Texas Instruments ISO122JUG4

Overview

ISO122JUG4 from Texas Instruments is a precision isolation amplifier with galvanic barrier isolation, 1500 V_rms rated withstand voltage, 140 dB IMR at 60 Hz, ±10 V output swing, and 50 kHz small-signal bandwidth. It operates from ±4.5 V to ±18 V dual supplies and delivers 0.020% maximum nonlinearity in industrial transducer signal conditioning circuits.

For engineers reviewing the ISO122JUG4 datasheet, ISO122JUG4 pinout, ISO122JUG4 application, or ISO122JUG4 equivalent, this page provides verified technical context, validated pin functions, confirmed isolation performance metrics, and real-world implementation guidance for ground-loop elimination and high-voltage sensor interfacing.

Technical Context

The ISO122JUG4 uses duty-cycle modulation-demodulation across an embedded 2-pF differential capacitive barrier, enabling digital transmission of analog signals without degradation from barrier characteristics. Its architecture includes matched input/output sections laser-trimmed for precision, with internal 500 kHz oscillator driving the modulator.

It features fixed unity-gain configuration, no external components required, and dual isolated supply domains (±VS1 on high side, ±VS2 on low side) referenced to separate ground pins (GND1 and GND2). The device contains 250 transistors and supports bipolar operation with ±10 V output compliance.

Key Specifications

Pinout & Package

ISO122JUG4 is housed in a 28-lead SOIC (DVA) package measuring 20.01 mm × 6.61 mm, with creepage and clearance optimized for reinforced isolation. Pin numbering follows TI's standard top-view orientation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar isolation amplifier applications.

Compared with AMC1301DWV and ISO124P, the ISO122JUG4 uniquely balances 50 kHz bandwidth, 0.020% nonlinearity, and proven 1500 V_rms reliability in mature industrial deployments-making it optimal for voltage-isolation tasks requiring both speed and precision without redesigning supply or layout.

Availability

ISO122JUG4 is available at Aetrix Electronics and suitable for industrial process control, motor control feedback, and isolated 4–20 mA loop applications requiring stable component supply across extended production lifecycles.

Supply support for ISO122JUG4 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in high-reliability isolation solutions.

The ISO122JUG4 belongs to TI's precision isolation amplifier product line, designed specifically for robust analog signal transfer across safety-critical galvanic barriers in harsh industrial environments.

FAQ

What is the isolation voltage rating of the ISO122JUG4?

The ISO122JUG4 is rated for 1500 V_rms continuous isolation voltage and 100% tested to 2400 V_rms using VDE0884 partial discharge methodology. This rating applies across the full operating temperature range (–25°C to +85°C) and ensures long-term reliability under sustained high-voltage stress. The ISO122JUG4 meets reinforced insulation requirements for many industrial safety standards.

Does the ISO122JUG4 require external components for basic operation?

No, the ISO122JUG4 operates in fixed unity-gain configuration with no external components required. Only supply bypassing (1 µF tantalum per VS pin) is mandated per datasheet Section 10.1. Unlike programmable gain isolators, the ISO122JUG4 integrates all trimming and compensation internally, eliminating resistor networks, calibration steps, or external op-amps for core functionality.

Can the ISO122JUG4 be used with single-supply configurations?

The ISO122JUG4 requires dual supplies on both sides (±VS1 and ±VS2) for specified performance. However, TI Application Note SBOA004 documents a validated single-supply workaround on the high side using a Zener diode to generate –VS1. This reduces input range to ±2 V to ±5 V depending on supply voltage and is not guaranteed across temperature - the ISO122JUG4 itself remains a dual-supply device.

What is the maximum input frequency supported by the ISO122JUG4 before aliasing occurs?

The ISO122JUG4 uses 500 kHz duty-cycle modulation, resulting in a Nyquist limit of 250 kHz. Input signals above 250 kHz produce aliased outputs below 250 kHz, as shown in Figure 9 of the datasheet. For linear operation, keep input frequencies ≤250 kHz; the device maintains 50 kHz small-signal bandwidth and 2 V/µs slew rate within this range. The ISO122JUG4 does not include anti-alias filtering - external low-pass filtering is required for broadband inputs.

How does the ISO122JUG4 handle high dV/dt transients on the isolation barrier?

The ISO122JUG4 achieves high-frequency transient immunity through its digital modulation scheme, but sense amplifier false triggering may occur above 1000 V/µs dV/dt. As documented in Section 9.1.3, reducing supply voltages below ±15 V lowers effective dV/dt and mitigates spurious errors. Layout best practices - including maximizing GND1–GND2 spacing and avoiding copper under the package - are critical to maintaining the ISO122JUG4's specified 140 dB IMR at 60 Hz.