Single-chip design regulates power in smart meters

Maxim Integrated Products introduces the MAX17497, a one-chip solution for all power requirements on the communications and metrology boards in smart meters. A high level of integration eases design, adds flexibility, increases accuracy, improves reliability, and lowers the total cost and footprint. This single power regulator is suitable for smart meter and smart grid applications as well as factory automation.

Traditional power solutions for smart meters integrate only the flyback controller and high-voltage FETs. This design, by itself, is usually expensive. To it, they add external regulators and other discrete devices to complete the application, increasing size and cost. The MAX17497 has been designed as a multi-output solution specifically for smart meters. It supports all the power-supply requirements for both the smart meter’s communications board and the metrology board.

The MAX17497 integrates the control circuitry required for the universal input (85 to 265 V), non-isolated flyback power supplies. It adds a secondary-side synchronous buck regulator with integrated MOSFETs. All of these integrated functions support the supplies for a powerline communication (PLC) driver or RF transceiver, the PLC/RF modem (2.5/3.3 V), a circuit-breaker relay, and the tightly regulated supplies for the sensitive metrology and application system on chips (SoCs).

Designed to operate at 250/500 kHz, the flyback regulator avoids the frequencies used in smart meter communications and thus mitigates frequency interference and delivers robust performance. The high-flyback-regulator and secondary buck-regulator frequency allows for optimization of the magnetic and filter components in the smart meter.

The MAX17497 also improves overall system reliability and accuracy through various user-defined thresholds and protection features. The inputs for undervoltage lockout (UVLO) and overvoltage thresholds are programmable. Over-temperature and short-circuit protection and an output power-ok signal improve system safety.

The MAX17497 fits in a 3 x 3 mm TQFN package and operates over the -40° to 125° C temperature range.

For more information, contact Maxim Integrated Products, 120 San Gabriel Dr., Sunnyvale, CA 94086. Phone: (408) 737-7600.