MAX5949 Datasheet, PDF (1/18 Pages) Maxim Integrated Products – -48V Hot-Swap Controllers with External RSENSE

19-3494; Rev 0; 11/04
-48V Hot-Swap Controllers
with External R_SENSE
General Description
The MAX5949A/MAX5949B are hot-swap controllers that
allow a circuit card to be safely hot plugged into a live
backplane. The MAX5949A/MAX5949B operate from
-20V to -80V and are well-suited for -48V power systems.
These devices are pin and function compatible with the
LT4250 and pin compatible with the LT1640.
The MAX5949A/MAX5949B provide a controlled turn-on
to circuit cards preventing glitches on the power-supply
rail and damage to board connectors and components.
The MAX5949A/MAX5949B provide undervoltage, over-
voltage, and overcurrent protection. These devices
ensure the input voltage is stable and within tolerance
before applying power to the load.
Both the MAX5949A and MAX5949B protect a system
against overcurrent and short-circuit conditions by turn-
ing off the external MOSFET in the event of a fault con-
dition. The MAX5949A/MAX5949B also provide
protection against input voltage steps. During an input
voltage step, the MAX5949A/MAX5949B limit the cur-
rent drawn by the load to a safe level without turning off
power to the load.
Both devices feature an open-drain power-good status
output (PWRGD for the MAX5949A or PWRGD for the
MAX5949B) that can be used to enable downstream
converters.
The MAX5949A/MAX5949B are available in an 8-pin SO
package. Both devices are specified for the extended
-40°C to +85°C temperature range.
Applications
Telecom Line Cards
Network Switches/Routers
Central-Office Line Cards
Server Line Cards
Base-Station Line Cards
Central-Office Switching
-48V Distributed Power Systems
Negative Power-Supply Controls
Typical Operating Circuit and Selector Guide appear at end
of data sheet.
Features
♦ Allow Safe Board Insertion and Removal
from a Live -48V Backplane
♦ Pin and Function Compatible with LT4250L
(MAX5949A)
♦ Pin Compatible with LT1640L (MAX5949A)
♦ Pin and Function Compatible with LT4250H
(MAX5949B)
♦ Pin Compatible with LT1640H (MAX5949B)
♦ Circuit-Breaker Immunity to Input Voltage Steps
and Current Spikes
♦ Withstand -100V Input Transients with No
External Components
♦ Programmable Inrush and Short-Circuit Current
Limits
♦ Operate from -20V to -80V
♦ Programmable Overvoltage Protection
♦ Programmable Undervoltage Lockout
♦ Power Up into a Shorted Load
♦ Power-Good Control Output
PART
MAX5949AESA
MAX5949BESA
TOP VIEW
Ordering Information
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 SO
8 SO
Pin Configuration
PWRGD
(PWRGD) ¹
OV 2
UV 3
V_EE 4
MAX5949A
MAX5949B
8 V_DD
7 DRAIN
6 GATE
5 SENSE
SO
( ) FOR MAX5949B.
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