CS3865C
CS3865C
High Performance Dual Channel
Current Mode Controller with ENABLE
Description
The CS3865C is a high perfor-
mance, fixed frequency, dual cur-
rent mode controller. It is used in
Off-Line and DC to DC converter
applications and require a mini-
mum number of external compo-
nents. This integrated circuit fea-
tures a unique oscillator for precise
duty cycle limit and frequency con-
trol, a temperature compensated
reference, two high gain error
amplifiers, two current sensing
comparators, and two high current
totem pole outputs ideally suited
for driving power MOSFETs. One
of the outputs V
OUT2
is switchable
via the ENABLE
2
pin.
Also included are protective fea-
tures consisting of input and refer-
ence undervoltage lockouts each
with hysteresis, cycle-by-cycle cur-
rent limiting, and a latch for single
pulse metering of each output.
The CS3865C has a 14V start volt-
age and is pin compatible with the
MC34065H.
Features
s
Oscillator has Precise
Duty Cycle
Limit and Frequency
Control
s
500kHz Current Mode
Operation
s
Automatic Feed Forward
Compensation
s
Separate Latching PWMs
for Cycle-By-Cycle
Current Limiting
s
Internally Trimmed
Reference with
Undervoltage Lockout
s
Switchable Second
Output
s
Two High Current Totem
Pole Outputs
s
Input Undervoltage
Lockout with Hysteresis
s
Low Start-Up and
Operating Current
Block Diagram
V
CC
V
REF
5.0V Ref
V
CC
Undervoltage
Lockout
V
REF
Undervoltage
Lockout
SYNC
C
T
R
T
Latching
PWM 1
Oscillator
V
OUT
1
Package Options
Sense
1
+
V
FB1
16L PDIP & SO Wide
SYNC
1
C
T
2
R
T
3
16
15
14
13
12
11
10
9
-
Error
Amp 1
COMP
1
ENABLE
2
Latching
PWM 2
V
OUT2
V
CC
V
REF
ENABLE
2
V
FB2
COMP
2
Sense
2
V
OUT2
Pwr Gnd
V
FB1
4
V
FB2
+
-
Error
Amp 2
COMP
2
Sense
2
COMP
1
5
Sense
1
6
V
OUT1
7
Gnd
8
Gnd
Pwr Gnd
Cherry Semiconductor Corporation
2000 South County Trail, East Greenwich, RI 02818
Tel: (401)885-3600 Fax: (401)885-5786
Email: info@cherry-semi.com
Web Site: www.cherry-semi.com
Rev. 12/16/96
1
A
®
Company
CHERRY [ CHERRY SEMICONDUCTOR CORPORATION ]
