UNISEM US2075CT, US2075CM Datasheet

US2075

5V

PWM SWITCHER CONTROLLER & 7.5A

LOW DROPOUT REGULATOR COMBO

PATENT PENDING

FEATURESFEATURES

The US2075 eliminates the need for a
seperate switching controller IC
Minimum part count allows lower system cost
Fixed 3.30V/7.5A LDO on board
On board MOSFET driver
Fastest transient response of any controller
method. ( 0 to 100% Duty Cycle in 100 nS )
1% internal voltage reference
Internal Thermal shutdown
Internal Under Voltage Lockout protects
MOSFET during start-up

APPLICATIONSAPPLICATIONS

Dual supply low voltage processor applications,
such as: P55C,CYRIX M2, POWER PC and
AMD

TYPICAL APPLICATIONTYPICAL APPLICATION

DESCRIPTIONDESCRIPTION

The US2075 is a dual function IC combining a switching
controller and a 7.5A low dropout regulator all in a com-
pact 7 pin TO220 and TO263 surface mount pack­ages providing a total solution for dual supply proces­sor applications such as an Intel P55C , AMD K6,
as well as Cyrix 6X86L and the M2processors.
Typically in these applications a dual supply regulator
converts 5V to 3.3V for I/O supply and a jumper pro­grammable supply of 2.8V to 3.5V for CORE supply .The
linear regulator portion in the US2075 is a fixed 3.30V
output and has a minimum of 7.5A current capability
designed to provide ample current for most applications
while the switching regulator controller uses the 5V sup­ply to power the controller and the 12V supply to drive
the power MOSFET, allowing a low cost N- MOS switch
to be used. The IC also includes an error comparator for
fastest transient response, a precise voltage reference
for setting the output voltage as well as a direct drive of
the MOSFET for the minimum part count.

V5

7

2075ap1a-1.0

US2075

12V

Vout

Vhyst

Gnd

Vfb

V12

Drv

6
5
4
3
2
1

3.30V / 7.5A

2.8V / 10A

Typical application of US2075 in a flexible mother board designed for Intel P55,P54

AMD K5,K6 as well as Cyrix M1 and M2 applications.

Notes: P54C,P55C are trade marks of Intel Corp. K5 & K6 are trade marks of AMD corp. Cyrix 6X86L,M1,M2 are trade marks of Cyrix
Corp. Power PC is trade mark of IBM Corp.

PACKAGE ORDER INFORMATIONPACKAGE ORDER INFORMATION

Tj (°C) 7 PIN PLASTIC 7 PIN PLASTIC
TO220 (T) TO263 (M)
0 TO 125 US2075CT US2075CM

Rev. 1.2
4/26/98

4-1

US2075

ABSOLUTE MAXIMUM RATINGSABSOLUTE MAXIMUM RATINGS

12V Supply Voltage ............................................................. 14V

5V Supply Voltage .............................................................. 7V

LDO Power Dissipation .................................... Internally Limited

FB Pin Voltage........................................................ -0.3V to 5V

Storage Temperature Range ................................. -65 TO 150°C

Operating Junction Temperature ............................... O TO 150°C

PACKAGE INFORMATIONPACKAGE INFORMATION

7 PIN PLASTIC TO220 (T) 7 PIN PLASTIC TO263 (M)

FRONT VIEW

7
6
5
4
3
2
1

V5
Vhyst
Vfb
Drv

Vout
Gnd
V12

θJT=2.7°C/W θJA=60°C/W θJA=35°C/W for 1" Square pad

FRONT VIEW

7

V5

6

Vout

5

Vhyst

4

Gnd

3

Vfb

2

V12

1

Drv

ELECTRICAL SPECIFICATIONSELECTRICAL SPECIFICATIONS

Unless otherwise specified the following specification applies over,V5=5V,V12=12V,and Tj=0 to 125°C.Low duty
cycle pulse testing are used which keeps junction and case temperatures equal to the ambient temperature.

LDO Section

PARAMETER SYM TEST CONDITION MIN TYP MAX UNITS

Output Voltage VOUT Io=0mA 3.400 V
Line Regulation Io=0mA, 4.75<V5<6V 0.2 %
Load Regulation (note 1) 0A<Io<7.5A 0.5 %
Maximum Output Current IMAX dVo=0.995*VOUT 7.5 A
Thermal Regulation 30 mS Pulse,V5=5V 0.01 0.02 %/W
Ripple Rejection f=120HZ ,Co=25uF Tan 70 dB

Io=1A

Switching Controller Section

PARAMETER SYM TEST CONDITION MIN TYP MAX UNITS

F.B Voltage Initial Accuracy Vfb TJ =25°C 1.237 1.250 1.262 V
F.B Voltage Total Variation Vfb Includes Temp & line,4.75 to 5.25V 1.225 1.250 1.275 V
F.B Input Bias Current Ifb Vfb=1.25V -2 +2 uA
Min On Time Vfb is sq wave with 300 ns on 400 600 800 nS

time and 2 uS off time

Min Off Time Vfb is sq wave with 300 ns off 400 600 800 nS

time and 2 uS on time
Vhyst pin output-HI Isource=500uA,Vfb=1.5V 11 V
Vhyst pin output-LO Isink=500uA,Vfb=1V 1 V
Supply Current Icc Vfb=1V 10 mA
Maximum Duty Cycle Dmax Vfb=1V 100 %
Minimum Duty Cycle Dmin Vfb=1.5V 0 %
Gate Drive Rise/Fall Time Vgate Load=IRL3303 70 nS

4-2

Rev. 1.2

4/26/98