74GTLPH16945VRE4

Overview

The SN74GTLPH16945 is a 16-bit LVTTL-to-GTLP bus transceiver partitioned into two 8-bit segments. It operates at VCC of 3.15V to 3.45V with B-port outputs providing 50mA drive current and A-port outputs providing ±24mA. The device supports bidirectional data transfer between LVTTL logic levels and GTLP signal levels, featuring propagation delays ranging from 2.1ns to 6.9ns depending on direction and load conditions.

Feature Summary

• Provides high-speed asynchronous communication between cards operating at LVTTL logic levels and backplanes operating at GTLP signal levels.
• Features TI-OPC circuitry that actively limits overshoot caused by improperly terminated backplanes or unevenly distributed cards during low-to-high signal transitions.
• Supports live insertion applications through Ioff, power-up 3-state, and BIASVCC circuitry to prevent damaging current backflow and driver conflicts.
• Includes active bus-hold circuitry on the A-port data inputs to maintain unused or undriven inputs at a valid logic state.

Applications

• High-speed interface between LVTTL logic level cards and GTLP signal level backplanes
• Asynchronous communication between data buses in distributed load environments
• Live insertion applications requiring hot-swap capability

Procurement Notes

Verify the specific package variant (DGG TSSOP, DGV TVSOP, or GQL VFBGA) required for your design, as ordering suffixes determine the physical footprint. Confirm RoHS compliance status and moisture sensitivity level ratings before finalizing procurement orders. Ensure compatibility with existing PCB layout constraints regarding pin counts and thermal requirements.

Selection Notes

Select this component when interfacing systems requiring translation between standard LVTTL voltage domains and the lower swing GTLP signaling standard. Consider the medium-drive output capability suitable for heavily loaded backplanes with equivalent load impedances down to 19 ohms. Evaluate the need for integrated overshoot protection and bus-hold features to simplify external component requirements.

Part Context

This device belongs to the Texas Instruments Widebus family of logic components. It is designed specifically for the Gunning Transceiver Logic (GTL) JEDEC standard derivative known as GTLP. The architecture allows for efficient signal integrity management in complex multi-drop bus topologies common in server and networking hardware architectures.

Replacement Considerations

SN74GTLPH16945GR

FAQ

How does the device handle live insertion?

The device supports live insertion via Ioff, power-up 3-state, and BIASVCC circuits. These features disable outputs when powered down, place outputs in a high-impedance state during power cycles, and precharge B-port connections to prevent disturbance of active data on the backplane.

What is the function of the TI-OPC circuitry?

TI-OPC circuitry actively limits overshoot caused by improperly terminated backplanes, unevenly distributed cards, or empty slots during low-to-high signal transitions. This improves signal integrity and maintains adequate noise margins at higher frequencies.