LTC4231_15 Datasheet, PDF (1/20 Pages) Linear Technology – Micropower Hot Swap Controller

LTC4231
Micropower Hot Swap
Controller
Features
Description
n _{Enables Safe Board Insertion and Removal from a}
Power Supply
n _{4µA Supply Current}
n _{0.3µA Shutdown Current}
n _{Wide Operating Voltage Range: 2.7V to 36V}
n _{Reverse Supply Protection to –40V}
n _{Adjustable Analog Current Limit with Circuit Breaker}
n _{Automatic Retry or Latchoff on Current Fault}
n _{Overvoltage and Undervoltage Monitoring}
n _{Controls Single or Back-to-Back N-Channel MOSFETs}
n _{12-Lead MSOP and 3mm × 3mm QFN Packages}
Applications
n _{Battery Powered Equipment}
n _{Solar Powered Systems}
n _{Portable Instruments}
n _{Energy Harvesting}
The LTC^®4231 is a micropower Hot Swap™ controller that
allows safe circuit board insertion and removal from a live
power supply. An internal high side switch driver controls
the gate of an external N-channel MOSFET. Back-to-back
MOSFETs can be used for reverse supply protection down
to –40V.
The LTC4231 provides a debounce delay and allows the
GATE to be ramped up at an adjustable rate. After start-
up, the LTC4231's quiescent current drops to 4µA during
normal operation with output active. UVL, UVH, OV and
GNDSW monitor overvoltage and undervoltage periodi-
cally, keeping total quiescent current low. Pulling SHDN
low shuts down the LTC4231 and quiescent current drops
to 0.3µA.
During an overcurrent fault, the LTC4231 actively limits
current while running an adjustable timer. The LTC4231-1
remains off after a current fault while the LTC4231-2
automatically reapplies power after a cool-down period.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Hot
Swap and PowerPath are trademarks of Linear Technology Corporation. All other trademarks are
the property of their respective owners.
Typical Application
Battery Hot Swap with Reverse Protection
SMAJ24CA
22.5mΩ
Si7164DP
1020k
SENSE
IN
GATE
SOURCE
UVL
STATUS
24V
1.65k
LTC4231
UVH
4.22k
OV
SHDN
32.4k
GNDSW
TIMER
GND
Si5410DU
V_OUT
24V
2A
220µF
20k
180nF
IN
20V/DIV
GATE
20V/DIV
SOURCE
20V/DIV
I_LOAD
5A/DIV
4231 TA01a
For more information www.linear.com/LTC4231
Power-Up Waveforms
CONTACT
BOUNCE
10ms/DIV
4231 TA01b
4231f
1