参数资料
型号: UC3844N
厂商: ON Semiconductor
文件页数: 11/16页
文件大小: 0K
描述: IC REG CTRLR PWM CM 8-DIP
产品变化通告: Product Discontinuation 15/May/2006
标准包装: 1,000
PWM 型: 电流模式
输出数: 1
频率 - 最大: 60kHz
占空比: 50%
电源电压: 10 V ~ 30 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: 0°C ~ 70°C
封装/外壳: 8-DIP(0.300",7.62mm)
包装: 管件
其它名称: UC3844NOS
UC3844, UC3845, UC2844, UC2845
7(12)
V CC
V in
+
I B
V in
+
5.0V ref
+
?
+
?
+
?
7(11)
0
?
Base
Charge
Removal
C 1
?
T
6(10)
R g
Q1
6(1)
Q1
?
+
S
R
Q
5(8)
5(8)
Comp/Latch
3(5)
R S
Series gate resistor R g will damp any high frequency parasitic oscillations
caused by the MOSFET input capacitance and any series wiring inductance
in the gate?source circuit.
Figure 25. MOSFET Parasitic Oscillations
3(5)
R S
The totem?pole output can furnish negative base current for enhanced
transistor turn?off, with the addition of capacitor C 1 .
Figure 26. Bipolar Transistor Drive
8(14)
R
R
Bias
7(12)
V CC
V in
4(7)
+
OSC
5.0V ref
+
?
I pk =
3 R S
?
+
?
+
?
T
S
Q
+ R
Comp/Latch
+
?
7(11)
6(10)
5(8)
Isolation
Boundary
R
Q1
V GS Waveforms
+ +
0 0
? ?
50% DC 25% DC
V (pin 1) ? 1.4 N P
N S
MCR
101
2N
3905
2(3)
1(1)
2N
3903
+
?
EA
1.0mA
2R
R
5(9)
3(5) C
R S
N S
N p
The MCR101 SCR must be selected for a holding of less than 0.5 mA at T A(min) .
The simple two transistor circuit can be used in place of the SCR as shown. All
resistors are 10 k.
Figure 27. Isolated MOSFET Drive
Figure 28. Latched Shutdown
R i
From V O
R i
R d C I
2(3)
R f
2.5V
+
?
EA
+
1.0mA
2R
R
From V O
R p
R d
C p
C I
2(3)
R f
2.5V
+
?
EA
+
1.0mA
2R
R
1(1)
1(1)
R f ≥ 8.8 k
5(9)
5(9)
Error Amp compensation circuit for stabilizing any current?mode topology except
for boost and flyback converters operating with continuous inductor current.
Error Amp compensation circuit for stabilizing current?mode boost and flyback
topologies operating with continuous inductor current.
Figure 29. Error Amplifier Compensation
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UC3844NG 功能描述:电流型 PWM 控制器 52kHz 1A Current PWM w/48% Duty Cycle Max RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14
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UC3844P 制造商:Texas Instruments 功能描述:
UC3844Q 制造商:未知厂家 制造商全称:未知厂家 功能描述:Current-Mode SMPS Controller
UC3844QTR 制造商:未知厂家 制造商全称:未知厂家 功能描述:Current-Mode SMPS Controller