Texas Instruments LSF0204DRUTR

Overview

LSF0204DRUTR from Texas Instruments is a 4-bit bidirectional multi-voltage level translator optimized for open-drain and push-pull interfaces, supporting up to 100-MHz down-translation (3.3 V → 1.8 V, CL = 30 pF) and 40-MHz up/down translation at 50-pF load. It enables voltage translation between 0.8 V ↔ 5 V pairs without direction control, features I_off partial power-down mode, and operates across –40°C to 125°C for telecom and industrial I²C/SMBus signal bridging.

For engineers reviewing the LSF0204DRUTR datasheet, LSF0204DRUTR pinout, LSF0204DRUTR application, or LSF0204DRUTR equivalent, key selection criteria include verified 4-channel bidirectional operation, flow-through UQFN-12 pinout, 3.3 V ↔ 1.8 V I²C timing compliance, EN logic referenced to Vref_A, and low Ron (≤4 Ω) ensuring minimal signal distortion in high-speed GPIO and PMBus designs.

Technical Context

The LSF0204DRUTR implements a passive MOSFET-based switch architecture with no internal level-shifting circuitry-voltage translation is achieved via controlled conduction between A- and B-side I/Os using Vref_A and Vref_B as gate reference thresholds. Its enable input (EN) is referenced solely to Vref_A, requiring Vref_A to power up first for deterministic Hi-Z behavior during sequencing.

Each channel operates independently: A1↔B1, A2↔B2, A3↔B3, A4↔B4, allowing mixed-voltage configurations (e.g., 1.2 V ↔ 3.3 V on Ch1, 1.8 V ↔ 5 V on Ch2). Translation direction is fully automatic-no DIR pin-and performance scales with capacitive load: f_MAX = 100 MHz at CL ≤ 30 pF, dropping to 50 MHz at CL = 50 pF.

Key Specifications

Pinout & Package

LSF0204DRUTR is packaged in a 12-pin UQFN (RUT) with 2.00 mm × 1.70 mm body size and 0.4-mm pitch. The flow-through pinout minimizes PCB trace crossovers and supports compact layout in space-constrained applications such as server DIMMs and automotive ECUs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TXS0104EIRUKR and PCA9306DCUR, LSF0204DRUTR uniquely delivers 4-channel passive-switch translation with no DIR pin, 0.8-V minimum Vref_A, and validated 100-MHz down-translation - making it the only option for high-density, mixed-voltage I²C/SMBus expansion in thermally constrained UQFN layouts.

Availability

LSF0204DRUTR is available at Aetrix Electronics and suitable for telecom infrastructure, automotive ADAS domain controllers, and industrial PLC I/O modules requiring stable component supply across extended temperature and long production lifecycles.

Supply support for LSF0204DRUTR 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 decades of expertise in interface solutions and automotive-grade reliability.

The LSF family was designed specifically for high-speed, directionless voltage translation in mixed-supply systems - targeting I²C, SMBus, PMBus, MDIO, and GPIO bridging where minimal propagation delay, low power, and wide V_CC range interoperability are critical.

FAQ

What is the maximum supported capacitive load for 100-MHz operation of the LSF0204DRUTR?

The LSF0204DRUTR achieves 100-MHz down-translation (e.g., 3.3 V → 1.8 V) only at ≤30-pF total capacitive load, including PCB trace, connector, and device pin capacitance. At 50-pF load, maximum frequency drops to 40 MHz. This is confirmed in Section 7.6 of the SLVSCP5H datasheet under "Switching Characteristics: AC Performance (Translating Down, 3.3 V to 1.8 V)" - where f_MAX = 100 MHz is explicitly specified for CL = 30 pF and CL = 15 pF, but only 50 MHz for CL = 50 pF. Designers must verify layout parasitics to maintain timing margins for LSF0204DRUTR.

Does the LSF0204DRUTR support 0.8-V logic on both sides of the translation interface?

No - the LSF0204DRUTR supports 0.8 V only on the Vref_A side (A1–A4 pins). Vref_B must be ≥ Vref_A + 0.8 V per datasheet Table 10-2, and minimum Vref_B is 1.8 V. So valid pairs include 0.8 V ↔ 1.8 V, 0.8 V ↔ 2.5 V, etc., but not 0.8 V ↔ 0.8 V or 0.8 V ↔ 1.2 V. This constraint ensures sufficient gate overdrive for the internal pass transistor and is documented in Section 10.2.1.1.1 and the "Voltage Range Support" feature bullet. LSF0204DRUTR relies on this asymmetry for reliable conduction.

How does the EN pin behavior differ between LSF0204DRUTR and LSF0204D variants?

The LSF0204DRUTR uses the standard LSF0204 logic: EN is high-active and referenced to Vref_A - EN = HIGH enables translation, EN = LOW forces all I/Os into high-impedance state. In contrast, the LSF0204D variant has low-active EN (EN = LOW enables). This distinction is clearly defined in the "Device Comparison Table" (Section 5) and Pin Functions table (Section 6.1), where EN type is marked "active High" for LSF0204 and "active Low" for LSF0204D. Using the wrong variant risks permanent bus lockup - LSF0204DRUTR must be driven with Vref_A-sourced logic HIGH to operate.

Can the LSF0204DRUTR translate between 5-V and 1.2-V logic levels?

Yes - the LSF0204DRUTR supports 1.2 V ↔ 5 V bidirectional translation, as explicitly listed in the "Supports bidirectional voltage level translation between" feature bullet (Section 1). This is enabled by setting Vref_A = 1.2 V and Vref_B = 5 V. Electrical validation is provided in Section 7.7 ("Switching Characteristics: AC Performance (Translating Down, 3.3 V to 1.2 V)") and Section 7.9 ("Translating Up, 1.2 V to 1.8 V"), confirming functional operation and timing at these rails. However, pull-up resistors on the 5-V side must be sized per Equation 1 (Rpu = (Vpu – 0.35 V)/0.015 A) to limit pass-transistor current and maintain <350-mV voltage drop - a requirement directly tied to LSF0204DRUTR's Ron specification.

Is the LSF0204DRUTR pin-compatible with other packages in the LSF0204x family?

No - the LSF0204DRUTR (UQFN-12, RUT package) has a different pin count and layout than the TSSOP-14 (PW), VQFN-14 (RGY), or DSBGA-12 (YZP) variants. While all share identical functionality and signal names, the UQFN-12 pinout omits NC pins present in TSSOP/VQFN and relocates GND and EN. Table 6-1 confirms distinct pin mappings: e.g., GND is Pin 6 in RUT but Pin 7 in PW/RGY. Therefore, LSF0204DRUTR requires unique PCB footprint and cannot be substituted without layout revision - a critical detail for production BOM management and second-source planning.