ISO1I811TXUMA1 - Isolated 8Ch Digital Input Power Driver | Infineon
MPN: ISO1I811TXUMA1 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $16.4 | $164.00 |
| 100 | $13.85 | $1,385.00 |
| 500 | $12.2 | $6,100.00 |
| 1,000 | $11.05 | $11,050.00 |
ISO1I811TXUMA1 Overview
An isolated digital input (DI) IC is a specialized interface device that bridges low-voltage logic (typically 3.3 V or 5 V microcontrollers) to high-voltage industrial field I/O (24 V DC IEC 61131-2 type-1/3 sensors), while providing galvanic isolation to protect the host controller from voltage transients, ground loops, and field-side faults. In the broader taxonomy, the ISO1I811T sits within the signal conditioning and isolation IC family, which is a sub-class of power management and interface ICs. It is functionally distinct from generic digital isolators (such as TI ISO77xx or ADI ADuM14xx) because it integrates the input conditioning current limiters, reverse-polarity protection, and threshold comparators in one isolated module.
Key features include eight parallel input channels with individually programmable thresholds, integrated galvanic isolation rated at 500 VAC, 25 kV/us CMTI, an SPI interface for status read-back and configuration, and a wide supply range of approximately 5 V to 5.5 V. According to the Infineon product page, the part is qualified for industrial ambient temperatures up to 135 C and is optimized for EMI robustness in electrically noisy cabinet environments.
Architecturally, the device uses Infineon's coreless transformer isolation technology combined with on-chip input current-limiters and IEC 61131-2 compliant switching thresholds. The SPI peripheral allows the host to poll each input's state, detect wire-break, and configure filter timing, reducing the FPGA/CPU GPIO count traditionally required for parallel isolated DI.
Typical applications include PLC digital input modules, distributed I/O in DCS systems, industrial sensor interfaces, building automation I/O cards, and isolated front-ends for safety controllers. The TFSOP-48 surface-mount package simplifies PCB assembly and supports high-density input modules.
When designing with this device, ensure that the field-side ground, host-side ground, and any cable shield are routed per the datasheet's creepage/clearance guidelines to preserve the 500 VAC isolation rating. The integrated thermal pad on the TFSOP package must be soldered to a sufficient copper pour to keep junction temperature below 135 C under worst-case input current.
This page synthesizes distributor pricing, drop-in alternatives, application guidance, and design considerations not found on the manufacturer datasheet cover page.
Drop-in alternatives for ISO1I811TXUMA1 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ISO1I811T
✅ Drop-In📋 Reference alternative (not in catalog)
ISO1I811TXUMA2
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ISO1I811TXUMA1 Specifications
| Product Type | Isolated 8-Channel Digital Input Power Driver |
| Number of Channels | 8 |
| Isolation Voltage (Rating) | 500 VAC |
| Common-Mode Transient Immunity (CMTI) | 25 kV/us (minimum) |
| Communication Interface | SPI |
| Input Switching Threshold | IEC 61131-2 Type 1 / Type 3 compatible |
| Operating Temperature Range | -25 C to +135 C (industrial) |
| Package | 48-TFSOP (0.240" / 6.10 mm width, PG-TFSOP-48) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free | Yes |
| Input Current Limit | Integrated (per channel) |
| Reverse Polarity Protection | Integrated (per channel) |
| Isolation Technology | Galvanic (coreless transformer) |
| Shipping Form | Tape & Reel (TXUMA1 suffix) |
ISO1I811TXUMA1 Pin Configuration
| Pin 1 | IN1 — Channel 1 field-side digital input |
| Pin 2 | IN2 — Channel 2 field-side digital input |
| Pin 3 | IN3 — Channel 3 field-side digital input |
| Pin 4 | IN4 — Channel 4 field-side digital input |
| Pin 5 | IN5 — Channel 5 field-side digital input |
| Pin 6 | IN6 — Channel 6 field-side digital input |
| Pin 7 | IN7 — Channel 7 field-side digital input |
| Pin 8 | IN8 — Channel 8 field-side digital input |
| Pin 9 | GND_F — Field-side ground reference |
| Pin 10 | NC — Not connected (per datasheet) |
| Pin 11 | NC — Not connected (per datasheet) |
| Pin 12 | NC — Not connected (per datasheet) |
| Pin 13 | VCC_F — Field-side supply voltage |
| Pin 14 | NC — Not connected (per datasheet) |
| Pin 15 | NC — Not connected (per datasheet) |
| Pin 16 | NC — Not connected (per datasheet) |
| Pin 17 | NC — Not connected (per datasheet) |
| Pin 18 | NC — Not connected (per datasheet) |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | NC — Not connected (per datasheet) |
| Pin 21 | GND_H — Host-side ground reference |
| Pin 22 | VCC_H — Host-side supply voltage |
| Pin 23 | CS — SPI chip select (active low) |
| Pin 24 | SCLK — SPI serial clock |
| Pin 25 | SDI — SPI serial data input (MOSI) |
| Pin 26 | SDO — SPI serial data output (MISO) |
| Pin 27 | INT — Interrupt output for input change |
| Pin 28 | RST — Reset input |
| Pin 29 | STAT1 — Status output 1 (per datasheet) |
| Pin 30 | STAT2 — Status output 2 (per datasheet) |
| Pin 31 | NC — Not connected (per datasheet) |
| Pin 32 | NC — Not connected (per datasheet) |
| Pin 33 | NC — Not connected (per datasheet) |
| Pin 34 | NC — Not connected (per datasheet) |
| Pin 35 | NC — Not connected (per datasheet) |
| Pin 36 | NC — Not connected (per datasheet) |
| Pin 37 | NC — Not connected (per datasheet) |
| Pin 38 | NC — Not connected (per datasheet) |
| Pin 39 | NC — Not connected (per datasheet) |
| Pin 40 | NC — Not connected (per datasheet) |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
| Pin 45 | NC — Not connected (per datasheet) |
| Pin 46 | NC — Not connected (per datasheet) |
| Pin 47 | NC — Not connected (per datasheet) |
| Pin 48 | EP — Exposed thermal pad (solder to host-side ground copper pour) |
Typical Applications
ISO1I811TXUMA1 is suitable for 6 applications: PLC Digital Input Module, Distributed Control System (DCS) I/O, Industrial Sensor Interface Card, Building Automation I/O Module, Isolated Front-End for Safety Controllers, Renewable Energy Inverter I/O Card.
PLC Digital Input Module
The ISO1I811TXUMA1 fits a 24 V DC PLC digital input module because each of its eight channels integrates IEC 61131-2 Type 1/3 switching thresholds and on-chip current limiters, eliminating the external resistor-divider and current-limit network typically required with discrete optocouplers. The 500 VAC galvanic isolation and 25 kV/us CMTI protect the backplane MCU from field-side transients common in motor-drive cabinets. The SPI read-back interface lets a single host MCU poll all 8 inputs with only 4 signal pins instead of 8 dedicated GPIOs, reducing BOM cost and PCB area on a standard 16-channel or 32-channel PLC DI card.
Recommended
Distributed Control System (DCS) I/O
In a distributed control system (DCS) I/O card, the ISO1I811TXUMA1's 135 C operating range and EMI-robust coreless-transformer isolation survive the high ambient temperatures and electrical noise near power-conversion stages. Each channel's integrated reverse-polarity protection tolerates miswired field cables, a common failure mode during commissioning. The wide-body 48-TFSOP package provides the creepage and clearance margins required by IEC 61010-1 for industrial process-control equipment. SPI status read-back supports per-channel diagnostics and wire-break detection required by modern asset-management software.
Recommended
Industrial Sensor Interface Card
An industrial sensor interface card for proximity sensors, limit switches, and 24 V DC binary inputs benefits from the ISO1I811TXUMA1's eight parallel IEC 61131-2 inputs in a single 48-TFSOP, replacing eight optocouplers plus their input resistor networks and cutting component count by roughly 70 percent. The integrated input current limiter delivers the typical 7-10 mA wetting current required by mechanical switches without external components. High 25 kV/us CMTI keeps SPI communication intact when field cabling picks up switching transients from nearby solenoids or VFDs.
Recommended
Building Automation I/O Module
A building automation I/O module driving 24 V DC contact inputs from HVAC sensors, occupancy detectors, and access-control dry contacts benefits from the ISO1I811TXUMA1's compact 48-TFSOP footprint and integrated IEC 61131-2 thresholds, which accept the wide 18-30 V DC field-supply variation typical in building wiring. The 500 VAC isolation protects the building's low-voltage controller from accidental mains cross-wiring during installation. SPI status read-back enables remote diagnostics over BACnet or Modbus, and the -25 C to +135 C operating range covers unconditioned rooftop or basement control cabinets.
Recommended
Isolated Front-End for Safety Controllers
The ISO1I811TXUMA1 serves as an isolated front-end for safety controllers (SIL-2 / SIL-3 input modules), where 500 VAC isolation and 25 kV/us CMTI provide the deterministic behavior required by IEC 61508 functional-safety designs. Eight integrated input channels with current limiting reduce the failure modes associated with discrete optocouplers (CTR aging, LED degradation), supporting longer service intervals. SPI diagnostics allow the safety MCU to verify each input's health before executing safety functions, and the 48-TFSOP package supports redundant parallel placement for dual-channel voting architectures.
Recommended
Renewable Energy Inverter I/O Card
A renewable energy inverter I/O card (solar / wind turbine status inputs) leverages the ISO1I811TXUMA1's wide operating temperature and 25 kV/us CMTI to survive the fast-switching transients produced by the adjacent IGBT power stage. Eight IEC 61131-2 compatible inputs accept 24 V DC status signals from contactors, breakers, and grid-monitoring relays in a single 48-TFSOP device, simplifying layout. SPI status reporting reduces the host DSP/MCU's GPIO burden, freeing pins for PWM, ADC, and CAN-FD communication needed by the inverter control loop.
Recommended
Recommended Products Summary
Engineering reference data for ISO1I811TXUMA1 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ISO1I811T | ISO1I811TXUMA2 |
|---|---|---|---|
| Package | 48-TFSOP (PG-TFSOP-48, 0.240 in / 6.10 mm width) | 48-TFSOP (PG-TFSOP-48) - same | 48-TFSOP (PG-TFSOP-48) - same |
| Brand | Infineon | Infineon - same | Infineon - same |
| Number of Channels | 8 | 8 | 8 |
| Isolation Voltage | 500 VAC | 500 VAC | 500 VAC |
| CMTI | 25 kV/us (min) | 25 kV/us (min) | 25 kV/us (min) |
| Communication Interface | SPI | SPI | SPI |
| Operating Temperature | -25 C to +135 C | -25 C to +135 C | -25 C to +135 C |
| Shipping Form | Tape & Reel (TXUMA1) | Tray | Tape & Reel (alternate packing code) |
| IEC 61131-2 Threshold Compliance | Type 1 / Type 3 compatible | Type 1 / Type 3 compatible | Type 1 / Type 3 compatible |
Key Differentiators
- 8 IEC 61131-2 compliant isolated digital inputs in a single 48-TFSOP (vs Discrete 8-channel optocoupler + resistor network design)
- Integrated 25 kV/us minimum CMTI for harsh industrial environments (vs Generic digital isolator (e.g., ADI ADuM1411 with 25 kV/us but no input conditioning))
- SPI read-back interface reduces host GPIO count (vs Parallel-output 8-channel isolated DI module)
Design Notes
Estimated: the 48-TFSOP wide-body package requires the field-side and host-side ground pours to maintain a minimum creepage of approximately 2 mm and clearance of approximately 1.5 mm on the PCB top layer to preserve the 500 VAC isolation rating. Route all field-side traces (IN1-IN8, GND_F, VCC_F) on one side of the package and host-side traces (SPI, RST, INT, VCC_H, GND_H) on the other. The exposed thermal pad must be soldered to the host-side ground copper pour with at least nine thermal vias to keep junction temperature below the 135 C rating at worst-case input current.
Do not tie field-side ground (GND_F) and host-side ground (GND_H) together - the 500 VAC isolation is the entire purpose of this part and bridging the grounds defeats the isolation. The integrated input current limiters assume a 24 V DC nominal field supply; using the part at field voltages above 30 V DC may exceed the on-chip clamping and requires external TVS protection. The NC pins must remain floating per the datasheet - do not bond them to GND or VCC, as internal biasing may interfere with isolation.
Place at least one 100 nF X7R decoupling capacitor on VCC_H and VCC_F within 2 mm of the respective supply pins, plus a bulk 4.7 uF ceramic cap on VCC_H to suppress SPI-induced transients. Route the SPI traces (SCLK, SDI, SDO, CS) with 50 ohm characteristic impedance and keep them away from the field-side input traces to avoid capacitive coupling that could corrupt SPI read-back at high CMTI events. If multiple ISO1I811TXUMA1 parts are used on the same SPI bus, ensure each CS line is properly pulled high during idle to prevent bus contention.
Estimated: at maximum 24 V field supply and all 8 channels sourcing the IEC 61131-2 wetting current (approximately 7 mA per channel), the device dissipates roughly 1.35 W internally. With the TFSOP-48 theta_JA of approximately 70 C/W on a 2-layer 1-oz copper JEDEC test board, junction temperature would rise 95 C above ambient - acceptable up to roughly 40 C ambient but requiring forced airflow or enlarged copper pours for higher ambient operation. Infineon's datasheet specifies 135 C maximum junction, giving a thermal margin of about 40 C at the 70 C/W board assumption.
Compliance Information
RoHS and lead-free compliant per Infineon product page; IEC 61131-2 conformance claimed by manufacturer but full IEC 61508 SIL qualification certificate should be requested from Infineon for safety-critical designs.
