Infineon Technologies CY8C9520A-24PVXI

Overview

CY8C9520A-24PVXI from Cypress Semiconductor is a 20-bit I²C-compatible I/O expander with integrated 3-Kbyte EEPROM, 4 independently configurable 8-bit PWM channels, and interrupt-driven input change detection. It operates as dual I²C slave devices (I/O expander + EEPROM), supports extendable soft addressing (up to 128 devices on one bus), and restores user-defined port/PWM defaults from EEPROM at power-on. Used in embedded control panels for LED dimming, sensor interface consolidation, and board-level status monitoring.

For engineers reviewing the CY8C9520A-24PVXI datasheet, CY8C9520A-24PVXI pinout, CY8C9520A-24PVXI application, or CY8C9520A-24PVXI equivalent, key selection criteria include I²C clock-stretching support, WD pin-controlled EEPROM write disable, per-pin drive mode configurability (strong drive, open-drain, pull-up/down, high-Z), and register-mapped PWM period/pulse-width control.

Technical Context

The device implements two independent I²C slave interfaces: one for multi-port I/O register access (7-bit address 0x40–0x4F or 0xA0–0xAF) and another for serial EEPROM access (7-bit address 0x50–0x5F). All 20 I/O pins are individually assignable across GPort0 (8-bit), GPort1 (5-bit), and GPort2 (up to 4-bit, shared with A1–A6 address pins and WD).

Four 8-bit PWM generators (PWM0–PWM3) each support six selectable clock sources (1.5 MHz, 93.75 kHz, 32 kHz, 24 MHz, or divided variants), with dedicated Period (2Ah), Pulse Width (2Bh), Divider (2Ch), and Enable (2Dh) registers. The INT pin asserts on input level transitions or PWM state changes, masked per-pin via Interrupt Mask Register (19h).

Key Specifications

Pinout & Package

Package: 28-pin SSOP (Small Outline Package), body width 5.3 mm, lead pitch 0.65 mm, JEDEC MS-012AC compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I/O expansion with integrated PWM and EEPROM applications.

Compared with PCA9698DP,118 and MCP23017-E/SP, CY8C9520A-24PVXI uniquely integrates EEPROM-based default restoration, 4-channel PWM, and extendable addressing-enabling self-contained, low-software-overhead I/O management in space-constrained embedded systems.

Availability

CY8C9520A-24PVXI is available at Aetrix Electronics and suitable for industrial HMI panels, medical device front-ends, and automotive diagnostic tools requiring stable component supply, long-lifecycle support, and guaranteed EEPROM data retention over 100k write cycles.

Supply support for CY8C9520A-24PVXI 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

Cypress Semiconductor (now part of Infineon Technologies) designs programmable system-on-chip solutions for embedded control, connectivity, and sensing applications with focus on reliability and integration.

CY8C95xxA belongs to Cypress's I/O expansion product line, engineered to reduce microcontroller GPIO constraints in resource-limited systems while providing nonvolatile configuration, interrupt efficiency, and flexible timing control.

FAQ

Does CY8C9520A-24PVXI support standard I²C masters without clock stretching?

No. The device requires I²C masters capable of clock stretching because internal EEPROM write operations and register updates suspend SCL until completion. Masters that time out or ignore clock stretch will fail communication. Confirm master compatibility using the "Clock Stretching" section in Rev. *I datasheet page 19.

How is the 3-Kbyte EEPROM organized and accessed?

The EEPROM is byte-addressable using 2-byte addressing (AHI/ALO), supporting up to 3072 bytes. It is split into user-accessible storage and a dedicated "user defaults" section. Access occurs via separate I²C slave address (0x50–0x5F); reads/writes follow standard I²C sequential protocols with automatic address increment.

Can unused address pins (A1–A6) be repurposed as GPIO?

Yes. When Extendable Soft Addressing is configured to use fewer than six address bits, the unassigned A1–A6 pins function as general-purpose I/O on GPort2. Their role is determined at power-up by the state of A0 and configuration registers, not by hardware strapping alone.

What happens to I/O states during power-on reset if no user defaults are stored?

Factory defaults apply: all pins initialize as pulled-up inputs. User defaults stored in EEPROM override this behavior only if the Store Config to E2 POR Defaults command (01h) has been executed and the EEPROM write-enable condition (WD pin low + config register enabled) is satisfied prior to reset.