HI-SINCERITY
MICROELECTRONICS CORP.
Spec. No. : HS200203
Issued Date : 2001.04.01
Revised Date : 2002.12.03
Page No. : 1/10
H3842S
HIGH PERFORMANCE CURRENT MODE CONTROLERS
Description
The H3842S is high performance fixed frequency current mode controllers. That is specifically designed for Off-
Line and DC To DC converter applications offering the designer a costeffective solution with minimal external
components. These integrated circuits feature a trimmed oscillator for precise duty cycle control. A temperature
compensated reference, high gain error amplifier, current sensing compara-tor, 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.
Features
• Trimmed Oscillator for Precise Frequency Control
• Oscillator Frequency Guaranteed at 250 kHz
• Current Mode Operation to 500 kHz
• Automatic Feed Forward Compensation
• Latching PWM for Cycle-By-Cycle Current Limiting
• Internally Trimmed Reference with Undervoltage Lockout
• High Current Totem Pole Output
• Undervoltage Lockout with Hysteresis
• Low Startup and Operating Current
Absolute Maximum Ratings
Symbol
Vi
Vi
Io
Eo
Ptot
Tstg
TJ
TL
Parameter
Supply Voltage (low impedance source)
Supply Voltage (Ii<30mA)
Output Current
Output Energy (capacitive load)
Analog Inputs (pin 2, 3)
Error Amplifier Output Sink Current
Power Dissipation at Tamb≤25oC
Storage Temperature Range
Junction Operating Temperature
Lead Temperature (soldering 10s)
Value
Unit
30
V
Self Limiting
±1
A
5
uJ
-0.3 to 5.5
V
10
mA
800
mW
-65 to 150
oC
-40 to 150
oC
300
oC
Block Diagram
Vcc
7
Ground
5
UVLO
34V
2.50V
RT/CT
4
VFB
2
COMP
1
Current
Sense 3
Error AMP.
+
-
OSC
S/R
5V
REF
VREF Good
Logic
Internal
Bias
2R
R
T
S
R
1V Current
Sense
Comparator
PWM Latch
8 VREF
5V 50mA
6
Output
H3842S
HSMC Product Specification