Texas Instruments SN74GTL2003RKSR

Overview

SN74GTL2003RKSR from Texas Instruments is an 8-bit bidirectional NMOS pass-transistor voltage-level translator IC, enabling seamless translation between 0.95 V and 5 V logic domains without direction control. It features 8 matched Sn/Dn channel pairs, ≤5.5 ns propagation delay at 50 MHz, 3.5–105 Ω ON-state resistance (dependent on gate voltage), and 5-V-tolerant inputs - deployed in server I²C bus interfacing and GTL-to-LVTTL signal bridging.

For engineers reviewing the SN74GTL2003RKSR datasheet, SN74GTL2003RKSR pinout, SN74GTL2003RKSR application, or SN74GTL2003RKSR equivalent, key selection criteria include bidirectional operation without control pins, flow-through VQFN-20 pinout for PCB routing efficiency, GTL/GTL+/LVTTL/TTL/CMOS compatibility, ESD robustness (±2000 V HBM), and support for hot insertion in high-reliability embedded systems.

Technical Context

The SN74GTL2003RKSR implements eight identical NMOS pass transistors with a shared gate (GREF) and integrated reference transistor (SREF/DREF), eliminating direction-control logic. Translation relies on clamp-based operation: when either Sn or Dn is LOW, the channel turns ON; when HIGH, output voltage is clamped to SREF or pulled to VCC via external resistors.

Its architecture supports three functional modes - bidirectional, unidirectional up-translation, and unidirectional down-translation - each requiring specific GREF/DREF/SREF biasing (e.g., GREF tied to DREF and pulled to VCC via 200 kΩ). Propagation delay is RC-limited by ON-resistance and load capacitance, with typical tPLH = 1.5 ns at 25°C and 50 pF.

Key Specifications

Pinout & Package

VQFN-20 package (RKS), 4.50 mm × 2.50 mm body, 0.5 mm pitch, exposed thermal pad. Pin numbering follows top-view orientation with GND at Pin 1, SREF at Pin 2, S1–S8 at Pins 3–10, D8–D1 at Pins 11–18, DREF at Pin 19, and GREF at Pin 20.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bidirectional voltage translation applications.

Compared with TXS0108E and SN74AVC8T245, the SN74GTL2003RKSR uniquely supports passive, directionless GTL/GTL+ translation with no supply rails - making it irreplaceable for legacy server and telecom backplane designs where signal integrity and hot-swap safety are non-negotiable.

Availability

SN74GTL2003RKSR is available at Aetrix Electronics and suitable for server BMC interfaces, HPC backplane interconnects, and medical device control buses requiring stable component supply across extended product lifecycles.

Supply support for SN74GTL2003RKSR 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and enterprise applications.

The SN74GTL2003RKSR belongs to TI's GTL-family of voltage translators, engineered specifically for high-speed, low-power, bidirectional signal bridging in mission-critical computing infrastructure - including servers, routers, and medical electronics.

FAQ

What is the primary function of the SN74GTL2003RKSR in a digital system?

The SN74GTL2003RKSR functions as an 8-bit bidirectional NMOS pass-transistor voltage-level translator. It enables seamless signal exchange between two different logic voltage domains - such as 1.2 V CPU I/O and 3.3 V chipset buses - without requiring a direction-control signal. Its design centers on low ON-resistance, minimal propagation delay, and inherent compatibility with GTL, GTL+, LVTTL, TTL, and CMOS standards. The SN74GTL2003RKSR achieves this using matched transistor pairs and a shared reference structure that maintains voltage thresholds across all channels.

Does the SN74GTL2003RKSR require external power supplies to operate?

No, the SN74GTL2003RKSR does not require a dedicated VCC supply. It operates passively using only the voltage present on its SREF, DREF, and GREF terminals - typically biased via external pullup resistors. This eliminates power supply sequencing concerns and makes the SN74GTL2003RKSR inherently latch-up immune and suitable for hot-insertion scenarios. However, external 200 kΩ pullup resistors to appropriate voltage rails (e.g., 3.3 V or 5 V) are mandatory on DREF/GREF, and SREF must be connected to the desired low-side reference voltage (e.g., 1.2 V or 1.8 V).

How does the SN74GTL2003RKSR handle bidirectional translation without a direction pin?

The SN74GTL2003RKSR uses an NMOS pass-transistor architecture where each channel behaves like a voltage-controlled switch. When either the Sn or Dn terminal is driven LOW, the transistor turns ON, creating a low-resistance path. When HIGH, the output is clamped to the SREF voltage (on Sn side) or pulled to VCC (on Dn side) via external resistors. This intrinsic behavior - governed by gate bias (GREF), reference (SREF/DREF), and signal polarity - eliminates the need for direction logic. The SN74GTL2003RKSR leverages this physics-based operation to achieve true bidirectional translation with zero added latency or control overhead.

What is the role of the SREF, DREF, and GREF pins on the SN74GTL2003RKSR?

SREF is the source terminal of the reference transistor and connects to the low-voltage domain supply (e.g., 1.2 V), setting the maximum output voltage on the Sn side. DREF is the drain terminal of the same reference transistor and must be tied directly to GREF, then pulled to the high-voltage domain supply (e.g., 3.3 V) via a 200 kΩ resistor. GREF is the common gate for all eight main channels and determines ON-resistance and translation threshold. Together, these three pins configure the SN74GTL2003RKSR for precise voltage-clamp behavior - a defining feature that distinguishes the SN74GTL2003RKSR from standard CMOS translators.

Can the SN74GTL2003RKSR be used for I²C bus level translation?

Yes, the SN74GTL2003RKSR is explicitly validated for I²C and SMBus applications, as confirmed in TI's datasheet Figure 9-1 and Section 9.2.1. Its bidirectional operation, low propagation delay (<5.5 ns), and compatibility with open-drain signaling make it ideal for translating between 1.8 V microcontrollers and 3.3 V or 5 V I²C peripherals. Designers must use 200 kΩ pullup resistors on both sides and ensure SREF is set to the controller's core voltage. The SN74GTL2003RKSR's lack of internal active circuitry prevents bus contention - a critical advantage over powered translators in multi-master I²C systems.