Nexperia USA Inc. LSF0108BQX

Overview

LSF0108BQX from Nexperia is an 8-channel bidirectional multi-voltage level translator supporting open-drain and push-pull interfaces, with no direction pin required, ≤100 MHz up-translation and ≥100 MHz down-translation at ≤30 pF load, 5 V tolerant I/O pins, and operation from –40 °C to +125 °C - used in I²C, SMBus, and PMBus voltage domain bridging between 0.95 V/1.2 V/1.8 V/2.5 V/3.3 V and 5.0 V logic domains.

For engineers reviewing the LSF0108BQX datasheet, LSF0108BQX pinout, LSF0108BQX application, or LSF0108BQX equivalent, this page delivers verified electrical parameters, DHVQFN20 package layout, real-world interface use cases, and validated alternative parts for mixed-voltage system design and PCB-level signal integrity planning.

Technical Context

The LSF0108BQX implements passive MOSFET-based bidirectional translation without internal level-shifting circuitry or direction control, enabling automatic signal flow in both directions per channel. Its reference voltage pins (refA and refB) independently set translation thresholds for A-side and B-side I/O banks.

It supports hot insertion and high-impedance I/O when EN = LOW, with R_ON as low as 3 Ω (typ.) at V_refA = 2.5 V and I_O = 32 mA, and C_io(on) ≤ 12.5 pF ensuring minimal capacitive loading on high-speed buses like I²C Fast-mode Plus (1 Mbps).

Key Specifications

Pinout & Package

DHVQFN20 (SOT764-1) package: 2.5 mm × 4.5 mm × 0.85 mm body, 20-terminal quad flat no-lead with exposed thermal pad (non-soldered by default), optimized for space-constrained routing and thermal performance in dense PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TXS0108E and PCA9306, LSF0108BQX offers full 8-channel independence, user-defined refA/refB voltages, push-pull compatibility, and DHVQFN thermal performance - making it the only option supporting 100 MHz translation and asymmetric domain bridging in compact industrial designs.

Availability

LSF0108BQX is available at Aetrix Electronics and suitable for industrial PLCs, telecom SFP+ modules, server BMC subsystems, and embedded sensor hubs requiring stable component supply across extended temperature and mixed-voltage operating conditions.

Supply support for LSF0108BQX 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

Nexperia is a global semiconductor expert focused on high-volume, high-reliability standard logic, analog, and power devices, headquartered in Nijmegen, Netherlands, with manufacturing in Europe and Asia.

The LSF series targets high-speed, flexible voltage translation in space- and power-constrained applications - designed specifically for I²C, SMBus, PMBus, and GPIO bridging in industrial, telecom, and computing infrastructure.

FAQ

What is the maximum capacitive load supported at 100 MHz translation?

The LSF0108BQX supports ≤100 MHz up-translation and ≥100 MHz down-translation only at ≤30 pF total load, as confirmed in Table 7 of the datasheet. At 50 pF, maximum speed drops to ≤50 MHz (up) and ≥50 MHz (down). Exceeding 30 pF at 100 MHz causes timing violations and signal integrity loss.

Can refA and refB be set to the same voltage?

Yes - refA and refB may be tied to identical voltages (e.g., both at 1.8 V) to enable symmetric 1.8 V ↔ 3.3 V translation. The device functions correctly in this configuration; however, independent setting unlocks asymmetric use cases like 1.2 V ↔ 5.0 V, which is a key differentiator versus fixed-ratio translators.

Is the exposed thermal pad on the DHVQFN20 package required to be soldered?

No - per datasheet section 6.1, the thermal pad (terminal 1) has no electrical or mechanical requirement to be soldered. If soldered, it must remain electrically floating or be connected to GND; improper connection risks latch-up or thermal stress. Most industrial designs leave it unsoldered unless thermal validation confirms benefit.

Does LSF0108BQX support hot insertion in live backplanes?

Yes - the datasheet explicitly lists "Hot insertion" as a feature (Section 2), enabled by its high-impedance I/O state during power ramp-up and EN-controlled shutdown. Combined with ±2000 V HBM ESD rating and JESD78 Class II latch-up immunity (>100 mA), it meets telecom backplane hot-swap reliability requirements.