ISO122JU - 50kHz Precision Isolation Amplifier | Texas Instruments
MPN: ISO122JU ✓ Active| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
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| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
ISO122JU Overview
An isolation amplifier is an analog signal-conditioning device that transfers a voltage signal across a galvanic-isolated barrier while preventing a conductive electrical connection between input and output circuits. The isolation amplifier hierarchy includes isolation amplifier, signal conditioner, analog interface, and semiconductor. ISO122JU places matched 1 pF capacitors inside the plastic package and transmits a duty-cycle-modulated representation of the input signal across the barrier. This architecture supports high-voltage isolation and reduces the need for external signal-conditioning components.
The principal ISO122 features include 0.020% maximum nonlinearity, 50 kHz signal bandwidth, and 200 V/°C input-offset-voltage drift. Its fixed unity-gain configuration simplifies circuit design because no external gain-setting network is required. The manufacturer states that no external components are required for operation. Its isolation-oriented construction is particularly useful when measuring voltage across a high-side shunt or when a control, instrumentation, or protection domain must remain electrically separated from a hazardous or high-voltage domain.
The device is available in an 8-pin SOIC package, identified by the JU ordering code. The verified distributor listing describes ISO122JU as a one-circuit, 8-SOIC isolation amplifier. Its power supplies must meet the stated 4.5 V to 18 V range, and the circuit designer should account for independent supply requirements on the input and output sides. The listed quiescent-current specifications are 5 mA on VS1 and ±5.5 mA on VS2, making supply budgeting important when several isolation channels share a regulated rail.
Typical applications include isolated current measurement in power converters, motor-control feedback, industrial sensor interfaces, medical-equipment signal acquisition, and high-voltage process monitoring. The fixed unity gain and 50 kHz bandwidth simplify many measurement paths, but applications requiring substantially wider bandwidth, higher accuracy, adjustable gain, or different isolation ratings should be compared against other isolation amplifiers before committing to the ISO122JU.
For PCB layout, treat the isolation barrier as a controlled high-voltage region rather than an ordinary signal path. Confirm the package pinout against the manufacturer datasheet, observe the creepage and clearance requirements applicable to the installation, and avoid placing unprotected copper or test pads across the isolation boundary. The component is an analog interface device rather than a power semiconductor, so SOA data is not applicable.
This page consolidates the verified manufacturer specifications, distributor package identification, official datasheet link, and practical selection considerations for engineers evaluating the ISO122JU.
Drop-in alternatives for ISO122JU — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
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Request AlternativesISO122JU Maximum Ratings & Electrical Characteristics
| Product Type | Precision isolation amplifier |
| Number of Isolation Channels | 1 channel |
| Signal Bandwidth | 50 kHz |
| Maximum Nonlinearity | 0.020% |
| Input-Offset-Voltage Drift | 200 V/°C |
| Power Supply Range | 4.5 V to 18 V |
| VS1 Quiescent Current | 5 mA |
| VS2 Quiescent Current | ±5.5 mA |
| Nominal Gain | Unity gain |
| Isolation Architecture | Input section and output section galvanically isolated by matched 1 pF capacitors |
| Internal Isolation Capacitors | 1 pF |
| Package | 8-pin SOIC |
| Mounting Type | Surface Mount |
| High-Voltage Breakdown Rating | 1500 Vrms |
| External Components Required for Operation | None |
| Bipolar Operation | ±10 V |
| High-Voltage Breakdown Test | 100% tested |
| Moisture Sensitivity Level | MSL 3 |
ISO122JU 8-pin soic Pin Configuration Guide
Pin configuration for ISO122JU (8-pin soic package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for ISO122JU.
Refer to the datasheet for full pin configuration.
Typical Applications
ISO122JU is suitable for 7 applications: Isolated Shunt Current Measurement, Industrial Sensor Signal Conditioning, Power-Converter Feedback, Motor-Control Current Feedback, Medical Equipment Signal Acquisition, High-Voltage Process Monitoring, Data-Acquisition Front Ends.
Isolated Shunt Current Measurement
ISO122JU fits isolated shunt-current measurement when the signal bandwidth remains below 50 kHz and unity gain is sufficient. Place the shunt in the input-side isolated domain and use the amplifier to transfer its voltage to the output-side measurement circuit without a conductive connection. The 0.020% maximum nonlinearity supports accurate signal conditioning, while the 4.5 V to 18 V supply range and 5 mA VS1 quiescent current help define the input-side power budget. The design must still verify shunt placement, isolation voltage, creepage, clearance, and the 1500 Vrms breakdown rating against the actual working voltage.
Recommended
Industrial Sensor Signal Conditioning
Use ISO122JU when a low-level industrial sensor signal must be transferred from a high-voltage or electrically noisy field domain into a controller or data-acquisition system. Its 50 kHz bandwidth is appropriate for many process and instrumentation signals, while fixed unity gain reduces the number of external configuration parts. The input-side and output-side supplies can be established within the stated 4.5 V to 18 V range, with quiescent currents of 5 mA and ±5.5 mA requiring separate supply budgeting. Confirm that the sensor output, isolation classification, grounding arrangement, and PCB clearances satisfy the end-equipment safety requirements.
Recommended
Power-Converter Feedback
ISO122JU can provide isolated feedback signaling in power-converter and gate-drive systems where the controller must not share a conductive ground with the power stage. The fixed unity-gain configuration is useful when the feedback network already establishes the correct voltage and current scaling. The 50 kHz bandwidth provides a defined upper limit for signal propagation, while the 0.020% maximum nonlinearity supports precise feedback representation. The circuit still needs local supply decoupling, controlled isolation-barrier layout, and verification that the converter switching frequencies and transient requirements remain compatible with the amplifier bandwidth.
Recommended
Motor-Control Current Feedback
ISO122JU is suitable for selected motor-control current-feedback paths when the required signal content fits within 50 kHz and the amplifier’s accuracy is adequate. Place the current-sense element on the isolated side of the bridge or shunt arrangement and transmit its measurement to the controller domain through the internal isolation capacitors. The one-channel architecture is practical for one sensed phase or a single shunt. Because motor systems can contain fast transients, the designer should verify transient immunity, supply startup behavior, isolation capacitance effects, and the complete safety-rated layout rather than relying only on nominal bandwidth.
Recommended
Medical Equipment Signal Acquisition
ISO122JU may be evaluated for low-bandwidth medical-equipment signal acquisition when the application can establish the required patient-protection isolation and system-level safety. Its isolation barrier and fixed unity-gain signal path can help separate a measurement domain from a processing domain, while the 50 kHz bandwidth supports many slow sensor signals. However, the supplied data does not state medical certification, creepage, clearance, leakage-current, or reinforced-insulation requirements. Those properties must be verified in the official safety documentation and validated as part of the finished equipment rather than inferred from the isolation-amplifier description.
Recommended
High-Voltage Process Monitoring
ISO122JU is applicable to process-monitoring systems that must transfer a sensor voltage from a high-voltage equipment domain to a local data-acquisition or control system. The 4.5 V to 18 V supply range supports conventional isolated-domain supply architectures, while the specified 5 mA VS1 and ±5.5 mA VS2 quiescent currents make power budgeting explicit. The internal matched capacitors help transmit the signal across the barrier, but the board must preserve the required creepage and clearance around the isolation region. Use the 1500 Vrms breakdown rating as a device specification, not as a substitute for an end-product working-voltage assessment.
Recommended
Data-Acquisition Front Ends
ISO122JU can serve as an isolated analog front end for data-acquisition equipment when the source signal is slower than the 50 kHz bandwidth and unity gain is appropriate. The fixed-gain architecture helps minimize calibration and external component count, while the separate input and output supply domains support isolation between a field connector and an ADC or controller. The designer should account for the 0.020% maximum nonlinearity, 200 V/°C offset drift, supply current, and isolation capacitance when setting system accuracy and noise budgets. Confirm the complete pinout and layout requirements from the Texas Instruments datasheet before layout release.
Recommended
Recommended Products Summary
Engineering reference data for ISO122JU — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ISO122U | ISO122U/1K | ISO124U | ||
|---|---|---|---|---|---|---|
| Product Type | Precision isolation amplifier | Isolation amplifier candidate | Isolation amplifier candidate | Isolation amplifier candidate | ||
| Manufacturer | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-pin SOIC | 8-pin SOIC candidate | 8-pin SOIC candidate | 8-pin SOIC candidate | 8-pin SOIC candidate | 8-pin SOIC candidate |
Key Differentiators
- Specified low-cost isolation performance (vs ISO122U)
- Fixed unity-gain operation (vs ISO124U)
- Defined supply and quiescent-current targets (vs ISO150AU)
Design Notes
Treat the isolation barrier as a controlled high-voltage region. Keep copper, test pads, assembly fixtures, and neighboring ground planes away from the barrier except where the manufacturer datasheet permits them. Verify the package-specific creepage and clearance for the maximum working voltage, pollution degree, and insulation system; do not infer safe board spacing solely from the 1500 Vrms breakdown statement.
Budget both isolated supplies independently. The verified specifications identify 5 mA quiescent current on VS1 and ±5.5 mA on VS2, while the allowed supply range is 4.5 V to 18 V. Confirm the required positive or negative supply configuration, startup sequencing, bypass-capacitor placement, and the maximum voltage applied to each domain before energizing the circuit.
Do not select ISO122JU solely from the isolation-amplifier function. Check the required signal bandwidth against the 50 kHz rating, confirm whether unity gain is acceptable, and include the 0.020% maximum nonlinearity and 200 V/°C input-offset-voltage drift in the accuracy budget. Also verify the official pinout because the supplied search snippets identify the 8-SOIC package but do not provide the complete numbered pin table.
Compliance Information
The supplied verified snippets do not explicitly state RoHS, REACH, lead-free, halogen-free, conflict-minerals, or automotive qualification status. The 1500 Vrms high-voltage breakdown rating and 100% testing are device specifications, not substitutes for regulatory compliance evidence.