DER-161: 35W, 24V @ 1.4A, 90 ~ 265VAC in

This engineering report describes an inkjet printer power supply design based on the Power Integrations® TOPSwitch®-HX TOP258MN. This power supply operates from a universal input (90 VAC – 265 VAC) and provides a 24 V, 35 W continuous output. To accommodate peak load power requirements this supply also delivers up to 80 W (peak power) for 40 ms durations, at regular intervals of 1060 ms (a 3.6% duty cycle).

The TOPSwitch-HX, by design, maintains constant efficiency across a very wide load range. This optimizes performance for existing and emerging energy efficiency regulations, such as 1 W standby and 3 W sleep mode requirements. This constant efficiency capability ensures a design based on the TOPSwitch-HX line is optimized for any future energy efficiency regulation changes, without the need for redesign.

This power supply design offers various protection features:
• Output overvoltage protection (OVP) or open-loop fault protection, with latching shutdown and fast AC reset
• Time-triggered latching overload protection with fast AC reset
• Auto-restart during brownout or line sags
• Accurate thermal overload protection with auto recovery using a large hysteresis

This document provides the specifications, schematic, bill of materials, and transformer design and construction details for this power supply. This document includes performance parameters such as regulation, efficiency, stand-by, transient load, power limiting data, and conducted EMI test results.