Pin arrangement of TOP209/210

The TOP209/210 series is a high-efficiency, low-power, pulse-width modulated three-terminal single-chip switching power supply successfully developed by Power Company in 1997. It is suitable for making low-power switching power supplies below 8W or stand-by power supplies for electrical equipment. Power). TOP209/210 is available in two packages: 8-pin dual in-line (DIP-8) and 8-pin surface mount (SMD-8). The pin arrangement is as shown in the figure. Because pins 2, 3, 6, and 7 are all empty pins (NC), it is still equivalent to a three-terminal device. Pin 1 and pin 8 are internally connected. The only difference is that when designing the printed circuit board, pin 1 is externally connected to the bias/feedback return terminal and the negative pole of the control terminal bypass capacitor, and pin 8 is externally connected to the primary high voltage return terminal (HVRTN). Pins 4 and 5 are the control terminal and drain terminal respectively. Its working principle is the same as that of TOP100, but a few points need to be explained: (1) The switching frequency of TOP209 is changed to 70kHz, and the switching frequency of TOP210 is still 100kHz; (2) The thermal shutdown temperature of both is 145oC, which is higher than TOPSwitch--Ⅱ 10 oC (3) The limit current values ​​of TOP209/210 are 0.15~O.23A, 0.23~0.30A respectively; (4) The withstand voltage value of the power MOSFET is 700V, suitable for 220V AC power supply.