Renesas UPD78F8040K8(R)-9B4-AX

Overview

UPD78F8040K8(R)-9B4-AX from Renesas Electronics is a 16-bit single-chip microcontroller with integrated IO-Link transceiver interface, 128 KB Flash memory, 8 KB RAM, and operating voltage range of 4.5–5.5 V. It supports IO-Link communication at 38.4 kbaud and features on-chip voltage regulators (VREGO), wake-up detection, and overcurrent protection for industrial sensor node applications.

For engineers reviewing the UPD78F8040K8(R)-9B4-AX datasheet, UPD78F8040K8(R)-9B4-AX pinout, UPD78F8040K8(R)-9B4-AX application, or UPD78F8040K8(R)-9B4-AX equivalent, key selection criteria include IO-Link transceiver integration, dual power domain support (VDD_IO/VDDH), dedicated ILIM/SILIM pins for current threshold control, and compliance with IEC 61131-9 for smart sensors.

Technical Context

This MCU implements the 78K0R CPU core with Harvard architecture, supporting both standard I/O mode and IO-Link mode via configurable port pins (P120–P121, P142–P144). Its internal block includes a dedicated IO-Link physical layer controller with programmable transfer baud rate (38.4 kbaud), wakeup detection circuitry tied to WAKE pin, and overcurrent sensing using ILIM and SILIM analog inputs.

The device uses separate power domains: VDDH (5.0 V ±10%) for high-voltage IO-Link drivers, VDD_IO (3.0–5.5 V) for digital I/O, and internal VREGO (5.0 V) for core logic. Reset is managed by external RESET pin with internal pull-up, and clocking supports crystal (X1/X2, 1–20 MHz) or external EXCLK input.

Key Specifications

Pinout & Package

UPD78F8040K8(R)-9B4-AX is housed in a 100-pin LQFP package (14 mm × 14 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are defined per Renesas User's Manual Rev.3.00 (Sep 2010), including dedicated IO-Link signaling and power domain separation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar IO-Link endpoint microcontroller applications.

Compared with R7F0E01082CFM and STM32G071RBT6, UPD78F8040K8(R)-9B4-AX delivers lower system-level BOM cost and smaller footprint by embedding the IO-Link physical layer, while maintaining deterministic timing and industrial temperature operation - critical for certified sensor endpoints.

Availability

UPD78F8040K8(R)-9B4-AX is available at Aetrix Electronics and suitable for industrial IO-Link sensors, smart field actuators, and condition monitoring nodes requiring stable component supply across extended product lifecycles.

Supply support for UPD78F8040K8(R)-9B4-AX 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

Renesas Electronics Corporation is a Japanese semiconductor manufacturer specializing in microcontrollers, analog, and power devices for industrial, automotive, and infrastructure markets.

The UPD78F8040K8(R)-9B4-AX belongs to the 78K0R family, designed specifically for IO-Link-compliant smart sensor and actuator endpoints requiring integrated physical layer control and industrial-grade reliability.

FAQ

What is the maximum operating frequency of the UPD78F8040K8(R)-9B4-AX CPU core?

The UPD78F8040K8(R)-9B4-AX integrates the 78K0R 16-bit CPU core with a maximum operating frequency of 20 MHz. This frequency is achievable under specified conditions: VDDH = 4.5–5.5 V, ambient temperature −40°C to +85°C, and use of external crystal (X1/X2) or EXCLK input. The core delivers 1.42 DMIPS/MHz, enabling real-time IO-Link frame processing within strict 2-ms cycle windows.

Does the UPD78F8040K8(R)-9B4-AX require an external IO-Link transceiver?

No, the UPD78F8040K8(R)-9B4-AX does not require an external IO-Link transceiver. It integrates a full IO-Link physical layer, including differential CQ driver circuitry (via P120/P121), RXD receiver, and dedicated control pins (ILIM, SILIM, WAKE, REGC). This eliminates the need for discrete transceivers like the MAX14824 or TJA1128, reducing bill-of-materials and PCB space in sensor endpoint designs.

What power supply domains does the UPD78F8040K8(R)-9B4-AX support?

The UPD78F8040K8(R)-9B4-AX supports three distinct power domains: VDDH (4.5–5.5 V) powers the IO-Link driver stage; VDD_IO (3.0–5.5 V) supplies digital I/O ports; and VREGO (5.0 V) is generated internally from VDDH to power the core logic. Separate GND1/GND2/GND3 pins isolate return paths, preventing noise coupling between high-current IO-Link signaling and sensitive digital circuits.

How is overcurrent protection implemented in the UPD78F8040K8(R)-9B4-AX?

Overcurrent protection in the UPD78F8040K8(R)-9B4-AX is implemented via hardware-controlled shutoff using the ILIM and SILIM pins. ILIM selects one of three fixed threshold levels (100 mA, 200 mA, or 400 mA), while SILIM scales the internal current sense amplifier gain. When overcurrent is detected, the IO-Link driver shuts off within <10 µs and asserts an interrupt - no firmware polling or ADC conversion is required for basic protection.

Is the UPD78F8040K8(R)-9B4-AX pin-compatible with other members of the 78F804x family?

Yes, the UPD78F8040K8(R)-9B4-AX is pin-compatible with UPD78F8041, UPD78F8042, and UPD78F8043 in the same 100-pin LQFP package. Differences among these variants relate to memory size (Flash/RAM), peripheral enablement (e.g., number of timers or ADC channels), and IO-Link feature subsets - but pin functions, power domains, and IO-Link interface signals (CQ, RXD, WAKE, ILIM, etc.) remain identical across the family.