lm5066pmhx National Semiconductor Corporation, lm5066pmhx Datasheet - Page 12

• Manufacturer Part Number: lm5066pmhx
• Description: High Voltage System Power Management And Protection Ic With Pmbus
• Manufacturer: National Semiconductor Corporation

www.national.com
Block Diagram
Functional Description
The inline protection functionality of the LM5066 is designed
to control the in-rush current to the load upon insertion of a
circuit card into a live backplane or other “hot” power source,
thereby limiting the voltage sag on the backplane’s supply
voltage, and the dV/dt of the voltage applied to the load. The
effects on other circuits in the system are minimized by pre-
venting possible unintended resets. A controlled shutdown
when the circuit card is removed can also be implemented
using the LM5066.
In addition to a programmable current limit, the LM5066 mon-
itors and limits the maximum power dissipation in the series
pass device to maintain operation within the device Safe Op-
erating Area (SOA). Either current limiting or power limiting
for an extended period of time results in the shutdown of the
series pass device. In this event, the LM5066 can latch off or
repetitively retry based on the hardware setting of the
12
RETRY pin. Once started, the number of retries can be set to
none, 1, 2, 4, 8, 16, or infinite. The circuit breaker function
quickly switches off the series pass device upon detection of
a severe over-current condition. Programmable under-volt-
age lockout (UVLO) and over-voltage lockout (OVLO) circuits
shut down the LM5066 when the system input voltage is out-
side the desired operating range.
The telemetry capability of the LM5066 provides intelligent
monitoring of the input voltage, output voltage, input current,
input power, temperature, and an auxiliary input. The LM5066
also provides a peak capture of the input power and pro-
grammable hardware averaging of the input voltage, current,
power, and output voltage. Warning thresholds which trigger
the SMBA pin may be programmed for input and output volt-
age, current, power and temperature via the PMBus interface.
Additionally, the LM5066 is capable of detecting damage to
the external MOSFET, Q
1
.
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