Diodes Incorporated PI7C9X762CZHEX

Overview

PI7C9X762CZHEX from Diodes Incorporated is a dual-channel I²C-bus/SPI-to-UART bridge controller with 64-byte TX/RX FIFOs per channel, backward-compatible register mapping to the 16C450 UART, and support for hardware/software flow control, RS-485 direction control, and IrDA SIR up to 1.152 Mbps. It operates across 1.8V/2.5V/3.3V supply rails and targets embedded industrial communication interfaces.

For engineers reviewing the PI7C9X762CZHEX datasheet, PI7C9X762CZHEX pinout, PI7C9X762CZHEX application, or PI7C9X762CZHEX equivalent, key selection criteria include dual UART channel independence, programmable FIFO trigger levels, SPI clock speed up to 33 Mbps, and GPIO-assisted RS-485 driver control - all in a 32-pin TQFN package with industrial temperature range (–40°C to +85°C).

Technical Context

The PI7C9X762CZHEX implements two independent UART channels (A and B), each with fully programmable framing (5–8 bit, parity, 1/1.5/2 stop bits), fractional baud rate generation, and local loopback mode. Its register set mirrors the industry-standard 16C450, enabling drop-in firmware compatibility while adding enhanced features like automatic RTS/CTS handshaking and Xon/Xoff character detection.

It supports dual interface modes: I²C-bus slave (fast-mode, up to 400 kHz) and SPI slave (mode 0, up to 33 MHz). Clock sources include internal crystal oscillator (up to 24 MHz) or external clock (up to 64 MHz), and the device integrates eight user-programmable GPIO pins with dual-function modem signal assignments (e.g., GPIO0/DSRB, GPIO5/DTRA).

Key Specifications

Pinout & Package

Package: 32-pin TQFN (ZH), 5 mm × 5 mm, exposed thermal pad (VSS-connected center pad required for thermal and electrical performance).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel UART bridge applications.

Compared with SC16IS752IPW and MAX3109ETJ+, the PI7C9X762CZHEX uniquely combines dual-interface flexibility (I²C/SPI), RS-485 direction control via RTS, and 8 GPIOs with 16C450 register compatibility - making it optimal for industrial designs requiring firmware portability and mixed-protocol connectivity.

Availability

PI7C9X762CZHEX is available at Aetrix Electronics and suitable for industrial automation gateways, embedded RS-485 sensor hubs, and mobile point-of-sale terminals requiring stable component supply and long-term lifecycle assurance.

Supply support for PI7C9X762CZHEX 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and integrated circuits, specializing in high-performance, energy-efficient solutions for industrial, computing, and communications markets.

The PI7C9X762 belongs to Diodes' high-integration UART bridge product line, designed specifically for protocol translation between modern host interfaces (I²C/SPI) and legacy serial peripherals (RS-232/RS-485/RS-422/IrDA) in space- and power-constrained embedded systems.

FAQ

Does PI7C9X762CZHEX support both I²C and SPI simultaneously?

No - the I2C/SPI pin selects one active interface mode at power-up: HIGH configures I²C-bus slave mode; LOW configures SPI slave mode. The device cannot operate both protocols concurrently, and pin function mapping (e.g., SDA vs. SI/SO) changes accordingly. This single-mode selection simplifies PCB routing and avoids bus contention.

How does RS-485 driver direction control work on PI7C9X762CZHEX?

RS-485 direction control is implemented using the RTSA or RTSB output pins, which can be configured to drive the DE/RE lines of an external RS-485 transceiver. The device supports polarity inversion of RTS via register bit, allowing direct connection to transceivers requiring active-HIGH or active-LOW enable. No external logic gates are needed.

What is the maximum UART baud rate achievable with PI7C9X762CZHEX?

The maximum UART baud rate is 16 Mbps when using 4× oversampling mode. This requires a minimum clock input of 64 MHz (e.g., external clock on XTAL1). With internal crystal oscillator (max 24 MHz), the practical upper limit is ~6 Mbps. Baud rate divisor is programmable down to 1, supporting precise fractional rates for non-standard serial links.

Can GPIO pins be used independently of modem functions?

Yes - all eight GPIO pins (GPIO0–GPIO7) are fully programmable as general-purpose digital I/Os. Their alternate modem functions (e.g., DSR, DTR, CD, RI) are enabled only when corresponding bits in the GPIO Control Register are set. In default configuration, they operate as bidirectional CMOS I/Os with internal pull-ups disabled and configurable drive strength.