AD8220WARMZ vs AD8223ARMZ-RL

The AD8220WARMZ is a JFET-input instrumentation amplifier with rail-to-rail output, specified for operation from ±2.25 V to ±18 V (or 4.5 V to 36 V single supply), featuring a typical input bias current in the picoampere range and a gain set by a single external resistor. The AD8223ARMZ-RL is a lower-cost instrumentation amplifier with a fixed gain of 5 (internally set), specified for operation from ±2 V to ±12 V (or 4 V to 24 V single supply), with bipolar input bias currents in the nanoampere range. The AD8220 offers user-programmable gain and wider supply range, while the AD8223 provides a fixed gain of 5 in a smaller, cost-optimized solution.

Both devices are offered in an 8-lead MSOP (RM) package, but they are not functionally pin-compatible. The AD8220 uses the standard instrumentation amplifier pinout with gain-setting resistor pins (RG) and a REF pin, whereas the AD8223 has a fixed internal gain and its pin functions differ. A direct drop-in replacement is not possible without verifying the pinout against the respective datasheets and redesigning the PCB accordingly.

The AD8220WARMZ gain is set by a single external resistor connected between the RG pins, allowing user-selectable gains (G = 1 + 49.4 kΩ/RG). The AD8223ARMZ-RL has a fixed gain of 5 set internally, requiring no external gain resistor. Designs requiring variable or high gain should use the AD8220, while fixed gain-of-5 applications can use the AD8223.

The AD8220WARMZ uses a JFET input stage with typical input bias current in the low picoampere range, making it suitable for high-impedance sensor interfaces. The AD8223ARMZ-RL uses a bipolar input stage with input bias current typically in the nanoampere range. For very high source impedance applications, the AD8220 is generally preferred to minimize offset errors.

The AD8220WARMZ operates from ±2.25 V to ±18 V dual supplies (4.5 V to 36 V single supply). The AD8223ARMZ-RL operates from ±2 V to ±12 V dual supplies (4 V to 24 V single supply). The AD8220 supports a wider maximum supply voltage, which may be advantageous in higher-voltage industrial systems.

Both devices are specified for low supply current, but the AD8223ARMZ-RL is positioned as a cost-optimized, lower-power instrumentation amplifier with a fixed gain of 5, making it suitable for space- and power-constrained designs where gain flexibility is not required. The AD8220WARMZ offers greater flexibility (programmable gain, wider supply range, lower input bias current) at the expense of additional external components. Selection should be based on the specific quiescent current and gain requirements verified in each datasheet.

Not directly. The AD8223ARMZ-RL has a fixed gain of 5 and a different pinout and supply range than the AD8220WARMZ, which uses an external gain resistor and supports a wider supply range. A replacement requires verifying gain requirements, supply voltage, input bias current, and PCB pinout against both datasheets, and redesigning the circuit where these parameters differ.