Renesas X4163P

Overview

X4163P from Xicor (now part of Renesas) is a CPU supervisor IC integrating power-on reset control, selectable watchdog timer, low-voltage detection, and 16 Kbit serial EEPROM in a single 8-lead SOIC package. It provides V_CC monitoring with four standard reset thresholds (adjustable down to 1 V), 400 kHz I²C-compatible 2-wire interface, and block-lock EEPROM write protection - used in embedded microcontroller systems requiring reliable boot sequencing and nonvolatile configuration storage.

For engineers reviewing the X4163P datasheet, X4163P pinout, X4163P application, or X4163P equivalent, key selection considerations include its programmable V_TRIP threshold, 200 ms reset timeout after power-up, 64-byte page write capability, active-low open-drain RESET output, and hardware write protection via WP pin and WPEN bit.

Technical Context

The X4163P implements a dual-function reset architecture: power-on reset (POR) holds RESET/RESET active for ≥200 ms after V_CC exceeds V_TRIP, and brownout detection asserts RESET/RESET when V_CC falls below V_TRIP for >250 ms. Its watchdog timer monitors SDA transitions during SCL HIGH and offers three timeout options (200 ms, 600 ms, 1.4 s) controlled by nonvolatile WD1/WD0 bits.

The integrated 2K × 8-bit EEPROM uses a 400 kHz 2-wire interface with byte and 64-byte page write modes, self-timed 5 ms typical write cycle, and multi-level write protection: volatile WEL/RWEL latches, nonvolatile BP2–BP0 block lock bits, and hardware WP/WPEN control. All nonvolatile register writes require a verified three-step sequence.

Key Specifications

Pinout & Package

Package: 8-lead JEDEC SOIC (3.9 mm × 4.9 mm, 1.27 mm pitch). Pinout validated per Xicor X4163/5 Rev 1.32 datasheet, Figure "PIN CONFIGURATION".

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar CPU supervisor with EEPROM applications.

Compared with MAX6361KA29+T and STM8T142M2U6, the X4163P uniquely combines field-programmable V_TRIP, three watchdog timeout options, and 16 Kbit EEPROM in an 8-pin SOIC - delivering higher functional density and design flexibility for cost-sensitive, space-constrained embedded systems.

Availability

X4163P is available at Aetrix Electronics and suitable for industrial PLC controllers, medical infusion pumps, automotive body control modules, smart energy meters, and battery-backed IoT gateways requiring stable component supply across extended product lifecycles.

Supply support for X4163P 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

Xicor was a fabless semiconductor company specializing in nonvolatile memory and power management ICs, acquired by Renesas Electronics in 2008. Known for high-reliability EEPROM and supervisor solutions.

The X4163P belongs to Xicor's CPU Supervisor with EEPROM family, designed to reduce system complexity in microcontroller-based applications by consolidating reset, watchdog, voltage monitoring, and configuration storage into one IC.

FAQ

What is the default V_TRIP threshold voltage for the X4163P?

The X4163P ships with one of four standard factory-set V_TRIP thresholds: 2.63 V, 2.93 V, 3.08 V, or 4.65 V. The exact value depends on the specific ordering option and is marked on the device top-side marking. This threshold is nonvolatile and remains stable over temperature and time unless explicitly reprogrammed using the VP pulse sequence on the WP pin.

Can the X4163P watchdog timer be disabled after power-up?

Yes, the X4163P watchdog timer can be disabled after power-up by setting WD1 and WD0 bits to '11' in the Control Register (address FFFFh). This requires executing the three-step write sequence (02h → 06h → 0Ch) with proper WEL and RWEL latching. Once disabled, the watchdog remains off until explicitly re-enabled or the device is power-cycled.

How does the X4163P handle EEPROM writes during a brownout event?

The X4163P guarantees completion of in-progress EEPROM writes even if RESET/RESET activates due to brownout. While RESET/RESET is asserted, new writes are blocked, but ongoing self-timed write cycles (typical 5 ms) continue to completion. This ensures atomic updates to critical parameters like calibration data or fault logs without corruption.

What is the function of the S0 and S1 pins on the X4163P?

The S0 and S1 pins on the X4163P configure the two most significant bits (A1, A0) of the I²C slave address, enabling up to four X4163P devices on the same 2-wire bus. S0 connects to A0 and S1 to A1; both are sampled at power-up and remain static during operation. Pulling them HIGH/LOW sets the device address to 0x50–0x53 range.

Does the X4163P support standard I²C protocol or a proprietary interface?

The X4163P implements a standard 400 kHz Fast-mode I²C-compatible 2-wire interface with START/STOP conditions, ACK/NACK signaling, and 7-bit slave addressing. It follows I²C electrical specifications including open-drain SDA/SCL, required pull-up resistors, and timing compliance - allowing direct interoperability with any standard I²C master controller without protocol translation.