Tiny Low Power Difference Amps from ADI

21st August 2009

Analog Devices

ES Admin

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Analog Devices has introduced three new low-power difference amplifiers that are as small as 4.9 mm x 3 mm and featuring slew rates up to 10 times faster than competing products. Designed for high-performance, power-critical applications, the AD8276, AD8277 and AD8278 difference amplifiers are half the size of competing devices and much smaller than discrete alternatives consisting of resistor arrays and operational amplifiers. The amplifiers also eliminate the added expense and design overhead associated with complex peripheral protection circuitry.

The slew rate of 1.1-V/μs (volts per microsecond) combined with an input range of two times the power supply make the AD827x products well suited for robust voltage and current sensing in process-control, motor-control, and power-management applications. In addition, the low price is unprecedented with versions available at under $1 USD each.

The AD827x low-power difference amplifiers combine the benefits of a wide supply range of 2.5-V to 36-V and low power with a 550-kHz bandwidth that is two times faster than other low-power difference amplifiers. In addition, these difference amplifiers feature 220-μA maximum quiescent current with an 86-dB CMRR (common-mode rejection ratio) that is 10-dB greater than competing devices. AD827x difference amplifiers reject external interferences in low-power systems without increasing system power dissipation. Response time includes a 1.1-V/μS slew rate and 15-μS settling time to 0.01 percent. The settling time is more than five times faster than other amplifiers in their class and ensures shorter propagation delays in control loops. On-chip resistors are laser-trimmed for accurate gain, low gain drift, and high common-mode rejection.