Overview
The LM27761DSGR, produced by Texas Instruments, is a low-noise, regulated, switched-capacitor voltage inverter. This device is designed to provide a very low-noise adjustable output voltage for input voltages ranging from 2.7 V to 5.5 V. It operates at a typical switching frequency of 2 MHz, which helps in reducing output resistance and voltage ripple. The LM27761 is particularly useful in applications requiring high-current, low-noise voltage supplies, such as powering data converters, operational amplifiers, and wireless communication systems.
Key Specifications
| Parameter | Value |
|---|---|
| Input Voltage Range | 2.7 V to 5.5 V |
| Output Voltage Range | −1.5 V to −5 V |
| Output Current | Up to 250 mA |
| Switching Frequency | 2 MHz (typical) |
| Inverter Output Impedance | 2.5 Ω (VIN = 5 V) |
| Quiescent Current | 370 µA (typical) |
| Shutdown Current | 7 µA (typical) |
| LDO PSRR at 2 MHz | 35 dB (typical) with 80-mA load current |
| LDO Dropout Voltage | 30 mV at 100 mA, VOUT = −5 V |
| Package | WSON (8-pin), 2.00 mm × 2.00 mm |
Key Features
- Low-noise regulated output with adjustable voltage range from −1.5 V to −5 V.
- High efficiency with charge-pump power efficiency greater than 80% for most loads.
- Low output ripple and high PSRR (Power Supply Rejection Ratio) of 35 dB at 2 MHz.
- Current limit and thermal protection for robust operation.
- Low quiescent current of 370 µA and shutdown current of 7 µA.
- Externally configurable output using gain-setting resistors.
- Uses four low-cost capacitors to deliver up to 250 mA of output current.
Applications
- Operational amplifier power supplies.
- Wireless communication systems.
- Cellular-phone power-amplifier biasing.
- Interface power supplies.
- Handheld instrumentation.
- Hi-Fi headphone amplifiers.
- Powering data converters.
Q & A
- What is the input voltage range of the LM27761?
The input voltage range of the LM27761 is from 2.7 V to 5.5 V. - What is the typical switching frequency of the LM27761?
The typical switching frequency of the LM27761 is 2 MHz. - What is the maximum output current of the LM27761?
The maximum output current of the LM27761 is up to 250 mA. - What is the quiescent current of the LM27761 in normal operation?
The quiescent current of the LM27761 is 370 µA (typical). - What is the shutdown current of the LM27761?
The shutdown current of the LM27761 is 7 µA (typical). - What is the LDO PSRR at 2 MHz for the LM27761?
The LDO PSRR at 2 MHz for the LM27761 is 35 dB (typical) with an 80-mA load current. - How is the output voltage of the LM27761 configured?
The output voltage of the LM27761 is externally configurable using gain-setting resistors. - What type of protection does the LM27761 have?
The LM27761 has current limit and thermal protection. - What are some common applications of the LM27761?
The LM27761 is commonly used in operational amplifier power supplies, wireless communication systems, cellular-phone power-amplifier biasing, and powering data converters. - What package options are available for the LM27761?
The LM27761 is available in an 8-pin WSON package with dimensions of 2.00 mm × 2.00 mm.
