LT1640HIS8#TR Linear Technology, LT1640HIS8#TR Datasheet - Page 13

• Manufacturer Part Number: LT1640HIS8#TR
• Description: IC CTRLR HOTSWAP NEG VOLT 8SOIC
• Manufacturer: Linear Technology
• Type: Hot-Swap Controllerr

Specifications of LT1640HIS8#TR

• 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)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

APPLICATIONS
When the DRAIN voltage of the LT1640L is high with
respect to V
and the PWRGD pin is in a high impedance state (Fig-
ure 12). The PWRGD pin will be pulled high by the module’s
internal pull-up current source, turning the module off.
When the DRAIN voltage drops below V
and the PWRGD pin will pull low, enabling the module.
The PWRGD signal can also be used to turn on an LED or
optoisolator to indicate that the power is good as shown
in Figure 13.
EE
, the internal pull-down transistor Q2 is off
* DIODES INC. SMAT70A
– 48V
GND
U
*
GND
9.09k
562k
10k
INFORMATION
1%
1%
1%
R4
R5
R6
* DIODES INC. SMAT70A
(SHORT PIN)
– 48V
U
GND
*
GND
3
2
R4
R5
R6
(SHORT PIN)
UV
OV
3
V
EE
W
4
1
3
2
Figure 13. Using PWRGD to Drive an Optoisolator
0.02
5%
R1
PG
LT1640L
UV
OV
3
, Q2 will turn on
+
–
SENSE
2
V
Figure 12. Active Low Enable Module
4
1
EE
V
4
5
PG
R1
U
SENSE
2
C1
150nF
25V
+
–
LT1640L
4
5
GATE
V
DD
IRF530
8
6
Q1
GATE
V
C1
DD
R2
10
5%
6
8
Q1
R2
18k
Gate Pin Voltage Regulation
When the supply voltage to the chip is more than 15.5V,
the GATE pin voltage is regulated at 13.5V above V
supply voltage is less than 15.5V, the GATE voltage will be
about 2V below the supply voltage. At the minimum 10V
supply voltage, the gate voltage is guaranteed to be greater
than 6V. The gate voltage will be no greater than 18V for
supply voltages up to 80V.
5%
R3
PWRGD
DRAIN
R3
V
EE
Q2
3.3nF
100V
C2
PWRGD
C2
DRAIN
1
7
1N4148
7
1N4148
+
1
1640 F12
C3
MOC207
R7
51k
5%
ENABLE MODULE
V
ON/OFF
V
ACTIVE LOW
IN
IN
+
–
V
V
OUT
OUT
LT1640L/LT1640H
+
–
+
C3
100 F
100V
1640 F13
PWRGD
EE
13
. If the
1640lhfb