NXP Semiconductors SC18IS601IBS,151

Overview

SC18IS601IBS,151 from NXP Semiconductors is an SPI-to-I²C bridge IC that enables a microcontroller's SPI interface to control I²C-bus slave devices. It operates as a single-master I²C controller with 400 kbit/s I²C speed, 1.2 Mbit/s SPI (Mode 3), 96-byte TX/RX buffers, and 2.4–3.6 V supply. Used in embedded systems where SPI hosts must interface with legacy or sensor I²C peripherals.

For engineers reviewing the SC18IS601IBS,151 datasheet, SC18IS601IBS,151 pinout, SC18IS601IBS,151 application, or SC18IS601IBS,151 equivalent, key selection criteria include its TSSOP16 package, GPIO configurability (quasi-bidirectional/push-pull/open-drain), power-down mode with WAKEUP/IO4, active-low interrupt output, and internal RC oscillator eliminating external clock components.

Technical Context

The SC18IS601IBS,151 implements a dedicated hardware I²C-bus controller with full protocol handling-including arbitration, START/STOP generation, ACK/NACK management, and time-out detection-offloading timing-critical tasks from the host MCU. Its SPI slave interface supports Mode 3 (CPOL=1, CPHA=0) with up to 1.2 Mbit/s data rate and automatic command parsing for write/read/I²C read-after-write operations.

Internal register mapping (e.g., I2CClk at 0x02, I2CTO at 0x03, IOConfig at 0x00) enables runtime configuration of I²C clock frequency (7.2–369 kHz), time-out threshold, and GPIO modes per pin. The device integrates a 7.3728 MHz ±1% internal RC oscillator, eliminating need for external crystal while supporting precise I²C timing via programmable divider.

Key Specifications

Pinout & Package

TSSOP16 (SOT403-1) package: plastic thin shrink small outline, 16-pin, 4.4 mm body width, surface-mount compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SC18IS602IPW,118, SC18IS601IBS,151 provides identical SPI-to-I²C master functionality in a smaller TSSOP16 package with lower BOM cost, while PCA9306DC,118 serves only level-shifting-not protocol translation-making it incompatible for SPI host integration.

Availability

SC18IS601IBS,151 is available at Aetrix Electronics and suitable for industrial sensor hubs, embedded MCU I²C expansion, and low-power IoT edge nodes requiring stable component supply throughout extended production lifecycles.

Supply support for SC18IS601IBS,151 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 company specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with leadership in interface, power management, and secure MCU technologies.

The SC18IS600 family-including SC18IS601IBS,151-is designed specifically for resource-constrained embedded systems needing reliable, low-footprint SPI-to-I²C protocol bridging without host CPU overhead.

FAQ

What is the maximum I²C clock frequency supported by SC18IS601IBS,151?

The SC18IS601IBS,151 supports I²C Fast-mode operation up to 400 kbit/s. This is fixed in hardware and cannot be exceeded; the I2CClk register adjusts only lower frequencies (7.2–369 kHz) for compatibility with slower slaves. The 400 kbit/s limit ensures interoperability with standard I²C peripherals while maintaining timing margin across temperature and voltage ranges. SC18IS601IBS,151 does not support Fast-mode Plus (1 Mbit/s).

Does SC18IS601IBS,151 require an external crystal or clock source?

No, SC18IS601IBS,151 includes a factory-trimmed 7.3728 MHz ±1% internal RC oscillator, eliminating the need for external crystals, capacitors, or clock generators. This oscillator drives both the SPI interface timing and I²C clock generation via programmable dividers. External clock input (CLKIN) is not available on SC18IS601IBS,151 - unlike some variants - making it fully self-contained for timing-critical I²C operations.

How many I²C slave devices can SC18IS601IBS,151 communicate with simultaneously?

SC18IS601IBS,151 supports communication with multiple I²C slave devices on the same bus, limited only by I²C address space (128 possible 7-bit addresses) and bus capacitance (≤400 pF). It acts as a single master, initiating transactions sequentially - not concurrently - using standard I²C addressing. Each transaction targets one slave address; arbitration is handled automatically if multiple masters exist, though SC18IS601IBS,151 itself does not support multi-master arbitration as a participant.

Can SC18IS601IBS,151 operate with 5 V logic levels on its I/O pins?

Yes, SC18IS601IBS,151 features 5 V-tolerant I/O pins (GPIO0–GPIO3, IO4/WAKEUP, IO5, SDA, SCL, INT, MOSI, MISO, CS, SCLK, RESET), allowing direct connection to 5 V systems without level shifters. However, when configured in quasi-bidirectional mode, applying 5 V causes increased current draw from the pin to VDD; thus, 5 V operation is recommended only in push-pull or open-drain configurations with appropriate external pull-ups. VDD must remain within 2.4–3.6 V.

What happens to SC18IS601IBS,151's GPIO pins during power-down mode?

During power-down mode (activated by SPI command 0x30+0x5A+0xA5), SC18IS601IBS,151 disables its internal oscillator and stops responding to SPI commands, but GPIO pins retain their last configured states - except IO4/WAKEUP, which must be held HIGH before entering power-down and is used to trigger wake-up via LOW pulse. All GPIOs remain electrically active (high-impedance or driven) as set prior to sleep, enabling them to hold control signals or maintain sensor biasing without host intervention.