FEATURES
· Simple Voltage Conversion, Including
– Negative Converter
– Voltage Doubler
· Wide Operating Range¼1.5 V to 10 V
· Requires Only Two External (Noncritical)
Capacitors
· No External Diode Over Full Temperature and
Voltage Range
· Typical Open-Circuit Voltage Conversion
Efficiency¼99.9%
· Typical Power Efficiency¼98%
· Full Testing at 3 V

APPLICATIONS
· On-Board Negative Supplies
· Data-Acquisition Systems
· Portable Electronics

DESCRIPTION/ORDERING INFORMATION
The TL7660 is a CMOS switched-capacitor voltage converter that perform supply-voltage conversions from
positive to negative. With only two noncritical external capacitors needed for the charge pump and charge
reservoir functions, an input voltage within the range from 1.5 V to 10 V is converted to a complementary
negative output voltage of –1.5 V to –10 V. The device can also be connected as a voltage doubler to generate
output voltages up to 18.6 V with a 10-V input.
The basic building blocks of the IC include a linear regulator, an RC oscillator, a voltage-level translator, and four
power MOS switches. To ensure latch-up-free operation, the circuitry automatically senses the most negative
voltage in the device and ensures that the N-channel switch source-substrate junctions are not forward biased.
The oscillator frequency runs at a nominal 10 kHz (for VCC = 5 V), but that frequency can be decreased by
adding an external capacitor to the oscillator (OSC) terminal or increased by overdriving OSC with an external
clock.
For low-voltage operation (VIN < 3.5 V), LV should be tied to GND to bypass the internal series regulator. Above
3.5 V, LV should be left floating to prevent device latchup.
The TL7660C is characterized for operation over a free-air temperature range of –40°C to 85°C. The TL7660I is
characterized for operation over a free-air temperature range of –40°C to 125°C.