AD604AR

The AD604AR is a pin compatible upgrade of Analog Devices’ popular AD604 instrumentation amplifier. As such, the AD604AR offers many of the same features as the AD604. The part operates at 3.2 V and 5 V Single Supply operation or between ±2.5 V and ±15 V Dual Supplies. It is specified to operate over the industrial temperature range of −40°C to +85°C.

At the heart of the AD604AR lies a traditional three op amp instrumentation amplifier. This topology consists of two inverting buffers and a differential amplifier stage. The features that make instrumentation amplifiers well suited for signal conditioning can primarily be attributed to their high gain and differential inputs. The high gain allows signal levels to be increased such that microvolt signals can be properly amplified for the signal conditioners such as ADCs or DACs. The differential inputs allow for suppressing of common-mode noise signals.

The AD604AR is optimized for low noise and low distortion operation, making it suitable for a variety of signal conditioning applications. Additionally, the pin compatible form factor of the AD604AR makes it easy to upgrade from the AD604 without having to change printed circuit board layout. This is especially useful when designing a board to operate across a range of gain settings. The AD604AR’s wide operating temperature range makes it suitable for use in a variety of different operation environments. The AD604AR’s combination of low noise, low distortion operation, wide operating temperature range, and pin compatible form factor makes it an ideal solution for a variety of signal conditioning applications.

The AD604AR’s input stage consists of two inverting buffer amplifiers and a differential amplifier stage. The two buffer amplifiers have unity voltage gain which allows for factory trimming of the common-mode gain and signal-to-noise ratio. The differential amplifier stage is unchecked and has enables the designer to select the gain of the signal conditioner by adjusting the feedback resistors on the amplifier.

The AD604AR’s outputs are connected to the output stage. The outputs are designed to be AC coupled to avoid saturation of the outputs due to DC bias which can occur in some applications. The outputs are also designed to be low impedance for stable operation. Additionally, the output stage offers protection against shorts to ground or to the power supplies.

The AD604AR is a powerful and versatile instrumentation amplifier whose features make it suitable for a variety of signal conditioning applications. It’s low noise and low distortion performance, wide operating temperature range, and pin compatible form factor make it an ideal solution for designers looking to upgrade from the AD604 and get better performance. The AD604AR’s input stage and output stage offer protection against short circuits and enable the designer to select the appropriate gain and bandwidth for their application.