The XD7660 super voltage converter is a monolithic CMOS voltage conversion integrated circuit that has significant performance advantages compared to other similar devices. It provides an extended operating supply voltage range of up to 12V and lower supply current. A frequency boost pin has been incorporated, allowing the user to achieve lower output impedance, albeit using smaller capacitors. All improvements are highlighted in the Electrical Specifications section on page 3. Key parameters are guaranteed over the entire commercial and industrial temperature range.
The XD7660 performs positive to negative supply voltage conversion over an input range of 1.5V to 12V, producing a complementary output voltage of -1.5V to -12V. Only two non-critical external capacitors are required to implement the charge pump and charge bank functions. The XD/XL7660 can be connected to a voltage doubler function and will generate up to 22.8V on a 12V input. They can also be used as voltage multipliers or voltage dividers.
Each chip contains a series of DC power regulators, RC oscillators, voltage level converters and four output power MOS switches. With no load, the oscillator oscillates at a nominal frequency of 10kHz and the input supply voltage is 5.0V. This frequency can be reduced by adding an external capacitor on the "OSC" terminal, or the oscillator can be overdriven by an external clock.
The “LV” terminal may be tied to GND to bypass the internal series regulator and improve low voltage (LV) operation. At medium to high voltages (3.5V to 10V), the LV pin is left floating to prevent device latchup.
In some applications, an external Schottky diode from VOUT to CAP- is needed to guarantee latchup free operation.
