Overview
The LM7705MME/NOPB, produced by Texas Instruments, is a switched capacitor voltage inverter designed to generate a low-noise, fixed negative bias voltage. This device is particularly useful in applications where amplifiers need to swing to zero volts, such as in true zero amplifier outputs and low-voltage split-power supplies. The LM7705 operates over a supply voltage range of 3 V to 5.25 V and provides a regulated output voltage of −0.23 V, which is essential for preventing amplifier output saturation and ensuring accurate signal processing.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage | 3 | - | 5.25 | V |
| Output Voltage | -0.232 | -0.23 | -0.228 | V |
| Output Voltage Tolerance | - | - | 5% | - |
| Output Voltage Ripple | - | - | 4 mVPP | - |
| Quiescent Current | - | 78 | 100 | µA |
| Shutdown Current | - | - | 20 | nA |
| Turn-on Time | - | 500 | - | µs |
| Operating Temperature Range | -40 | - | 125 | °C |
| Package | - | - | 8-Pin VSSOP | - |
Key Features
- Regulated output voltage of −0.23 V with a tolerance of 5%
- Low output voltage ripple of 4 mVPP
- High conversion efficiency up to 98%
- Low quiescent current of 78 µA and shutdown current of 20 nA
- Fast turn-on time of 500 µs
- Operating temperature range from −40°C to 125°C
- Compact 8-Pin VSSOP package
Applications
- True zero amplifier outputs: Enables amplifiers to swing to zero volts, improving signal accuracy.
- Portable instrumentation: Suitable for battery-powered devices due to low power consumption.
- Low-voltage split-power supplies: Provides a negative bias voltage without the need for a separate negative power supply.
Q & A
- What is the primary function of the LM7705MME/NOPB? The LM7705MME/NOPB is a switched capacitor voltage inverter that generates a low-noise, fixed negative bias voltage of −0.23 V.
- What is the supply voltage range for the LM7705MME/NOPB? The device operates over a supply voltage range of 3 V to 5.25 V.
- What is the output voltage tolerance of the LM7705MME/NOPB? The output voltage tolerance is 5%.
- How much quiescent current does the LM7705MME/NOPB consume? The quiescent current is typically 78 µA.
- What is the shutdown current of the LM7705MME/NOPB? The shutdown current is 20 nA.
- What is the turn-on time of the LM7705MME/NOPB? The turn-on time is 500 µs.
- What is the operating temperature range of the LM7705MME/NOPB? The operating temperature range is from −40°C to 125°C.
- In what package is the LM7705MME/NOPB available? The device is available in an 8-Pin VSSOP package.
- What are some common applications of the LM7705MME/NOPB? Common applications include true zero amplifier outputs, portable instrumentation, and low-voltage split-power supplies.
- How does the LM7705MME/NOPB improve amplifier performance? It prevents amplifier output saturation by providing a small negative supply voltage, allowing the amplifier to swing to zero volts and maintaining an accurate zero through the signal processing chain.
