The MAX16545B/C is a circuit-breaker protection IC with an
integrated low-resistance MOSFET and lossless current-sense
circuitry featuring PMBus™ /SMBus control and reporting. The
IC is designed to provide the optimum solution for distribution,
control, monitoring and protection of the system’s 12V power
supply. An internal LDO provides the bias supply voltage for
the protection IC.
If no fault is detected, the MAX16545B/C initiates the startup.
The device has been designed to provide controlled, monotonic
startup. Programmable soft-start ramp and delay is implemented
to limit the inrush current during startup. The MAX16545B is set
for 16A Startup OCP, and the MAX16545C is set for 24A Startup
OCP.
The IC monitors the current and the voltage of the 12V system
power rail and provides multiple levels of protection with fast
turn off if a fault is detected. Three methods of overcurrent
protection are provided. Programmable moderate OCP level
allows surge currents for a limited time. User-selectable severe
OCP level provides a fast disconnect if a current exceeding
the severe OCP threshold is detected. An additional fixed high
shutdown OCP level provides instantaneous disconnect to
further protect the device.
The lossless current sense provides high-accuracy current
sensing over load and temperature, improving overall system
energy efficiency, and reducing dissipation. A signal proportional
to the load current is reported through an analog output and
extensive reporting is provided through the SMBus/PMBus.
Output voltage is monitored at all times. If at any time the
output voltage falls below the programmable output undervoltage
lockout threshold, the PWRGD signal is asserted low. If
at any time the input voltage falls below the programmable
input undervoltage lockout threshold, the PWRGD signal
is asserted low. The MAX16545B/C can be programmed
through PMBus to provide input overvoltage protection. Input
overvoltage protection is disabled by default. When enabled
through PMBus, if the input voltage exceeds a programmable
overvoltage threshold, the MOSFET is latched off and a fault
is communicated.
The IC is used to distribute and control power to a system
from the +12V power supply.
Applications
- Integrated Protection IC on 12V: Circuit Breaker, Hot Swap, Inrush Control
- Servers, Networking, Storage, Communication Equipment and AC/DC Power Supplies
