TI introduces smart AC/DC linear regulator
Texas Instruments has 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 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. This design results in higher efficiency and a reduced capacitor size compared to linear regulators in traditional capacitor-drop solutions utilizing a Zener diode.
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. 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. The TPS7A78 is free of costly magnetic shielding, thus meeting the IEC 61000-4-8 standard required by applications such as electronic metering. The TPS7A78 is offered in a 14-pin, 5x 6.5-mm TSSOP.