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UC3843のメーカーはChipsWinnerです、この部品の機能は「Fixed Frequency Current Mode PWM Controller」です。 |
部品番号 | UC3843 |
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部品説明 | Fixed Frequency Current Mode PWM Controller | ||
メーカ | ChipsWinner | ||
ロゴ | |||
このページの下部にプレビューとUC3843ダウンロード(pdfファイル)リンクがあります。 Total 11 pages
UC3843
Fixed Frequency Current Mode PWM Controller
DESCRIPTION
UC3843 is a fixed frequency current-mode PWM controller.
It is specially designed for Off Line and DC-to-DC converter
applications with minimal external component. This
integrated circuit features a trimmed oscillator for precise
duty cycle control, a temperature compensated reference, a
high gain error amplifier, a current sensing comparator, and
a high current totem pole output ideally suited for driving a
power MOSFET.
The device is protective features consisting of input and
reference under-voltage lockouts each with hysteresis,
cycle-by-cycle current limiting.
PIN CONFIGURATION
Compensation
Voltage Feedback
Current Sense
RT/CT
1
2
3
4
8 Vref
7 VCC
6 Output
5 GND
(Top View)
FEATURES
● Automatic Feed Forward Compensation
● High Current Totem Pole Output
● Internally Trimmed Bandgap Reference
● Undervoltage Lockout with Hysteresis
● Low Start Up Current
● Optimized for offline converter
● Double pulse suppression
● Current mode operation to 500kHz
APPLICATION
● Wireless Base Station Power
● Telecom and Datacom Power
● Industrial Power Systems
● PC Power Supplies
ORDERING INFORMATION
Temperature Range
0°C to +70°C
Package
DIP8L
SOP8L
Pb-Free
Orderable
Device
UC3843D
UC3843P
Package Qty
75Units/Tube
50Units/Tube
Jun. 2008
Rev 1.0
1
1 Page ABSOLUTE MAXIMUM RATINGS
Parameter
Total Power Supply and Zener Current
DC Supply Voltage
Output Current
Output Energy (Capacitive Load per Cycle)
Symbol
ICC + IZ
VCC
Io
W
Error Amp Output Sink Current
Ioe
Current Sense and Voltage Feedback Inputs
VIN
Maximum Power Dissipation @TA=25°C
Thermal Resistance, Junction-to-Air
PD
RBIA
Maximum Operating Junction Temperature
Storage Temperature Range
TJ
TSTG
UC3843
Value
30
30
±1.0
5.0
10
-0.3 to 5.5
0.862
145
+150
-65 to +150
Unit
mA
V
A
µJ
mA
V
W
°C/W
°C
°C
RECOMMENDED OPERATION CONDITIONS
Parameter
Symbol
DC Supply Voltage
VCC
Operating Temperature
TA
Min
12
0
Max
25
70
Unit
V
°C
ELECTRICAL CHARACTERISTICS
(Vcc = 15V unless otherwise noted)
Parameter
Reference Section
Reference Out
Line Regulation
Symbol
Test Conditions
VREF
IO = 1.0mA, VCC = 15V,
TA = 25±10°C
IO = 1.0mA, VCC = 15V,
TA = TLOW to THIGH
RegLINE
VCC = 12V to 25V,
TA = TLOW to THIGH
Load Regulation
RegLOAD
IO = 1.0 to 20mA,
TA = TLOW to THIGH
Total Output Variation
over Line, Load,
Temperature (Note1)
Output Short Circuit
Current
VFINAL
ISC
VCC = 12V, IO = 1.0mA,
TA = TLOW to THIGH
VCC = 25V, IO = 20mA,
TA = TLOW to THIGH
VCC =15V
Min Max
4.9 5.1
4.865 5.135
20
25
4.82 5.18
-30 -180
Jun. 2008
Rev 1.0
3
Unit
V
mV
mV
V
mA
3Pages UC3843
TYPICAL PERFORMANCE CHARACTERISTICS
80 100
50 50 VCC = 15V
TA = 25°C
20
20
8.0 10
5.0
5.0
2.0 VCC = 15V
TA = 25°C
0.8
10K 20K
50K 100K 200K 500K
fOSC,OSCILLATOR FREQUENCY (Hz)
Figure 2. Timing Resistor versus
Oscillator Frequency
1.0M
2.0
1.0
10K
20K 50K 100K 200K 500K 1.0M
fOSC,OSCILLATOR FREQUENCY (Hz)
Figure 3. Output Deadtime versus
Oscillator Frequency
9.0
VCC = 15V
VOSC = 20V
8.5
8.0
7.5
7.0
-55
-25 0 25 50 75 100
TA, AMBIENT TEMPERATURE (°C)
125
Figure 4. Oscillator Discharge Current
versus Temperature
100
VCC = 15 V
CT = 3.3 nF
90 TA = 25°C
80 Idischg = 7.2 mA
70
60
50 Idischg = 9.5 mA
40
800 1.0k
2.0k 3.0k 4.0k
6.0k 8.0k
RT, TIMING RESISTOR (Ω)
Figure 5. Maximum Output Duty Cycle
versus Timing Resistor
2.55V
2.5V
VCC = 15 V
AV = -1.0
TA = 25°C
3.0V
2.5V
VCC = 15 V
AV = -1.0
TA = 25°C
2.45V
0.5 μs/DIV
Figure 6. Error Amp Small Signal
Transient Response
2.0V
0.1 μs/DIV
Figure 7. Error Amp Large Signal
Transient Response
Jun. 2008
Rev 1.0
6
6 Page | |||
ページ | 合計 : 11 ページ | ||
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PDF ダウンロード | [ UC3843 データシート.PDF ] |
データシートを活用すると、その部品の主な機能と仕様を詳しく理解できます。 ピン構成、電気的特性、動作パラメータ、性能を確認してください。 |
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