NXP Semiconductors SC18IM704PWJ

Overview

SC18IM704PWJ from NXP Semiconductors is a UART-to-I²C-bus bridge IC that serves as an I²C-bus controller, enabling microcontrollers without native I²C hardware to communicate with I²C peripherals via ASCII-commanded UART interface. It operates from 1.71 V to 3.6 V, supports Fast-mode I²C up to 375 kHz, and integrates 256-byte TX/RX FIFOs for robust serial bridging in industrial control systems.

For engineers reviewing the SC18IM704PWJ datasheet, SC18IM704PWJ pinout, SC18IM704PWJ application, or SC18IM704PWJ equivalent, this page delivers verified technical context, validated pin functions, real-world use cases, and confirmed alternative parts - all grounded in NXP's Rev. 1.0 product data sheet dated 22 September 2021.

Technical Context

The SC18IM704PWJ implements a full-featured UART interface (8N1 format, up to 460.8 kbit/s) paired with autonomous I²C-bus controller logic that handles arbitration, clock stretching, START/STOP generation, and multi-controller bus compliance. Its internal state machine executes I²C transactions-including repeated START for read-after-write-without host CPU intervention.

It features eight programmable GPIOs configurable as push-pull, open-drain, or input-only per pin, with Schmitt-triggered inputs and glitch suppression. The device enters Deep Power-down mode via ASCII command 'Z' + 0x5A 0xA5, exiting only on RX pin assertion, and reports version ID via 'V'+'P' command.

Key Specifications

Pinout & Package

TSSOP16 package (SOT403-1), 4.4 mm body width, 0.65 mm pitch, lead-free and RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar UART-to-I²C bridge applications.

Compared with SC18IM704PWJ, SC18IM700PW offers pin-level compatibility but lacks low-voltage operation and extended temperature capability, while MAX31820 serves an entirely different sensing function and cannot substitute for protocol bridging functionality.

Availability

SC18IM704PWJ is available at Aetrix Electronics and suitable for industrial control, medical instrumentation, and automotive diagnostic applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SC18IM704PWJ 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

NXP Semiconductors is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT markets, with deep expertise in interface and mixed-signal ICs.

The SC18IM704PWJ belongs to NXP's interface bridge product line, designed specifically to simplify I²C integration for resource-constrained microcontrollers lacking native I²C peripherals.

FAQ

What UART data format does SC18IM704PWJ support?

The SC18IM704PWJ supports fixed 8N1 format: one start bit, eight data bits, no parity, and one stop bit. It does not support odd/even parity, 7-bit data, or 2-stop-bit configurations. Baud rate is programmable via BRG registers, with default 9600 bit/s after reset. The SC18IM704PWJ responds to host commands only when receiving valid ASCII characters within the defined protocol frame.

How does SC18IM704PWJ enter and exit Deep Power-down mode?

SC18IM704PWJ enters Deep Power-down mode upon receiving the exact ASCII sequence 'Z' followed by hexadecimal bytes 0x5A and 0xA5. To exit, the RX pin must be driven LOW; the device remains in Deep Power-down as long as RX is HIGH (via pull-up resistor or external drive). The SC18IM704PWJ ignores the first character received after wake-up but resumes normal operation immediately thereafter.

Can SC18IM704PWJ operate as a multi-controller I²C bus master?

Yes, SC18IM704PWJ fully supports multi-controller I²C operation. Its internal logic handles arbitration, clock synchronization, and collision detection per the NXP I²C-bus specification. It can coexist with other I²C masters on the same bus without external arbitration circuitry, making SC18IM704PWJ suitable for distributed control systems where multiple devices initiate I²C transactions.

Which GPIO pins on SC18IM704PWJ are 5 V tolerant?

SC18IM704PWJ GPIO pins 0–4, 6–7, SDA, and SCL are 5 V tolerant when VDD ≥ 1.71 V. GPIO5 is explicitly 3 V tolerant only and must not be exposed to 5 V signals. This distinction is critical for mixed-voltage system design - violating it risks permanent damage to GPIO5, while other I/Os tolerate 5 V inputs safely during level translation or hot-swap scenarios.

What is the maximum I²C clock frequency supported by SC18IM704PWJ?

The SC18IM704PWJ supports Fast-mode I²C up to 375 kHz, as specified in its datasheet. While the I²C timing characteristics table lists 400 kHz as a theoretical limit under standard conditions, the functional description and register documentation confirm 375 kHz as the guaranteed operational maximum. Users configuring I2CClkH/I2CClkL registers must ensure the resulting clock period aligns with this 375 kHz ceiling for reliable bus performance.