HI-SINCERITY
MICROELECTRONICS CORP.
Spec. No. : HP200202
Issued Date : 1998.08.01
Revised Date : 2002.12.03
Page No. : 1/10
H3842P
HSMC Product Specification
H3842P / HSMC3842
HIGH PERFORMANCE CURRENT MODE CONTROLERS
Description
The H3842P/HSMC3842 are high performance fixed frequency current mode
controllers. They are specifically designed for Off-Line and DC To DC converter
applications offering the designer a cost-effective solution with minimal external
components. These integrated circuits feature a trimmed oscillator for precise duty
cycle control. A temperature compensa-ted 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.
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
Parameter
Value
Unit
Vi
Supply Voltage (low impedance source)
30
V
Vi
Supply Voltage (Ii<30mA)
Self Limiting
Io
Output Current
1
A
Eo
Output Energy (capacitive load)
5
uJ
Analog Inputs (pin 2, 3)
-0.3 to 5.5
V
Error Amplifier Output Sink Current
10
mA
Ptot
Power Dissipation at Tamb
25
o
C
1.25
W
Tstg
Storage Temperature Range
-65 to 150
o
C
TJ
Junction Operating Temperature
-40 to 150
o
C
TL
Lead Temperature (soldering 10s)
300
o
C
Block Diagram
DIP-8Pin
1V
34V
2R
R
1
2
3
4
5
6
7
8
Vcc
Ground
VFB
COMP
Current
Sense
+
-
Error AMP.
VREF Good
Logic
2.50V
Current
Sense
Comparator
T
UVLO
5V
REF
Internal
Bias
PWM Latch
Output
VREF
5V 50mA
S/R
RT/CT
S
R
OSC
HI-SINCERITY
MICROELECTRONICS CORP.
Spec. No. : HP200202
Issued Date : 1998.08.01
Revised Date : 2002.12.03
Page No. : 2/10
H3842P
HSMC Product Specification
Pin Connection
(Top View)
DIP-8P
Function
Description
Pin1: Compensation
This pin is the Error Amplifier output and is made available for
loop compensation.
Pin2: Voltage Feedback
This is the inverting input of the Error Amplifier. It's normally
connected to the switching power supply output through a
resistor divider.
Pin3: Current Sense
A voltage proportional to inductor current is connected to this
input. The PWM uses this information to terminate the output
switch conduction.
Pin4: RT/CT
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.
Pin5: Ground
This pin is the combined control circuitry and power ground.
Pin6: Output
This output directly drives the gate of a power MOSFET. Peak
currents up to 1A are sourced and sunk by this pin.
Pin7: Vcc
This pin is the positive supply of the control IC.
1
2
3
4
5
6
7
8
Pin8: Vref
This is the reference output. It provides charging current for
capacitor CT through resistor RT.
Thermal Data
Symbol
Description
Max.
Units
Rth j-amb
Thermal Resistance Junction-ambient
100
o
C/W
Electrical Specifications
Parameter
Test Conditions
Min.
Typ.
Max.
Units
Under-Voltage Lockout Section
Start Threshold
14.5
16
17.5
V
Min. Operating Voltage
After Turn On
8.5
10
11.5
V
Electrical Characteristics
Unless otherwise stated, specifications apply for 0
Ta
70
C Vcc =15V
(Note 1)
; RT=680
, 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
Tj=25
C,Io=1mA
4.90
5
5.1
V
Line Regulation
12V
Vin
25V
-
2.0
20
mV
Load Regulation
1mA
Io
20mA
-
3.0
25
mV
Temperature. Stability
(Note 2)
-
0.2
-
mV/
C
Total Output Variation
Line , Load , Temp
(Note 2)
4.82
-
5.18
V
Output Noise Voltage
10Hz
f
10kHz,Tj=25
C
(Note 2)
-
50
-
uV
Long Term Stability
Ta=125
C,1000Hrs
(Note 2)
-
5
-
mV
Output Short current
Ta=25
C
-30
-100
-180
mA
Oscillator Section
Tj=25
C
47
52
57
KHz
Frequency
Tlow
Ta
Thigh
46
52
60
KHz
Frequency Chnge with Temperature
12V
Vcc
25V
-
0.2
1
%
Tlow
Ta
Thigh
(Note 2)
-
5
-
%
Frequency Change with Temperature
Tj=25
C
-
0.5
-
%
Oscillator Voltage Swing
Peak to Peak
-
1.7
-
V
Tj=25
C
7.8
8.3
9.3
mA
Discharge Current
Tlow
Ta
Thigh
7.2
-
9.5
mA
HI-SINCERITY
MICROELECTRONICS CORP.
Spec. No. : HP200202
Issued Date : 1998.08.01
Revised Date : 2002.12.03
Page No. : 3/10
H3842P
HSMC Product Specification
Parameter
Test Conditions
Min.
Typ.
Max.
Units
Error Amplifier Section
Voltage Feedback Input
Vo=2.5V
2.42
2.50
2.58
V
Input Bias Current
VFB=5.0V
-
-0.1
-2.0
uA
Open Loop Voltage Gain
2
Vo
4 V
65
90
-
dB
Unity Gain Bandwidth
Tj=25
C
(Note 2)
0.7
1.0
-
MHz
Power Supply Rejection Ratio
12V
Vcc
25V
60
70
-
dB
Sink (Vo=1.1V, VFB=2.7V)
2.0
12
-
mA
Output Current
Source (Vo=5.0V, VFB=2.3V)
-0.5
-1.0
-
mA
Output Voltage Swing
High State
VFB=2.3V, RL=15K to ground
5
6
-
V
Low State
VFB=2.7V, RL=15K to Vref
-
0.7
1.1
V
Current Sense Section
Current Sense Input Voltage Gain
(Notes 3 & 4)
2.85
3.0
3.15
V/V
Maximum Current Sense Input
Thresold
(Note 3)
0.9
1.0
1.1
V
Ppwer Supply Rejection Ratio
12V
Vcc
25V
(Note 3)
-
70
-
dB
Input Bias Current
-
-2.0
-10
uA
Propagation Delay
Tj=25
C
(Note 2)
-
150
300
nS
Output Section
Low State (Isink=20mA)
-
0.1
0.4
V
Low State (Isink=200mA)
-
1.5
2.2
V
High State (Isource=20mA)
13
13.5
-
V
Output Voltage
High State (Isource=200mA)
12
13.4
-
V
Output Voltage Rise Time
Tj=25
C, CL=1.0nF
(Note 2)
-
50
150
nS
Output Voltage Fall Time
Tj=25
C, CL=1.0nF
(Note 2)
-
50
150
nS
Output Voltage with UVLO Activated
Vcc=6V , Isink=1.0mA
-
-0.1
-1.1
V
Total Device
Start-Up Current
-
0.1
0.5
mA
Operating Supply Current
Vpin2=Vpin3=0, RT=10K, CT=3.3nF
-
11
17
mA
Vcc Zener Voltage
Icc=25 mA
-
34
-
V
Note 1: Adjust Vcc above the start threshold before setting at 15V.
Note 2: These parameters, although guaranteed are not 100% tested in production.
Note 3: Parameter measured at trip point of latch with Vpin2=0.
Note 4: Gain defined as: A=Vpin1/Vpin3, 0
Vpin3
0.8V
HI-SINCERITY
MICROELECTRONICS CORP.
Spec. No. : HP200202
Issued Date : 1998.08.01
Revised Date : 2002.12.03
Page No. : 4/10
H3842P
HSMC Product Specification
Characteristics Curve
Oscillator Frequency & Timing Resistance
1K
10K
100K
1000K
10000K
100
1000
10000
100000
RT()
fo
(
H
z
)
CT=1.0nF
CT=2.2nF
CT=4.7nF
Maximum Duty Cycle & Timing Resistance
0
20
40
60
80
100
100
1000
10000
100000
RT()
fo
(
H
z
)
Current Sense Input Threshold & Error Amp
Output Voltage
0
0.2
0.4
0.6
0.8
1
1.2
0
2
4
6
8
Vo (V)
Vt
h
(
V
)
Ta=125
o
C
Ta=-40
o
C
Ta=25
o
C
Vcc=15V
Reference Voltage Change & Source Current
0
10
20
30
40
50
60
0
20
40
60
80
100
120
Iref (mA)
Ta=125
o
C
Ta=25
o
C
Ta=-40
o
C
Vcc=15V
Oscillator Discharge Current & Temperate
7
7.5
8
8.5
9
-50
-25
0
25
50
75
100
125
TA (
o
C)
I
d
i
sch
g
(
m
A
)
Vi=15V
Vosc=2V
Error Amp Open-Loop Gain and Phase &
Frequency
-20
0
20
40
60
80
100
10
100
1000
10000
100000 1000000 10000000
f (Hz)
(d
B
)
Gain
Phase
Vcc=15V
Vo=2V to 4V
R
L
=100K
Ta=25
o
C
30
60
90
120
150
180
HI-SINCERITY
MICROELECTRONICS CORP.
Spec. No. : HP200202
Issued Date : 1998.08.01
Revised Date : 2002.12.03
Page No. : 5/10
H3842P
HSMC Product Specification
Reference Short Circuit Current &Temperature
50
60
70
80
90
100
110
-50
-25
0
25
50
75
100
125
TA (
o
C)
I
sc (
m
A
)
Vcc=15V
RL0.1
Supply Current & Supply Voltage
0
5
10
15
20
25
0
10
20
30
40
Vi (V)
Ii
(
m
A
)
R
T
=10K
C
T
=3.3nF
Output Saturation Voltage & Load Current
0
1
2
3
4
0
200
400
600
800
Io (mA)
Vs
a
t
(
V
)
Sink Saturation
(Load to Vcc)
Ta=-40
o
C
Ta=25
o
C
Vcc=15V
80us Pulsed Load
120Hz Rate
Output Saturation Voltage & Load Current
-4
-3
-2
-1
0
0
200
400
600
800
Io (mA)
Vs
a
t
(
V
)
Source Saturation
(Load to Ground)
Ta=25
o
C
Ta=-40
o
C
Vcc=15V
80us Pulsed Load
120Hz Rate
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