LM27761 Low-Noise Regulated Switched-Capacitor Vol

By Texas Instruments 88

LM27761 Low-Noise Regulated Switched-Capacitor Vol

Texas Instruments' LM27761 low-noise regulated switched-capacitor voltage inverter delivers a very low-noise adjustable output for an input voltage in the range of 2.7 V to 5.5 V. Four low-cost capacitors are used in the application solution to provide up to 250 mA of output current. The regulated output for the device is adjustable between -1.5 V and -5 V. The LM27761 operates at 2 MHz (typical) switching frequency to reduce output resistance and voltage ripple. With an operating current of only 370 µA (charge-pump power efficiency greater than 80% with most loads) and 7 µA typical shutdown current, the LM27761 provides ideal performance when driving power amplifiers, DAC bias rails, and other high-current, low-noise voltage applications.

Features
  • Inverts and regulates the input supply voltage
  • Low output ripple
  • Shutdown lowers quiescent current to 7 µA (typical)
  • Up to 250 mA output current
  • 2.5 Ω inverter output impedance, VIN = 5 V
  • ±4% regulation at peak load
  • 370 µA quiescent current
  • 2 MHz (typical) low-noise fixed-frequency operation
  • 35 dB (typical) LDO PSRR at 2 MHz with 80 mA load current
  • 30 mV LDO dropout voltage at 100 mA, VOUT = -5 V
  • Current limit and thermal protection

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