Renesas X4163PZ

Overview

X4163PZ from Xicor (now Renesas) is a CPU supervisor IC integrating power-on reset control, watchdog timer, supply voltage supervision, and 16K-bit serial EEPROM in a single 8-lead SOIC package. It provides active-low reset assertion down to V_CC = 1V, selectable watchdog timeout (200 ms / 600 ms / 1.4 s), and 400 kHz 2-wire interface - used in microcontroller-based embedded systems for reliable boot sequencing and data retention.

For engineers reviewing the X4163PZ datasheet, X4163PZ pinout, X4163PZ application, or X4163PZ equivalent, key selection criteria include its programmable V_TRIP threshold, block-lock EEPROM protection, low-power standby current (<20 µA with watchdog enabled), and compatibility with I²C-compatible 2-wire bus timing.

Technical Context

The X4163PZ implements a dual-function reset architecture: power-on reset with 250 ms timeout and brownout detection with hysteresis, asserting RESET/RESET until V_CC exceeds V_TRIP for 200 ms. Its watchdog timer monitors SDA transitions during SCL HIGH and supports three fixed timeout intervals via nonvolatile WD1/WD0 bits.

EEPROM operation uses 64-byte page writes with self-timed 5 ms typical write cycles; write protection combines volatile WEL/RWEL latches, nonvolatile BP2–BP0 block lock bits, and hardware WP pin + WPEN bit control. The device operates across 2.7V–5.5V and maintains full functionality down to V_CC = 1V during reset assertion.

Key Specifications

Pinout & Package

Package: 8-lead JEDEC SOIC (3.9 mm × 4.9 mm, 1.27 mm pitch).

Key Features

Applications

Equivalent & Alternatives

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

Compared with X4163PZ, MAX6361KA29+T offers lower power but sacrifices programmability and memory capacity, while STM8T142M2U6 trades simplicity and analog integration for design flexibility and firmware control - neither provides identical drop-in replacement capability.

Availability

X4163PZ is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic devices, automotive body control modules, smart energy meters, and embedded telemetry gateways requiring stable component supply across extended product lifecycles.

Supply support for X4163PZ 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. Its legacy products emphasize reliability and integration for embedded control.

The X4163PZ belongs to Xicor's CPU Supervisor + EEPROM family, designed to reduce board space and system cost in microcontroller-based applications where robust power sequencing, data retention, and fail-safe recovery are critical.

FAQ

What is the function of the WP pin on the X4163PZ?

The WP (Write Protect) pin on the X4163PZ enables hardware-level EEPROM write protection when held HIGH and the WPEN bit is set in the control register. In this state, no writes - including to block lock bits or the control register - are permitted, even if WEL and RWEL latches are set. This prevents unauthorized or accidental modification of critical firmware or calibration data during field operation or service.

Can the X4163PZ reset threshold voltage be customized, and how?

Yes, the X4163PZ V_TRIP threshold can be reprogrammed to a custom voltage using a high-voltage pulse (12–15 V) applied to the WP pin while holding V_CC at the desired trip level. The procedure requires setting the WEL bit, issuing a specific two-byte write command (A0h followed by 00h), and then pulling WP LOW to complete programming. This allows precise alignment with system-specific brownout margins without external components.

How does the watchdog timer in the X4163PZ get reset?

The X4163PZ watchdog timer resets on detection of a HIGH-to-LOW transition on the SDA pin while SCL is HIGH - i.e., a standard I²C start condition. This design eliminates the need for a dedicated watchdog input pin and leverages existing bus activity as proof of MCU liveness. If no such transition occurs within the selected timeout interval (200 ms / 600 ms / 1.4 s), RESET/RESET is asserted to force system recovery.

What EEPROM write protection mechanisms does the X4163PZ provide?

The X4163PZ implements three layered EEPROM write protections: (1) volatile WEL/RWEL latches that must be set before any control register change; (2) nonvolatile BP2–BP0 bits enabling selective lock of 64-byte to full-array memory segments; and (3) hardware WP pin + WPEN bit combination that permanently disables all writes when both are HIGH. These operate concurrently to prevent corruption during power loss, ESD, or software faults.

Is the X4163PZ compatible with standard I²C timing specifications?

Yes, the X4163PZ is fully compatible with standard I²C Fast-mode (400 kHz) timing, supporting START/STOP conditions, ACK/NACK handshaking, and 7-bit slave addressing with device-select inputs S0/S1. It responds to slave addresses beginning with '1010' and supports byte writes, page writes (64 bytes), current-address reads, random reads, and sequential reads - all conforming to I²C protocol semantics without requiring special host-side modifications.