The LM25066A combines a high-performance hot-swap controller with a PMBus™ compliant
SMBus/I2C interface to accurately measure, protect and control the
electrical operating conditions of computing and storage blades connected to a backplane power bus.
The LM25066A continuously supplies real-time power, voltage, current, temperature and fault data to
the system management host via the SMBus interface.
The LM25066A control block includes a unique hot-swap architecture that provides current
and power limiting to protect sensitive circuitry during insertion of boards into a live system
backplane, or any other power source. A fast acting circuit
breaker prevents damage in the event of a short circuit on the output. The input undervoltage and
overvoltage levels and hysteresis are configurable, as well as the insertion delay time and fault
detection time. A temperature monitoring block on the LM25066A interfaces with a low-cost external
diode for monitoring the temperature of the external MOSFET or other thermally sensitive
components. The POWER GOOD output provides a fast indicator when the input and/or output voltages
are outside their programmed range. LM25066A current measurement accuracy is ±1% over
The LM25066A monitoring block computes both the real-time and average values of
subsystem operating parameters (VIN, IIN,
PIN, VOUT) as well as the peak power. Accurate power
averaging is accomplished by averaging the product of the input voltage and current. A black box
(Telemetry/Fault Snapshot) function captures and stores telemetry data and device status in the
event of a warning or a fault.