UNISEM US1175CS, US1175CP, US1175CM Datasheet
US1175
7.5A ULTRA LOW DROPOUT POSITIVE
ADJUSTABLE REGULATOR
PRELIMINARY DATASHEET
FEATURESFEATURES
0.5V Dropout at 7.5A (Equivalent of 67mΩ)Ω)
Fast Transient Response
1% Voltage Reference Initial Accuracy
Built-in Thermal Shutdown
APPLICATIONSAPPLICATIONS
3.3V to 2.7V Intel I740 chip set.
TYPICAL APPLICATIONTYPICAL APPLICATION
3.3V
Vin
DESCRIPTIONDESCRIPTION
The US1175 product is a 7.5A regulator with extremely
low dropout voltage using a proprietary Bipolar process that achieves comparable equivalent on resistance to that of discrete MOSFETs. This product is
specifically designed to provide well regulated supply for
applications requiring very low dropout such as
2.8V from 3.3V ATX power supplies where the same
efficiency as the switcher can be achieved without
the cost and complexity associated with switching
regulators. One such application is the new graphic
chip sets that requires 2.7V supply such as the Intel
I740 chip set.
C1
5
Vctrl
4
Vout
US1175
Vsense
1175app1-1.0
5V
3
Adj
2
1
C2
Typical application of US1175 .
R1
C3
R2
PACKAGE ORDER INFORMATIONPACKAGE ORDER INFORMATION
Tj (°C) 5 PIN PLASTIC 5 PIN PLASTIC 8 PIN PLASTIC
TO263 (M) POWER FLEX (P) SOIC (S)
0 TO 125 US1175CM US1175CP US1175CS
2.7V
Rev. 1.2
11/29/99
2-1
US1175
ABSOLUTE MAXIMUM RATINGSABSOLUTE MAXIMUM RATINGS
Input Voltage (Vin) ........................................................... 6V
Control Input Voltage (Vctrl) .................................................. 14V
Power Dissipation............................................. Internally Limited
Storage Temperature Range ................................... -65°C TO 150°C
Operating Junction Temperature Range ..................... 0°C TO 150°C
PACKAGE INFORMATIONPACKAGE INFORMATION
8 PIN PLASTIC SOIC ( S ) 5 PIN PLASTIC TO263 ( M ) 5 PIN PLASTIC POWER FLEX (P)
FRONT VIEW
5
Vin
4
Vctrl
3
Vout
2
Adj
1
Vsense
Vctrl
Vin
Adj
TOP VIEW
1
2
3
4
8
Vout
7
Vout
6
Vout
5
VoutVsense
θJA=55°C/W for 1" Sq pad area θJA=35°C/W for 0.5" square pad θJA=35°C/W for 0.5" square pad
FRONT VIEW
5
Vin
4
Vctrl
3
Vout
2
Adj
1
Vsense
ELECTRICAL SPECIFICATIONSELECTRICAL SPECIFICATIONS
Unless otherwise specified ,these specifications apply over ,Cin=1uF,Cout=10uF, and Tj=0 to 125°C.Typical
values refer to Tj=25°C. Vout=Vsense.
PARAMETER SYM TEST CONDITION MIN TYP MAX UNITS
Reference Voltage Vref Vctrl=2.75V,Vin=2V,Io=10mA 1.243 1.250 1.257 V
Tj=25,Vadj=0V
Vctrl=2.7to12V,Vin=2.05V to 5.5V, 1.237 1.250 1.263
Io=10mA to 7.5A,Vadj=0V
Line Regulation Vctrl=2.5Vto7V,Vin=1.75Vto5.5V
,Io=10mA ,Vadj=0V 0.5 3 mV
Load Regulation (note 1) Vctrl=2.75V,Vin=2.1V,Io=10mA
to 7.5A,Vadj=0V 2 6 mV
Dropout Voltage (note 2) Vadj=0V for all conditions below.
(Vctrl - Vout) Vin=2.05V,Io=1.5A 0.95 V
Vin=2.05V,Io=3A 1.00
Vin=2.05V,Io=5A 1.05
Vin=2.05V,Io=7.5A 1.15 1.30
Dropout Voltage (note 2) Vadj=0V for all conditions below.
(Vin - Vout) Vctrl=2.75V,Io=1.5A 0.100 0.130 V
Vctrl=2.75V,Io=3A 0.200 0.260
Vctrl=2.75V,Io=5A 0.330 0.430
Vctrl=2.75V,Io=7.5A 0.500 0.650
Current Limit Vctrl=2.75V,Vin=2.05V,
dVo=100mV Vadj=0V 7.7 9 A
Minimum Load Current (note 3) Vctrl=5V,Vin=3.3V,Vadj=0V, 5 10 mA
Thermal Regulation 30 mS Pulse 0.01 0.02 %/W
Ripple Rejection Vctrl=5V,Vin=5V,Io=3A,Vadj=0V 60 70 dB
Tj=25,Vripple=1Vpp at 120Hz
2-2
Rev. 1.2
11/29/99
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