HGSEMI LMC7660M/TR

The LMC7660 is a monolithic CMOS power supply circuit offering distinct performance advantages over previous devices. It converts input voltages in the range of +1.5V to +10V to corresponding complementary output voltages of -1.5V to -10V. Only two non-critical external capacitors are required to implement the charge pump and charge storage functions. The LMC7660 can also be configured as a voltage doubler, capable of producing output voltages up to +18.6V with a +10V input. The chip integrates an internal series DC power supply regulator, RC oscillator, voltage level translator, and four output power MOSFET switches. A unique logic cell detects the most negative voltage within the device, ensuring that the source-to-substrate junctions of the output N-channel switches are never forward biased, thereby guaranteeing latch-up-free operation. With no load and an input supply voltage of 5.0V, the nominal frequency of the internal oscillator is 10kHz. This frequency can be reduced by connecting an external capacitor to the OSC pin, or the device can be driven by an external clock. Connecting the LV pin to ground bypasses the internal series regulator to 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.

• Simple conversion from +5V logic supply to ±5V supplies
• Simple voltage multiplication (VOUT = (-) nVIN)
• Typical open-circuit voltage conversion efficiency: 99.9%
• Typical power efficiency: 98%
• Wide operating voltage range: 1.5V to 10V
• Easy to use — only 2 non-critical external passive components required

• On-board negative supply for dynamic RAM
• Local microprocessor (8080-type) negative supply
• Low-cost negative supply
• Data acquisition systems