RT1720 Datasheet, PDF (1/19 Pages) Richtek Technology Corporation – 60V Hot Swap Controller with Fault Timer

RT1720
60V Hot Swap Controller with Fault Timer
General Description
The RT1720 is an over-voltage and over-current
protection circuit. It monitors a circuit’s input voltage
and current with its adjustable over-voltage and
over-current thresholds and drives an external
N-MOSFET switch to connect the input to the output
voltage only when it is safe. Its wide input voltage
range makes it useful for high-voltage applications and
in systems that experience large transient voltages and
currents, such as automotive, telecom, and industrial
applications.
During over-voltage events, the RT1720 quickly
reduces the gate drive of the external MOSFET to
regulate the output voltage at the level chosen by its
external FB resistors. During over-current events, when
the load draws excessive current, the RT1720 reduces
the gate drive to regulate the output current at the level
set by its external current sense resistor. In both cases
the output voltage or current is linearly regulated,
thermally stressing the MOSFET load switch. However,
an externally-adjustable timer limits the duration of
MOSFET stress, eventually signaling a fault and then
turning off the MOSFET. The RT1720 then periodically
restarts operation to test if the fault has cleared. The
timer protects the MOSFET while allowing the load
circuit to temporarily operate normally through voltage
and current surges, such as load dump in automobiles
or spinning up disk drives.
The RT1720 features include soft-start, open-drain
fault and power-good outputs, and a shutdown input
that can be used as a threshold comparator or a linear
regulator controller.
The RT1720 is available in the MSOP-10 package.
Features
 Wide Input Operation Range : 5V to 80V
 Negative Input Voltage Rating to −60V
 Adjustable Output Clamp Voltage
 Adjustable Over-Current Protection
 Programmable Timer for Fault Protection
 Low Shut Down Current
 Internal Charge Pump N-MOSFET Drive
 Fast 80mA MOSFET Shut-off for Overvoltage
 Fault Output Indication
Applications
 Automotive/Avionic Surge Protection
 Hot Swap/Live Insertion
 High-Side Switch for Battery Powered Systems
 Intrinsic Safety Applications
Simplified Application Circuit
V_IN
5V to 80V
R_SNS
R3
VCC
SHDN
SNS
GATE
VOUT
RT1720
C_TMR
FB
TMR
FLT
PGOOD
GND
Q1
V_OUT
V_{OUT_Max} = 60V
C_OUT
R2
FAULT _R1
POWER
GOOD
Copyright © 2014 Richtek Technology Corporation. All rights reserved.
DS1720-00 November 2014
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1