| Vin (Min) (V) | 1.5 |
| Vin (Max) (V) | 10 |
| Vout (Min) (V) | -1.5 |
| Vout (Max) (V) | -10 |
| Iout (Max) (A) | 0.1 |
| Regulated outputs (#) | 1 |
| Switching frequency (Min) (kHz) | 3 |
| Switching frequency (Max) (kHz) | 100 |
| Iq (Typ) (mA) | 0.11 |
| Rating | Catalog |
- Simple Voltage Conversion, Including
- Negative Converter
- Voltage Doubler
- Wide Operating Range. . .1.5 V to 10 V
- Requires Only Two External (Noncritical) Capacitors
- No External Diode Over Full Temperature and Voltage Range
- Typical Open-Circuit Voltage Conversion Efficiency. . .99.9%
- Typical Power Efficiency. . .98%
- Full Testing at 3 V
- APPLICATIONS
- On-Board Negative Supplies
- Data-Acquisition Systems
- Portable Electronics
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.
