Texas Instruments SN74ALVCH16245DLR

Overview

SN74ALVCH16245DLR from Texas Instruments is a 16-bit dual-octal noninverting bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between two 16-bit buses operating at 1.65 V to 3.6 V. It features ±24-mA output drive at 3.3 V, 3 ns max propagation delay, bus-hold circuitry on all I/O pins, and 5.5-V tolerant inputs-enabling voltage translation (e.g., 5 V → 3.3 V) in server backplanes and telecom interface modules.

For engineers reviewing the SN74ALVCH16245DLR datasheet, SN74ALVCH16245DLR pinout, SN74ALVCH16245DLR application, or SN74ALVCH16245DLR equivalent, this page delivers verified functional modes, SSOP-48 package mapping, real-world timing behavior under load, bus-hold design implications, and validated alternatives for industrial bus isolation and level-shifting use cases.

Technical Context

The SN74ALVCH16245DLR implements dual independent 8-bit transceivers (A↔B), each controlled by dedicated DIR and OE signals. Direction control is synchronous with enable: when OE is low and DIR is high, data flows A→B; when OE is low and DIR is low, data flows B→A; OE high forces both ports into high-impedance state regardless of DIR.

All 32 I/O pins (16 A-side, 16 B-side) feature active bus-hold circuitry eliminating external pull resistors, and tolerate input voltages up to 5.5 V irrespective of VCC-supporting mixed-voltage system interfacing without additional level translators.

Key Specifications

Pinout & Package

SN74ALVCH16245DLR uses a 48-pin SSOP (Shrink Small Outline Package) with 0.635 mm pitch and 7.50 mm × 15.80 mm body size. Pin 1 is located at the top-left corner adjacent to the index notch; pin numbering proceeds counterclockwise.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus transceiver applications.

Compared with SN74ALVCH16245DLR, SN74LVC16245ADGGR offers lower system cost in single-rail designs but sacrifices robustness in mixed-voltage environments, while 74ALVC16245PW provides pin-compatible migration from older ALVC families yet requires redesign for bus-hold and overvoltage protection.

Availability

SN74ALVCH16245DLR is available at Aetrix Electronics and suitable for server backplanes, LED display controllers, telecom line cards, and industrial I/O expanders requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74ALVCH16245DLR 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 technologies with over 50 years of innovation in high-reliability logic and interface solutions.

The SN74ALVCH16245DLR belongs to TI's Widebus™ family, engineered for high-speed, low-voltage bidirectional bus interfacing in computing, communications, and industrial automation systems demanding robust voltage translation and noise immunity.

FAQ

What is the maximum data rate supported by SN74ALVCH16245DLR?

The SN74ALVCH16245DLR does not specify a fixed data rate, but its 3 ns maximum propagation delay at 3.3 V enables reliable operation with clock periods ≥6 ns - supporting effective data rates up to ~167 MHz in well-terminated parallel bus configurations. Actual throughput depends on load capacitance, trace length, and signal integrity design; TI recommends limiting total capacitive load to ≤50 pF per pin for optimal timing margin.

Does SN74ALVCH16245DLR require external pullup resistors on DIR and OE pins?

No - SN74ALVCH16245DLR does not require external pullup resistors on DIR or OE inputs because they are standard CMOS inputs with no internal weak pullups. However, TI strongly recommends tying OE to VCC through a pullup resistor (e.g., 10 kΩ) during power-up/down to guarantee high-impedance state and prevent bus contention. DIR may be driven directly from logic outputs or pulled to VCC/GND as needed for fixed-direction operation.

Can SN74ALVCH16245DLR translate 5 V signals to 1.8 V logic levels?

Yes - SN74ALVCH16245DLR accepts input voltages up to 5.5 V regardless of VCC setting, making it suitable for down-translation (e.g., 5 V microcontroller outputs to 1.8 V FPGA inputs). When powered at 1.8 V, its outputs swing rail-to-rail (0 V to 1.8 V), and its 5.5-V tolerant inputs safely interface with 5 V sources without clamping diodes or external components.

How does bus-hold functionality work on SN74ALVCH16245DLR?

SN74ALVCH16245DLR integrates active bus-hold circuitry on all 32 I/O pins that detects undriven or floating states and applies a weak current (±75 µA at 3 V) to maintain the last-valid logic level. This eliminates need for external pull resistors, reduces BOM count, and prevents undefined states in I/O expanders or hot-swap interfaces - but TI explicitly warns against combining bus-hold with external pullup/pulldown resistors due to potential conflict and increased power draw.

What is the thermal resistance (RθJA) of SN74ALVCH16245DLR in its SSOP-48 package?

The junction-to-ambient thermal resistance (RθJA) for SN74ALVCH16245DLR in the SSOP-48 (DL) package is 63 °C/W, as specified in TI's SCES015M datasheet Section 6.4. This value assumes standard JEDEC high-K test board conditions (2S2P); actual thermal performance improves with proper PCB copper pour, thermal vias, and airflow - critical for sustained ±24-mA output operation in enclosed industrial enclosures.