ISO121G

Overview

The ISO121G is a precision, low-cost isolation amplifier manufactured by Texas Instruments. It features galvanic isolation with an insulation voltage of 3500 Vrms and a 60 kHz bandwidth. The device offers a common-mode rejection ratio of 115 dB and an input offset voltage of 10 mV. It operates on a single supply ranging from 4.5 V to 18 V with a typical current consumption of 5 mA. The gain error is specified at 0.01%. Designed for through-hole mounting, it is housed in a DIP-40 package and supports an operating temperature range from -55°C to +125°C.

Feature Summary

• Provides galvanic isolation for signal transmission between circuits with different ground potentials.
• Delivers high accuracy with low gain error and low input offset voltage specifications.
• Features high common-mode rejection capability to suppress noise in noisy environments.

Applications

• Industrial process control systems requiring precise analog signal isolation
• Medical equipment needing patient isolation and safety compliance
• Test and measurement instrumentation for accurate data acquisition

Procurement Notes

Verify the specific package type and pinout configuration against your PCB layout requirements before ordering. Confirm that the thermal management strategy accommodates the power dissipation characteristics within the intended operating temperature range. Ensure that the supply voltage limits are strictly observed to prevent device damage. Check for any specific handling precautions related to the through-hole mounting process.

Selection Notes

Select this component when high precision and cost-effective isolation are required for analog signals. Consider the 60 kHz bandwidth limit for signal frequency requirements. Evaluate the DIP-40 package size constraints against available board space. Compare the 3500 Vrms isolation rating against system safety standards to ensure adequate protection margins.

Part Context

The ISO121G belongs to the ISO121 family of isolation amplifiers from Texas Instruments. This series is designed to provide reliable signal isolation in demanding industrial and medical applications. The family emphasizes precision and low cost, making it suitable for applications where traditional optocouplers or transformer-based isolators may be too slow or expensive.

Replacement Considerations

Consult official datasheets for direct replacements within the ISO121 family or comparable isolation amplifiers from other manufacturers. Verify compatibility regarding pinout, package dimensions, and electrical specifications such as bandwidth and isolation voltage before substituting.