供应UC2842电流模式PWM控制器电源IC

AC/DC 与隔离式DC/DC 电源- PWM 与谐振控制器- UC2842

说明:

UC1842/3/4/5的家庭控制设备提供了必要的功能来实现脱机或直流对直流固定频率电流型控制方案具有最小外部零件数。在内部实现电路包括低压闭锁展示启动电流小于1 mA,精密参考削减准确性在误差放大器输入,逻辑来确保锁住操作,一个PWM比较器也提供了限流控制,和一个图腾柱输出级设计源

The UC1842/3/4/5 family of control devices provides the necessary features to implement off-line or dc-to-dc fixed frequency current mode control schemes with a minimal external parts count. Internally implemented circuits include under-voltage lockout featuring start up current less than 1 mA, a precision reference trimmed for accuracy at the error amp input, logic to insure latched operation, a PWM comparator which also provides current limit control, and a totem pole output stage designed to source or sink high peak current. The output stage, suitable for driving N-Channel MOSFETs, is low in the off state.

Differences between members of this family are the under-voltage lockout thresholds and maximum duty cycle ranges. The UC1842 and UC1844 have UVLO thresholds of 16 VON and 10 VOFF, ideally suited to off-line applications. The corresponding thresholds for the UC1843 and UC1845 are 8.4 V and 7.6 V. The UC1842 and UC1843 can operate to duty cycles approaching 100%. A range of zero to 50% is obtained by the UC1844 and UC1845 by the addition of an internal toggle flip flop which blanks the output off every other clock cycle

特性:

优化了脱机和直流对直流转换器
　　低的启动电流(< 1 mA)
　　自动进料ForwardCompensation
　　脉冲,脉冲电流限制
　　增强负载响应特性
　　欠压锁定与滞后
　　双脉冲抑制
　　高电流图腾柱输出
　　内部装饰带隙基准
　　500千赫操作
　　低RO误差放大器的修剪准确性误差放大器输入,逻辑来确保锁住操作,一个PWM比较器也提供了限流控制,和一个

Optimized For Off-line and DC-to-DC Converters
Low Start-Up Current (<1 mA)
Automatic Feed ForwardCompensation
Pulse-by-Pulse Current Limiting
Enhanced Load Response Characteristics

Under-Voltage Lockout With Hysteresis
Double Pulse Suppression
High Current Totem Pole Output
Internally Trimmed Bandgap Reference
500-kHz Operation
Low RO Error Amp

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