TI's smart AC/DC linear regulator achieves breakthrough in efficiency and power density

Texas Instruments TPS7A78

The industry's most integrated linear regulator delivers 75 percent efficiency and provides two times more power density than other linear regulators

Texas Instruments - TPS7A78

Texas Instruments (TI) expanded its broad portfolio of over 500 linear regulators by introducing a first-of-its-kind smart AC/DC linear regulator. With 75 percent higher efficiency and two times the power density of other linear regulators, this device achieves the best balance between high efficiency and ultra-low noise while shrinking power-supply size. The fully integrated TPS7A78 linear regulator uses a unique 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 functional diagram
The TPS7A78 functional diagram.

The TPS7A78 is a nonisolated linear regulator that delivers up to 0.5 W from AC to DC with smaller, fewer components. This smart design optimizes 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 utilizing a Zener diode.

Typical TPS7A78 Schematic
Typical TPS7A78 Schematic.
 
Dropout vs IOUT with DC Supply for 5.0 V
Dropout vs IOUT with DC Supply for 5.0 V.

Key features and benefits of the TPS7A78

  • Low standby power:
    A unique dynamic active bridge clamp pre-regulates the input voltage for optimal performance to reduce standby power to 10 mW, 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.

Availability, packaging and pricing

Available through the TI store and authorized distributors, the TPS7A78 is offered in a 14-pin, 5-mm-by-6.5-mm thin-shrink small-outline package (TSSOP) and priced in small reels at US$1.00 in 1,000-unit quantities.

TPS7A78EVM-011 Evaluation module
TPS7A78EVM-011 Evaluation module.