Diodes Incorporated PI7C9X760CZDEX

Overview

PI7C9X760CZDEX from Diodes Incorporated is a single-channel I²C-bus/SPI-to-UART bridge controller with 64-byte TX/RX FIFOs, 16C450 register compatibility, hardware/software flow control, and RS-485/RS-232 protocol support. It operates at 1.8V/2.5V/3.3V, supports up to 33 Mbps SPI clock, and integrates eight programmable GPIOs for embedded serial interface bridging in space-constrained industrial systems.

For engineers reviewing the PI7C9X760CZDEX datasheet, PI7C9X760CZDEX pinout, PI7C9X760CZDEX application, or PI7C9X760CZDEX equivalent, key selection criteria include UART register compatibility, dual-interface (I²C/SPI) flexibility, FIFO trigger programmability, IrDA SIR support up to 1.152 Mbps, and RS-485 auto-direction control via RTS - all validated in Diodes' DS40305 Rev 8-2.

Technical Context

The PI7C9X760CZDEX implements a fully bidirectional protocol converter between I²C-bus (fast-mode, up to 400 kHz) or SPI (mode 0, slave-only, up to 33 MHz) and UART serial interfaces. Its register map is backward-compatible with the industry-standard 16C450, enabling drop-in firmware reuse while adding enhanced features like fractional baud rate generation and independent RX/TX FIFO trigger level programming via TLR and FCR registers.

It supports automatic RS-485 half-duplex driver direction control using RTS polarity inversion, built-in IrDA encoder/decoder for SIR-compliant infrared communication, and dual Xon/Xoff software flow control with configurable character matching logic. Hardware reset, power-on reset, and software-initiated UART reset are functionally identical and restore all internal registers except DLL/DLH/XON1/XON2/XOFF1/XOFF2.

Key Specifications

Pinout & Package

PI7C9X760CZDEX uses a 24-pin TQFN (ZD) package with an exposed center thermal pad that must be soldered to PCB ground for thermal and electrical integrity. Pin numbering follows standard QFN convention with pin 1 at top-left corner adjacent to index marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SC16IS752IPW and MAX3107EEG+, the PI7C9X760CZDEX uniquely combines dual-interface selection (I²C/SPI), RS-485 auto-direction, IrDA SIR, and eight GPIOs - making it optimal for compact, multi-protocol embedded gateways where board space and interface agility are critical.

Availability

PI7C9X760CZDEX is available at Aetrix Electronics and suitable for industrial computing, factory process control, and battery-operated handheld devices requiring stable component supply across extended temperature ranges (−40°C to +85°C).

Supply support for PI7C9X760CZDEX 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 semiconductor company specializing in discrete, analog, and mixed-signal solutions for industrial, computing, and consumer markets, with manufacturing certified to IATF 16949 and quality standards aligned with AEC-Q200.

The PI7C9X760 belongs to Diodes' high-performance interface bridge product line, designed specifically for low-latency, low-power protocol translation between embedded processors and legacy serial peripherals in space-constrained environments.

FAQ

What voltage levels does the PI7C9X760CZDEX support, and how does it handle level translation?

The PI7C9X760CZDEX operates natively at 1.8 V, 2.5 V, or 3.3 V - selectable via VDD supply only; no external level shifters are needed for I²C or SPI interface logic. Its GPIOs and UART pins are CMOS-compatible at the chosen VDD, and internal pull-up resistors on IRQ scale with VDD (1 kΩ at 3.3 V, 1.5 kΩ at 2.5 V). The device does not perform voltage translation between interfaces - all digital I/O must share the same VDD domain.

How is RS-485 driver direction controlled, and what configuration registers are involved?

RS-485 direction control is managed automatically via the RTS pin, enabled by setting EFR[3] = 1 (RTS inversion) and configuring the Enhanced Feature Register (EFR) and Transmission Control Register (TCR). When enabled, RTS asserts low to enable the driver during transmission and de-asserts to enable the receiver - eliminating external direction-control logic. The TCR defines halt/resume FIFO levels that trigger RTS state changes, ensuring precise timing alignment with data flow.

Does the PI7C9X760CZDEX support simultaneous I²C and SPI operation, and how is interface selection enforced?

No - the PI7C9X760CZDEX supports only one serial host interface at a time. Interface selection is hardwired at power-up via the I2C/SPI pin: HIGH selects I²C mode (activating SDA/SCL, disabling SI/SO/SCLK/CS), LOW selects SPI mode (activating SI/SO/SCLK/CS, requiring SDA to be tied to VSS). This strapping occurs during reset and cannot be changed dynamically; switching interfaces requires hardware reconfiguration or device reset with updated pin state.

What is the functional difference between the two Xon/Xoff character sets, and how are they applied in software flow control?

Xon1/Xoff1 and Xon2/Xoff2 are independently programmable 8-bit characters stored in dedicated registers. Their usage depends on EFR[3:0] configuration: software flow control can be set to compare only Xon1/Xoff1, only Xon2/Xoff2, or both sequentially (e.g., Xoff1 followed by Xoff2 to halt). Transmit flow sends Xon/Xoff characters using the same UART formatting (data bits, parity, stop bits) as regular data - preserving protocol consistency without requiring special encoding logic in host firmware.