Renesas X4163PIZ

Overview

X4163PIZ from Xicor is a CPU supervisor IC integrating power-on reset control, watchdog timer, supply voltage supervision, and 16 Kbit serial EEPROM in a single 8-pin SOIC package. It provides selectable watchdog timeout (200 ms / 600 ms / 1.4 s), low-V_CC reset assertion down to 1 V, and 400 kHz 2-wire interface - used in microcontroller-based embedded systems for reliable boot sequencing and data retention.

For engineers reviewing the X4163PIZ datasheet, X4163PIZ pinout, X4163PIZ application, or X4163PIZ equivalent, key selection criteria include programmable V_TRIP threshold, block-lock EEPROM protection, watchdog restart via SDA edge, and dual active-low/high RESET output behavior under brownout or timeout conditions.

Technical Context

The X4163PIZ implements a dedicated low-voltage detection circuit with four factory-standard reset thresholds (2.63 V, 2.93 V, 3.08 V, 4.65 V) and user-programmable V_TRIP via nonvolatile control sequence using V_P = 12–15 V on WP pin. Its watchdog timer monitors SDA transitions while SCL is HIGH and asserts RESET/RESET if no valid start condition occurs within the selected timeout window.

Internally, it combines a 2K × 8-bit EEPROM array with 64-byte page write capability, self-timed 5 ms typical write cycle, and hardware/software write protection including Block Lock (BP2–BP0), WPEN bit, and volatile WEL/RWEL latches. The device operates across 2.7 V to 5.5 V and draws <1 µA standby current with watchdog disabled.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (JEDEC MS-012), 150 mil width, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6361KA29+T and STM8T142M2U6, the X4163PIZ uniquely combines field-programmable reset threshold, 16 Kbit EEPROM, and watchdog restart via standard I²C start condition - enabling fewer external components, flexible voltage margining, and simplified firmware integration.

Availability

X4163PIZ is available at Aetrix Electronics and suitable for industrial PLC controllers, medical infusion pumps, automotive body control modules, smart energy meters, and battery-backed data loggers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for X4163PIZ 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 Inc. was a fabless semiconductor company specializing in nonvolatile memory and power management ICs, acquired by Intersil in 2001 and later integrated into Renesas Electronics.

The X4163/5 product line was designed to consolidate reset supervision, watchdog protection, and serial EEPROM into a single IC for space-constrained microcontroller systems - targeting reliability-critical applications in industrial, medical, and automotive markets.

FAQ

What is the function of the S0 and S1 pins on the X4163PIZ?

The S0 and S1 pins on the X4163PIZ serve as device-select inputs that configure the two most significant bits (A1, A0) of the 7-bit I²C slave address. This allows up to four X4163PIZ devices to share the same 2-wire bus without address collision. Each combination of S0/S1 logic levels selects a unique base address (1010xx0), enabling independent access to individual EEPROM arrays and supervisor functions in multi-node systems.

How does the X4163PIZ watchdog timer get reset?

The X4163PIZ watchdog timer is reset by a falling edge on the SDA pin while SCL is held HIGH - which corresponds to a standard I²C start condition. This design eliminates the need for a dedicated watchdog strobe signal, leveraging existing bus activity. If no such transition occurs within the selected timeout period (200 ms, 600 ms, or 1.4 s), the device asserts RESET/RESET to force a system reset. The timeout value is set nonvolatily via WD1/WD0 bits in the control register.

Can the reset threshold voltage of the X4163PIZ be changed after soldering?

Yes, the reset threshold voltage (V_TRIP) of the X4163PIZ can be reprogrammed post-assembly using a nonvolatile programming sequence. This requires applying the desired V_TRIP voltage to VCC, 12–15 V to the WP pin, setting the WEL bit, and issuing a specific two-byte write command. The procedure is detailed in the datasheet and enables field calibration or adaptation to varying supply tolerances without hardware changes - a capability not found in most fixed-threshold supervisors.

What EEPROM protection mechanisms does the X4163PIZ provide?

The X4163PIZ provides three layers of EEPROM protection: (1) volatile Write Enable Latch (WEL) that must be set before any write operation; (2) nonvolatile Block Lock bits (BP2–BP0) enabling write protection of 64-byte to full-array segments; and (3) hardware write protect via WP pin + WPEN bit, which disables all writes when both are HIGH. These features prevent accidental or malicious overwrites of critical calibration data, firmware flags, or event logs stored in the 16 Kbit EEPROM array.

Is the X4163PIZ pin-compatible with the X4165PIZ?

No, the X4163PIZ is not pin-compatible with the X4165PIZ. While both share the same 8-pin SOIC package and core functionality, the X4165PIZ features an active-high RESET output (labeled RESET), whereas the X4163PIZ provides an active-low output (labeled RESET/RESET). This difference affects reset polarity handling in the target MCU and requires schematic revision - they are functionally related but not drop-in replacements. Always verify reset signal polarity requirements before substitution.