Renesas X4163PZ-4.5A

Overview

X4163PZ-4.5A from Xicor (now Renesas) is a CPU supervisor IC integrating power-on reset control, selectable watchdog timer, low-V_CC voltage monitoring, and 16 Kbit serial EEPROM in a single 8-pin SOIC package. It asserts an active-low RESET signal during power-up, brownout (down to V_CC = 1 V), or watchdog timeout; supports 400 kHz I²C interface; and operates from 2.7 V to 5.5 V - used in embedded microcontroller systems requiring reliable boot sequencing and nonvolatile configuration storage.

For engineers reviewing the X4163PZ-4.5A datasheet, X4163PZ-4.5A pinout, X4163PZ-4.5A application, or X4163PZ-4.5A equivalent, key selection criteria include its programmable V_TRIP threshold (factory-set to 4.5 V), 200 ms reset timeout, 64-byte page write capability, and hardware write protection via WP pin and Block Lock bits.

Technical Context

The X4163PZ-4.5A implements a dual-function reset architecture: power-on reset with 250 ms delay and low-V_CC detection with hysteresis, both driving the same open-drain RESET output. 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.

EEPROM functionality uses a 2-wire I²C-compatible interface with slave address 0xA0–0xA7 (determined by S0/S1 pins), supports byte and 64-byte page writes with self-timed 5 ms typical write cycle, and includes write protection via volatile WEL/RWEL latches and nonvolatile BP2–BP0 block lock bits.

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-4.5A, MAX6361KA29+T trades V_TRIP flexibility and EEPROM capacity for lower cost in simple 3 V systems, while STM8T142M2U6 replaces passive supervision with active firmware-controlled safety logic - making X4163PZ-4.5A optimal for cost-sensitive, fixed-function designs needing field-adjustable reset thresholds and robust 16 Kbit storage.

Availability

X4163PZ-4.5A is available at Aetrix Electronics and suitable for industrial PLC controllers, medical infusion pumps, smart energy meters, automotive body control modules, and battery-backed IoT gateways requiring stable component supply and long-term lifecycle support.

Supply support for X4163PZ-4.5A 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 Intersil in 2001 and later integrated into Renesas Electronics.

The X4163/5 product line was designed to consolidate reset, watchdog, voltage monitoring, and EEPROM functions into a single chip for space-constrained microcontroller systems - reducing board area and improving system reliability over discrete solutions.

FAQ

What is the factory-set V_TRIP threshold for the X4163PZ-4.5A?

The X4163PZ-4.5A is shipped with a factory-programmed V_TRIP threshold of 4.5 V ±100 mV. This value is laser-trimmed during production and remains stable over temperature and time unless reprogrammed using the VP pulse method on the WP pin. The part number suffix "-4.5A" explicitly denotes this 4.5 V nominal trip point.

Does the X4163PZ-4.5A support I²C multi-master bus configurations?

Yes, the X4163PZ-4.5A supports standard I²C multi-master operation because its SDA and SCL pins implement open-drain outputs with built-in arbitration logic. It responds only to its assigned slave address (0xA0–0xA7, determined by S0/S1 pins) and follows I²C protocol rules for START/STOP, ACK/NACK, and clock stretching - enabling coexistence with other I²C peripherals on the same bus.

How does the watchdog timer in the X4163PZ-4.5A get reset?

The X4163PZ-4.5A watchdog timer is reset by a HIGH-to-LOW transition on the SDA pin while SCL is held HIGH - matching the I²C START condition. This design allows the host MCU to service the watchdog using standard I²C bus activity without dedicated GPIO lines. If no such transition occurs within the selected timeout period (200 ms, 600 ms, or 1.4 s), the device asserts RESET/RESET.

Can the EEPROM in the X4163PZ-4.5A be written while the RESET output is active?

No. While RESET/RESET is active - whether due to power-up, brownout, or watchdog timeout - the X4163PZ-4.5A disables all serial communication and blocks new EEPROM write operations. In-progress writes are allowed to complete, but no new commands are accepted until RESET/RESET is deasserted and V_CC stabilizes above V_TRIP for 200 ms, ensuring data integrity during supply faults.

What package type is used for the X4163PZ-4.5A?

The X4163PZ-4.5A is supplied in an 8-lead JEDEC-standard SOIC package (3.9 mm × 4.9 mm body, 1.27 mm lead pitch). This surface-mount package is RoHS-compliant, reflow-solderable, and pin-compatible with other members of the X4163/5 family - enabling drop-in replacement where footprint and thermal requirements match.