XL7660

XD/XL7660 is a CMOS voltage converter that converts positive voltages in the +2V to +10V range to corresponding negative voltages in the -2V to -10V range. Only two non-critical external capacitors are required to implement the charge pump and charge storage functions. The device can also be configured as a voltage doubler, producing output voltages up to +18.6V with a +10V input. An integrated frequency boost pin allows users to achieve lower output impedance even with smaller capacitors. Each chip contains a series DC power regulator, RC oscillator, voltage level converter, and four output power MOS switches. With no load and an input supply voltage of 5.0V, the nominal oscillator frequency is 10kHz. This frequency can be reduced by adding an external capacitor to the OSC terminal, or overdriven by an external clock. Grounding the LV terminal bypasses the internal series regulator to improve low-voltage (LV) 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 40μA, no load)
• Wide operating voltage range: 2V to 10V, 100% tested at 5V
• Improved minimum open-circuit voltage conversion efficiency up to 99%
• Boost pin (Pin 1) provided for higher switching frequency
• Improved SCR latch-up protection
• Easy to use, only two non-critical external passive components required