YOUDA YD3843

YD3843
YOUDA INTEGRATED CIRCUIT
CURRENT MODE PWM CONTROL CIRCUITS—YD3843
DESCRIPTION
The YD3843 provides the necessary features to implement off-line or DC to DC fixed frequency current mode
control schemes with a minimal external parts count.
FEATURES
*Optimized for off-line and DC to DC converts
*Low start up current(<1mA)
*Automatic feed forward compensation
*Pulse-by-Pulse current limiting
*Enhanced load response characteristic
*Under-voltage lookout with hysteresis.
*Double pulse Suppression
*High current totem pole output
*Internally trimmed band-gap reference
*500kHz operation
*Low Ro error amp
BLOCK DIAGRAM
8
7
6
5
UVL
1/2
5V
REF
S/R
VCC
R S
+
EA
-
1/3
OSC
1V
1
2
3
4
WuXi YouDa Electronics Co., Ltd
Add: No.5 Xijin Road, National Hi-Tech Industrial Development Zone, Wuxi Jiangsu China
Tel: 86-510-85205117
86-510-85205106
Fax: 86-510-85205110 Website: www.e-youda.com
SHENZHEN OFFICE Tel: 86-755-83740369
Fax: 86-755-83741418
Ver 5.0
1 of 4
2006-7-10
YD3843
YOUDA INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATINGS(Tamb=25℃)
PARAMETER
SYMBOL
VALUE
UNIT
Supply Voltage(Low impedance Source)
Vcc
30
V
Supply Voltage(Icc<30mA)
Vcc
Self Limiting
V
Output Current
Io
±1
A
5
μJ
VI(ANA)
-0.3 to +6.3
V
lSINK(EA)
10
mA
Power Dissipation
PD
At Tamb≤25℃ 1.0
W
Lead Temperature
Tlead
300
℃
Storage Temperature
Tstg
-65—+150
℃
Output Energy(Capacitive Load)
Analog Inputs(pin 2, 3)
Error Amplifier Output Sink Current
Note 1:Ta>25℃, PD derated with 8mW/℃.
ELECTRICAL CHARACTERISTICS
(Vcc=15V, RT =10kΩ, CT =3.3nF, Tamb=0℃~70℃, unless otherwise specified)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
VREF
Tj=25℃, Io=1mA
4.90
5.00
5.10
V
Reference Section
Output Voltage
Line Regulation
△
VREF
12≤VIN≤25V
6
20
mV
Load Regulation
△
VREF
1≤lo=20mA
6
25
MV
10Hz≤f≤10kHz,
Tj=25℃(note 2)
50
6
mV
Ta=25℃, 1000Hrs(note
2)
5
25
mV
-30
-100
-180
mA
47
52
57
kHz
12≤Vcc≤25V
0.2
1
%
Tmin≤TA≤Tmax(note
2)
5
%
Vosc
Vpin 4 peak to peak
1.7
V
Input Voltage
VI(EA)
Vpin 1=2.5V
Input Bias Current
lBIAS
Output Noise Voltage
Vose
Long Term Stability
Output Short Circuit
lsc
Oscillator Section
Initial Accuracy
f
Voltage Stability
△ △
f/ Vcc
Temp Stability
Amplitude
Tj=25℃
Error Amplifier Section
2.42
2.50
2.58
V
-0.3
-2
μA
AVOL
2≤Vo≤4V
60
90
Unity Gain
Bandwidth
Tj=25℃(note 2)
0.7
1
PSRR
12≤Vcc≤25V
60
70
dB
Vpin2=2.7V,
Vpin 1=1.1V
2
6
mA
Output Sink Current
WuXi YouDa Electronics Co., Ltd
lsink
2 of 4
dB
6.0
mHz
Website: www.e-youda.com
YD3843
YOUDA INTEGRATED CIRCUIT
Output Source
Current
lsource
Vpin 2=2.3V, Vpin
1=5V
-0.5
-0.8
mA
Vout High
VOH
Vpin 2=2.3V, RL=15kΩ
to GND
5
6
V
Vout Low
VOL
Vpin 2=2.7V, Vpin
1=1.1V
Gain
Gv
(note 3, 4)
Maximum Input
Signal
VI(MAX)
Vpin 1=5V(note 3)
0.7
1.1
V
2.85
3
3.15
V/V
0.9
1
1.1
V
Current Sense Section
PSRR
12≤Vcc≤25V
Input Bias Current
70
-2
-10
μA
Vpin 3=0 to 2V
150
300
ns
lsink=20mA
0.1
0.4
V
lsink=200mA
1.5
2.2
V
lBIAS
Delay to Output
dB
Output Section
Output Low Level
VOL
Output High Level
VOH
Rise Time
tR
Fall Time
tF
UVLO Saturation
lsource=20mA
13
13.5
V
lsource=200mA
12
13.5
V
Tj=25℃, CL=1nF
(note 2)
Tj=25℃, CL=1nF(note 2)
Vcc=5V, lsink=10mA
50
150
ns
50
150
ns
0.7
1.2
V
Under-Voltage Lockout Output Section
Start Threshold
VTH(ST)
7.8
8.4
9.0
V
Min. Operating
Voltage
After Turn On
VOPR(min)
7.6
8.0
8.4
V
Maximum Duty
Cycle
D(MAX)
95
07
100
%
Minimum Duty
Cycle
D(MIN)
0
%
0.5
1
mA
17
mA
PWM Section
Total Standby Current
Start-up Current
lST
Operating Supply
Current
Icc(OPR)
Vpin 2=Vpin 3=0V
11
Vcc Zener Voltage
Vz
Icc=25mA
34
WuXi YouDa Electronics Co., Ltd
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V
Website: www.e-youda.com
YD3843
YOUDA INTEGRATED CIRCUIT
APPLICATION CIRCUIT
4.7KΩ
Vref
5κΩ
8
2
7
3
6
4
5
A
0.1μF
Isense
Adjust
4.7KΩ
Error Amp
Adjust
1
0.1μF
100KΩ
RT
VCC
1κΩ
/1W
OUTPUT
CT
OUTLINE DRAWING
WuXi YouDa Electronics Co., Ltd
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Website: www.e-youda.com