8.1 Overview

The TPS61088-Q1 is a fully-integrated synchronous boost converter with a 21.3-mΩ power switch and a 24.4-mΩ rectifier switch to output high power from a single cell or two-cell Lithium batteries. The device is capable of providing an output voltage of 12.6 V and delivering up to 30-W power from a 5-V input.

The TPS61088-Q1 uses adaptive constant off-time peak current control topology to regulate the output voltage. In moderate to heavy load condition, the TPS61088-Q1 works in the quasi-constant frequency pulse width modulation (PWM) mode. The switching frequency in the PWM mode is adjustable ranging from 200 kHz to 2.2 MHz by an external resistor. In light load condition, the device has two operation modes selected by the MODE pin. When the MODE pin is left floating, the TPS61088-Q1 works in the pulse frequency modulation (PFM) mode. The PFM mode brings high efficiency at the light load. When the MODE pin is short to ground, the TPS61088-Q1 works in the forced PWM mode (FPWM). The FPWM mode can avoid the acoustic noise and other problems caused by the low switching frequency. The TPS61088-Q1 implements cycle-by-cycle current limit to protect the device from overload conditions during boost switching. The switch peak current limit is programmable by an external resistor. The TPS61088-Q1 uses external loop compensation, which provides flexibility to use different inductors and output capacitors. The adaptive off-time peak current control scheme gives excellent transient line and load response with minimal output capacitance.