Texas Instruments TL16C554APN

Overview

TL16C554APN from Texas Instruments is a quadruple UART IC implementing four independent asynchronous communication channels, each featuring 16-byte transmit/receive FIFOs, programmable baud-rate generation (up to 1-Mbaud), and full modem control (CTS/RTS/DSR/DTR/RI/DCD). It operates at 3.3 V or 5 V with up to 16-MHz clock input and supports TL16C450- and FIFO-mode operation for legacy compatibility and interrupt reduction in industrial serial gateways.

For engineers reviewing the TL16C554APN datasheet, TL16C554APN pinout, TL16C554APN application, or TL16C554APN equivalent, key selection considerations include its 80-pin TQFP (PN) package, four-channel parallel bus interface with A0–A2 address decoding, auto-RTS/CTS flow control timing (≤2 baudout cycles), and support for 5–8-bit characters with parity and 1/1.5/2 stop bits in embedded communications controllers.

Technical Context

The TL16C554APN integrates four enhanced TL16C550C ACE cores sharing a common 8-bit bidirectional data bus (D0–D7), with independent chip-select lines (CSA–CSD) and interrupt outputs (INTA–INTD) routed through a prioritized interrupt controller. Each channel includes a 16× clock generator driven by divisor latches (DLL/DLM), receiver/transmitter FIFOs with configurable trigger thresholds, and full modem-status/control registers accessible via A0–A2 address lines.

It supports dual operational modes: TL16C450 mode (using hold/shift registers without FIFO buffering) and FIFO mode (enabling 16-byte buffers per channel with autoflow control logic that asserts RTS based on receive FIFO threshold and deasserts it after reading the last byte). The device uses internal timing derived from XTAL1/XTAL2 (or external clock) and provides RXRDY/TXRDY handshaking signals for DMA coordination.

Key Specifications

Pinout & Package

TL16C554APN is packaged in an 80-pin thin quad flatpack (TQFP) with exposed pad, designated PN package per TI SLLS509E. Pin functions are defined per channel (A–D) with shared bus signals (D0–D7, A0–A2, IOR/IOW, RESET) and dedicated modem/control I/O.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL16C554APN, XR16L788IQ-F offers larger FIFOs and integrated LDOs but sacrifices 5-V compatibility and legacy register alignment; SP505ECA-L delivers higher density and throughput yet removes hardware autoflow - making TL16C554APN optimal for dual-voltage industrial retrofits requiring minimal firmware change.

Availability

TL16C554APN is available at Aetrix Electronics and suitable for industrial serial gateways, legacy system upgrades, communications controllers, and point-of-sale terminals requiring stable component supply and long-term manufacturability.

Supply support for TL16C554APN 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity solutions, with decades of leadership in interface ICs and industrial communication components.

The TL16C554APN belongs to TI's legacy asynchronous communications element (ACE) product line, designed specifically for high-reliability, multi-port serial bridging in industrial automation, telecom infrastructure, and embedded computing where register compatibility and deterministic timing are critical.

FAQ

What is the maximum clock frequency supported by TL16C554APN?

The TL16C554APN supports an input clock frequency of up to 16 MHz, enabling reliable operation at 1-Mbaud serial data rates when using the internal 16× oversampling clock. This maximum applies across both 3.3-V and 5-V supply conditions per TI SLLS509E specifications, and timing margins remain valid up to 70°C ambient temperature.

Does TL16C554APN support both 3.3-V and 5-V operation?

Yes, TL16C554APN is explicitly rated for dual-supply operation: 3.0–3.6 V and 4.75–5.25 V. Electrical characteristics including VOH (≥2.4 V), VOL (≤0.4 V), and ICC (40 mA typical at 3.3 V, 50 mA at 5 V) are separately validated for each voltage domain, allowing direct integration into mixed-voltage backplanes without level translation.

How does auto-RTS flow control work in TL16C554APN?

In TL16C554APN, auto-RTS is enabled via the MCR register (bit 1) and controlled by the FIFO Control Register (FCR). When enabled, RTS is asserted when the receive FIFO reaches a programmable threshold (1/4/8/14 bytes); it is deasserted only after the CPU reads the last byte in the FIFO, with propagation delay ≤2 baudout cycles per TI timing specs.

What package type is used for TL16C554APN?

TL16C554APN uses an 80-pin thin quad flatpack (TQFP) package designated PN per TI documentation. It features gull-wing leads, 0.5-mm pitch, and an exposed thermal pad - distinct from the 68-pin PLCC (FN) and 64-pin PQFP (PM) variants of the same family.

Can TL16C554APN be used as a drop-in replacement for TL16C550C?

TL16C554APN is not a drop-in replacement for TL16C550C due to differing pin count (80 vs. 44), package, and bus interface - but each of its four internal UARTs is functionally and register-compatible with TL16C550C. System-level replacement requires PCB redesign to accommodate the TQFP footprint and multiplexed address/data bus.