NXP Semiconductors 74ALVCH32501EC,557

Overview

74ALVCH32501EC,557 from NXP Semiconductors (formerly Philips) is a 36-bit universal bus transceiver with direction control and 3-state outputs, operating across 1.2 V to 3.6 V supply range, delivering ±24 mA drive at 3.0 V, supporting transparent/latched/clocked modes, and featuring integrated bus-hold circuitry for floating input stabilization in high-density memory or processor interconnect applications.

For engineers reviewing the 74ALVCH32501EC,557 datasheet, 74ALVCH32501EC,557 pinout, 74ALVCH32501EC,557 application, or 74ALVCH32501EC,557 equivalent, key selection criteria include dual 18-bit or single 36-bit bidirectional data flow control, active HIGH/LOW complementary OE pins (OEAB/OEBA), latch/clock enable flexibility, LFBGA114 package compatibility, and JEDEC 8-1A compliance for mixed-voltage system interfacing.

Technical Context

The 74ALVCH32501EC,557 implements two independent 18-bit transceiver channels sharing common control logic, each supporting A-to-B and B-to-A data paths with separate output enables (OEAB active HIGH, OEBA active LOW), latch enables (LEAB/LEBA), and clock inputs (CPAB/CPBA). Its D-type latches and flip-flops enable operation in transparent, edge-triggered clocked, or level-sensitive latched modes.

Bus-hold circuitry actively maintains valid logic levels on unused inputs without external pull-ups/downs, reducing board space and power overhead. Propagation delays are specified at 2.8 ns (CL = 30 pF, VCC = 2.5 V) and 3.0 ns (CL = 50 pF, VCC = 3.3 V), with 3-state enable/disable times under 6.3 ns, enabling high-speed synchronous bus arbitration in DDR memory subsystems and FPGA-to-ASIC bridging.

Key Specifications

Pinout & Package

Package: LFBGA114 (SOT537-1), plastic low-profile fine-pitch ball grid array, 16 mm × 5.5 mm × 1.05 mm body, 114 solder balls, 0.5 mm pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar universal bus transceiver applications.

Compared with SN74ALVCH32501KR, the 74ALVCH32501EC,557 offers identical performance but leverages NXP's long-term industrial support roadmap; versus 74LVC32501BQ, it provides critical bus-hold functionality and LFBGA114 mechanical compatibility for high-density memory modules where pin count and signal integrity are prioritized over package size.

Availability

74ALVCH32501EC,557 is available at Aetrix Electronics and suitable for memory interface bridging, FPGA-to-ASIC data aggregation, high-speed processor bus extension, and industrial PLC backplane interconnect requiring stable component supply across extended product lifecycles.

Supply support for 74ALVCH32501EC,557 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

NXP Semiconductors is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT applications, with roots in Philips' pioneering logic and interface IC development.

The 74ALVCH32501EC,557 belongs to NXP's advanced ALVCH logic family, engineered specifically for high-speed, low-voltage, mixed-signal system interconnects where bus integrity, voltage translation, and latch-controlled data staging are essential.

FAQ

What is the recommended power-up sequence for the 74ALVCH32501EC,557 to ensure reliable 3-state initialization?

For reliable high-impedance startup, tie nOEBA to VCC via a pull-up resistor and nOEAB to GND via a pull-down resistor. The minimum resistor value must respect the driver's current-sinking (nOEAB) and current-sourcing (nOEBA) capability per datasheet Section "DESCRIPTION". This prevents bus contention during VCC ramp-up and guarantees all outputs enter high-Z before control logic stabilizes. The 74ALVCH32501EC,557 does not include internal power-on reset circuitry, so external biasing is mandatory.

Does the 74ALVCH32501EC,557 support true bidirectional data flow on the same pin pairs, or are A and B sides physically separated?

The 74ALVCH32501EC,557 features physically separated A-side (nAn) and B-side (nBn) I/O terminals - there is no shared pin that switches direction. Data flows A→B or B→A through dedicated, non-overlapping pins. Each side has independent 3-state control (nOEAB/nOEBA), latch enable (nLEAB/nLEBA), and clock (nCPAB/nCPBA), enabling simultaneous or time-multiplexed bidirectional operation without pin contention. This architecture is confirmed in the Pin Configuration (Fig.1) and Function Table of the 74ALVCH32501EC,557 datasheet.

How does the bus-hold circuitry in the 74ALVCH32501EC,557 affect input leakage current specifications?

The bus-hold circuitry increases input leakage current relative to standard CMOS inputs: IBHL is +45 µA (2.3 V) and IBHH is −45 µA (2.3 V), versus typical ±0.1 µA quiescent leakage. This intentional current injection sustains valid logic levels on floating inputs but must be accounted for in ultra-low-power designs. The 74ALVCH32501EC,557 datasheet specifies ∆ICC = 150–750 µA additional quiescent current per enabled bus-hold I/O pin, directly impacting system-level sleep-mode current budgets.

Can the 74ALVCH32501EC,557 operate reliably at 1.2 V supply, and what performance trade-offs apply?

Yes, the 74ALVCH32501EC,557 is fully specified down to 1.2 V per JEDEC 8-1A, but AC performance degrades: propagation delay increases to 5.1 ns (CL = 30 pF), maximum clock frequency drops to 150 MHz, and output drive falls to ±12 mA. DC parameters remain valid, but timing margins shrink significantly. The 74ALVCH32501EC,557 is optimized for 2.5 V and 3.3 V operation; use 1.2 V only in power-constrained applications where speed is secondary.

What is the significance of the complementary OE polarity (nOEAB active HIGH, nOEBA active LOW) in the 74ALVCH32501EC,557?

The complementary OE polarity allows independent, conflict-free control of A→B and B→A data paths using simple single-ended logic signals - no external inverters needed. For example, asserting nOEAB HIGH and nOEBA LOW simultaneously enables full-duplex communication. This design reduces gate count and propagation delay in bus arbitration logic. The 74ALVCH32501EC,557 datasheet explicitly defines this behavior in the Function Table and DESCRIPTION section, confirming it is an intrinsic feature, not a configuration option.