Renesas X5328PI

Overview

X5328PI from Renesas Electronics is a CPU supervisor IC integrating power-on reset control, supply voltage supervision, and 32Kbit SPI EEPROM memory in an 8-lead SOIC package. It asserts an active-low RESET signal during power-up (≥200ms) and under low-VCC conditions (down to 1V), while supporting reprogrammable VTRIP thresholds (e.g., 2.55–2.7V or 2.85–3.0V) and 2MHz SPI communication with 32-byte page writes.

For engineers reviewing the X5328PI datasheet, X5328PI pinout, X5328PI application, or X5328PI equivalent, this device serves as a system-level power integrity and nonvolatile configuration storage solution for microcontroller-based embedded systems requiring deterministic reset timing, brownout protection, and field-programmable EEPROM with block-lock security.

Technical Context

The X5328PI implements dual-function supervision: a precision low-VCC detector with five factory-set trip points (configurable via external VP programming pulses on SCK/SI) and a power-on reset generator that activates at ~1V and holds RESET/RESET active for 100–280ms until VCC stabilizes above VTRIP. Its internal timing base ensures consistent tPURST across temperature.

Its SPI EEPROM subsystem uses a CMOS serial interface compliant with modes 0,0 and 1,1, supports MSB-first data transfer, includes a volatile Write Enable Latch (WEL), and features Block Lock™ protection controlled by nonvolatile BL0/BL1 bits-enabling selective write-protection of 0%, 25%, 50%, or 100% of the 4KB memory array.

Key Specifications

Pinout & Package

Package: 8-lead narrow-body SOIC (M8.15E), RoHS-compliant, Pb-free plus anneal.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6369KA+T and STM8AF6266TCX, the X5328PI uniquely combines field-reprogrammable VTRIP, 32Kbit EEPROM with Block Lock™, and guaranteed sub-1V reset validity - making it optimal for applications demanding both configurability and certification-grade reliability without MCU overhead.

Availability

X5328PI is available at Aetrix Electronics and suitable for industrial automation, medical diagnostics, automotive body electronics, and smart metering applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for X5328PI 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 is a global semiconductor leader delivering microcontrollers, analog, power, and SoC solutions for automotive, industrial, infrastructure, and IoT markets.

The X5328PI belongs to Renesas' CPU Supervisor with Integrated EEPROM product line, designed specifically to consolidate power monitoring, reset generation, and secure nonvolatile storage into a single chip for space-constrained, safety-aware embedded systems.

FAQ

What is the function of the WP pin on the X5328PI?

The WP (Write Protect) pin on the X5328PI works in conjunction with the nonvolatile WPEN bit in the Status Register to enable In-Circuit Programmable ROM mode. When WP is held LOW and WPEN = 1, all nonvolatile writes to the Status Register-including Block Lock bits-are disabled. This prevents accidental corruption of protection settings during field operation while allowing full functionality when WP is HIGH. The X5328PI thus supports secure manufacturing programming followed by permanent lockdown.

Does the X5328PI support multiple VTRIP voltage options?

Yes, the X5328PI offers four factory-configured VTRIP ranges: 2.55–2.7V, 2.85–3.0V, 4.25–4.5V, and 4.5–4.75V. Crucially, its VTRIP threshold is also reprogrammable in-system using a defined VP pulse sequence applied to SCK and SI pins-allowing fine-tuning for application-specific accuracy or adjustment after board-level validation. This capability is documented in the FN8132 datasheet Sections 4 and 16.

How does the X5328PI ensure reliable reset assertion during power-up?

The X5328PI asserts RESET/RESET active at approximately 1V during power-up and holds it for a minimum of 100ms (typ. 200ms, max. 280ms) after VCC rises above the selected VTRIP level. This tPURST timing is internally generated and temperature-compensated, guaranteeing sufficient delay for power supply and oscillator stabilization before the host microcontroller begins code execution. The X5328PI's design ensures deterministic behavior independent of external RC networks.

What EEPROM protection mechanisms does the X5328PI provide?

The X5328PI implements three layered EEPROM protections: (1) Power-up/power-down write inhibit circuitry that clears the Write Enable Latch (WEL) automatically; (2) Block Lock™ bits (BL0/BL1) that nonvolatily protect 0%, 25%, 50%, or 100% of the 4KB array from writes; and (3) In-Circuit Programmable ROM mode, activated by WP + WPEN, which locks Status Register writes entirely. These features collectively prevent inadvertent or malicious EEPROM modification in the X5328PI.

Is the X5328PI pin-compatible with other members of the X5328/X5329 family?

Yes, all X5328 and X5329 variants-including X5328PI-share identical 8-lead SOIC pinouts, electrical characteristics, and functional architecture. The primary differences lie in VTRIP voltage range (e.g., -2.7 vs. -4.5 suffixes) and reset polarity (X5328 = active-low RESET, X5329 = active-high RESET/RESET). Therefore, X5328PI can be substituted for any X5328 variant with matching VTRIP and temperature grade without PCB changes, provided reset polarity requirements are verified.