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7 TNY263-268 2.5 W CV/CC Cell-Phone Charger As an example, Figure 14 shows a TNY264 based 5 V, 0.5 A, cellular phone charger operating over a universal input range (85 VAC to 265 VAC). The inductor (L1) forms a π-filter in conjunction with C1 and C2. The resistor R1 damps resonances in the inductor L1. Frequency jittering operation of TinySwitch-II allows the use of a simple π-filter described above in combination with a single low value Y1-capacitor (C8) to meet worldwide conducted EMI standards. The addition of a shield winding in the transformer allows conducted EMI to be met even with the output capacitively earthed (which is the worst case condition for EMI). The diode D6, capacitor C3 and resistor R2 comprise the clamp circuit, limiting the leakage inductance turn-off voltage spike on the TinySwitch-II DRAIN pin to a safe value. The output voltage is determined by the sum of the optocoupler U2 LED forward drop (~1 V), and Zener diode VR1 voltage. Resistor R8 maintains a bias current through the Zener diode to ensure it is operated close to the Zener test current. A simple constant current circuit is implemented using the VBE of transistor Q1 to sense the voltage across the current sense resistor R4. When the drop across R4 exceeds the VBE of transistor Q1, it turns on and takes over control of the loop by driving the optocoupler LED. Resistor R6 assures sufficient voltage to keep the control loop in operation down to zero volts at the output. With the output shorted, the drop across R4 and R6 (~1.2 V) is sufficient to keep the Q1 and LED circuit active. Resistors R7 and R9 limit the forward current that could be drawn through VR1 by Q1 under output short circuit conditions, due to the voltage drop across R4 and R6. 10 and 15 W Standby Circuits Figures 15 and 16 show examples of circuits for standby applications. They both provide two outputs: an isolated 5 V and a 12 V primary referenced output. The first, using TNY266P 更多：https://www.bmcx.com/ , provides 10 W, and the second, using TNY267P, 15 W of output power. Both operate from an input range of 140 VDC to 375 VDC, corresponding to a 230 VAC or 100/115 VAC with doubler input. The designs take advantage of the line undervoltage detect, auto-restart and higher switching frequency of TinySwitch-II. Operation at 132 kHz allows the use of a smaller and lower cost transformer core, EE16 for 10 W and EE22 for 15 W. The removal of pin 6 from the 8 pin DIP TinySwitch-II packages provides a large creepage distance which improves reliability in high pollution environments such as fan cooled power supplies. Capacitor C1 provides high frequency decoupling of the high voltage DC supply, only necessary if there is a long trace length from the DC bulk capacitors of the main supply. The line sense resistors R2 and R3 sense the DC input voltage for line under-voltage. When the AC is turned off, the undervoltage detect feature of the TinySwitch-II prevents auto-restart glitches at the output caused by the slow discharge of large storage capacitance in the main converter. This is achieved by preventing the TinySwitch-II from switching when the input voltage goes below a level needed to maintain output regulation, and keeping it off until the input voltage goes above the undervoltage threshold, when the AC is turned on again. With R2