Renesas ASI4UE-F-G1-ST

Overview

ASI4UE-F-G1-ST from Integrated Device Technology is a universal AS-i interface IC compliant with AS-Interface Complete Specification V3.0, functioning as physical-layer transceiver and protocol handler in master, slave, repeater, or bus-monitor nodes. It delivers 55 mA current drive via on-chip electronic inductor, supports -40°C to +85°C operation, and integrates EEPROM for configuration storage. Used in industrial sensor/actuator networks with two-wire AS-i bus powering and data transmission.

For engineers reviewing the ASI4UE-F-G1-ST datasheet, ASI4UE-F-G1-ST pinout, ASI4UE-F-G1-ST application, or ASI4UE-F-G1-ST equivalent, this device requires attention to IRD input mode selection, Safety Mode activation for safety-critical timing, LED status mapping per V3.0, and SSOP28 thermal derating above 70°C.

Technical Context

The ASI4UE-F-G1-ST implements Manchester-II modulation/demodulation for AS-i bus communication and includes dual-channel UART support: one for standard AS-i data exchange and another for IR-addressing via the IRD pin. Its internal oscillator supports automatic detection of 8 MHz or 16 MHz crystals.

It features configurable digital I/O (4 inputs / 4 outputs), programmable data pre-processing (bit-selective inversion, input filtering), and dedicated safety logic that disables non-essential functions to guarantee ≤10 ms fault reaction time when enabled. The FID pin provides external fault indication with power-failure detection capability in master/monitor modes.

Key Specifications

Pinout & Package

ASI4UE-F-G1-ST uses a 28-pin SSOP package (0.635 mm pitch, 10.2 mm × 5.3 mm body) with exposed thermal pad. Pin assignments are validated per IDT datasheet Figure 6.1 and Table 6.1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar AS-i interface applications.

Compared with ASI4UE-F-G1-ST, ASI4UE-G1-ST lacks -40°C capability but shares identical pinout and firmware; ASI4UE-E-G1-ST offers +105°C operation but mandates PCB layout change due to SOP28 package and altered thermal pad geometry.

Availability

ASI4UE-F-G1-ST is available at Aetrix Electronics and suitable for AS-i slave modules, AS-i master controllers, AS-i safety subsystems, and AS-i bus monitoring equipment requiring stable component supply across extended industrial temperature ranges.

Supply support for ASI4UE-F-G1-ST 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

Integrated Device Technology (IDT), now part of Renesas Electronics, designs high-performance timing, interface, and RF solutions for industrial, communications, and computing markets.

The ASI4U family was developed to replace legacy A²SI ICs in AS-i networks while adding V3.0 compliance, safety mode, and extended addressing - targeting retrofit and new-build industrial automation nodes.

FAQ

What is the guaranteed fault reaction time of ASI4UE-F-G1-ST in Safety Mode?

The ASI4UE-F-G1-ST guarantees ≤10 ms fault reaction time when Safety Mode is enabled via EEPROM configuration. This is achieved by disabling data input filters and synchronous I/O, enforcing a minimal hardware data path. The timing is validated per AS-Interface Safety Profile and documented in Section 1.1 of the datasheet. ASI4UE-F-G1-ST must be configured with safety code sequences containing '1110' and external microcontroller firmware adapted accordingly.

Does ASI4UE-F-G1-ST require an external crystal, and what frequencies are supported?

Yes, ASI4UE-F-G1-ST requires an external crystal connected to OSC1/OSC2 pins. It supports both 8 MHz and 16 MHz fundamental-mode crystals with automatic frequency detection - no configuration register setting needed. Internal load capacitance eliminates external capacitors. Crystal stability and drive level must meet parameters in Table 4.22 of the datasheet to ensure reliable AS-i cycle timing.

Can ASI4UE-F-G1-ST operate without an external coil?

Yes, ASI4UE-F-G1-ST includes an on-chip electronic inductor capable of delivering 55 mA drive current, enabling full AS-i bus operation without an external coil in standard-power applications. For high-power or extended-range deployments, external coils can still be used via the U5R and CAP pins per Figure 3.2 and Figure 3.3 in the datasheet. The internal inductor reduces BOM count and improves thermal consistency.

How is the IRD pin used in ASI4UE-F-G1-ST for wireless setup?

The IRD pin on ASI4UE-F-G1-ST accepts infrared addressing signals for tool-free node commissioning. It operates in AC current mode (for phototransistor-based IR receivers) or CMOS mode (for logic-level IR demodulators), selectable via EEPROM. In master mode, it transmits Manchester-II-coded addressing data; in slave mode, it receives and decodes IR setup commands. Configuration details are in Sections 4.3 and 4.9.2 of the datasheet.

Is ASI4UE-F-G1-ST pin-compatible with the legacy A²SI IC?

Yes, ASI4UE-F-G1-ST is function and pin compatible with IDT's A²SI IC, enabling drop-in replacement in existing board layouts per Section 1.1 of the datasheet. However, safety-critical applications require EEPROM reconfiguration to enable Safety Mode and update the external microcontroller's safety code table to include '1110' sequences. Standard-mode operation introduces up to 40 ms additional fault reaction time versus A²SI.