The SMH4044 is a fully integrated hot swap controller that
provides complete power control for add-in cards ranging
in use for basic hot swap systems to high availability
systems. It detects proper insertion of the card and
senses valid supply voltage levels at the backplane.
Utilizing external low on-resistance N-channel MOS-
FETs, card power is ramped by two high-side driver
outputs that are slew-rate limited at 250V/s.
The internal 256 × 8 E2PROM can be used as configura-
tion memory for the individual card or as general purpose
Programming of configuration, control and calibration
values by the user can be simplified with the interface
adapter and Windows GUI software obtainable from
The SMH4044 continuously monitors the host supplies,
the add-in card supplies and the add-in card currents. If
the SMH4044 detects the current is higher than the
programmed value it will shut down the MOSFETs and
issue a fault status to the host.
MONITOR 2 30
Simplified Application Drawing — Triple Voltage Hot Swap (5V, 3.3V, 1.8V)
2057 1.x 8/16/01
SUMMIT MICROELECTRONICS, Inc.