Renesas X5165S8Z-4.5A

Overview

X5165S8Z-4.5A from Intersil (now Renesas) is a CPU supervisor IC integrating power-on reset control, watchdog timer, supply voltage supervision, and 16Kbit SPI EEPROM in an 8-lead SOIC package. It asserts active-low RESET at VCC ≥ 1V, provides selectable watchdog timeout (200/600 ms/1.4 s), supports 4.5–5.5V operation with factory-set 4.5–4.75V reset threshold, and delivers <50µA standby current with watchdog enabled - used in industrial microcontroller systems requiring reliable brownout protection and nonvolatile configuration storage.

For engineers reviewing the X5165S8Z-4.5A datasheet, X5165S8Z-4.5A pinout, X5165S8Z-4.5A application, or X5165S8Z-4.5A equivalent, this page delivers verified technical context, exact pin functions, real-world use cases, and validated alternative parts - all grounded in FN8128 Rev 4.00 and Renesas product documentation.

Technical Context

The X5165S8Z-4.5A implements a dual-function CS/WDI pin for chip select and watchdog input, with internal power-on reset generation active down to 1V and 200ms timeout after VCC stabilization. Its low-voltage detection circuit uses a precision comparator with 20mV hysteresis and factory-trimmed 4.5V nominal trip point, reprogrammable via VP-based sequence to ±25mV accuracy.

EEPROM functionality includes 16Kbit (2K × 8) array with Block Lock™ protection (0/¼/½/all), 32-byte page write mode, 5ms typical write cycle, and SPI interface compliant with modes 0,0 and 1,1 at up to 2MHz. The Status Register contains volatile WIP and flag bits plus nonvolatile WD0/WD1, BL0/BL1, and WPEN bits accessible via RDSR/WRSR instructions.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (RoHS-compliant, MDP0027 drawing).

Key Features

Applications

Equivalent & Alternatives

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

Compared with X5165S8Z-4.5A, MAX6369KA26+T offers identical EEPROM size and supply range but lacks VTRIP programmability, while STM6805RWY6F trades EEPROM integration for lower power and fixed watchdog - making X5165S8Z-4.5A optimal for designs needing field-tunable reset thresholds and self-contained nonvolatile storage.

Availability

X5165S8Z-4.5A is available at Aetrix Electronics and suitable for industrial PLC modules, medical infusion pumps, and telecom management cards requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for X5165S8Z-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

Renesas Electronics (formerly Intersil) is a global semiconductor leader specializing in microcontrollers, analog, power management, and timing solutions for industrial, automotive, and communications markets.

The X5165S8Z-4.5A belongs to Renesas' CPU Supervisor family designed for embedded systems requiring coordinated power sequencing, fault detection, and persistent configuration storage - targeting applications where reliability, compactness, and field adaptability are critical.

FAQ

What is the factory-set VTRIP range for X5165S8Z-4.5A?

The X5165S8Z-4.5A has a factory-programmed VTRIP range of 4.5V to 4.75V, optimized for 5V systems with ±5% supply tolerance. This threshold is stored in nonvolatile circuitry and remains stable over temperature and time unless reprogrammed using the VP-based sequence defined in FN8128 Rev 4.00. The hysteresis is 20mV to prevent chatter near the trip point.

Can the watchdog timeout period of X5165S8Z-4.5A be changed after power-up?

Yes, the watchdog timeout period of X5165S8Z-4.5A can be changed after power-up by writing to the nonvolatile WD0 and WD1 bits in the Status Register using the WRSR instruction. Once written, the new timeout (200ms, 600ms, or 1.4s) persists across power cycles - no reconfiguration is needed on each boot. The watchdog remains disabled only if WD1=WD0=1.

Does X5165S8Z-4.5A support both active-low and active-high reset outputs?

No, X5165S8Z-4.5A provides only an active-low RESET/RESET output (open-drain). The part number suffix "X5165" denotes active-low reset; the "X5163" variant provides active-high. This device does not support software-selectable polarity - the output state is fixed by silicon design and cannot be inverted via register setting or pin configuration.

How is EEPROM write protection implemented in X5165S8Z-4.5A?

X5165S8Z-4.5A implements EEPROM write protection through three independent mechanisms: (1) hardware WP pin combined with nonvolatile WPEN bit for Status Register lock, (2) Block Lock™ bits (BL0/BL1) enabling 0/¼/½/all array protection, and (3) Write Enable Latch (WEL) requiring WREN instruction before any write. All protections remain active after power cycling unless explicitly disabled via WRSR.

What is the minimum VCC required for X5165S8Z-4.5A to assert RESET/RESET?

X5165S8Z-4.5A asserts RESET/RESET as soon as VCC reaches 1V and maintains it until VCC rises above the VTRIP threshold (4.5–4.75V) for 200ms. This 1V activation ensures fail-safe behavior during slow power ramps or deep brownouts - critical for preventing illegal opcode execution in microcontrollers that may become unstable below 2V.