Op amp eschews micropower trend, delivers significant power

-- EDN, 1/6/2000

Many industrial applications, such as driving motors, actuators, and valves, as well as audio applications and automated test equipment, need substantial power and are thus not obsessed with micropower issues as much as with delivered load current and voltage. Burr-Brown's OPA549 monolithic op amp provides as much as 10A peak/8A continuous output current from a supply of 8 to 60V or ±4 to ±30V. Slew rate for this device's output is as much as 9V/µsec, and the output is fully protected against overload and other debilitating conditions. In the event of a shutdown, the op amp activates a status line so you know of the condition; alternatively, you can drive the same line low to disable the output stage and disconnect the load.

ou set the current limit via an external resistor or DAC, using a 0- to 633-µA control signal. To maximize performance, the op amp does not sense the output current in the conventional way, via a resistor in series with the load. Instead, it indirectly senses the load, eliminating the need for a low-value power resistor and thus reducing installed cost and board space. Available in an 11-lead power ZIP with an integral copper tab for heat-sink attachment, the OPA549 operates at -40 to +85°C, and price is $10.83 (1000).

Burr-Brown Corp, 1-520-746-1111, www.burr-brown.com.

-by Bill Schweber