHANNEL ONE)
CHARGE
PUMP
CC1
CHANNEL TWO
LTC1647-3
CHANNEL ONE
FAULT
CP
Electronic Circuit Breaker
Each channel of the LTC1647 features an electronic circuit
breaker to protect against excessive load current and short-
circuits. Load current is monitored by sense resistor R1 as
shown in Figure 1. The circuit breaker threshold, V
50mV and it exhibits a response time, t
300ns. If the voltage between V
for more than t
pulls GATE low with a 50mA current sink. The MOSFET turns
off and FAULT pulls low. The circuit breaker is cleared by
pulling the ON pin low for a period of at least t
A timing diagram of these events is shown in Figure 2.
The value of the sense resistor R1 is given by:
R1 = V
SELECTION
V
CC
CB
/I
TRIP
FAULT
(Ω)
, the circuit breaker trips and immediately
CP
10μA
50μA
CC
and SENSE exceeds V
FAULT
1647-1/2/3 BD3
13
12
, of approximately
GATE1
GATE2
RESET
(50μs).
CB
1647fa
, is
CB