LT1640LIS8#PBF Linear Technology, LT1640LIS8#PBF Datasheet - Page 12
![IC CONTRLR HOTSWAP NEGVOLT 8SOIC](/photos/7/35/73584/lt1640lis8_pbf_sml.jpg)
LT1640LIS8#PBF
Manufacturer Part Number
LT1640LIS8#PBF
Description
IC CONTRLR HOTSWAP NEGVOLT 8SOIC
Manufacturer
Linear Technology
Type
Hot-Swap Controllerr
Datasheet
1.LT1640LCS8PBF.pdf
(16 pages)
Specifications of LT1640LIS8#PBF
Applications
General Purpose
Internal Switch(s)
No
Voltage - Supply
-10 V ~ -80 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
8-SOIC (0.154", 3.90mm Width)
Output Voltage
1.5V
Internal Switch
No
Supply Voltage Range
10V To 80V
Digital Ic Case Style
SOIC
No. Of Pins
8
Operating Temperature Range
-40°C To +85°C
Msl
MSL 1 - Unlimited
Rohs Compliant
Yes
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
APPLICATIONS
LT1640L/LT1640H
The new threshold voltage when the input moves from low
to high is:
where V
The new threshold voltage when the input moves from
high to low is:
where V
The new hysteresis value will be:
With R1 = 562k, R2 = 16.9k and R3 = 1.62M, V
and V
(from low to high) and 37.6V (from high to low). The
hysteresis is 5.4V. A separate resistor divider should be
used to set the overvoltage threshold given by:
12
V
V
UV HL
HYS
V
UV LH
,
UVHY
,
UVH
UVL
V
UVHY
V
= 20mV, the undervoltage threshold will be 43V
UVL
V
UVH
is typically 1.223V.
is typically 1.243V.
R
R
R
2
2
2
•
•
U
R
R
•
R
3
3
3
* DIODES INC. SMAT70A
– 48V
GND
R
R
R R
R R
INFORMATION
R
2
2
U
1
1
R R
*
2
•
•
•
•
1
GND
R
R
•
•
R
3
3
3
3
R4
R5
R6
(SHORT PIN)
3
3
R R
R R
3
2
R R
1
1
W
•
•
1
UV
OV
LT1640H
•
3
+
–
2
2
V
4
2
1
EE
V
–
Figure 11. Active High Enable Module
PG
R1
GATE
V
V
SENSE
2
GATE
GATE
U
+
–
4
5
= 13.5V
•
•
R
R
R
R
V
C1
3
DD
1
1
3
6.5k
8
R7
GATE
Q1
V
EE
Q3
6
R2
With R4 = 506k, R5 = 8.87k and V
overvoltage threshold will be 71V.
PWRGD/PWRGD Output
The PWRGD/PWRGD output can be used to directly en-
able a power module when the input voltage to the module
is within tolerance. The LT1640L has a PWRGD output for
modules with an active low enable input, and the LT1640H
has a PWRGD output for modules with an active high
enable input.
When the DRAIN voltage of the LT1640H is high with
respect to V
turned off and R7 and Q2 clamp the PWRGD pin one diode
drop ( 0.7V) above the DRAIN pin. Transistor Q2 sinks
the module’s pull-up current and the module turns off.
When the DRAIN voltage drops below V
shorting the bottom of R7 to DRAIN and turning Q2 off.
The pull-up current in the module then flows through R7,
pulling the PWRGD pin high and enabling the module.
PWRGD
Q2
R3
DRAIN
V
OV
C2
1
7
2 1N4148
V
OVH
EE
+
R
(Figure 11), the internal transistor Q3 is
4
1640 F11
R
C3
5
R
ENABLE MODULE
5
V
V
ON/OFF
ACTIVE HIGH
IN
IN
+
–
V
V
OUT
OUT
+
–
OVH
PG
, Q3 will turn on,
= 1.223V, the
1640lhfb