ISO122U - Precision Isolated Amplifier, 50kHz, SOIC-8 | TI
MPN: ISO122U ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $23.8687 | $23.87 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
ISO122U Overview
An isolation amplifier is a differential amplifier whose input and output domains are electrically separated by a reinforced isolation barrier. This category belongs to the precision amplifier hierarchy, which includes instrumentation amplifiers, operational amplifiers, buffer amplifiers, and signal-conditioning ICs. ISO122U is intended to transfer measured analog signals across high potential differences while limiting ground current and protecting equipment on opposite sides of the barrier.
Key features include 100% high-voltage breakdown testing, fixed unity gain, a 4.5 V to 18 V power-supply range, and low supply demand. The verified data specifies approximately 5 mA quiescent current on VS1 and ±5.5 mA on VS2. These characteristics suit compact, cost-sensitive industrial systems where accurate voltage sensing and galvanic isolation are more important than high bandwidth.
The isolation amplifier converts a differential input voltage into a ground-referenced output on the secondary side. Its 0.020% maximum nonlinearity limits gain-related error, while the 50 kHz bandwidth supports relatively fast control or measurement loops. The 200 V/°C offset-drift specification helps control error as temperature changes, although system-level accuracy still depends on input and reference components.
Typical uses include motor-drive current sensing, industrial sensor interfaces, power-inverter feedback, isolated voltage measurement, and high-side sensing where the source can be several hundred volts above the controller ground. The isolation barrier also helps prevent ground faults and switching transients from corrupting measurements or endangering downstream circuitry.
A critical design consideration is to preserve the isolation barrier by keeping input-side and output-side copper, components, and external networks physically separated according to the manufacturer layout guidance. Decoupling and grounding should remain independent on both sides; joining them defeats the purpose of galvanic isolation. Supply voltage and signal limits should also be checked at temperature rather than only at room temperature.
This page combines verified manufacturer specifications, distributor availability and pricing information, explicit data gaps, and cross-reference results. Because the supplied evidence does not establish five verified pin-to-pin alternatives, the alternatives array is omitted rather than padded with unverified package or reel-code variants.
Drop-in alternatives for ISO122U — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ISO122U (same form factor and footprint) — differing in Device Type, Input Offset-Voltage Drift, Mounting Type, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
No drop-in alternatives available for this product.
Request AlternativesISO122U Maximum Ratings & Electrical Characteristics
| Device Type | Precision isolation amplifier |
| Number of Channels | 1 circuit |
| Input Signal Range | ±10 V |
| Maximum Nonlinearity | 0.020% |
| Signal Bandwidth | 50 kHz |
| Input Offset-Voltage Drift | 200 V/°C |
| Isolation Voltage | 1500 Vrms |
| Power-Supply Range | 4.5 V to 18 V |
| VS1 Quiescent Current | 5 mA |
| VS2 Quiescent Current | ±5.5 mA |
| Gain Configuration | Fixed unity gain |
| External Components Required | None |
| High-Voltage Breakdown Test Coverage | 100% |
| Package | 8-pin SOIC |
| Mounting Type | Surface mount |
| Operating Voltage | ±4.5 V to ±18 V |
ISO122U Pin Configuration
| Pin 1 | [DATA_NEEDED: pin 1 name] — [DATA_NEEDED: pin 1 function] |
| Pin 2 | [DATA_NEEDED: pin 2 name] — [DATA_NEEDED: pin 2 function] |
| Pin 3 | [DATA_NEEDED: pin 3 name] — [DATA_NEEDED: pin 3 function] |
| Pin 4 | [DATA_NEEDED: pin 4 name] — [DATA_NEEDED: pin 4 function] |
| Pin 5 | [DATA_NEEDED: pin 5 name] — [DATA_NEEDED: pin 5 function] |
| Pin 6 | [DATA_NEEDED: pin 6 name] — [DATA_NEEDED: pin 6 function] |
| Pin 7 | [DATA_NEEDED: pin 7 name] — [DATA_NEEDED: pin 7 function] |
| Pin 8 | [DATA_NEEDED: pin 8 name] — [DATA_NEEDED: pin 8 function] |
Typical Applications
ISO122U is suitable for 6 applications: Industrial Voltage Sensing, Motor-Drive Feedback, Power-Inverter Monitoring, Isolated Sensor Interface, High-Side Current Measurement, Isolated Test and Measurement.
Industrial Voltage Sensing
The ISO122U fits industrial voltage sensing because it accepts a ±10 V differential input while electrically separating the measurement from the processing side with a 1500 Vrms isolation rating. Its 0.020% maximum nonlinearity limits signal-chain distortion, and the fixed unity gain removes the need for an external gain-setting network. For a sensor conditioned to ±10 V, the amplifier can sit between the high-potential input and an ADC or controller. Engineers should preserve separate input-side and output-side grounding and allow for 200 V/°C input-offset drift when defining total accuracy over the full temperature range.
Recommended
Motor-Drive Feedback
The ISO122U is appropriate for isolated motor-control feedback when the available signal is within ±10 V and the loop bandwidth can remain near the device's 50 kHz capability. Its isolation barrier prevents the high-side or power-stage domain from being tied directly to the controller ground, while fixed unity gain simplifies the analog path. The tradeoff is that no adjustable gain is available, so the upstream sensor or amplifier must scale the feedback signal. The 200 V/°C offset-drift specification should be included in the error budget before closing a precision current or voltage loop.
Recommended
Power-Inverter Monitoring
The ISO122U supports power-inverter monitoring when a controller must receive a low-voltage representation of an analog signal from a switching or high-voltage domain. Its ±10 V input range covers bipolar sensed voltages, and its 1500 Vrms isolation rating supports robust separation. The 50 kHz bandwidth accommodates many supervisory and measurement functions, though it is not intended to replace a dedicated high-speed current-control amplifier. Designers should keep switching-node copper away from the isolated input area and account for the component's 0.020% maximum nonlinearity and temperature-related offset drift.
Recommended
Isolated Sensor Interface
The ISO122U is useful when a pressure, position, level, or other transducer produces a bipolar voltage from a location that cannot share ground with the control electronics. The ±10 V input range and fixed unity gain provide a straightforward conditioning path, while isolation limits dangerous ground-current paths between domains. Because the part requires no external components for operation, the basic function can remain compact. The system designer should still verify common-mode limits, sensor settling behavior, and the 50 kHz bandwidth against the sensor's dynamic response before production release.
Recommended
High-Side Current Measurement
The ISO122U can be used in a high-side measurement chain when a differential shunt amplifier or sensor produces a signal inside the ±10 V input range. Its isolation permits measurement across a substantial potential difference without connecting the power return to the controller ground. The fixed unity gain is advantageous when the upstream amplifier already provides correct scaling, but it limits flexibility if attenuation is needed. Designers should calculate the combined error from offset drift, nonlinearity, shunt tolerance, and amplifier bandwidth rather than relying on the isolation rating alone.
Recommended
Isolated Test and Measurement
The ISO122U is appropriate for bench and industrial measurement equipment that must observe a bipolar voltage without connecting the source ground to the instrument ground. Its 1500 Vrms isolation rating supports reinforced separation, while the 50 kHz bandwidth allows measurement beyond static voltage readings. Fixed unity gain provides predictable scaling and no external gain components are required for operation. A practical design must still define input filtering, safe working voltage, barrier creepage, and protection against transients. The component should not be assumed to tolerate every surge or fault condition solely from its isolation rating.
Recommended
Recommended Products Summary
Engineering reference data for ISO122U — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product |
|---|---|
| Package | 8-pin SOIC |
| Brand | Texas Instruments |
| Device Type | Precision isolation amplifier |
| Input Range | ±10 V |
| Maximum Nonlinearity | 0.020% |
| Signal Bandwidth | 50 kHz |
| Isolation Rating | 1500 Vrms |
| Power-Supply Range | 4.5 V to 18 V |
| Gain Configuration | Fixed unity gain |
| External Components Required | None |
Key Differentiators
- Fixed unity gain simplifies basic isolated voltage sensing (vs ISO124U)
- Verified signal bandwidth supports moderate-speed analog measurements (vs ISO124U)
- No external components required for basic operation (vs ISO122JP)
Design Notes
Preserve the isolation barrier from the first placement operation. Route input-side and output-side copper, ground returns, decoupling, and test pads without crossings or unintended copper bridges. The isolated domains may operate at different potentials, so connecting them through a ground pour, shield, connector shell, or long copper trace can defeat the 1500 Vrms isolation rating.
Do not treat the 1500 Vrms figure as permission for every overvoltage condition. Confirm the orderable device's reinforced-insulation rating, working voltage, package creepage, clearance, and pollution-degree assumptions against the manufacturer datasheet. Add input protection and define safe fault behavior for transients; isolation ratings alone do not specify surge withstand or unlimited fault voltage.
Keep each supply reference associated only with its own isolated circuit domain and follow the manufacturer decoupling recommendations. The verified specifications list approximately 5 mA quiescent current on VS1 and ±5.5 mA on VS2, but total system demand also includes sensor and downstream loads. Check both rails at minimum, nominal, and maximum voltage before releasing the layout.
Use the 50 kHz bandwidth as an upper design constraint, not as a guaranteed usable control-loop rate in every board. Include the sensor, isolation amplifier, protection network, anti-alias filter, and ADC in the complete response calculation. Also include the 200 V/°C input-offset drift and 0.020% maximum nonlinearity when translating circuit accuracy into system accuracy.
Compliance Information
The supplied search results do not contain an unambiguous compliance declaration for the exact ISO122U orderable MPN. Compliance must be confirmed with Texas Instruments or the authorized distributor.