CS51033 Datasheet, PDF (1/8 Pages) Cherry Semiconductor Corporation – Fast PFET Buck Controller Does Not Require Compensation

CS51033
Fast PFET Buck Controller
Does Not Require Compensation
Description
Features
The CS51033 is a switching con-
troller for use in DC-DC converters.
It can be used in the buck topology
with a minimum number of exter-
nal components. The CS51033 con-
sists of a 1.0A power driver for con-
trolling the gate of a discrete P-
channel transistor, fixed frequency
oscillator, short circuit protection
timer, programmable soft start, pre-
cision reference, fast output voltage
monitoring comparator, and output
stage driver logic with latch.
The high frequency oscillator
allows the use of small inductors
and output capacitors, minimizing
PC board area and systems cost.
The programmable soft start
reduces current surges at start up.
The short circuit protection timer
significantly reduces the PFET duty
cycle to approximately 1/30 of its
normal cycle during short circuit
conditions.
The CS51033 is available in 8L SO
and 8L PDIP plastic packages.
s 1A Totem Pole Output
Driver
s High Speed Oscillator
(700kHz max)
s No Stability
Compensation Required
s Lossless Short Circuit
Protection
s 2% Precision Reference
s Programmable Soft Start
Typical Application Diagram
3.3V_IN
C_IN
100µF
R_C
D₄
10Ω 1N5818
D₂
1N4148
D₃
1N4148
C₁
0.1µF
C₂
C₃
C_OSC
1µF
100µF
150pF
V_C
V_CC
V_GATE
U1
CS51033
C_OSC
V_FB
R_G
10Ω
0.01µF
IRF 7404
4.7µH
Gnd
CS
PGnd
CS
0.1µF
100
.1µF
D₁
1N5821
C₀
C₄
100µF ^0.1µF
1.5V_OUT
@3Amp
100µF
Gnd
Gnd
R_A
1.5k
R_B
300
NOTE: Capacitors C₂, C₃ and C₄ are low ESR tantalum
caps used for noise reduction.
Package Options
8 Lead SO Narrow & PDIP
V_GATE 1
PGnd
C_OSC
Gnd
V_C
CS
V_CC
V_FB
Rev. 2/13/98
Cherry Semiconductor Corporation
2000 South County Trail, East Greenwich, RI 02818
Tel: [phone] Fax: [phone]
Email: [e-mail]
Web Site: www.cherry-semi.com
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® Company