点击上方名片关注了解更多. 一、 tl431介绍 tl431是由美国德州仪器公司（ti）和motorola公司生产的2.50~36v可调精密并联稳压器，它是一种具有可调电流输出能力的基准电压源，tl431系列产品包括tl431c、tl431ac、tl431i、tl431ai、tl431m、tl431y，共6种型号。 它们的内部电路完全相同，仅个别技术指标略有差异。

震荡频率在70kHz左右。TL431开环频率特性显示， 相位0°，对应的频率为4.75kHz。TL431环路满足震荡条件了。 ※ 总 结 ※. 本 文测试了TL431参考电压源电路的环路频率特性。利用一个高频变压器在TL431参考端注入测试信号，测量稳压输出的频率特性。

由于Ib和TL431反馈脚的电流很小很小，可以忽略不计，所以这个恒流源可以由下式计算： Io = 2.495V / Rref 以上恒流源电路在合理范围改变Rload的大小 ...

LTwiki, The TL431 spice model; Texas Instruments, Spice model of the TL431; Video of the VCO in action; Download the LTSpice files (“save as”, then, remove the .txt extension). Also see: TL431 Model; ...

Since the TL431 imposes 2.5 V across R low, then with a 1 mA current imposed by R upp, R low becomes 2.5 V/1 mA = 2.5 kΩ. Then, R upp simply equals 12 V- 2.5 V/1 mA = 9.5 kΩ.

In designs that omit a voltage amplifier, a shunt regulator can serve as an inexpensive op amp. Resistors R I and R set the power supply’s dc output voltage, and optocoupler IC 2 provides galvanic ...

And for a truly esoteric use of the TL431, here’s a crystal radio design that abuses the TL431 as an audio amplifier. What do you think of Ralph’s charger design?

The TL431's internal functional blocks consist of a 2.5V reference connected to an op-amp's negative input, with the op-amp output used to drive an open collector transistor's base.

Inside the TL431, [Ken] discovers that transistors aren’t made up of the three layer NPN or PNP sandwich we’ve come to know and love. In fact, the base isn’t even in the middle.