1 Features

1• Input Voltage Range 0.9V to 5V

• Startup Voltage 1.5V at 20mA Load

• Pin Selectable Output Voltages: 3.3V, 3V, 2.5V

• 15nA typical Quiescent Current in Bypass Mode

• 5.7μA typical Quiescent Current in Boost Mode

• Bypass Switch from VIN to VOUT

• IOUT > 200mA at 3.3V VOUT, VIN = 1.8V

• Internal Feedback Divider Disconnect (Bypass

Mode)

• Controlled Bypass Transition Prevents Reverse

Current into Battery

• Power-Save Mode at Light Loads

• Overtemperature Protection

• Redundant Overvoltage Protection

• Small 2mm x 2mm SON 6-pin package

2 Applications

• Metering (Gas, Water, Smart Meters)

• Remote Controls

• Home Security / Home Automation

• Single 3V Li-MnO2 or 2 x 1.5V Alkaline Cell

Powered Applications

3 Description

The TPS61291 is a boost converter with pin

selectable output voltages and an integrated bypass

mode. In bypass operation, the device provides a

direct path from the input to the system and allows a

low power micro controller (MCU) such as the

MSP430 to operate directly from a single 3V Li-MnO2

battery or dual alkaline battery cells.

In bypass mode the integrated feedback divider

network for boost mode operation is disconnected

from the output and the quiescent current

consumption drops down to only 15nA (typical).

In boost mode the device provides a minimum output

current of 200mA at 3.3V VOUT from 1.8V VIN. The

boost mode is used for system components which

require a regulated supply voltage and cannot directly operate from the input source. The boost converter is

based on a current-mode controller using

synchronous rectification to obtain maximum

efficiency and consumes typically 5.7uA from the

output. During startup of the boost converter, the

VSEL pin is read out and the integrated feedback network sets the output voltage to 2.5V, 3V or 3.3V.

Bypass mode or boost mode operation is controlled by the system via the EN/BYP pin.

The device integrates an enhanced bypass mode control to prevent charge, stored in the output

capacitor during boost mode operation, from flowing

back to the input and charging the battery.

The device is packaged in a small 6-pin SON

package (DRV) measuring 2.0mm × 2.0mm x

0.75mm.