UCC2918_08 Datasheet, PDF (1/10 Pages) Texas Instruments – LOW ON-RESISTANCE HOT SWAP POWER MANAGER

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UCC2918/81510
LOW ONĆRESISTANCE HOT SWAP POWER MANAGER
D Integrated 0.075-Ω Power MOSFET
D 3 V to 6 V Operation
D External Analog Control of Fault Current
From 0 A to 4 A
D Independent Analog Control of Current
Limit up to 5 A
D Fast Overload Protection
D Unidirectional Switch
D Minimal External Components
D 1-µA I_CC When Disabled
D Programmable On Time
D Programmable Start Delay
D Fixed 3% Duty Cycle
SLUS457C − JULY 2000 - REVISED APRIL 2001
DP PACKAGE
(TOP VIEW)
VIN
1
VIN
2
VIN
3
GND*
4
GND*
5
FAULT
6
SHTDWN
7
IFAULT
8
16
VOUT
15
VOUT
14
VOUT
13
GND*
12
GND*
11
NC
10
CT
9
IMAX
Pin 5 serves as the lowest impedance to the electrical
ground. Pins 4, 12, and 13, serve as heat sink/ground.
These pins should be connected to large etch PCB areas
to help dissipate heat.
description
The UCC2918 low on-resistance hot swap power manager provides complete power management, hot swap
capability, and circuit breaker functions. The only components needed to operate the device, other than supply
bypassing, are a timing capacitor and two programming resistors. All control and housekeeping functions are
integrated and externally programmable. These include the fault current level, maximum output sourcing
current, maximum fault time, and startup delay. In the event of a constant fault, the internal fixed 3% duty cycle
ratio limits the average output power. The IFAULT pin allows linear programming of the fault level current from
0 A to 4 A.
functional block diagram
OVERLOAD
COMPARATOR
+
CHARGE
PUMP
+
REVERSE
COMPARATOR
+
20mV
+ VOUT
CURRENT SENSE
1 ^VIN
2 ^VIN
3 ^VIN
IMAX 9
+
MAXIMUM
CURRENT
LEVEL
CURRENT
FAULT LEVEL
OVERCURRENT
COMPARATOR
+
IFAULT 8
ON TIME
CONTROL
3% DUTY
CYCLE
H = OPEN
THERMAL
SHUTDOWN
INTERNAL
BIAS
14 VOUT
15 VOUT
16 VOUT
1.5V
+
7 SHTDWN
5
4
13 12
10
6
GND ^{HEAT SINK GND}
CT
FAULT
PINS
UDG−00101
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
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Copyright  2001, Texas Instruments Incorporated
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