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.