MAX5949BESA+T Maxim Integrated Products, MAX5949BESA+T Datasheet - Page 8

• Manufacturer Part Number: MAX5949BESA+T
• Description: IC CNTRLR HOT SWAP 8-SOIC
• Manufacturer: Maxim Integrated Products
• Type: Hot-Swap Controllerr

Specifications of MAX5949BESA+T

• Applications: General Purpose
• Internal Switch(s): No
• Voltage - Supply: -20 V ~ -80 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX5949A/MAX5949B are integrated hot-swap
controllers for -48V power systems. They allow circuit
boards to be safely hot plugged into a live backplane
without causing a glitch on the power-supply rail. When
circuit boards are inserted into a live backplane without
hot-swap control, the bypass capacitors at the input of
the board’s power module or switching power supply
can draw large inrush currents as they charge. The
inrush currents can cause glitches on the system
power-supply rail and damage components on the
board.
-48V Hot-Swap Controllers
with External R
8
MAX5949A MAX5949B
_______________________________________________________________________________________
—
1
2
3
4
5
6
7
8
PIN
—
1
2
3
4
5
6
7
8
Detailed Description
PWRGD
PWRGD
SENSE
DRAIN
NAME
GATE
V
V
OV
UV
DD
EE
Power-Good Signal Output. PWRGD is an active-low open-drain status output referenced
to V
indicating a power-good condition. PWRGD is open drain otherwise.
Power-Good Signal Output. PWRGD is an active-high open-drain status output referenced
to DRAIN. PWRGD latches in a high-impedance state when V
V
DRAIN otherwise.
Input Pin for Overvoltage Detection. OV is referenced to V
V
OV pin voltage reduces to V
Input Pin for Undervoltage Detection. UV is referenced to V
V
UV is also used to reset the circuit breaker after a fault condition. To reset the circuit
breaker, pull UV below V
condition; however, the device does not restart until a t
the fault.
Device Negative Power-Supply Input. Connect to the negative power-supply rail.
Current-Sense Voltage Input. Connect to an external sense resistor and the external
MOSFET source. The voltage drop across the external sense resistor is monitored to detect
overcurrent or short-circuit fault conditions. Connect SENSE to V
limiting feature.
Gate-Drive Output. Connect to the gate of the external n-channel MOSFET.
Output-Voltage Sense Input. Connect to the output-voltage node (drain of the external
n-channel MOSFET).
Positive Power-Supply Rail Input. This is the power ground in the negative-supply voltage
system. Connect to the higher potential of the power-supply inputs.
GATE
OVH
UVH
SENSE
EE
voltage, the GATE is enabled. When UV is pulled below V
voltage, the GATE pin is immediately pulled low. The GATE pin remains low until the
. PWRGD is latched low when V
> (∆V
GATE
- V
GH
), indicating a power-good condition. PWRGD is pulled low to
UVL
OVL
. The reset command can be issued immediately after a fault
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.
Both the MAX5949A and MAX5949B provide undervolt-
age, overvoltage, and overcurrent protection. The
MAX5949A/MAX5949B ensure the input voltage is sta-
ble and within tolerance before applying power to the
load. The devices also provide protection against input
voltage steps. During an input voltage step, the
MAX5949A/MAX5949B limit the current drawn by the
load to a safe level without turning off power to the load.
.
DRAIN
FUNCTION
- V
EE
≤ V
DL
OFF
and V
EE
EE
delay time has elapsed after
. When OV is pulled above the
DRAIN
. When UV is pulled above the
GATE
UVL
EE
Pin Description
, GATE is pulled low.
to disable the current-
- V
> (∆V
EE
≤ V
GATE
DL
- V
and
GH
),