Texas Instruments SN74GTLP1395GQNR

Overview

SN74GTLP1395GQNR from Texas Instruments is a dual 1-bit LVTTL-to-GTLP bidirectional bus transceiver with split LVTTL port, adjustable edge-rate control (ERC), selectable polarity, and live-insertion support. It provides level translation between 3.3-V GTLP backplanes (VTT = 1.5 V) and 5-V-tolerant LVTTL logic (VCC = 3.3 V), delivers 100 mA GTLP output drive, supports incident-wave switching down to 11 Ω load impedance, and enables diagnostics via dedicated A/Y feedback path - deployed in IEEE 1394 backplane systems for clock/data distribution.

For engineers reviewing the SN74GTLP1395GQNR datasheet, SN74GTLP1395GQNR pinout, SN74GTLP1395GQNR application, or SN74GTLP1395GQNR equivalent, key selection criteria include GTLP/LVTTL level translation capability, ERC-controlled rise/fall times (1.0–2.6 ns), TI-OPC™/OEC™ signal integrity features, 5-V-tolerant LVTTL I/O, and VFBGA-48 (GQN) package compatibility with high-density backplane card layouts.

Technical Context

This device implements two independent 1-bit transceivers, each with separate LVTTL input (A), GTLP bidirectional I/O (B), and LVTTL output (Y) - enabling true transparent or inverted data flow controlled by T/C and OEAB/OEBY signals. The B-port differential receiver uses VREF = 1 V (GTLP mode) and supports termination at VTT = 1.5 V, while TI-OPC™ actively suppresses overshoot on unevenly loaded backplanes.

Edge-rate control is implemented via the ERC pin: ERC = L selects fast edge rates (tr = 1.0 ns, tf = 2.0 ns), ERC = H selects slow (tr = 1.5 ns, tf = 2.6 ns), optimizing signal integrity vs. timing margin in distributed RLC loads. Live insertion is enabled by coordinated Ioff, power-up 3-state, and BIAS VCC precharge circuitry - ensuring no disturbance to active backplane signals during hot-plug events.

Key Specifications

Pinout & Package

VFBGA-48 (GQN) package, 3.5 mm × 4.5 mm, 0.5 mm pitch, bottom-side ball layout per TI SCES349C. Pin mapping validated from official TI datasheet top-view diagram and terminal assignment table.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LVTTL-to-GTLP bus transceiver applications.

Compared with SN74GTLP1395GQNR, the SN74GTLP1394PWR consolidates functionality into half the channel count but sacrifices diagnostic feedback flexibility, while the SN74GTLP1399DGVR scales channel count at the cost of package size and thermal resistance - making SN74GTLP1395GQNR optimal for space-limited, dual-channel 1394 backplane implementations requiring independent strobe/data routing and live-insertion robustness.

Availability

SN74GTLP1395GQNR is available at Aetrix Electronics and suitable for IEEE 1394 backplane clock distribution, hot-pluggable diagnostic bus interfaces, and multislot ATM read/write clocking requiring stable component supply, long-term lifecycle support, and traceable sourcing for industrial embedded systems.

Supply support for SN74GTLP1395GQNR 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 90 years of innovation in high-performance interface solutions.

The SN74GTLP1395GQNR belongs to TI's GTLP family of backplane interface ICs, designed specifically to enable robust, high-speed, hot-pluggable communication between LVTTL logic and GTLP-terminated backplanes in IEEE 1394, VME64, and proprietary chassis systems.

FAQ

What is the function of the BIAS VCC pin on the SN74GTLP1395GQNR?

The BIAS VCC pin supplies 3.3 V to the SN74GTLP1395GQNR's live-insertion precharge circuitry, which conditions the B-port I/O connections prior to VCC application. This prevents disturbance of active signals on the GTLP backplane during card insertion or removal. For proper operation, BIAS VCC must be connected before VCC - as specified in TI SCES349C Note 5 - and remains active even when VCC is powered down. The SN74GTLP1395GQNR relies on this sequence to achieve true hot-plug capability without data loss.

How does the ERC pin affect timing performance of the SN74GTLP1395GQNR?

The ERC pin on the SN74GTLP1395GQNR selects between two edge-rate modes: ERC = L enables fast edges (B-port tr = 1.0 ns, tf = 2.0 ns), while ERC = H enables slow edges (tr = 1.5 ns, tf = 2.6 ns). These values are measured into distributed RLC loads per Figure 3 in SCES349C. Fast edges reduce propagation delay (A→B typical = 3.4 ns) but increase EMI risk on unterminated stubs; slow edges improve noise margin at higher frequencies. The SN74GTLP1395GQNR's ERC feature allows designers to tune signal integrity versus timing budget per actual backplane layout.

Can the SN74GTLP1395GQNR operate with GTL (VTT = 1.2 V) instead of GTLP (VTT = 1.5 V)?

Yes, the SN74GTLP1395GQNR supports both GTL (VTT = 1.2 V, VREF = 0.8 V) and GTLP (VTT = 1.5 V, VREF = 1.0 V) signal levels, as confirmed in the "description" section of SCES349C. However, all ac specifications - including propagation delay, skew, and edge rates - are guaranteed only at GTLP levels. When operating in GTL mode, users must verify noise margins and timing margins independently, and TI recommends consulting application reports SCEA019 and SCEA017 for implementation guidance. The SN74GTLP1395GQNR maintains full dc compatibility across both standards.

What is the purpose of the split LVTTL port (A and Y pins) in the SN74GTLP1395GQNR?

The split LVTTL port - comprising separate A (input) and Y (output) pins per channel - provides an isolated feedback path for control and diagnostics monitoring, as explicitly stated in the device description. This architecture allows the SN74GTLP1395GQNR to route LVTTL data from a controller (A) to the GTLP backplane (B) while simultaneously feeding a copy (Y) to local monitoring logic - without loading the B-port or introducing timing skew into the primary data path. The SN74GTLP1395GQNR uses this for real-time PHY status reporting and fault detection in live-insertion systems.

Does the SN74GTLP1395GQNR support true bidirectional data flow on the B port?

Yes, the SN74GTLP1395GQNR supports true bidirectional operation on each B port: data flows from A→B under OEAB control, and from B→Y under OEBY control, with polarity selectable via T/C. The functional description confirms that when OEAB and OEBY are both low, A data drives B and B data drives Y - enabling simultaneous upstream/downstream communication. This bidirectional capability is fundamental to its use in IEEE 1394 backplane PHY interfaces, where the SN74GTLP1395GQNR handles both data and strobe signals across the same GTLP bus.