The HCPL-7800-000E is an Isolation Amplifier for current sensing in electronic motor drives. The high CMR capability of isolation amplifier provides the precision and stability needed to accurately monitor motor current in high noise motor control environments, providing for smoother control in various types of motor control applications. In a typical implementation the motor current flows through an external resistor and the resulting analogue voltage drop is sensed by the amplifier. A differential output voltage is created on the other side of the amplifier optical isolation barrier. It is designed to ignore very high common-mode transient slew rates.

• 15kV/µs Common-mode rejection at VCM = 1000V
• Advanced sigma-delta A/D converter technology
• Compact and auto-insertable
• Fully differential circuit topology

The AD8278 and AD8279 are general-purpose difference amplifiers intended for precision signal conditioning in power critical applications that require both high performance and low power. The AD8278 and AD8279 provide exceptional commonmode rejection ratio (80 dB) and high bandwidth while amplifying input signals that are well beyond the supply rails. The on-chip resistors are laser trimmed for excellent gain accuracy and high CMRR. They also have extremely low gain drift vs. temperature.

The common-mode range of the amplifier extends to almost triple the supply voltage (for G = ½), making the amplifer ideal for single-supply applications that require a high commonmode voltage range. The internal resistors and ESD circuitry at the inputs also provide overvoltage protection to the op amp. The AD8278 and AD8279 can be used as difference amplifiers with G = ½ or G = 2. They can also be connected in a high precision, single-ended configuration for non inverting and inverting gains of −½, −2, +3, +2, +1½, +1, or +½.

The AD8278 and AD8279 provide an integrated precision solution that has a smaller size, lower cost, and better performance than a discrete alternative.