VIN

EN

LM2776

GND

VOUT

C1+

C1-

2.2 PF

2.2 PF

1 PF

Boost or Battery

+

PP / PC

VS+

VS-

11

LM2776

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SNVSA56A – MAY 2015 – REVISED FEBRUARY 2016

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8 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component

specification, and TI does not warrant its accuracy or completeness. TI’s customers are

responsible for determining suitability of components for their purposes. Customers should

validate and test their design implementation to confirm system functionality.

8.1 Application Information

The LM2776 CMOS charge-pump voltage converter inverts a positive voltage in the range of 2.7 V to 5.5 V to

the corresponding negative voltage of

−2.7 V to −5.5 V. The device uses three low-cost capacitors to provide up

to 200 mA of output current. The LM2776 operates at 2-MHz oscillator frequency to reduce output resistance and

voltage ripple under heavy loads. With an operating current of only 100 µA (operating efficiency greater than

91% with most loads) and 1-µA typical shutdown current, the LM2776 provides ideal performance for battery-

powered systems.

8.2 Typical Application - Voltage Inverter

Figure 18. Voltage Inverter

8.2.1 Design Requirements

Example requirements for typical voltage inverter applications:

DESIGN PARAMETER

EXAMPLE VALUE

Input voltage range

2.7 V to 5.5 V

Output current

0 mA to 200 mA

Boost switching frequency

2 MHz