Overview
The TL7660IDR, produced by Texas Instruments, is a CMOS switched-capacitor voltage converter designed to perform supply-voltage conversions from positive to negative. This device is highly versatile and can be used in various applications requiring negative voltage supplies or voltage doubling. It operates within a wide voltage range of 1.5 V to 10 V and can generate output voltages up to 18.6 V when configured as a voltage doubler. The TL7660IDR is characterized by its high efficiency, simplicity, and reliability, making it suitable for a range of electronic systems, including data-acquisition systems, portable electronics, and other applications requiring negative voltage supplies.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC Supply Voltage | 1.5 | - | 10 | V |
| Operating Free-Air Temperature (TL7660C) | -40 | - | 85 | °C |
| Operating Free-Air Temperature (TL7660I) | -40 | - | 125 | °C |
| ICC Supply Current (VCC = 5 V, LV = Open) | - | 45 | 120 | µA |
| ROUT Output Source Resistance (VCC = 5 V, IO = 20 mA) | - | 125 | - | Ω |
| fOSC Oscillator Frequency (VCC = 5 V) | - | 10 kHz | - | kHz |
| ηPOWER Power Efficiency (RL = 5 kΩ) | 95 | 98 | - | % |
| ηVOUT Voltage Conversion Efficiency (RL = ∞) | 99 | 99.9 | - | % |
Key Features
- Simple voltage conversion from positive to negative with only two noncritical external capacitors required.
- Wide operating range: 1.5 V to 10 V input voltage, generating –1.5 V to –10 V output voltage.
- Voltage doubler configuration to generate output voltages up to 18.6 V with a 10-V input.
- High efficiency: Typical power efficiency of 98% and voltage conversion efficiency of 99.9%.
- No external diode required over the full temperature and voltage range.
- Low power consumption: Typical supply current of 45 µA at VCC = 5 V.
- Adjustable oscillator frequency: Can be decreased by adding an external capacitor or increased by overdriving the OSC terminal.
- Latch-up free operation: Automatic sensing and adjustment of substrate bias to prevent latch-up.
Applications
- Data-acquisition systems: Generating negative supply voltages for analog-to-digital converters and other components.
- Portable electronics: Providing negative voltage supplies in battery-powered devices.
- Voltage doubling: Generating higher output voltages from a lower input voltage.
- Cascading devices: Multiple TL7660 devices can be cascaded to achieve higher negative multiplication of the initial supply voltage.
- Paralleling devices: Multiple devices can be paralleled to reduce output resistance and improve overall performance.
Q & A
- What is the primary function of the TL7660IDR?
The TL7660IDR is a CMOS switched-capacitor voltage converter that converts positive input voltages to negative output voltages.
- What is the operating voltage range of the TL7660IDR?
The device operates within a voltage range of 1.5 V to 10 V.
- How many external capacitors are required for the TL7660IDR?
Only two noncritical external capacitors are required for the charge pump and charge reservoir functions.
- What is the typical power efficiency of the TL7660IDR?
The typical power efficiency is 98%.
- Can the TL7660IDR be used as a voltage doubler?
- How can the oscillator frequency be adjusted?
The oscillator frequency can be decreased by adding an external capacitor to the OSC terminal or increased by overdriving the OSC terminal with an external clock.
- What is the purpose of the LV terminal?
The LV terminal should be tied to GND for low-voltage operation (VIN < 3.5 V) to bypass the internal series regulator, and left floating for supply voltages greater than 3.5 V to prevent device latch-up.
- Can multiple TL7660IDR devices be cascaded or paralleled?
- What are the typical applications of the TL7660IDR?
The device is commonly used in data-acquisition systems, portable electronics, and other applications requiring negative voltage supplies or voltage doubling.
- What are the operating temperature ranges for the TL7660C and TL7660I?
The TL7660C operates from –40°C to 85°C, and the TL7660I operates from –40°C to 125°C.
