XD7660

XD/XL7660 is a CMOS voltage converter that converts positive voltages in the range of +2V to +10V to corresponding negative voltages of -2V to -10V. Only two non-critical external capacitors are required to implement the charge pump and charge storage functions. The XD/XL7660 can also be connected as a voltage doubler, capable of producing output voltages up to +18.6V with a +10V input. The device integrates a frequency boost pin, allowing users to achieve lower output impedance even with smaller capacitors. Each chip contains a series DC power supply regulator, RC oscillator, voltage level converter, and four output power MOS switches. With no load and an input supply voltage of 5.0V, the oscillator operates at a nominal frequency of 10kHz. This frequency can be reduced by adding an external capacitor to the "OSC" terminal, or overdriven by an external clock. The "LV" terminal can be grounded to bypass the internal series regulator and improve low-voltage operation. At medium to high voltages (3.5V to 10V), the LV pin should be left floating to prevent device latch-up. In certain applications, an external Schottky diode connected between VOUT and CAP- is required to ensure latch-up-free operation.

Key features

• Simple conversion from +5V logic supply to ±5V supplies
• Simple voltage multiplication: VOUT = (-) n×VIN
• Low quiescent current (typical 40uA, no load)
• Wide operating voltage range: 2V to 10V
• 100% tested at 5V
• Improved minimum open-circuit voltage conversion efficiency up to 99%
• Pin 1 (Boost pin) for higher switching frequency
• Improved SCR latch-up protection
• Easy to use — only two non-critical external passive components required