Diodes Incorporated PI7C9X1170ACLE

Overview

PI7C9X1170 from Diodes Incorporated is a single-channel I²C-bus/SPI-to-UART bridge controller with 64-byte TX/RX FIFOs, 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 from 1.8V–3.3V, supports baud rates up to 16 Mbps (4× sampling), and integrates eight programmable GPIOs - ideal for embedded industrial gateways interfacing legacy serial peripherals over I²C or SPI buses.

For engineers reviewing the PI7C9X1170 datasheet, PI7C9X1170 pinout, PI7C9X1170 application, or PI7C9X1170 equivalent, key selection considerations include its dual-interface flexibility (I²C or SPI slave), 64-byte FIFO programmability, auto RTS/CTS flow control timing behavior, RS-485 half-duplex driver control via RTS inversion, and compatibility with standard 16C450 software stacks in resource-constrained microcontroller systems.

Technical Context

The PI7C9X1170 implements a fully register-compatible UART core with extended FIFO and flow control logic, supporting both I²C-bus (fast-mode, up to 400 kHz) and SPI (mode 0, slave-only, up to 33 MHz) host interfaces. Its internal clock domain derives from either a 24 MHz crystal (XTAL1/XTAL2) or external 64 MHz clock, enabling precise fractional baud rate generation across 1–16 Mbps.

It features dual interrupt architecture: seven prioritized UART-level interrupts (including Xoff detection, RX timeout, and modem status changes) plus independent GPIO interrupt capability. The device supports automatic RS-485 direction control via RTS signal polarity inversion and built-in IrDA encoder/decoder compliant with SIR physical layer at 115.2 kbps or optional 1.152 Mbps.

Key Specifications

Pinout & Package

PI7C9X1170 is housed in a 24-pin TQFN package (ZD variant) with exposed thermal pad. Pin functions are electrically validated per DS40307 Rev 8-2 and support both I²C and SPI configurations via strapping pin I2C/SPI# (Pin 4).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SC16IS752IPW and MAX3107EAE+T, the PI7C9X1170 uniquely combines dual-interface flexibility (I²C/SPI), integrated RS-485 direction control, and IrDA SIR support - making it optimal for space-constrained, mixed-protocol industrial edge nodes requiring minimal external components.

Availability

PI7C9X1170 is available at Aetrix Electronics and suitable for industrial computing, factory process control, and battery-operated devices requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant green packaging.

Supply support for PI7C9X1170 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 analog, logic, and interface solutions for industrial, computing, and communications markets.

The PI7C9X1170 belongs to Diodes' high-integration UART bridge product line, designed specifically to simplify serial peripheral connectivity in resource-limited embedded systems while maintaining full 16C450 software compatibility.

FAQ

Does PI7C9X1170 support both I²C and SPI simultaneously?

No. The I2C/SPI# pin (Pin 4) is a hardwired interface select: HIGH configures I²C-bus mode (SDA/SCL active), LOW configures SPI mode (SO/SCLK/CS# active). Both interfaces cannot operate concurrently, and pin strapping must be fixed at power-up.

What is the minimum pulse width required on RESET# to ensure proper initialization?

A LOW pulse of at least 40 ns on RESET# is mandatory to reset all internal registers, outputs, and operational mode strapping. This ensures reliable initialization of the UART core, FIFO pointers, and GPIO direction registers per DS40307 Rev 8-2.

Can the GPIO pins be used as interrupt sources independent of UART activity?

Yes. Pins GPIO0–GPIO7 support individual interrupt enable/disable via the IOIntEna register. Each GPIO can generate an interrupt on rising/falling edge (configurable per pin), reported as priority level 5 in the IIR register - fully independent of UART transmit/receive events.

How does the PI7C9X1170 handle baud rate accuracy at high speeds like 16 Mbps?

It uses a 16-bit fractional baud rate generator with divisor range 1–65535, referenced to the crystal or external clock (up to 64 MHz). At 16 Mbps with 4× oversampling, timing error remains within ±0.5% across temperature and voltage ranges, verified in DS40307 electrical characteristics tables.