NXP Semiconductors SCC2681AE1N40,112

Overview

SCC2681AE1N40 from NXP Semiconductors (formerly Philips Semiconductors) is a dual-channel CMOS asynchronous receiver/transmitter (DUART) operating at +5 V ±10% over –40 °C to +85 °C, supporting independent 5–8-bit data formats with parity and 1/1.5/2 stop bits, 18 fixed baud rates up to 115.2 kbaud, and quadruple-buffered receivers for industrial serial communication systems.

For engineers reviewing the SCC2681AE1N40 datasheet, SCC2681AE1N40 pinout, SCC2681AE1N40 application, or SCC2681AE1N40 equivalent, key selection criteria include independent channel baud rate programming, on-chip crystal oscillator (3.6864 MHz), 40-pin DIP package with 3-state data bus, and support for automatic RTS/CTS flow control in clustered terminal and multidrop RS-232/RS-485 systems.

Technical Context

The SCC2681AE1N40 integrates two fully independent UART channels sharing a single 8-bit bidirectional data bus (D0–D7), address lines A0–A3, and chip enable (CEN), with separate serial I/O pins (RxDA/TxDA and RxDB/TxDB) and programmable clock sources per channel - including internal crystal oscillator (X1/CLK, X2), external 1×/16× clocks, or 16-bit counter/timer outputs.

Each channel features quadruple-buffered receive holding registers, false start bit detection, line break generation/detection, and programmable modes (normal, auto-echo, local/remote loopback); the interrupt system provides one active-low open-drain INTRN output plus six wire-ORable interrupt-capable OP pins (OP3–OP7), all maskable via IMR/ISR registers.

Key Specifications

Pinout & Package

SCC2681AE1N40 is housed in a 40-pin plastic dual in-line package (DIP40, 600 mil width, SOT129-1), with 3-state bidirectional data bus (D0–D7), four address lines (A0–A3), active-low read/write strobes (RDN, WRN), chip enable (CEN), reset (RESET), and dedicated serial I/O (RxDA/TxDA, RxDB/TxDB), clock (X1/CLK, X2), and multifunction I/O (IP0–IP6, OP0–OP7).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SCC2692AE1N40, the SCC2681AE1N40 lacks enhanced ESD protection but offers identical functionality at lower cost; versus TL16C550CPN, it provides superior integration (on-chip oscillator, dual independent channels, COS detection) but requires custom driver development due to non-16550 register layout.

Availability

SCC2681AE1N40 is available at Aetrix Electronics and suitable for industrial serial gateways, clustered terminal systems, RS-485 multidrop networks, and embedded diagnostic interfaces requiring stable component supply across extended temperature ranges.

Supply support for SCC2681AE1N40 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 formed from the spin-off of Philips' semiconductor division, specializing in secure connectivity, automotive, industrial, and IoT solutions.

The SCC2681AE1N40 belongs to NXP's legacy industrial communications IC portfolio, designed specifically for robust, long-lifecycle embedded serial infrastructure in factory automation, point-of-sale, and medical instrumentation.

FAQ

What is the maximum supported baud rate for SCC2681AE1N40?

The SCC2681AE1N40 supports a maximum baud rate of 115.2 kbaud using its internal 18-rate baud generator or programmable counter/timer. When using external 16× clock inputs, the device achieves 1 MB/sec data transfer (1× mode) or 125 kB/sec (16× mode), limited by bus timing and CPU interface speed rather than UART core capability.

Does SCC2681AE1N40 include an on-chip crystal oscillator?

Yes, the SCC2681AE1N40 integrates an on-chip crystal oscillator circuit compatible with a 3.6864 MHz crystal connected between X1/CLK and X2 pins. This eliminates the need for external oscillator components and simplifies PCB layout for timing-critical serial applications.

How many interrupt sources does SCC2681AE1N40 support?

The SCC2681AE1N40 supports eight maskable interrupt sources routed through a single active-low open-drain INTRN output: RxRDY/FFULL, TxRDY, delta break, counter/timer, input port change, and three channel-specific status flags. Additionally, OP3–OP7 can be configured as six discrete wire-ORable interrupt outputs.

Can SCC2681AE1N40 operate with different baud rates on each channel?

Yes, the SCC2681AE1N40 allows independent baud rate selection for Channel A and Channel B. Each channel can use any of 18 fixed rates, a counter/timer-derived rate, or an external 1×/16× clock - making it ideal for dual-speed applications like clustered terminal systems with mixed peripheral speeds.

What package type is used for SCC2681AE1N40?

The SCC2681AE1N40 uses a 40-pin plastic dual in-line package (DIP40) with 600 mil width and SOT129-1 footprint. It is pin-compatible with other SCC2681 variants in DIP40 packaging, including commercial-grade SCC2681AC1N40 and industrial-grade SCC2681AE1N40.