Texas Instruments SN74GTLPH16945VR

Overview

SN74GTLPH16945VR from Texas Instruments is a 16-bit LVTTL-to-GTLP bidirectional bus transceiver partitioned into two 8-bit segments, supporting asynchronous data flow between LVTTL logic-level cards and GTLP backplanes. It delivers medium-drive GTLP outputs (50 mA), LVTTL-compatible 5-V-tolerant inputs, and live-insertion support via Ioff, power-up 3-state, and BIAS VCC. Used in high-speed backplane interconnects for telecom line cards and modular computing systems.

For engineers reviewing the SN74GTLPH16945VR datasheet, SN74GTLPH16945VR pinout, SN74GTLPH16945VR application, or SN74GTLPH16945VR equivalent, key selection considerations include GTLP/LVTTL level translation capability, distributed-load backplane timing (tPLH/tPHL ≤ 6.3 ns), live-insertion robustness, and TVSOP-48 (DGV) package compatibility with high-density PCB layouts.

Technical Context

The SN74GTLPH16945VR implements dual 8-bit directional control with independent DIR/OE per segment, enabling A→B or B→A data flow under noninverting logic. Its TI-OPC™ circuitry actively suppresses overshoot on unevenly terminated backplanes, while OEC™ design minimizes bus settling time and EMI.

It supports dual-voltage operation: LVTTL-side (VCC = 3.15–3.45 V, 5-V-tolerant inputs) and GTLP-side (VTT = 1.5 V, VREF = 1 V), with BIAS VCC precharging B-port I/O during hot-plug events. The device meets JESD 78 Class II latch-up immunity (>100 mA) and operates across –40°C to 85°C.

Key Specifications

Pinout & Package

SN74GTLPH16945VR uses the TVSOP-48 (DGV) package: 48-pin, 0.4 mm pitch, 6.1 mm × 12.5 mm body, 1.2 mm max height, JEDEC MO-153 compliant. Pin mapping validated per TI SCES292D datasheet Figure 1 (DGV top view).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74GTLPH16945GR and SN74GTLPH16945KR, the SN74GTLPH16945VR offers the smallest PCB area (6.1 mm × 12.5 mm) and lowest profile (1.2 mm max), making it optimal for slim-line modular systems requiring high pin density and hot-swap reliability without BGA assembly complexity.

Availability

SN74GTLPH16945VR is available at Aetrix Electronics and suitable for telecom line cards, modular server backplanes, industrial PLC I/O modules, and test equipment backplane interfaces requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74GTLPH16945VR 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 logic solutions, with over 90 years of innovation in high-reliability interface and signal-chain components.

The SN74GTLPH16945VR belongs to TI's Widebus™ family of high-speed bus interface devices, engineered specifically for robust, low-noise communication between LVTTL logic and GTLP backplanes in modular, hot-pluggable systems.

FAQ

What voltage levels does the SN74GTLPH16945VR support on its A-port and B-port?

The SN74GTLPH16945VR A-port operates at LVTTL logic levels (VCC = 3.15–3.45 V) and accepts 5-V-tolerant inputs. The B-port operates at GTLP signal levels requiring VTT = 1.5 V and VREF = 1 V. This dual-voltage architecture enables direct interfacing between 3.3-V LVTTL logic and 1.5-V GTLP backplanes without external level shifters. The SN74GTLPH16945VR datasheet specifies absolute maximum ratings up to 7 V on A-port inputs, confirming true 5-V tolerance.

How does the SN74GTLPH16945VR support live insertion in backplane systems?

The SN74GTLPH16945VR supports live insertion through three integrated features: Ioff limits reverse current when powered down, power-up 3-state holds outputs in high-impedance during VCC ramp (0–1.5 V), and BIAS VCC precharges B-port lines before VCC application. These functions collectively prevent bus conflicts, backfeeding, and signal disturbances during card insertion/removal. The SN74GTLPH16945VR is validated per TI's hot-insertion test methodology using distributed RLC backplane models.

What is the function of the BIAS VCC pin on the SN74GTLPH16945VR?

The BIAS VCC pin on the SN74GTLPH16945VR supplies precharge voltage to the B-port I/O circuitry during live-insertion sequences. It must be applied before VCC to precondition GTLP lines and prevent transient disturbances on an active backplane. BIAS VCC is typically tied to 3.3 V and is disabled once VCC is connected. This feature is essential for achieving true hot-plug capability and is explicitly required in the SN74GTLPH16945VR connection sequence per SCES292D Section 2.2.

Does the SN74GTLPH16945VR include bus-hold circuitry, and where is it implemented?

Yes, the SN74GTLPH16945VR includes active bus-hold circuitry exclusively on the A-port data inputs (1A1–1A8, 2A1–2A8). This eliminates the need for external pullup or pulldown resistors on undriven LVTTL lines, maintaining valid logic states during floating conditions. Bus-hold current specifications (IBHL = 75 µA, IBHH = –75 µA) are defined in the SN74GTLPH16945VR electrical characteristics table and apply only to A-port pins-not control inputs or B-port signals.

What are the key timing parameters for the SN74GTLPH16945VR in A-to-B and B-to-A directions?

The SN74GTLPH16945VR has asymmetric timing: A-to-B propagation delay (tPLH/tPHL) is 2.1–6.3 ns, while B-to-A is faster at 2.1–5.3 ns. Enable/disable times (ten/tdis) are 0.3–5.7 ns for B-to-A and 2–6.9 ns for A-to-B. Rise/fall times for B outputs are tr = 2.5 ns and tf = 2.1 ns (20%/80%). All values are specified at VCC = 3.3 V, TA = 25°C, and GTLP conditions (VTT = 1.5 V, VREF = 1 V), as documented in the SN74GTLPH16945VR switching characteristics tables.