NXP Semiconductors SC28L194A1BE,551

Overview

SC28L194A1BE,551 from NXP Semiconductors (formerly Philips) is a quad-channel CMOS UART IC supporting both 3.3 V and 5.0 V single-supply operation, featuring four independent full-duplex asynchronous serial channels, 16-byte transmit/receive FIFOs per channel, programmable baud rates up to 500 kbaud, and hardware/software flow control (RTS/CTS and Xon/Xoff). It serves as a high-density serial interface controller in industrial terminal servers and data concentrators.

For engineers reviewing the SC28L194A1BE,551 datasheet, SC28L194A1BE,551 pinout, SC28L194A1BE,551 application, or SC28L194A1BE,551 equivalent, key selection criteria include its 80-pin LQFP package, dual-voltage compatibility, vectored interrupt architecture with channel-level context reporting, and support for multi-drop wake-up via address recognition - all critical for deterministic embedded serial subsystem design.

Technical Context

The SC28L194A1BE,551 integrates four independent UART channel blocks, each with dedicated 16-byte TX/RX FIFOs, programmable data format (5–8 data bits, 1/1.5/2 stop bits, parity options), and false start-bit detection. Its timing subsystem includes an on-chip crystal oscillator (2–8 MHz), a fixed-rate baud generator (22 standard rates), and two 16-bit reload counters for non-standard baud synthesis.

Interrupt arbitration uses a priority-bidding mechanism across 64 sources - including FIFO fill/empty thresholds, change-of-state detection on I/O pins, receiver watchdog timeout, and Xon/Xoff/address character recognition - with context reported via a Current Interrupt Register (CIR) that drives programmable interrupt vectors and global registers for rapid service routing.

Key Specifications

Pinout & Package

SC28L194A1BE,551 is housed in an 80-pin Low Profile Quad Flat Pack (LQFP, SOT315-1) with 0.5 mm pitch, designed for surface-mount assembly and thermal reliability in industrial applications. Power distribution includes four Vss_ic (input/noise-sensitive ground), four Vcc_i (input supply), four Vss_o (output ground), two Vcc_o (output supply), and two Vcc_c (clock supply) pins to isolate noise domains.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SC28L194A1A,551, the SC28L194A1BE,551 offers superior thermal performance in surface-mount systems and tighter layout density, while the XR16L788IQ-F trades legacy compatibility for higher speed and modern connectivity - making SC28L194A1BE,551 optimal for cost-sensitive, noise-immune industrial serial consolidation.

Availability

SC28L194A1BE,551 is available at Aetrix Electronics and suitable for industrial data concentrators, terminal servers, and process control hubs requiring stable component supply, long-term lifecycle assurance, and guaranteed traceable sourcing.

Supply support for SC28L194A1BE,551 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 heritage in communications ICs dating to Philips' semiconductor division.

The SC28L194 product line was engineered for high-reliability serial infrastructure in industrial automation and telecom edge equipment, emphasizing deterministic interrupt handling, multi-drop efficiency, and single-supply flexibility across legacy and mixed-voltage systems.

FAQ

What voltage supplies does the SC28L194A1BE,551 support?

The SC28L194A1BE,551 operates from a single 3.3 V ±10 % or 5.0 V ±10 % supply - no dual-rail design needed. Its I/O pins are TTL-compatible at both voltages, and internal logic adapts automatically. This eliminates level-shifting circuitry in mixed-voltage systems and simplifies power sequencing during startup.

Does the SC28L194A1BE,551 include an on-chip oscillator?

Yes, the SC28L194A1BE,551 integrates an on-chip crystal oscillator supporting 2–8 MHz crystals connected between X1/CCLK and X2 pins. With a standard 3.6864 MHz crystal, it generates exact industry-standard baud rates (e.g., 9600, 19200, 38400) without external timing components - reducing BOM count and board area.

How does the interrupt arbitration system work in the SC28L194A1BE,551?

The SC28L194A1BE,551 uses a priority-bidding arbitration system across 64 interrupt sources. Each source (e.g., RX FIFO fill level, TX FIFO empty, change-of-state) encodes its urgency as a 4-bit value concatenated with channel and type. The highest-bidder wins, and its full context - channel number, source type, and FIFO level - is captured in the Current Interrupt Register (CIR) for immediate service.

Can the SC28L194A1BE,551 generate non-standard baud rates?

Yes, the SC28L194A1BE,551 supports non-standard baud rates up to 500 kbaud using two independent 16-bit programmable BRG timers. These timers divide selected clock sources (X1, BRG output, or external inputs) to produce precise 16× baud clocks. The formula n = (BRG Timer Input Frequency) / (2 × 16 × Desired Baud Rate) – 1 determines reload values.

What is the purpose of the "Change of State Detectors" on the I/O pins of the SC28L194A1BE,551?

Each of the 16 I/O pins (I/O0–3 per channel) in the SC28L194A1BE,551 includes a Change of State Detector that flags transitions (0→1 or 1→0) after 25–50 µs stabilization. These detectors generate interrupts independently of UART activity - enabling reliable monitoring of modem control signals (e.g., DCD, RI) or external event triggers without CPU polling.