NXP Semiconductors SC16IS850LIBS,128

Overview

SC16IS850LIBS,128 from NXP Semiconductors is a single-channel UART IC with dual I²C-bus/SPI slave interface, 128-byte TX/RX FIFOs, IrDA SIR support up to 115.2 kbit/s, and RS-485 automatic direction control via RTS. It operates at 1.8 V, supports baud rates up to 5 Mbit/s (with 80 MHz clock), and targets low-power industrial serial bridging in handheld and battery-operated systems.

For engineers reviewing the SC16IS850LIBS,128 datasheet, SC16IS850LIBS,128 pinout, SC16IS850LIBS,128 application, or SC16IS850LIBS,128 equivalent, key selection criteria include its HVQFN24 package, 1.8 V operation, 128-byte FIFO programmability, auto RS-485 driver control, and compatibility with legacy 16C850 register sets for software porting.

Technical Context

The SC16IS850LIBS,128 integrates a fully programmable UART core with dual-mode serial host interface (I²C Fast-mode at 400 kbit/s or SPI Mode 0 at 12 Mbit/s), selectable 5/6/7/8-bit character length, and parity/stop-bit configuration. Its internal rational baud rate generator uses DLL/DLM/CLKPRES registers to achieve precise rates up to 5 Mbit/s using an external 80 MHz clock or 1.5 Mbit/s with crystal oscillator.

It implements extended mode with 128-byte FIFOs, four programmable interrupt trigger levels per FIFO, and hardware/software flow control - including automatic RTS/CTS assertion, Xon/Xoff detection, and RS-485 turn-around timing via AFCR2/RS485TIME registers. The device supports internal loopback, line break generation/detection, and modem status monitoring (DSR/CD/RI/DTR).

Key Specifications

Pinout & Package

HVQFN24 package (SOT616-3), 4 × 4 × 0.85 mm body, thermally enhanced exposed pad requiring PCB thermal vias and soldered thermal pad for optimal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SC16IS750IBS,128 and MAX3107EASA+, the SC16IS850LIBS,128 uniquely combines 128-byte FIFOs, dual I²C/SPI support, IrDA SIR, and automatic RS-485 direction control in a 1.8 V HVQFN24 package - enabling compact, low-power, feature-rich serial bridging without external components.

Availability

SC16IS850LIBS,128 is available at Aetrix Electronics and suitable for factory automation, portable diagnostics, and cellular data terminal designs requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for SC16IS850LIBS,128 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 applications, with deep expertise in mixed-signal and interface IC design.

The SC16IS850LIBS,128 belongs to NXP's SC16IS family of intelligent UARTs, engineered specifically for low-voltage, low-power serial bridging in space-constrained and battery-sensitive embedded systems.

FAQ

What communication interfaces does the SC16IS850LIBS,128 support?

The SC16IS850LIBS,128 supports two host-side interfaces: I²C-bus slave (Fast-mode, up to 400 kbit/s) and SPI slave (Mode 0, up to 12 Mbit/s). Interface selection is controlled by the logic level on the I2C/SPI pin - HIGH for I²C, LOW for SPI. Both interfaces access the same internal UART registers and FIFOs, enabling flexible host processor integration without hardware redesign.

Does the SC16IS850LIBS,128 support automatic RS-485 driver direction control?

Yes, the SC16IS850LIBS,128 provides full automatic RS-485 driver direction control via its RTS output. When enabled through the Enhanced Feature Register (EFR[6]), the device asserts RTS before transmission and de-asserts it after the final stop bit, with configurable turn-around delay via the RS485TIME register. This eliminates external direction logic and ensures reliable half-duplex bus operation.

What is the maximum UART data rate achievable with the SC16IS850LIBS,128?

The SC16IS850LIBS,128 achieves up to 5 Mbit/s UART data rate when driven by an 80 MHz external clock input in 16× clock mode. With a crystal oscillator (e.g., 1.8432 MHz), the maximum rate is 1.5 Mbit/s. Baud rate precision is enhanced by the fractional CLKPRES register, allowing accurate custom rates across wide input clock ranges.

How does the SC16IS850LIBS,128 manage power in battery-operated applications?

The SC16IS850LIBS,128 enters ultra-low-power sleep mode drawing less than 5 µA at 1.8 V when the RX line is idle, TX FIFO and shift register are empty, and only THR-related interrupts are pending. Wake-up occurs automatically on RX activity or IRQ assertion, making it ideal for intermittent-communication portable devices like handheld diagnostic tools.

Is the SC16IS850LIBS,128 software-compatible with legacy UARTs?

Yes, the SC16IS850LIBS,128 maintains full register-level compatibility with the industry-standard 16C450 and 16C850 UARTs. After power-on, external reset, or software reset, its internal register map, bit definitions, and initialization behavior match these legacy parts - enabling direct software porting without modification to existing UART drivers or firmware stacks.