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Texas Instruments ISO124U/1KG4
- Part No.:
- ISO124U/1KG4
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 28-SOIC (0.295", 7.50mm Width), 8 Leads
- Datasheet:
-
ISO124U/1KG4.pdf
- Description:
- IC OPAMP ISOLATION 1 CIRC 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,513
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Product details
Overview
ISO124U/1KG4 from Texas Instruments is a precision analog isolation amplifier with galvanic isolation via integrated 2-pF differential capacitive barrier, ±10-V input/output range, 50-kHz signal bandwidth, and 140-dB isolation mode rejection at 60 Hz - used in industrial transducer isolation and 4–20 mA loop systems requiring high-voltage safety and ground-loop elimination.
For engineers reviewing the ISO124U/1KG4 datasheet, ISO124U/1KG4 pinout, ISO124U/1KG4 application, or ISO124U/1KG4 equivalent, this page delivers verified specifications, SOIC-28 package mapping, functional pin roles, real-world use cases in thermocouple amplification and battery monitoring, and two validated alternative isolation amplifiers with documented technical distinctions.
Technical Context
The ISO124U/1KG4 implements duty-cycle modulation-demodulation: input voltage drives a 500-kHz triangular waveform across dual embedded capacitors, enabling digital transmission without analog barrier dependency. Its modulator integrates VIN/200 kΩ against a switched ±100-µA current source, while the demodulator reconstructs analog output using feedback through a 200-kΩ resistor and sample-and-hold stages to suppress ripple.
It features fixed unity gain (1 V/V), no external components required, and operates from independent ±4.5 V to ±18 V supplies on both sides - with IVS1 = ±5.0 mA and IVS2 = ±5.5 mA quiescent current. The device contains 250 transistors and achieves 0.010% max nonlinearity and 200 µV/°C input offset drift.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Isolation Rating | 1500 Vrms continuous AC (60 Hz); 2400 Vrms 100% tested for partial discharge ≤5 pC |
| Input/Output Range | ±10 V full-scale; supports bipolar operation without level-shifting circuitry |
| Signal Bandwidth | 50 kHz small-signal bandwidth; preserves fidelity for industrial sensor signals up to 250 kHz before aliasing onset |
| Nonlinearity | ±0.010% FSR maximum; ensures <1 mV error over ±10 V span in precision measurement |
| IMR @ 60 Hz | 140 dB; rejects common-mode interference from mains-coupled ground loops |
| Supply Range | ±4.5 V to ±18 V per side; enables flexible power architecture in isolated systems |
| Input Offset Drift | ±200 µV/°C; maintains DC accuracy across industrial temperature range (–25°C to +85°C) |
Pinout & Package
ISO124U/1KG4 is supplied in a 28-pin SOIC (DVA) package measuring 20.01 mm × 6.61 mm, with gull-wing leads and standard JEDEC MS-013 footprint. It features dual isolated supply domains and separate ground references for high-side and low-side sections.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| +VS1 | High-side positive analog supply | Provides +4.5 V to +18 V to input section; must be bypassed with 1-µF tantalum capacitor |
| –VS1 | High-side negative analog supply | Provides –4.5 V to –18 V to input section; referenced to Gnd 1 |
| VIN | High-side analog input | Differential input node with 200 kΩ input resistance; accepts ±10 V full-scale signal |
| –VS2 | Low-side negative analog supply | Provides –4.5 V to –18 V to output section; referenced to Gnd 2 |
| +VS2 | Low-side positive analog supply | Provides +4.5 V to +18 V to output section; powers VOUT stage |
| Gnd 2 | Low-side ground reference | Return path for output section and +VS2/–VS2; galvanically isolated from Gnd 1 |
| VOUT | Low-side analog output | Unity-gain buffered output delivering ±10 V; includes 20 mVp-p residual ripple at 500 kHz |
| Gnd 1 | High-side ground reference | Return path for input section and +VS1/–VS1; galvanically isolated from Gnd 2 |
Key Features
| Feature | Design Value |
|---|---|
| Digital barrier transmission | 500-kHz duty-cycle modulation eliminates analog barrier sensitivity - ensures stable performance despite capacitor aging or temperature drift |
| Embedded capacitive isolation | Two 1-pF matched capacitors molded into plastic package body - enables 1500 Vrms rating without external isolation components |
| Fixed unity-gain configuration | No external resistors or gain-setting components required - reduces BOM count and layout complexity in isolated signal chains |
| High IMR at power-line frequencies | 140 dB rejection at 60 Hz - effectively suppresses ground-loop noise in industrial PLC and motor control environments |
| Low output ripple with filter compatibility | 20 mVp-p typical ripple at 500 kHz - compatible with simple Sallen-Key filters to achieve ripple-free 50-kHz bandwidth |
Applications
| Thermocouple Amplifier | Battery Stack Monitor |
|---|---|
Use Scenario: Isolated temperature measurement using K-type thermocouple with cold-junction compensation in noisy factory environments. IC Role / Device Role / Timing Role: ISO124U/1KG4 isolates the thermocouple signal path from the measurement system ground, rejecting CM noise while preserving µV-level resolution. Use Value: Enables accurate sub-1°C readings in presence of 60 Hz ground gradients >10 V, eliminating offset drift caused by thermal EMFs in long conduit runs. |
Use Scenario: Monitoring individual cell voltages in a 600-V lithium-ion battery stack for EV or energy storage systems. IC Role / Device Role / Timing Role: ISO124U/1KG4 provides galvanic isolation between high-voltage cell taps and low-voltage monitoring MCU, preventing fault propagation. Use Value: Supports direct connection to cell terminals without auxiliary isolated power - simplifies design versus optocoupler-based solutions requiring extra biasing. |
| 4–20 mA Loop Isolation | Motor SCR Control Interface |
Use Scenario: Isolating analog current loop signals between field instruments and DCS controllers in hazardous process plants. IC Role / Device Role / Timing Role: ISO124U/1KG4 converts 4–20 mA loop current to isolated ±10 V output for ADC interfacing, breaking ground loops between zones. Use Value: Maintains 0.01% linearity over full loop range - critical for SIL-2 compliant systems where calibration drift impacts safety integrity. |
Use Scenario: Providing isolated gate drive enable/disable signals to SCR firing circuits in AC motor drives subject to high dv/dt transients. IC Role / Device Role / Timing Role: ISO124U/1KG4 transmits control logic across isolation barrier while rejecting >1 kV/µs common-mode transients induced by switching IGBTs. Use Value: Achieves 140 dB IMR at 60 Hz and withstands 1500 Vrms continuous - prevents false triggering during commutation events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar precision isolation amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ISO122P | PDIP-16 package; 1000 Vrms isolation rating; 0.05% max nonlinearity; 25 kHz bandwidth | Lower isolation and bandwidth - suitable only for non-safety-critical lab equipment or low-noise benchtop instruments | Select ISO122P only when board space allows PDIP and 1500 Vrms rating is not mandated by IEC 61000-4-5 or UL 508. |
| AMC1301DWVR | SOIC-8; reinforced 5000 Vrms isolation; 7.5 MHz bandwidth; 0.1% gain error; current-input (±250 mV) architecture | Requires external shunt resistor and signal conditioning; optimized for motor phase current sensing, not general-purpose voltage isolation | Choose AMC1301DWVR for high-speed current monitoring in inverters; avoid for voltage-input applications like RTD or thermocouple interfaces. |
Compared with ISO122P and AMC1301DWVR, the ISO124U/1KG4 uniquely balances 1500 Vrms isolation, ±10 V voltage-input capability, and 50 kHz bandwidth in a single SOIC-28 package - making it the only option among the three that supports direct high-fidelity analog voltage isolation without external gain or level-shifting circuitry.
Availability
ISO124U/1KG4 is available at Aetrix Electronics and suitable for industrial process control, battery management systems, and motor control applications requiring stable component supply, long-term lifecycle support, and traceable sourcing for safety-critical designs.
Supply support for ISO124U/1KG4 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, precision amplification, and industrial-grade signal conditioning ICs.
The ISO124U/1KG4 belongs to TI's precision isolation amplifier product line, engineered specifically for analog signal integrity across high-voltage barriers in harsh industrial environments - emphasizing low drift, high linearity, and certified safety compliance.
FAQ
What is the isolation voltage rating of the ISO124U/1KG4?
The ISO124U/1KG4 is rated for 1500 Vrms continuous isolation voltage at 60 Hz and undergoes 100% production testing at 2400 Vrms for partial discharge ≤5 pC. This meets IEC 60747-5-2 and UL 1577 requirements for reinforced insulation in industrial applications, ensuring reliable operation under sustained high-voltage stress without degradation.
Does the ISO124U/1KG4 require external components to operate?
No, the ISO124U/1KG4 operates in fixed unity-gain configuration with no external resistors or capacitors required for basic functionality. Only 1-µF tantalum bypass capacitors on each supply pin (+VS1, –VS1, +VS2, –VS2) are mandatory per the datasheet - all signal conditioning, modulation, and demodulation are fully integrated within the ISO124U/1KG4 die.
What is the maximum input frequency supported by the ISO124U/1KG4 before aliasing occurs?
The ISO124U/1KG4 uses 500-kHz duty-cycle modulation, resulting in a Nyquist limit of 250 kHz. Input signals above 250 kHz produce aliased outputs - for example, a 800-kHz input generates spurious components at 200 kHz. For linear operation, keep input frequencies ≤250 kHz; the specified 50-kHz signal bandwidth applies to small-signal fidelity, not aliasing threshold.
Can the ISO124U/1KG4 be used with single-supply operation on the high side?
Yes, the ISO124U/1KG4 supports single-supply operation on the high side using an external Zener diode (e.g., 5.1 V) to generate –VS1 from a positive rail. As documented in Figure 21 of the datasheet, this configuration maintains ±10 V input range and full functionality - though output swing remains limited to ±10 V by the low-side dual supplies (+VS2/–VS2).
How does the ISO124U/1KG4 handle ground loop interference in industrial settings?
The ISO124U/1KG4 achieves 140 dB isolation mode rejection (IMR) at 60 Hz, directly suppressing ground potential differences between high-side and low-side domains. This eliminates offset errors and noise coupling in multi-ground systems - such as PLC I/O modules connected to remote sensors via long shielded cables - without requiring star grounding or additional filtering.
ISO124U/1KG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 28-SOIC (0.295", 7.50mm Width), 8 Leads
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Amplifier Type:
- Isolation
- Number of Circuits:
- 1
- Output Type:
- -
- Slew Rate:
- 2V/µs
- Gain Bandwidth Product:
- -
- -3db Bandwidth:
- 50 kHz
- Current - Input Bias:
- -
- Voltage - Input Offset:
- 20 mV
- Current - Supply:
- 5mA
- Current - Output / Channel:
- 15 mA
- Voltage - Supply Span (Min):
- 9 V
- Voltage - Supply Span (Max):
- 36 V
- Operating Temperature:
- -25°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
ISO124U/1KG4 FAQ
1.How can I place an order for ISO124U/1KG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for ISO124U/1KG4 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for ISO124U/1KG4 reliable?
The price and inventory of ISO124U/1KG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISO124U/1KG4 is usually 5 days.
3.What payment methods are accepted for ISO124U/1KG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISO124U/1KG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISO124U/1KG4?
ISO124U/1KG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISO124U/1KG4 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for ISO124U/1KG4?
For technical support, including ISO124U/1KG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISO124U/1KG4 requirements.
6.How does Aetrix verify that ISO124U/1KG4 is sourced from the original manufacturer or authorized distributors?
All ISO124U/1KG4 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ISO124U/1KG4 meets industry standards.
7.What is the process for return or replacement of ISO124U/1KG4?
All ISO124U/1KG4 units undergo pre-shipment inspection (PSI). If there is an issue with ISO124U/1KG4, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The ISO124U/1KG4 part is unused and in its original packaging.
Return procedure for ISO124U/1KG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ISO124U/1KG4 Tags
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LM358DT
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LM358DR
Texas Instruments
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MCP6006UT-E/OT
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