UCC2915 Datasheet, PDF (1/5 Pages) Texas Instruments – 15V Programmable Hot Swap Power Manager

UCC2915
UCC3915
15V Programmable Hot Swap Power Manager
FEATURES
• Integrated 0.15 Ohm Power
MOSFET
• 7V to 15V Operation
• Digital Programmable Current Limit
from 0A to 3A
• 100 A I_CC when Disabled
• Programmable ON Time
• Programmable Start Delay
• Fixed 2% Duty Cycle
• Thermal Shutdown
• Fault Output Indicator
• Maximum Output Current can be set
to 1A above the Programmed Fault
Level or to a full 4A
• Power SOIC and TSSOP, Low
Thermal Resistance Packaging
DESCRIPTION
The UCC3915 Programmable Hot Swap Power Manager provides com-
plete power management, hot swap capability, and circuit breaker functions.
The only external component required to operate the device, other than
power supply bypassing, is the fault timing capacitor, C_T. 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 2% duty cycle ratio limits average output power.
The internal 4 bit DAC allows programming of the fault level current from 0
to 3A with 0.25A resolution. The IMAX control pin sets the maximum
sourcing current to 1A above the trip level or to a full 4A of output current
for fast output capacitor charging.
When the output current is below the fault level, the output MOSFET is
switched ON with a nominal ON resistance of 0.15 . When the output cur-
rent exceeds the fault level, but is less than the maximum sourcing level,
the output remains switched ON, but the fault timer starts, charging CT.
Once CT charges to a preset threshold, the switch is turned OFF, and re-
mains OFF for 50 times the programmed fault time. When the output cur-
rent reaches the maximum sourcing level, the MOSFET transitions from a
switch to a constant current source.
BLOCK DIAGRAM
IMAX 10
H = 4A
4A
MAX
CURRENT
LEVEL
CHARGE
PUMP
REVERSE VOLTAGE
COMPARATOR
30mV
V_OUT
CURRENT SENSE
H = OPEN
1A
ABOVE
FAULT
CURRENT FAULT
LEVEL 0–3 AMPS
LINEAR CURRENT
AMPLIFIER
OVER CURRENT
COMPARATOR
ON TIME
CONTROL
2% DUTY
CYCLE
2
VIN
3
POWER
FET
*
14
VOUT
15
0–3A
0.25
RES
6
7
8
9
B3 B2 B1 B0
4 BIT DAC
5 4 13 12
GND HEAT SINK
GND PINS
Note: Pin numbers refer to DIL-16 and SOIC-16 packages.
SLUS198A - FEBRUARY 2000
THERMAL
SHUTDOWN
INTERNAL
BIAS
1.5V
+
–
11
16
CT FAULT
* BODY DIODE
1 SHTDWN
UDG-99174