MAX4944ELA+T Maxim Integrated Products, MAX4944ELA+T Datasheet - Page 5

• Manufacturer Part Number: MAX4944ELA+T
• Description: IC CTLR OVP W/FET 6.35V 8-UDFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX4944ELA+T

• Applications: *
• Mounting Type: Surface Mount
• Package / Case: 8-µDFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: MAX4944ELA+T; MAX4944ELA+TTR

The MAX4943–MAX4946/MAX4949 overvoltage-protec-
tion devices feature a low R
low-voltage systems against voltage faults up to +28V. If
the input voltage exceeds the overvoltage threshold, the
internal MOSFET is turned off to prevent damage to the
protected components. These devices also drive an
Figure 1. Functional Diagram
6, 7, 8
PIN
1, 2
3
4
5
ACOK
GND
GP
IN
NAME
ACOK
GND
OUT
_______________________________________________________________________________________
GP
IN
Overvoltage-Protection Controllers with
Detailed Description
Voltage Input. IN powers the charge pump required to turn on the internal switch. When the correct
adapter is plugged in, a 15ms (typ) debouncer prevents false turn-on of the internal switch. Bypass
IN to GND with a 1µF ceramic capacitor as close as possible to the device to enable ±15kV (HBM)
ESD protection on IN.
pFET Gate-Drive Output. GP pulls the external pFET gate down when the input is above ground.
Active-Low Open-Drain Adapter-Voltage Indicator Output. ACOK is driven low after the adapter
voltage is stable between V
the logic I/O voltage of the host system.
Ground
Output Voltage. Output of internal switch. Short all pins together for proper operation.
ON
internal FET and protect
V
V
OVLO
UVLO
+
-
+
-
UVLO
and V
optional external pFET to protect down to -28V. If the
adapter voltage drops below ground, the pFET turns off
to prevent damage to the protected components due to
negative voltage exposure. The internal charge pump’s
15ms (typ) debounce time prevents false turn-on of the
internal switch during startup. An open-drain, active-low
logic output is available to signal that a successful
power-up has occurred.
OVLO
RESET
for 30ms (typ). Connect a pullup resistor from ACOK to
FUNCTION
RETRY TIME
DEBOUNCE
TIMER AND
OSCILLATOR
30ms (typ)
15ms (typ)
CHARGE
TIMER
PUMP
CHARGE-PUMP
ENABLED
MAX4943–MAX4946/MAX4944L/
MAX4945L/MAX4949
RESET
Internal FET
OVERCURRENT
THERMAL
FAULTS
OR
Pin Description
OUT
5