9.1 Overview

The TPS8269xSIP is a standalone synchronous step-down converter operating at a regulated 3-MHz frequency pulse width modulation (PWM) at moderate to heavy load currents (up to 500 mA / 800mA output current). At light load currents, the TPS8269xSIP's converter operates in power-save mode with pulse frequency modulation (PFM).

The converter uses a unique frequency locked ring oscillating modulator to achieve best-in-class load and line response. One key advantage of the non-linear architecture is that there is no traditional feedback loop. The loop response to change in V_O is essentially instantaneous, which explains the transient response. Although this type of operation normally results in a switching frequency that varies with input voltage and load current, an internal frequency lock loop (FLL) holds the switching frequency constant over a large range of operating conditions.

Combined with best in class load and line transient response characteristics, the low quiescent current of the device (ca. 23μA) allows to maintain high efficiency at light load, while preserving fast transient response for applications requiring tight output regulation.

The TPS8269xSIP integrates an input current limit to protect the device against heavy load or short circuits and features an undervoltage lockout circuit to prevent the device from misoperation at low input voltages.