US2076
PWM SWITCHER CONTROLLER & 7.5A
ADJUSTABLE LOW DROPOUT REGULATOR COMBO
FEATURES
The US2076 eliminates the need for a
seperate switching controller IC
Minimum part count allows lower system cost
Adjustable 7.5A LDO on board
1.1V Dropout at 7.5A
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
DESCRIPTION
PATENT PENDING
PRELIMINARY DATASHEET
APPLICATIONS
Dual supply low voltage processor applications,
such as: P55C™,CYRIX M2™, POWER PC™ and
AMD K6™
The US2076 is a dual function IC combining a
switching controller and a 7.5A adjustable low
dropout regulator all in a compact 7 pin TO220 and
TO263 surface mount
packages providing a
total so-
lution
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 sup-
ply and a jumper programmable supply of 1.25V to 3.5V
for CORE supply.The linear regulator portion in the
US2076 is an adjustable one that can be programmed
to 3.30V output and has a minimum of 7.5A current ca-
pability designed to provide ample current for most ap-
plications. The US2076 uses an internal regulator gen-
erated from the 12V supply to power the switching con-
troller as well as the 12V supply to drive the power
MOSFET, allowing a low cost N channel MOSFET
switch to be used. The IC also includes an error com-
parator for fast transient response, a precise voltage ref-
erence for setting the output voltage as well as a direct
drive of the MOSFET for the minimum part count.
TYPICAL APPLICATION
L1
5V
C1
Vin
Vout
Vfb2
C6
R6
5V
R7
D2
R8
I/O
US2076
Gnd
Vfb1
V12
Drv
7
6
5
4
3
2
1
CPU
Vcc2 Det
L2
R1
Q2
R4
C2
C7
Core
2076app1-1.2
12V
C3
D1
R5
Typical application of US2076 in a flexible motherboard 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 INFORMATION
Tj (°C)
0 TO 125
Rev. 1.3
4/26/98
7 PIN PLASTIC
TO220 (T)
US2076CT
7 PIN PLASTIC
TO263 (M)
US2076CM
4-1
UNISEM [ UNISEM ]
