
Block Diagram
Ordering Information
The TS3842B and TS3843B series are high performance fixed frequency current mode controllers.
This is specifically designed for Off-Line and DC-to-DC converter applications offering the designer a
cost effective solution with minimal external components. This integrated circuits feature a trimmed
oscillator for precise duty cycle control, a temperature compensated reference, high gain error
amplifier, current sensing comparator, and a high current totem pole output ideally suited for driving
a power MOSFET.
Also included are protective features consisting of input and reference undervoltage lockouts each
with hysteresis, cycle-by-cycle current limiting, programmable output deadtime, and a latch for
single pulse metering.
This device is available in 8-pin dual-in-line plastic packages as well as the 8-pin plastic surface
mount (SOP-8). The SOP-8 package has separate power and ground pins for the totem pole output
stage.
The TS3842B has UVLO thresholds of 16V (on) and 10V (off), ideally suited for off-line converters.
Features
Trimmed Oscillator Discharge Current for
Precise Duty Cycle Control
Current Mode Operation to 500KHz
Automatic Feed Forward Compensation
Latching PWM for Cycle-By-Cycle Current
Limiting
General Description
TS3842B/3843B
High Performance Current Mode Controller
Internally Trimmed Reference with Undervoltage
Lockout
High Current Totem Pole Output
Undervoltage Lockout with Hystersis
Low Start-Up and Operating Current
SOP-8
DIP-8
5.0V
Reference
LPWM
V
UnLockout
Oscillator
Error
Amplifier
7(12)
V
C
7(11)
Output
6(10)
Power
Ground
5(8)
Current
Sense
Input
3(5)
V
ref
8(14)
4(7)
2(3)
1(1)
R
T
/C
T
Voltage
FeeInput
R
R
+
-
ref
UndeV
Lockout
CompeOutput
V
CC
The document contains information on a new product.Specifications and
information herein are subject to change without notice.
Designed for Off-Line and DC-to-DC
converter applications.
TS3842/3843BCD
TS3842/3843BCS
DIP-8
SOP-8
-20 to +85
DEVICE
(Ambient)
PACKAGE
OPERATING TEMPERATURE