MAX5949A_11 Datasheet, PDF (1/18 Pages) Maxim Integrated Products – -48V Hot-Swap Controllers with External RSENSE

19-3494; Rev 1; 8/11
-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
o Allow Safe Board Insertion and Removal
from a Live -48V Backplane
o Pin and Function Compatible with LT4250L
(MAX5949A)
o Pin Compatible with LT1640L (MAX5949A)
o Pin and Function Compatible with LT4250H
(MAX5949B)
o Pin Compatible with LT1640H (MAX5949B)
o Circuit-Breaker Immunity to Input Voltage Steps
and Current Spikes
o Withstand -100V Input Transients with No
External Components
o Programmable Inrush and Short-Circuit Current
Limits
o Operate from -20V to -80V
o Programmable Overvoltage Protection
o Programmable Undervoltage Lockout
o Power Up into a Shorted Load
o Power-Good Control Output
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX5949AESA+
-40°C to +85°C
8 SO
MAX5949BESA+
-40°C to +85°C
8 SO
+Denotes a lead(Pb)-free/RoHS-compliant package.
TOP VIEW
Pin Configuration
PWRGD
+
(PWRGD) ¹
OV 2
UV 3
MAX5949A
MAX5949B
V_EE 4
8 V_DD
7 DRAIN
6 GATE
5 SENSE
SO
( ) FOR MAX5949B.
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.