LM27761 Low-Noise, Regulated, Switched-Capacitor Voltage Inverter

1 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, V_IN = 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,
  V_OUT = –5 V
• Current Limit and Thermal Protection
• Create a Custom Design Using the LM27761 With the WEBENCH® Power Designer

2 Applications

• Operational Amplifier Power
• Wireless Communication Systems
• Cellular-Phone Power-Amplifier Biasing
• Interface Power Supplies
• Handheld Instrumentation
• Hi-Fi Headphone Amplifiers
• Powering Data Converters

3 Description

The 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.

1. For all available packages, see the orderable addendum at the end of the data sheet.

Device Images

Typical Application

4 Revision History

Changes from B Revision (February 2016) to C Revision

• Added links for WEBENCH Go

Changes from A Revision (December 2015) to B Revision

• Changed reversed "C1" and "C2" in Typ App drawing Go
• Deleted footnote 3 to Abs Max table Go
• updated Specifications tablesGo
• Added Condition statement for Typical CharcteristicsGo
• Changed Figures 3 and 4; added Figures 16 through 18 Go
• Changed "... reducing the quiescent current to 1 µA" to "...reducing the quiescent current to 7 µA"Go
• Changed "1-µA typical shutdown current" to "7-µA typical shutdown current"Go
• Changed "C2 is charging C3" to "C1 is charging C3"Go
• Changed "VOUT" to "CPOUT" on Figure 20Go
• Changed "C2" to "C1" Go
• Changed "R_SW" to "(2 × R_SW)"Go
• Changed equation 1 Go
• Changed "–1.2 V" to "–1.22 V" Go

Changes from * Revision (October 2015) to A Revision

• Changed device from one-page product preview to full advance information data sheet Go

5 Pin Configuration and Functions

DSG Package

8-Pin WSON With Thermal Pad

Top View