US3036 Datasheet, PDF (1/7 Pages) UNISEM – 8 PIN PWM SWITCHER CONTROLLER IC

US3036
FEATURES
8 pin SOIC Switching Controller with
HICCUP Current Limiting Reduces Diode Power
Dissipation to Less than 1% of Normal Opera-
tion
Soft Start Capacitor allows for smooth Output
Voltage ramp up
On board MOSFET driver
Fastest transient response of any controller
method. ( 0 to 100% Duty Cycle in 100 nS )
1% internal voltage reference
Internal Under Voltage Lockout protects
MOSFET during start-up
APPLICATIONS
Single input Switching Regulators such as Simple
5V to 2.5V switcher for RDRAM regulator
8 PIN PWM SWITCHER
DESCRIPTION
CONTROLLER IC
PRELIMINARY DATASHEET
The US3036 IC provides an 8 pin low cost switching
controller with true short circuit protection all in a
compact 8 pin surface mount package, providing a
low cost switching solution for applications that re-
quire a simple switching regulator from the 5V input where
there is no other supply available. One type of such
application is generating 2.5V standby from the dual
5V(5V and 5V standby) for the next generation proces-
sors. The IC starts below 4.5V supply and drives an
external Pch MOSFET or and external low cost PNP as
the switching element. 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
ATX
P.S.
5V
5V(S.B.)
C8
L1
C1
8765
SS CS+ CS- Gnd
US3036
Drv Vcc Vfb NC
C6
1234
C3
R3
C5 R6
R1
L2
Q2
C2
C4
R2 D1
R4
R5
3036app2-1.0
R7
Vout
C7
Typical application of US3036
PACKAGE ORDER INFORMATION
TA (°C)
0 TO 70
8 PIN PLASTIC
SOIC (S)
US3036CS
Rev. 1.1
12/4/98
4-1