MAX6399 Datasheet, PDF (1/10 Pages) Maxim Integrated Products – High-Voltage, Overvoltage/Undervoltage, Protection Switch Controller

19-3655; Rev 1; 3/06
High-Voltage, Overvoltage/Undervoltage,
Protection Switch Controller
General Description
The MAX6399 is a small overvoltage and undervoltage
protection circuit. The device can monitor a DC-DC out-
put voltage and quickly disconnect the power source
from the DC-DC input load when an overvoltage condi-
tion occurs. A power-OK output signals when the
DC-DC input voltage falls below an adjustable thresh-
old. This controller architecture provides the ability to
size the external n-channel MOSFET to meet specific
load current requirements.
When the DC-DC monitored output voltage is below the
user-adjustable overvoltage threshold, the GATE output
of the MAX6399 goes high to enhance the n-channel
MOSFET. The MAX6399 offers internal charge-pump
circuitry that allows the GATE voltage to be 10V above
the input voltage (V_GS = 10V) to fully enhance the
external n-channel MOSFET, thus minimizing the drain-
to-source resistance.
When the monitored output voltage rises above the
user-adjusted overvoltage threshold, the GATE output
rapidly pulls low to shut off the MOSFET. The MOSFET
remains latched off until either the MAX6399 input
power or SHDN input is cycled. The MAX6399 includes
a logic-low shutdown input that disables the GATE. An
internal overtemperature detector also disables the
gate when the MAX6399 temperature reaches the ther-
mal-shutdown threshold.
The device operates over a wide supply voltage range
(5.75V to 72V) and is offered in a small TDFN package,
fully specified from -40°C to +125°C.
Applications
Networking
Server
Telecom
RAID
Pin Configuration
TOP VIEW
8765
MAX6399
*EP
12 34
Features
♦ Wide Supply Voltage Range (5.75V to 72V)
♦ Internal Charge Pump Ensures n-Channel
MOSFET is Fully Enhanced During Normal
Operation (V_GS = 10V)
♦ Fast GATE Shutoff During Overvoltage with 20mA
Sink Capability
♦ Latches Off External n-Channel MOSFET During
High-Voltage Transients
♦ Adjustable DC-DC Input Undervoltage Threshold
Power-OK Output
♦ Adjustable DC-DC Output Overvoltage
Thresholds
♦ Overtemperature Shutdown Protection
♦ Fully Specified from -40°C to +125°C
Ordering Information
PART
PIN-PACKAGE
MAX6399ATA-T 8 TDFN-8
TOP
MARK
ANE
PKG
CODE
T833-2
Typical Operating Circuit
12V
IN
GATE
OUT
MAX6399
SHDN
OUT_SET
SET
POK
GND
DC-DC
CONVERTER
IN
OUT
EN GND
LOAD
3.3V
TDFN
*EXPOSED PAD. CONNECT TO GND.
________________________________________________________________ Maxim Integrated Products 1
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