機能 of モノリシック スイッチング 電源 電源
(1) TOpSWitch-II internally includes an oscillator, error amplifier, pulse width modulator, gate circuit, high-voltage power switching tubes (MOSFETs), bias circuit, over-current protection circuit, over-temperature protection and power-on reset circuit, and shutdown/auto restart circuit. It completely isolates the output from the power grid by means of a high-frequency transformer, which is safe to use*. It belongs to the current-controlled switching power supply with open drain output. The power consumption of the device is significantly reduced due to the use of CMOS circuitryに属します。
(2) There are only three outputs: control terminal C, source S, drain D, comparable to the the three-terminal linear regulator, can be the simplest way to form a flyback switching power supply without frequency transformer. In order to complete a variety of control, bias and protection functions, C, D are multi-functional pin out, to achieve a pin multi-purpose. Take the control terminal as an example, it has three functions: (1) the end of the voltage VC for the オンチップ パラレル レギュレータ and gate drive stage to provide bias voltage; (2) the end of the current IC can adjust the duty cycle; (3) the end of the power supply branch circuit and automatic restart/compensating capacitor as a point of connection, through the external bypass capacitor to determine the 周波数 の 自動 再起動 と 補正 の コントロール ループ。
(3) 範囲 of input AC voltage is extremely wide. For fixed voltage input, 220V±15% AC can be selected, and the maximum output power will be reduced by 40% if it is equipped with 85~265V wide range AC. The input frequency range of the switching power supply is 47~440Hz.
(4) typical value of switching frequency is 100KHz, and the duty cycle adjustment range is 1.7%~67%. The efficiency of the power supply is about 80%, up to 90%, which is nearly double that of the linear integrated regulated power supply. Its operating temperature range is 0 to 70 degree chip maximum junction temperature Tjm=135 degree .
(5) TOpSwitch-II's basic principle of operation is to use the feedback current IC to regulate the duty cycle D, to achieve the purpose of voltage regulation. For example, when the output voltage of the switching power supply VOT due to some reason, after the optocoupler feedback circuit will make Ic↑→error voltage Vrt→D↓→Vo↓, so that Vo remains unchange. And vice versa.
(6) シンプル ペリフェラル 回路, 低 コスト. 外部 のみ 必要 接続 整流器 フィルタ, 高 周波数 トランス, 一次 保護 回路, フィードバック 回路 および 出力 回路 使用 of such chips can also reduce the electromagnetic interference generated by the switching power supply。
