Texas Instruments ISO150AUG4

Overview

ISO150AUG4 from Texas Instruments is a dual-channel, galvanically isolated bidirectional digital coupler in SO-28 package, delivering 80 MBaud typical data rate, 25 mW per channel power consumption, and 2400 Vrms partial discharge tested isolation barrier-used in isolated RS-485 interfaces and A/D converter grounding isolation.

For engineers reviewing the ISO150AUG4 datasheet, ISO150AUG4 pinout, ISO150AUG4 application, or ISO150AUG4 equivalent, this page provides verified pin functions, real-world timing behavior (27 ns propagation delay, <2 ns skew), isolation-mode transient immunity (1.6 kV/µs), and validated alternatives for industrial serial interface redesigns.

Technical Context

The ISO150AUG4 implements capacitive coupling via two 0.4 pF on-chip isolation capacitors with Faraday shielding, rejecting isolation-mode transients up to 1.6 kV/µs. Each of its two independent channels supports user-programmable bidirectional data flow via dedicated R/T control pins.

It uses Bi-CMOS circuitry operating from 3 V to 5.5 V, with HCT-compatible logic thresholds (≈1.3 V at 5 V, 400 mV hysteresis) and CMOS output drivers capable of driving 15 LS-TTL loads. The device features indeterminate output state during mode switching, requiring input transition to re-establish valid output tracking.

Key Specifications

Pinout & Package

SO-28 surface-mount package with 7.2 mm creepage distance, 0.10 mm internal isolation barrier, and dual-side isolated power domains (VSA/GA for Side A; VSB/GB for Side B).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISO150AUG4, ISO7221CDR offers superior transient immunity but doubles component count for dual-channel needs, while ADUM1201ARZ delivers higher speed and lower skew but sacrifices the user-programmable bidirectionality essential for adaptive interface protocols.

Availability

ISO150AUG4 is available at Aetrix Electronics and suitable for isolated RS-485 interfaces, A/D converter grounding isolation, and microprocessor system interface applications requiring stable component supply across extended product lifecycles.

Supply support for ISO150AUG4 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, embedded processing, and high-reliability components for industrial, automotive, and communications markets.

The ISO150AUG4 belongs to TI's legacy isolation portfolio designed specifically for replacing optocouplers in high-speed digital interfaces-emphasizing low power, programmable direction, and robust capacitive isolation for factory automation and test equipment.

FAQ

What is the maximum data rate supported by the ISO150AUG4?

The ISO150AUG4 supports a typical data rate of 80 MBaud under standard conditions (CL = 50 pF, TA = 25°C, VS = 5 V). Its minimum guaranteed data rate is 50 MBaud, calculated from pulse width distortion limits. Performance scales with supply voltage and capacitive load-actual achievable rate in a given design depends on PCB layout, termination, and signal integrity margins.

Does the ISO150AUG4 require external components for basic operation?

Yes, the ISO150AUG4 requires 0.1 µF ceramic + 1 nF ceramic bypass capacitors placed adjacent to each supply pin (VSA and VSB) to suppress high-frequency noise and ensure stable operation. No pull-up/down resistors are needed on R/T or data pins, as internal logic thresholds are self-biasing. External series resistors may be added for ESD protection or impedance matching depending on trace length and environment.

How does the ISO150AUG4 handle direction changes during live operation?

The ISO150AUG4 supports on-the-fly direction changes via its R/T control pins. However, when R/T state transitions, the corresponding Dx output enters an indeterminate state (high or low) until the first valid input edge arrives-then output begins tracking input. This behavior is documented in Note 9 of the datasheet and requires protocol-level synchronization to avoid glitches in full-duplex streaming applications.

What isolation certifications apply to the ISO150AUG4?

The ISO150AUG4 is UL 1577 recognized (File E181974) with 2400 Vrms isolation rating for 1 second, and meets basic insulation requirements per regulatory testing. It has been 100% partial discharge tested at 2400 Vrms, 60 Hz, with failure threshold set at ≤5 pulses ≥5 pC. It is not certified to IEC 60747-5-2 (VDE 0884-10) or IEC 61000-4-5, so system-level certification must account for these gaps.

Can the ISO150AUG4 operate from a 3.3 V supply?

Yes, the ISO150AUG4 operates across 3.0 V to 5.5 V, including 3.3 V nominal supplies. At 3.3 V, VOH drops to ≈2.3 V (min) and VOL rises to ≈0.55 V (max), maintaining TTL compatibility. Propagation delay increases slightly (~32 ns typ), and power consumption decreases proportionally. Logic thresholds scale with supply voltage-designers must verify interfacing ICs meet updated VIH/VIL margins at 3.3 V.