AC/DC linear regulator achieves huge increase in efficiency

The fully integrated TPS7A78 linear regulator uses a switched-capacitor architecture to eliminate discrete components, including external inductors and transformers and miniature circuit breakers and interrupters, for tamper-resistant designs in applications including electronic metering in grid infrastructure and building automation.

The TPS7A78 is a non-isolated linear regulator that delivers up to 0.5W from AC to DC with smaller, fewer components. This smart design optimises regulation through an active bridge, switch capacitor and integrated low-dropout regulator (LDO). This design results in higher efficiency and a reduced capacitor size compared to linear regulators in traditional capacitor-drop solutions utilising a Zener diode.

Features and benefits of the TPS7A78

• Low standby power: A dynamic active bridge clamp pre-regulates the input voltage for optimal performance to reduce standby power to ten milliwatts, which is up to 75% lower compared to traditional capacitor-drop solutions.
• Higher power density: The switched-capacitor architecture eliminates up to 26 discrete components, including the bridge rectifier. This architecture reduces capacitor size by 25% compared to traditional capacitor-drop solutions.
• Tamper-proof design: The TPS7A78 is free of costly magnetic shielding, thus meeting the International Electrotechnical Commission (IEC) 61000-4-8 standard required by applications such as electronic metering.

Available through the TI store and authorised distributors, the TPS7A78 is offered in a 14-pin, 5x6.5mm thin-shrink small-outline package (TSSOP) and priced in small reels at $1.00 in 1,000-unit quantities.