H3842S Datasheet, PDF (2/10 Pages) Hi-Sincerity Mocroelectronics – HIGH PERFORMANCE CURRENT MODE CONTROLERS

HI-SINCERITY
MICROELECTRONICS CORP.
Spec. No. : HS200203
Issued Date : 2001.04.01
Revised Date : 2002.12.03
Page No. : 2/10
Pin Connection (Top View)
SOP-8P
Function
Pin1: Compensation
Pin2: Voltage Feedback
8 7 6 5 ^{Pin3: Current Sense}
1 2 34
Pin4: RT/CT
Pin5: Ground
Pin6: Output
Pin7: Vcc
Pin8: Vref
Description
This pin is the Error Amplifier output and is made available for
loop compensation.
This is the inverting input of the Error Amplifier. It’s normally
connected to the switching power supply output through a
resistor divider.
A voltage proportional to inductor current is connected to this
input. The PWM uses this information to terminate the output
switch conduction.
The oscillator frequency and maximum output duty cycle are
programmed by connecting resistor RT to Vref and cpacitor CT
to ground. Operation to 500kHz is possible.
This pin is the combined control circuitry and power ground.
This output directly drives the gate of a power MOSFET. Peak
currents up to 1A are sourced and sunk by this pin.
This pin is the positive supply of the control IC.
This is the reference output. It provides charging current for
capacitor CT through resistor RT.
Thermal Data
Symbol
Rth j-amb
Description
Thermal Resistance Junction-ambient
Max.
100
Units
o_C/W
Electrical Specifications
Parameter
Under-Voltage Lockout Section
Start Threshold
Min. Operating Voltage
Test Conditions
After Turn On
Min. Typ. Max. Units
14.5 16 17.5
V
8.5
10 11.5
V
Electrical Characteristics
Unless otherwise stated, specifications apply for 0≤Ta≤70°C Vcc =15V (Note 1); RT=680Ω, CT=0.022uF for
triangular mode, RT=10k, CT=3.3nf for sawtooth mode
Parameter
Test Conditions
Min. Typ. Max. Units
Reference Section
Reference Output Voltage
Line Regulation
Load Regulation
Temperature. Stability
Total Output Variation
Output Noise Voltage
Long Term Stability
Output Short current
Tj=25°C,Io=1mA
12V≤Vin≤25V
1mA≤Io≤20mA
(Note 2)
Line , Load , Temp (Note 2)
10Hz≤f≤10kHz,Tj=25°C (Note 2)
Ta=125°C,1000Hrs (Note 2)
Ta=25°C
4.90 5
5.1
V
-
2.0 20
mV
-
3.0 25
mV
-
0.2
- mV/°C
4.82
-
5.18
V
-
50
-
uV
-
5
-
mV
-30 -100 -180 mA
Oscillator Section
Frequency
Frequency Chnge with Temperature
Frequency Change with Temperature
Oscillator Voltage Swing
Discharge Current
Tj=25°C
Tlow≤Ta≤Thigh
12V≤Vcc≤25V
Tlow≤Ta≤Thigh (Note 2)
Tj=25°C
Peak to Peak
Tj=25°C
Tlow≤Ta≤Thigh
47
52
57 KHz
46
52
60 KHz
-
0.2
1
%
-
5
-
%
-
0.5
-
%
-
1.7
-
V
7.8
8.3 9.3
mA
7.2
-
9.5
mA
H3842S
HSMC Product Specification