Renesas X5165S8I

Overview

X5165S8I from Intersil (now Renesas) is a CPU supervisor IC with integrated 16Kbit SPI EEPROM, combining power-on reset control, watchdog timer, supply voltage supervision, and block-lock protected memory in a single 8-lead SOIC package. It provides active-low RESET output, supports 4.5V–5.5V supply, features programmable 4.5V–4.75V VTRIP 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 X5165S8I datasheet, X5165S8I pinout, X5165S8I application, or X5165S8I equivalent, this page delivers verified functional identity, confirmed SOIC-8 pin mapping, exact VTRIP and watchdog timing values, EEPROM endurance (100k cycles), and two validated alternative parts with documented technical and application differences - all derived from FN8128 Rev 4.00 and Renesas product documentation.

Technical Context

The X5165S8I implements a dual-function supervisory architecture: its analog voltage monitor asserts RESET/RESET when VCC drops below the factory-set or user-programmed 4.5V–4.75V trip point, with 200ms timeout release and valid operation down to 1V; simultaneously, its digital watchdog circuit monitors CS/WDI transitions and triggers reset if no HIGH-to-LOW edge occurs within the selected timeout (200ms, 600ms, or 1.4s).

Its SPI EEPROM subsystem operates at up to 2MHz using modes 0,0 and 1,1, supports 32-byte page writes with 5ms typical write cycle time, and integrates Block Lock™ protection enabling selective write-protection of 0%, 25%, 50%, or 100% of the 16Kbit array via nonvolatile status register bits BL0/BL1.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (MDP0027, RoHS-compliant, -40°C to +85°C operating range).

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 STM6806RWDY6F, the X5165S8I uniquely combines field-programmable VTRIP, 16Kbit Block Lock™ EEPROM, and selectable watchdog timeout in one SOIC-8 package - delivering higher integration, greater design flexibility for brownout tuning, and stronger data protection without external components.

Availability

X5165S8I is available at Aetrix Electronics and suitable for industrial automation, medical diagnostics, automotive telematics, and smart metering applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for X5165S8I 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 infrastructure markets.

The X5165S8I belongs to Renesas' CPU Supervisor family, designed to replace discrete reset ICs and EEPROMs in resource-constrained embedded systems - emphasizing reliability, low power, and field-programmable voltage thresholds.

FAQ

What is the exact VTRIP voltage range for X5165S8I?

The X5165S8I has a factory-set VTRIP range of 4.5V to 4.75V, specified per ordering option X5165S8IZ-4.5A. This threshold is reprogrammable using the VP programming sequence described in FN8128 Rev 4.00 Section 5, allowing fine-tuning for application-specific brownout margins. The device guarantees valid RESET assertion down to VCC = 1V.

Does X5165S8I support both active-low and active-high reset outputs?

No - X5165S8I provides only an active-low open-drain RESET/RESET output. The "X5165" designation specifically identifies the active-low variant; the active-high counterpart is the X5163 series. The X5165S8I pin 7 output drives LOW during reset conditions and requires an external pull-up resistor for proper logic level translation.

How is the watchdog timeout period selected on X5165S8I?

The watchdog timeout on X5165S8I is selected via nonvolatile WD0 and WD1 bits in the status register, programmed using the WRSR instruction. Valid combinations yield 200ms (WD1=1, WD0=0), 600ms (WD1=0, WD0=1), or 1.4s (WD1=0, WD0=0); WD1=1, WD0=1 disables the watchdog. These settings persist across power cycles and cannot be altered without explicit WRSR writes.

Can X5165S8I's EEPROM be written to while the watchdog is enabled?

Yes - X5165S8I allows concurrent EEPROM writes and watchdog operation. The watchdog timer monitors CS/WDI transitions independently of SPI memory access. However, during EEPROM write cycles (typical 5ms), the device ignores CS/WDI edges; the watchdog timeout is extended by the write duration unless the host toggles CS/WDI before and after the write sequence.

What package and temperature grade does X5165S8I use?

X5165S8I uses an 8-lead SOIC package (package drawing MDP0027) rated for –40°C to +85°C operation. The "I" suffix in the part number explicitly denotes the industrial temperature grade, and the device is RoHS-compliant with Pb-free plus anneal termination finish compatible with both SnPb and lead-free reflow processes.