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2022-09-24 23:33:15
TC7660H - DC-DC Voltage Converter for High Frequency 7660...
The TC7660H is a pin compatible, high frequency upgrade to the industry standard TC7660 charge pump voltage converter. It converts a +1.5 V to +10 V input to a corresponding -1.5V to -10V output, using only two low-cost capacitors, eliminating the need for an inductor and its associated cost, size, and EMI. TC7660H (instead of TC7660 at 10kHz at 120kHz), 1.0mF external capacitor is allowed. The oscillation frequency can be reduced (for lower supply current applications) by connecting an external capacitor from OSC to ground. The TC7660H is available in 8-pin DIP and small outline in commercial and extended temperature (SOIC) package ranges. The TC7660H contains all the necessary circuitry to implement the high voltage inverter, with the exception of two external capacitors, which may be inexpensive 1.0mF electrodeless capacitors. The action is best understood considering Figure 2 which shows an idealized high voltage inverter. Capacitor C1 charges to voltage V+, half cycle when switches S1 and S3 are closed. (Note: Switches S2 and S4 are open during this half cycle in the second half). Cycling operation, switches S2 and S4 are closed, and S1 and S3 are open, thereby connecting the negative of V to capacitor C1 to +volts. The sales fee is then transferred, this way, from C1 to C2. It is the voltage V+ on C2, assuming ideal switching and no load on C2.