Nexperia USA Inc. 74LVC8T245BZX

Overview

74LVC8T245BZX from Nexperia is an 8-bit dual-supply translating transceiver with 3-state outputs, enabling bidirectional level translation between independent voltage domains (1.2 V to 5.5 V). It features separate VCC(A) and VCC(B) supplies, DIR-controlled data direction, active-low OE for bus isolation, and IOFF circuitry for partial power-down protection. Used in mixed-voltage I²C, SPI, and parallel bus interfacing between FPGA/ASIC and legacy peripherals.

For engineers reviewing the 74LVC8T245BZX datasheet, 74LVC8T245BZX pinout, 74LVC8T245BZX application, or 74LVC8T245BZX equivalent, key selection criteria include dual-rail voltage flexibility (1.2–5.5 V per rail), 24-pin DHXQFN package thermal performance, suspend-mode behavior during rail loss, bus-hold capability (74LVCH variant), and propagation delay asymmetry (A→B vs B→A).

Technical Context

This device implements a dual-voltage CMOS transceiver architecture with independent input referencing: An, DIR, and OE pins are referenced to VCC(A); Bn pins to VCC(B). Direction control is synchronous and non-latched - data flows A→B when DIR = HIGH, B→A when DIR = LOW. Output enable (OE) is active-low and overrides direction control to force high-impedance on both ports.

The IOFF circuit ensures leakage current remains ≤±2 μA when either VCC rail is at GND, enabling safe hot-insertion and partial power-down operation. Suspend mode activates automatically if VCC(A) = 0 V or VCC(B) = 0 V, placing both A and B ports in high-impedance OFF-state without external intervention.

Key Specifications

Pinout & Package

DHXQFN24 package (SOT8024-1): 2 mm × 4 mm × 0.48 mm body, 0.4 mm pitch, 24-terminal leadless construction with exposed thermal pad (non-soldered or floating per datasheet). Optimized for space-constrained PCBs and thermal dissipation in high-density designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supply translating transceiver applications.

Compared with SN74AVC8T245RHLR, the 74LVC8T245BZX provides superior power sequencing safety via IOFF and suspend mode; compared with 74LVCH8T245BZX, it trades bus-hold for lower static current (30 μA vs 45 μA), making it preferable in always-on monitoring applications.

Availability

74LVC8T245BZX is available at Aetrix Electronics and suitable for industrial PLC backplane interfaces, automotive ADAS camera links, and server memory subsystem isolation requiring stable component supply across extended temperature ranges.

Supply support for 74LVC8T245BZX 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 essential efficiency technologies, delivering high-performance logic, analog, and MOSFET solutions for automotive, industrial, and consumer markets.

The 74LVC/LVCH family delivers robust, low-power, dual-supply level translation for mixed-voltage digital systems - designed specifically to replace discrete resistor networks and simplify voltage domain bridging in space- and power-constrained designs.

FAQ

What is the maximum allowable voltage difference between VCC(A) and VCC(B)?

The datasheet permits any combination within 1.2 V to 5.5 V per rail, including ΔVCC = 4.3 V (e.g., VCC(A) = 1.2 V, VCC(B) = 5.5 V). Absolute maximum ratings allow -0.5 V to +6.5 V per supply, but recommended operation stays within 1.2–5.5 V. No derating is required for large inter-rail differentials.

Can DIR and OE be driven from a different voltage domain than VCC(A)?

No. DIR and OE inputs are strictly referenced to VCC(A) and must be driven between 0 V and VCC(A). Driving them from another rail (e.g., VCC(B)) violates the input voltage specification and may cause undefined behavior or damage. External level shifting is required if control signals originate outside VCC(A) domain.

Does the 74LVC8T245BZX support hot-swap insertion while VCC(B) is powered?

Yes - IOFF circuitry limits power-off leakage to ≤±2 μA when VCC(A) = 0 V and VCC(B) = 1.2–5.5 V, preventing backfeed into the unpowered A-side. This enables safe hot-swap of modules where B-side remains live while A-side is inserted or removed.

How does propagation delay vary with load capacitance and supply voltage?

tpd decreases with higher VCC and lower CL: e.g., A→B delay is 5.4 ns (typ) at VCC(A)=3.3 V, VCC(B)=5.0 V, CL=15 pF, but rises to 13.5 ns at VCC(A)=1.2 V, same CL. Graphs Fig. 6–8 show tPLH/tPHL vs CL across six VCC(B) values - design must use worst-case values from Table 11 for timing closure.