Infineon Technologies CY7C63221A-PC

Overview

CY7C63221A-PC from Cypress Semiconductor is a low-speed USB peripheral controller with integrated 8-bit RISC microcontroller, internal 6-MHz oscillator, 3 KB EPROM, 96 bytes RAM, and 10 configurable GPIO pins. It supports USB HID v1.1 compliance, auto-configures between USB and PS/2 modes without external components, and delivers 50 mA sink per I/O pin for direct LED or switch interfacing in human interface devices.

For engineers reviewing the CY7C63221A-PC datasheet, CY7C63221A-PC pinout, CY7C63221A-PC application, or CY7C63221A-PC equivalent, this device is selected for embedded USB peripheral designs requiring dual-mode (USB/PS/2) operation, minimal BOM count, internal voltage regulation, and suspend-mode wake-up timer functionality without external timing components.

Technical Context

The CY7C63221A-PC implements a Harvard-architecture 8-bit RISC core running at 12 MHz CPU clock derived from internal or external 6-MHz source. Its USB Serial Interface Engine (SIE) handles low-speed (1.5 Mbps) enumeration, endpoint management (1 control + 1 data), and D+/D– line control with integrated transceiver and 3.3V VREG output for pull-up resistor biasing.

It integrates dual-mode protocol support: automatic detection and configuration between USB and PS/2 protocols without GPIO mode selection or external switches. The device includes a programmable 12-bit free-running timer, watchdog reset, brown-out reset (active at 4.0V), and low-voltage reset at 3.75V - all operating within 4.0–5.5V supply range and 0–70°C ambient.

Key Specifications

Pinout & Package

Package: 16-pin Plastic Dual In-line Package (PDIP), body width 0.300 inch, lead pitch 0.100 inch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-speed USB peripheral controller applications.

Compared with CY7C63231A-PC, the CY7C63221A-PC offers identical functionality in PDIP packaging for through-hole prototyping and legacy manufacturing, while the ISP1301 serves a fundamentally different role - it provides USB PHY only and cannot execute firmware or manage HID endpoints autonomously.

Availability

CY7C63221A-PC is available at Aetrix Electronics and suitable for optical mice, gaming joysticks, dual-mode keyboards, and industrial control panels requiring stable component supply and long-term obsolescence management.

Supply support for CY7C63221A-PC 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) is a fabless semiconductor company specializing in mixed-signal and programmable system-on-chip solutions for USB, memory, and embedded control applications.

The enCoRe™ USB product line was designed specifically for cost-sensitive, low-pin-count human interface devices requiring seamless USB and PS/2 interoperability with minimal external components.

FAQ

Does CY7C63221A-PC support full-speed USB?

No. The CY7C63221A-PC supports low-speed USB only (1.5 Mbps), as defined in USB 2.0 specification Section 7.1. It does not implement full-speed (12 Mbps) or high-speed (480 Mbps) transceivers or protocol layers. Its SIE is optimized for HID-class peripherals where low-speed bandwidth suffices.

Can the internal oscillator be used for both USB and PS/2 timing?

Yes. The internal 6-MHz oscillator provides the base clock for both USB and PS/2 modes. In USB mode, it feeds the SIE's bit-timing logic; in PS/2 mode, it drives the serial data rate generator. No external clock source is required for either protocol.

What is the maximum current rating for GPIO pins in open-drain mode?

Each GPIO pin supports up to 50 mA sink current in open-drain or CMOS output mode, verified under DC characteristics (Table 23.0, VDD = 5.0 V, TA = 25°C). This allows direct driving of LEDs, small relays, or logic-level indicators without external drivers.

Is the 3 KB EPROM field-programmable after soldering?

Yes. The EPROM is programmed via standard industry programmers supporting Cypress's parallel programming interface (documented in Section 25.0). It supports multiple erase/write cycles and retains data for 10 years at 25°C, enabling post-assembly firmware updates during manufacturing test or field calibration.