1
dc1575bfa
DEMO MANUAL DC1575B
DESCRIPTION
LTC4362-2:
Monolithic Overvoltage/
Overcurrent Protector
Demonstration circuit 1575B features the
monolithic overvoltage/overcurrent protector that safe-
guards 2.5V to 5.5V systems from power supply over-
voltage. It is designed for portable devices with multiple
power supply options including wall adaptors, car battery
adaptors and USB ports.
The LTC4362 controls an internal 40mΩ N-channel MOSFET
in series with the input power supply. During overvoltage
transients, the LTC4362 turns off the MOSFET within 1μs,
isolating downstream components from the input supply.
In most applications, the LTC4362 rides through induc-
tive cable transients without requiring transient voltage
suppressors or other external components. An internal
current sense resistor is used to implement overcurrent
protection.
The LTC4362 has a delayed start-up at plug-in and con-
trolled dV/dt ramp-up for inrush current limiting. A
PWRGD
pin provides power good monitoring for V
IN
. The LTC4362
PARAMETER
CONDITION
VALUE
Input Voltage
JP2: OV/OC
JP2: OV/OC/NV
0V to 28V
–30V to 28V
Output Voltage
Input Range for Gate Turn-On
2.1V to 5.8V
Overcurrent Threshold
Internal Sense Resistor
1.5A
Overcurrent Retry
LTC4362-2
Auto-Retry
PERFORMANCE SUMMARY
features a soft-shutdown controlled by the ON pin and
drives an optional external P-channel MOSFET for negative
voltage protection. Following an overvoltage condition,
the LTC4362 automatically restarts with a 130ms delay.
After an overcurrent fault, the LTC4362-1 remains off while
the LTC4362-2 (featured on the DC1575B) automatically
restarts after a 130ms delay.
DC1575B demonstrates two protection schemes selected
with a jumper. The first selection is overvoltage and
overcurrent protection. The second selection is overvolt-
age, overcurrent, and negative voltage protection. Also
on the DC1575B is ON control with another jumper, input
LEDs indicating positive or negative input voltage, output
LED and connection for USB protected output.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1575B
L
, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
(T
A
= 25°C)
