Diodes Incorporated PI7C9X1170CZDE

Overview

PI7C9X1170CZDE from Diodes Incorporated is a single-channel I²C-bus/SPI-to-UART bridge controller with 64-byte TX/RX FIFOs, programmable baud rates up to 16 Mbit/s (4× sampling), RS-485 auto-direction control via RTS#, and IrDA SIR support up to 1.152 Mbps. It operates from 1.8 V to 3.6 V, supports industrial temperature range (–40°C to +85°C), and is pin-compatible with legacy 16C450 UART register sets - deployed in factory automation gateways requiring low-power serial protocol conversion.

For engineers reviewing the PI7C9X1170CZDE datasheet, PI7C9X1170CZDE pinout, PI7C9X1170CZDE application, or PI7C9X1170CZDE equivalent, key selection criteria include SPI/I²C interface select logic, GPIO mapping for DSR#/DTR#/CD#/RI# functions, RS-485 half-duplex driver control timing, and FIFO trigger level programmability in TLR/FCR registers.

Technical Context

The PI7C9X1170CZDE implements a dual-mode serial interface: I²C-bus slave (fast-mode, 400 kHz) or SPI slave (Mode 0, up to 33 MHz), selected by the I2C/SPI# pin. Its UART core features fractional baud rate generation using a 16-bit divisor, supporting precise rates across crystal (≤24 MHz) or external clock (≤64 MHz) inputs.

Hardware flow control integrates Auto-RTS (triggered by RX FIFO level vs. TCR[3:0] halt threshold) and Auto-CTS (transmit gating synchronized to CTS edge at stop-bit midpoint), eliminating overrun errors without host CPU intervention. RS-485 direction control is implemented via RTS# output with polarity inversion capability and automatic slave address detection.

Key Specifications

Pinout & Package

PI7C9X1170CZDE is packaged in a 24-pin TSSOP (JEDEC MO-153, 3.5 mm × 7.8 mm) with exposed thermal pad. Pin functions are validated per Diodes DS40307 Rev 3-2, including dual-role pins (e.g., GPIO5/DTR#, GPIO4/DSR#) and interface-select logic on I2C/SPI#.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SC16IS752IPW and MAX3107EEG+, the PI7C9X1170CZDE uniquely combines I²C/SPI dual interface, integrated RS-485 direction control, IrDA PHY, and eight GPIOs - enabling single-chip serial bridging in space-constrained industrial and medical designs without external logic.

Availability

PI7C9X1170CZDE is available at Aetrix Electronics and suitable for industrial PLC gateways, smart meter communication modules, factory asset trackers, and medical device serial adapters requiring stable component supply across extended product lifecycles.

Supply support for PI7C9X1170CZDE 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 and mixed-signal solutions for industrial, computing, and communications markets.

The PI7C9X1170 belongs to Diodes' serial interface bridge product line, designed specifically to simplify protocol translation between modern microcontrollers (I²C/SPI) and legacy serial peripherals (RS-232/RS-485/IrDA) in cost-sensitive, low-power embedded systems.

FAQ

What interface modes does PI7C9X1170CZDE support, and how is mode selection implemented?

The PI7C9X1170CZDE supports I²C-bus slave (400 kHz fast-mode) and SPI slave (Mode 0, up to 33 MHz) interfaces. Mode selection is controlled by the logic level on the I2C/SPI# pin: HIGH selects I²C (activating SDA/SCL), LOW selects SPI (activating SO/SI/SCLK/CS#). This pin must be hardwired during PCB layout and cannot be changed dynamically in operation.

How does RS-485 half-duplex direction control work on PI7C9X1170CZDE, and what configuration is required?

RS-485 direction control uses the RTS# pin to drive the DE/!RE input of an external transceiver. The device supports polarity inversion via the Enhanced Features Register (EFR[4]), allowing direct connection to both inverting and non-inverting transceivers. No external logic or timing delays are needed - direction switching occurs automatically within one UART bit time after TX FIFO empty or RX FIFO full conditions.

Can PI7C9X1170CZDE operate with a 1.8 V supply, and what impact does voltage have on I/O levels?

Yes, PI7C9X1170CZDE operates from 1.8 V to 3.6 V. I/O voltage levels track VDD: at 1.8 V, logic HIGH is ≥1.26 V (70% VDD), logic LOW is ≤0.54 V (30% VDD); at 3.3 V, thresholds scale accordingly. The internal 1.2 V LDO ensures consistent core timing across all supply voltages, maintaining baud accuracy and FIFO timing integrity regardless of rail selection.

What is the function of the GPIO pins, and how are they mapped to modem control signals?

The eight GPIO pins (GPIO0–GPIO7) are software-configurable I/Os. GPIO4–GPIO7 map directly to standard modem control signals: GPIO4/DSR#, GPIO5/DTR#, GPIO6/CD#, GPIO7/RI#. Each pin's function is selected via the GPIO Control Register (GPIOR[7:0]); when configured as modem signals, they adhere to EIA/TIA-232 timing and electrical specifications, including assertion/deassertion delays and status reporting in the Modem Status Register.