US2076 Datasheet, PDF (1/4 Pages) UNISEM – PWM SWITCHER CONTROLLER & 7.5A ADJUSTABLE LOW DROPOUT REGULATOR COMBO

US2076
PWM SWITCHER CONTROLLER & 7.5A
FEATURES
ADJUSTABLE LOW DROPOUT REGULATOR COMBO
PATENT PENDING
PRELIMINARY DATASHEET
DESCRIPTION
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
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
5V
US2076
Vin 7
Vout 6
Vfb2 5
Gnd 4
Vfb1 3
V12 2
Drv 1
2076app1-1.2
12V
C3
L1
C1
D2
R1
C2
Q2
D1
R6
R7
L2
5V
R8
R4
I/O
C6
CPU
Vcc2 Det
Core
C7
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
7 PIN PLASTIC
TO220 (T)
US2076CT
7 PIN PLASTIC
TO263 (M)
US2076CM
Rev. 1.3
4/26/98
4-1