Diodes Incorporated PI7C9X762BLEX

Overview

PI7C9X762BLEX from Diodes Incorporated is a dual-channel, full-duplex I²C/SPI-to-UART bridge controller with 64-byte TX/RX FIFOs per channel, programmable baud rates up to 16 Mbit/s (4× sampling), hardware/software flow control, and RS-485 direction control via RTS. It operates at 1.8 V, 2.5 V, or 3.3 V and supports industrial temperature range (−40 °C to +85 °C) in TQFN32 package.

For engineers reviewing the PI7C9X762BLEX datasheet, PI7C9X762BLEX pinout, PI7C9X762BLEX application, or PI7C9X762BLEX equivalent, key selection considerations include dual UART channel independence, I²C/SPI interface selectability, GPIO programmability (8 pins), IrDA SIR support up to 1.152 Mbps, and register compatibility with legacy 16C450 UARTs.

Technical Context

The PI7C9X762BLEX 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 auto-flow control logic using RTS/CTS signals. Its register set mirrors the 16C450 architecture while extending functionality via Enhanced Features Register (EFR) and Trigger Level Register (TLR).

It supports both I²C-bus (fast-mode, 400 kHz) and SPI (mode 0, slave-only, up to 33 MHz) host interfaces, selectable via the I2C/SPI pin. Internal clocking accepts crystal (up to 24 MHz) or external clock (up to 64 MHz), enabling precise timing for high-speed serial communication in embedded edge nodes.

Key Specifications

Pinout & Package

PI7C9X762BLEX is housed in a 32-pin TQFN (5 mm × 5 mm, 0.5 mm pitch) with exposed thermal pad requiring PCB ground connection. Pin functions are identical across I²C and SPI configurations, differing only in usage of CS/A0, SI/A1, SO, and SCL/SCLK pins.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SC16IS752IPW and MAX3107ETJ+, PI7C9X762BLEX uniquely combines I²C/SPI dual-interface support, RS-485 driver control, 8 GPIOs, and IrDA SIR - making it optimal for space-constrained industrial gateways requiring multi-protocol serial bridging.

Availability

PI7C9X762BLEX is available at Aetrix Electronics and suitable for industrial PLC gateways, smart meter communication modules, factory HMI terminals, and embedded network appliances requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for PI7C9X762BLEX 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 connectivity solutions for industrial, computing, and consumer markets.

The PI7C9X762BLEX belongs to Diodes' serial interface bridge product line, designed specifically to simplify protocol translation between modern host interfaces (I²C/SPI) and legacy serial peripherals (RS-232/RS-485/IrDA) in resource-constrained embedded systems.

FAQ

Does PI7C9X762BLEX support both I²C and SPI simultaneously?

No. The I2C/SPI pin selects interface mode: HIGH enables I²C (SDA/SCL active), LOW enables SPI (CS/SI/SO/SCLK active). Both interfaces share the same register map and UART functionality, but only one can be used at a time. This design avoids signal contention and simplifies PCB routing while offering flexibility across different host platforms.

How does RS-485 driver direction control work on PI7C9X762BLEX?

RTSA/RTSB outputs directly control RS-485 transceiver DE/!RE pins. When Auto-RTS is enabled, the UART asserts RTS before transmitting and deasserts it after the final stop bit - automatically managing bus direction. Polarity inversion (via EFR[4]) accommodates transceivers requiring active-HIGH enable, eliminating external inverters or resistor networks.

What is the function of the center thermal pad on the TQFN32 package?

The exposed center pad on the PI7C9X762BLEX TQFN32 package is electrically connected to VSS and must be soldered to a solid PCB ground plane. This provides critical thermal dissipation (reducing junction temperature by up to 25 °C) and improves electrical noise immunity for sensitive UART signaling - failure to connect it risks thermal shutdown or intermittent communication errors.

Can PI7C9X762BLEX operate at 1.8 V while maintaining full 16 Mbit/s baud rate?

Yes. The datasheet specifies 16 Mbit/s maximum baud rate under 4× oversampling at all supported supply voltages (1.8 V, 2.5 V, 3.3 V). At 1.8 V, internal clock generation remains stable up to 64 MHz input, and UART timing margins meet specification - verified across −40 °C to +85 °C with 100 pF load capacitance per channel.