Texas Instruments

PC16550D - UART with 16-Byte FIFOs | Texas Instruments

부품 번호: PC16550D ✗ 단종
재고 있음 영업일 기준 1~3일 내 발송
40-pin DIP (PC16550DN) Package
시작가 $6.35 USD / 개
MOQ: 1 |
가격 업데이트: 2026-10-19
볼륨 가격
수량 단가 합계
1 $8.95 $8.95
10 $8.2 $82.00
100 $7.45 $745.00
500 $6.9 $3,450.00
1,000 $6.35 $6,350.00
ℹ️ 모든 가격은 USD 기준입니다

PC16550D 개요

The Texas Instruments PC16550D is a Universal Asynchronous Receiver/Transmitter (UART) with integrated 16-byte transmit and receive FIFOs, housed in a 40-pin DIP package (offered as PC16550DN from TI). It operates as a single-channel serial-to-parallel and parallel-to-serial converter for CPU-based systems, with the FIFO buffers relieving the processor of per-character interrupt overhead.

A UART (Universal Asynchronous Receiver/Transmitter) is a serial communication IC that converts parallel data from a processor bus into asynchronous serial data streams, and back. It sits within the broader hierarchy of interface ICs under the serial communication device class, alongside synchronous counterparts such as USARTs and SPI interfaces. UARTs handle framing, start/stop bit generation, parity checking, and baud-rate generation without a shared clock between endpoints.

The PC16550D is an improved version of the original 16450 UART. On power-up it is functionally identical to the 16450 in CHARACTER mode, and it can also be reset to 16450-mode behavior under software control, ensuring backward compatibility with legacy PC and embedded BIOS software. Entering FIFO mode enables the 16-byte buffers on both the transmit and receive paths, dramatically reducing CPU interrupt load compared with the 16450's single-character holding registers.

Technical depth: the device includes a programmable baud-rate generator, a modem-control block (DTR, DSR, RTS, CTS, DCD, RI), full line-status reporting, and independently controllable transmit and receive FIFO triggers via its FIFO Control Register (FCR). The RXRDY and TXRDY DMA-handshake signals allow direct memory access transfers, further offloading the host processor in high-throughput serial links.

Typical applications include legacy ISA/PCI-era PC COM ports, industrial automation equipment with RS-232/RS-485 links, terminal servers and console-management systems, and embedded processors that need an external memory-mapped UART with modem control.

Design consideration: because PC16550D and PC16552D are discontinued by TI, new designs should evaluate the pin/function-compatible TL16C550 family, which TI explicitly discusses as a replacement path in its support forums; verify FIFO trigger behavior and maximum baud rate against the target application.

This page synthesizes distributor availability data, the TI/National Semiconductor datasheet, and drop-in replacement analysis not found in the manufacturer datasheet alone.

드롭인 대체품: PC16550D — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.

빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:

PC16550DN

✅ 드롭인
📦 DIP-40
same die/function as PC16550D, active listing at DigiKey (1 channel, 16-byte FIFO, 40-DIP)

📋 참조 대체품 (카탈로그에 없음)

PC16550DIN

✅ 드롭인 ⚠️ 사양 미검증
📦 DIP-40
industrial temperature range variant of the same PC16550D die in the same 40-pin DIP package

📋 참조 대체품 (카탈로그에 없음)

PC16550CFN

✅ 드롭인 ⚠️ 사양 미검증
📦 DIP-40
commercial temperature grade of the same family in 40-pin DIP; same register set and 16-byte FIFOs

📋 참조 대체품 (카탈로그에 없음)

TL16C550CJ

✅ 드롭인
📦 DIP-40
TI's active 16550-compatible UART with 16-byte FIFOs in 40-pin DIP; discussed by TI support as the PC16550D replacement - verify FCR trigger behavior and max baud rate

📋 참조 대체품 (카탈로그에 없음)

PC16550D 사양

기능 Universal Asynchronous Receiver/Transmitter (UART)
UART Channels 1
FIFO Size (TX) 16 byte
FIFO Size (RX) 16 byte
Compatibility Upward-compatible with 16450 (CHARACTER mode at power-up)
Operating Mode CHARACTER mode (16450-compatible) and FIFO mode (software selectable)
Modem Control Signals DTR, DSR, RTS, CTS, DCD, RI
DMA Support RXRDY and TXRDY handshake signals
Baud Rate Generator Programmable, on-chip
패키지 40-pin DIP (PC16550DN)
실장 유형 Through-Hole
Interrupt Output INTR, programmable via IER
수명 주기 상태 Discontinued (per TI E2E forum); PC16550DN listed active at DigiKey

PC16550D 40-pin dip (pc16550dn) 핀 구성 가이드

PC16550D(40-pin dip (pc16550dn) 패키지)의 핀 구성입니다. 핀 번호, 기능, 연결 다이어그램은 제조사 데이터시트에 정의되어 있습니다. 정확한 풋프린트와 솔더링 지침은 해당 문서를 참조하십시오.

PC16550D의 40-pin dip (pc16550dn) 패키지 핀아웃 다이어그램

다음에 대한 상세 핀아웃 데이터 없음: PC16550D.

다음을 참조하십시오: 데이터시트 전체 핀 구성은 다음을 참조하십시오.

일반적인 애플리케이션

PC16550D 적합 용도: 6 애플리케이션s: Legacy PC COM Ports, Industrial RS-485 / RS-232 Networks, Console and Terminal Servers, Embedded Processors Needing a Hardware UART, Retrofit and Legacy Equipment Maintenance, Point-of-Sale and Peripheral Interfacing.

🖥️

Legacy PC COM Ports

The PC16550D was the de-facto standard UART for IBM PC-compatible COM ports through the ISA era. Its power-up compatibility with the 16450 in CHARACTER mode means PC BIOS and DOS-era drivers operate without modification, while enabling FIFO mode unlocks the 16-byte buffers for higher-throughput modem and serial links. The on-chip programmable baud generator derives standard PC baud rates from the 1.8432 MHz clock, and the full modem-control block (DTR, DSR, RTS, CTS, DCD, RI) supports dial-up modem handshaking. RXRDY/TXRDY signals permit ISA DMA transfers, offloading the CPU during large file transfers.

🏭

Industrial RS-485 / RS-232 Networks

In factory automation and building-control equipment, the PC16550D provides the asynchronous serial engine behind RS-232 line drivers or RS-485 transceivers. The 16-byte FIFOs smooth burst traffic from PLCs and field devices, while the RTS modem-control output can gate RS-485 driver-enable with software-controlled turnaround timing. The programmable baud generator covers standard industrial rates, and the line-status register exposes overrun, parity, and framing errors for robust error handling. RXRDY/TXRDY DMA handshake reduces interrupt jitter on deterministic polling loops in multi-drop networks.

🌐

Console and Terminal Servers

Console-management and terminal-server products aggregate many serial ports for out-of-band administration of servers and network switches. A PC16550D per port gives each channel independent 16-byte FIFOs, a full modem-control set, and the industry-standard 16550 register interface that mature multi-port drivers target directly. FIFO mode minimizes per-character interrupt load across dozens of concurrent channels, and the DMA handshake supports high-aggregate throughput. The software-selectable 16450 compatibility mode aids bring-up and legacy diagnostics before enabling FIFO operation in production firmware.

🧩

Embedded Processors Needing a Hardware UART

Microcontrollers and DSP systems without a spare hardware UART, or lacking modem-control signals, can memory-map a PC16550D onto the external bus. The device decodes chip selects (CS0-CS2) with an ADS address-strobe option for multiplexed buses, and its 8-bit data bus connects directly to standard 8/16-bit host interfaces. The INTR output ties to the MCU interrupt controller, while RXRDY/TXRDY feed DMA controllers for low-latency streaming. Software-selectable FIFO trigger levels let firmware balance interrupt latency against throughput for the specific application.

🔧

Retrofit and Legacy Equipment Maintenance

Service organizations maintaining avionics test sets, medical instrumentation, and process-control gear built around the 16550 need exact-form-factor replacements. The PC16550DN retains the 40-pin DIP through-hole package and 16450 power-up compatibility, letting existing boards and firmware run unchanged. Where the bare PC16550D marking is unavailable, the pin-compatible TL16C550CJ in 40-DIP is the TI-discussed successor, requiring only datasheet-level verification of FIFO trigger timing. Sourcing through residual distributor stock keeps legacy fleets alive without PCB redesign or driver recertification.

⚡

Point-of-Sale and Peripheral Interfacing

Receipt printers, barcode scanners, card readers, and cash drawers historically communicate over RS-232 serial links driven by a 16550-class UART. The PC16550D's modem-control lines implement the busy/ready handshaking many POS peripherals expect, and its FIFOs absorb printer burst data without host stalls. The programmable baud generator covers the legacy rates (9600 to 115.2 kbps) common in retail hardware, and the line-status register lets POS firmware detect cable faults via framing-error monitoring, improving transaction reliability in electrically noisy retail environments.

추천 제품 요약

PC16550DN Active-suffix variant of the same UART 사용처: Legacy PC COM Ports, Retrofit and Legacy Equipment Maintenance TL16C550CJ Active TI 16550-compatible UART for new builds 사용처: Legacy PC COM Ports, Embedded Processors Needing a Hardware UART, Retrofit and Legacy Equipment Maintenance, Point-of-Sale and Peripheral Interfacing SN65HVD3082E RS-485 transceiver on the UART serial pins 사용처: Industrial RS-485 / RS-232 Networks MAX232 RS-232 level translator 사용처: Industrial RS-485 / RS-232 Networks, Point-of-Sale and Peripheral Interfacing PC16552D Dual-channel version for higher port density 사용처: Console and Terminal Servers TL16C554A Quad UART for dense console aggregation 사용처: Console and Terminal Servers TL16C750 Higher-speed 64-byte FIFO UART option 사용처: Embedded Processors Needing a Hardware UART
What is the PC16550D?
The PC16550D is a Universal Asynchronous Receiver/Transmitter (UART) with integrated 16-byte transmit and receive FIFOs, originally from National Semiconductor and now under Texas Instruments. It is an improved version of the 16450 UART: on power-up it is functionally identical to the 16450 in CHARACTER mode and can be placed into FIFO mode under software control to reduce CPU interrupt overhead. It is packaged in a 40-pin DIP (PC16550DN).
What is the difference between PC16550D and 16450?
The main difference is the FIFO buffers: the PC16550D integrates 16-byte transmit and receive FIFOs, while the 16450 has only single-character holding registers. According to the TI datasheet, the PC16550D is functionally identical to the 16450 on power-up (CHARACTER mode) and can even be reset to 16450 mode under software control. In FIFO mode the 16550 significantly reduces CPU interrupt service overhead, and it adds RXRDY/TXRDY DMA handshake signals absent on the 16450.
Is the PC16550D discontinued?
Yes, the PC16550D and PC16552D are discontinued by Texas Instruments. A TI E2E support forum thread confirms that PC16550D and PC16552D are discontinued and discusses the TL16C550C as the replacement candidate. However, the PC16550DN suffix variant was still listed as a purchasable UART IC (1 channel, 16-byte FIFO, 40-DIP) on DigiKey at the time of verification, so residual stock may exist through distribution.
What is the best drop-in replacement for PC16550D?
The best replacement path is Texas Instruments' TL16C550C family, which TI support engineering discusses as the substitute for the discontinued PC16550D. The TL16C550C offers a 16-byte FIFO UART with a compatible register set. When selecting a package, confirm the exact suffix (for example 40-pin DIP) for pin-to-pin compatibility with your existing PC16550D footprint, and verify FIFO trigger behavior and maximum baud rate against your software before committing to a board spin.
What is the difference between PC16550D and PC16552D?
The PC16552D is the dual-channel version of the PC16550D. According to FindIC's comparison, the PC16552D integrates two completely independent 16550-style serial channels, sharing only a common CPU interface and crystal input. Both parts are now discontinued, so designers needing dual UARTs should evaluate dual-channel parts in the TL16C552 or equivalent families rather than the legacy PC prefix parts.
How much does the PC16550DN cost?
Pricing for the PC16550D family varies by suffix and channel, and the base PC16550D has no active factory pricing because the part is discontinued. The PC16550DN variant was listed as a buyable item on DigiKey, where pricing follows TI's single-quantity to volume tier structure. Prices shown on this page are representative distributor-tier estimates as of 2026-10-20; always confirm live pricing and stock on the distributor product page before ordering.
Where can I buy PC16550D online?
You can buy the PC16550DN suffix variant on DigiKey, which lists it as a TI UART IC with 1 channel, 16-byte FIFO, in 40-DIP with same-day shipping availability. The bare PC16550D marking is discontinued, so sourcing beyond residual distributor stock typically requires broker channels such as those listed on Octopart or specialized EOL-part suppliers. XAIPART supports quote-based ordering for discontinued inventory - contact us with your quantity and date-code requirements.
What is the lead time for PC16550DN?
Because the PC16550DN is a residual-stock item rather than a factory-scheduled product, lead time depends entirely on available distributor and broker inventory. DigiKey historically offered same-day shipping on in-stock PC16550DN quantity. For volumes exceeding distributor stock, broker-sourced lead times typically run 2-8 weeks including incoming inspection. For new designs, TI recommends migrating to the active TL16C550 family, which carries standard factory lead times.
Where can I download the PC16550D datasheet PDF?
The PC16550D datasheet PDF is freely available from Texas Instruments via the DigiKey document mirror at media.digikey.com, and Mouser also hosts the TI revision PDF. The original National Semiconductor document (22 pages, approximately 344 KB per archive listings) describes the register set, FIFO operation, baud generator, and AC/DC characteristics. Avoid third-party paywalled sites; the DigiKey and Mouser links are direct manufacturer-derived copies.
What are the key specifications of PC16550D that engineers should know?
Key PC16550D specifications: it is a single-channel UART with 16-byte transmit and receive FIFOs, 16450 register compatibility at power-up with software-selectable FIFO mode, a programmable on-chip baud-rate generator, full modem control (DTR, DSR, RTS, CTS, DCD, RI), RXRDY/TXRDY DMA handshake signals, an INTR interrupt output, and a 40-pin DIP package (PC16550DN). It is discontinued, so replacement evaluation against TL16C550C should be part of any new design review.
Is PC16550D the same as TL16C550C?
No, they are not identical, but they are closely related. The TL16C550C is TI's active 16-byte-FIFO UART that shares the 16550 register architecture, while the PC16550D is the older National Semiconductor-derived part now discontinued. A TI E2E forum thread addresses exactly this substitution question. Differences to verify include package options, FIFO trigger level behavior, maximum baud rate, and exact AC timing parameters - consult both datasheets and re-run your driver validation before swapping.
Can TL16C550C replace PC16550D in my design?
In most designs, yes, with verification. TI's own support forum discusses TL16C550C as the go-forward option after PC16550D discontinuation. The TL16C550C implements the 16550 register set with 16-byte FIFOs, so legacy 16550 drivers generally work unchanged. Verify three items: the package pinout matches your footprint (the family spans DIP, PLCC, and QFP), FIFO mode trigger and timer behavior in the FCR, and timing margins if your bus runs near the maximum rated frequency.
Is PC16550D suitable for RS-485 industrial networks?
Yes, the PC16550D's UART function is protocol-agnostic and works well behind an external RS-485 transceiver for industrial networks. The RXRDY/TXRDY DMA handshake signals let the host service half-duplex RS-485 turnarounds efficiently, and the FIFO buffers smooth burst traffic at standard baud rates. For RS-485 direction control, derive the DE/RE enable from the RTS modem output with software turnaround timing, or use an automatic-direction transceiver to avoid driver enable latency.
When should I choose PC16550D over a software UART or MCU-integrated UART?
Choose the PC16550D when you need a memory-mapped UART with a register interface that legacy PC-standard software already targets, when the host MCU lacks a hardware UART or modem-control signals, or when maintaining an existing 16550-based board without software changes. Choose an MCU-integrated UART for new cost-sensitive designs, and choose the active TL16C550C rather than discontinued PC16550D stock for any new production build requiring long-term supply.
How do the 16-byte FIFOs in PC16550D reduce CPU load?
In the 16450's CHARACTER mode, the CPU receives an interrupt for every single transmitted or received character, so a 115.2 kbps stream can generate thousands of interrupts per second. The PC16550D's FIFO mode lets the CPU move up to 16 characters per interrupt on receive (with a programmable FIFO trigger level in the FCR) and fill the 16-byte transmit buffer in one burst. According to the TI datasheet, this dramatically relieves CPU software overhead, which is the headline improvement over the 16450.

엔지니어링 참조 데이터: PC16550D — 비교, 설계 지침 및 규정 준수 정보.

선택 가이드

Choose the PC16550D (or its PC16550DN suffix) only for maintaining existing 16550-based boards where form, firmware, and 16450 power-up compatibility must be preserved exactly - it is discontinued, so plan for end-of-life sourcing risk. For commercial-temperature legacy repairs, PC16550DN retains DigiKey availability; for industrial temperature, PC16550DIN is broker-only. For any new design, select the active Texas Instruments TL16C550CJ in 40-pin DIP: it implements the same 16550 register set with 16-byte FIFOs and is the replacement TI support engineering discusses, requiring only datasheet verification of FIFO trigger behavior, maximum baud rate, and bus timing margins. If you need two channels, remember PC16552D is also discontinued - evaluate dual- or quad-UART active equivalents instead of stockpiling legacy parts.

대체품과의 비교

파라미터 이 제품 PC16550DN PC16550DIN PC16550CFN TL16C550CJ
Package 40-pin DIP 40-pin DIP - same 40-pin DIP - same 40-pin DIP - same 40-pin DIP - same
Brand Texas Instruments (National Semiconductor heritage) Texas Instruments Texas Instruments Texas Instruments Texas Instruments
UART Channels 1 1 1 1 1
FIFO Size 16 byte TX / 16 byte RX 16 byte 16 byte 16 byte 16 byte
16450 Compatibility Mode Yes (CHARACTER mode at power-up) Yes Yes Yes Yes
DMA Handshake (RXRDY/TXRDY) Yes Yes Yes Yes Yes
Lifecycle Status Discontinued (residual stock possible) Listed active at DigiKey (residual) Discontinued Discontinued Active (recommended for new designs)

주요 차별점

  • Software-selectable 16450 compatibility mode (vs TL16C550CJ)
  • Active distributor availability of the DN suffix (vs PC16550DIN)
  • Legacy PC-standard register interface (vs TL16C750)

설계 노트

The single most important design decision with the PC16550D today is sourcing, not electronics: TI confirms on its E2E forum that PC16550D and PC16552D are discontinued. For any new production build, qualify the active TL16C550C family instead, and verify the exact package suffix for footprint compatibility. For legacy repairs, buy PC16550DN from authorized distributors while residual stock lasts, and be wary of remarked parts from unverified brokers when buying date-code-sensitive obsolete silicon.

As a 40-pin DIP through-hole device, the PC16550D needs no thermal copper, but layout still matters for signal integrity on the serial lines. Place the RS-232 transceiver (e.g., MAX232) close to the SIN/SOUT pins, keep the modem-control ribbon stubs short, and decouple VCC with a 100 nF ceramic capacitor directly at pin 40 to VSS. If you derive RS-485 driver-enable from RTS, route RTS to the transceiver DE pin without crossing the clock lines to minimize turnaround glitch risk.

Confirm the supply-voltage and operating-temperature ratings in the TI datasheet for your exact suffix (commercial vs industrial: DN vs DIN) before finalizing the power budget - these values are not reproduced on this page and must not be assumed. Because CMOS UART idle current is small, system power impact is negligible, but legacy 5V-only operation means level shifting is mandatory when interfacing to 3.3V MCUs; use a level translator on the 8-bit data and control bus rather than relying on marginal logic thresholds.

규정 준수 정보

RoHS
Unknown
REACH
Unknown
AEC-Q100
Not Applicable
무연
Unknown
무할로겐
Unknown
분쟁 광물
Unknown

Compliance data was not present in the provided web data. As a legacy National Semiconductor-era part, older date codes are unlikely to be RoHS/lead-free compliant; verify per date code with the supplier.

데이터 검증일: 2026-10-20 — XAIPART 부품 엔지니어링 팀이 검증하고 관리한 데이터

관련 검색

PC16550D datasheet PDF PC16550D Texas Instruments UART PC16550D vs 16450 difference PC16550D equivalent substitute PC16550DN buy price PC16550D drop-in replacement TL16C550C 16550 UART 16 byte FIFO 40 pin DIP is PC16550D discontinued PC16550D pinout 40 DIP legacy PC COM port UART IC PC16550D RS-485 industrial serial what can replace PC16550D

관련 부품 & 용어

Texas Instruments National Semiconductor PC16550D PC16550DN PC16552D TL16C550C 16450 UART UART Universal Asynchronous Receiver/Transmitter FIFO mode 16-byte FIFO DIP-40 CHARACTER mode RS-232 RS-485 baud-rate generator RXRDY/TXRDY DMA handshake modem control (DTR/DSR/RTS/CTS/DCD/RI) IBM PC COM port console server industrial automation interface IC
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