TPS54231DR

The TPS54231DR from Texas Instruments is a 2A non-synchronous step-down DC-DC converter in an 8-pin SOIC package. Operating from 3.5V to 28V input, it integrates an 80mOhm high-side MOSFET and supports adjustable output down to 0.8V. The 570kHz fixed switching frequency uses current mode control with internal slope compensation, simplifying external compensation. Eco-mode pulse skipping automatically activates at light loads for high efficiency. A 1uA shutdown current suits battery-powered applications. The device includes adjustable UVLO, overvoltage transient protection, cycle-by-cycle current limit, and thermal shutdown.

The TPS54231 uses peak current mode control with a fixed 570kHz oscillator. An error amplifier compares the divided output voltage with a 0.8V internal reference, generating a control voltage. This voltage is compared with the current-sense signal from the high-side MOSFET to determine the PWM duty cycle. Internal slope compensation prevents sub-harmonic oscillation at duty cycles above 50%. In Eco-mode, when the output current drops below a threshold, the device skips switching pulses to reduce switching losses. The external catch diode conducts during the off-time. Current limit is cycle-by-cycle, and frequency foldback provides additional protection during severe overloads.

• 12V/24V to 3.3V/5V distributed power conversion
• Set-top box and CPE equipment power supply
• LCD display and peripheral power rails
• Industrial and car audio DC-DC conversion
• Battery-powered equipment regulation