onsemi 29F52SPC

Overview

29F52SPC from Fairchild Semiconductor is a non-inverting 8-bit registered transceiver with dual independent registers, separate clock (CPA/CPB), clock enable (CEA/CEB), and 3-STATE output enable (OEA/OEB) controls per register, 24 mA sink capability on A-side outputs (A0–A7), 64 mA on B-side outputs (B0–B7), and operates at +4.5V to +5.5V supply voltage for bidirectional data buffering in bus isolation applications.

For engineers reviewing the 29F52SPC datasheet, pinout, applications, or equivalent options, this device supports precise timing-critical bidirectional data flow between two buses with independent register control, high-drive outputs, and industrial-grade DC/AC electrical specifications verified across 0°C to +70°C ambient.

Technical Context

The 29F52SPC implements two back-to-back 8-bit D-type registers-one for A→B direction, one for B→A-each with dedicated edge-triggered clock inputs (CPA, CPB), asynchronous clock enables (CEA, CEB), and independent 3-STATE output enables (OEA, OEB). It uses standard TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max) and delivers guaranteed drive strength: 24 mA sink on A0–A7, 64 mA sink on B0–B7.

Its AC performance includes tPLH/tPHL propagation delays of 3.0–7.5 ns (typ/max at +25°C, CL = 50 pF), tPZH/tPZL output enable/disable times down to 2.5 ns, and setup/hold times of 4.0 ns/2.0 ns for data-to-clock alignment-enabling reliable operation in synchronous bus systems operating up to ~100 MHz effective data rate.

Key Specifications

Pinout & Package

29F52SPC is housed in a 24-lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" wide, with through-hole mounting and industry-standard pin spacing.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit registered transceiver applications.

Compared with Am2952PC, 29F52SPC offers identical functionality and drop-in compatibility; compared with 74F245N, 29F52SPC adds essential clocked registration, independent directional control, and higher drive strength-critical for synchronous bus arbitration and noise-immune data capture.

Availability

29F52SPC is available at Aetrix Electronics and suitable for microprocessor bus isolation, memory expansion interface, and industrial control backplane applications requiring stable component supply, long-lifecycle support, and verified 5 V TTL interoperability.

Supply support for 29F52SPC 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

Fairchild Semiconductor was a U.S.-based semiconductor manufacturer specializing in analog, power, and interface ICs before its acquisition by ON Semiconductor in 2016.

The 29F52SPC belongs to Fairchild's registered transceiver product line, designed specifically for high-reliability bidirectional bus interfacing in industrial and computing systems requiring deterministic timing and robust drive capability.

FAQ

What is the key functional difference between 29F52SPC and 29F53SPC?

The 29F52SPC is a non-inverting registered transceiver, while the 29F53SPC provides inverting logic on both A→B and B→A data paths. Both share identical pinout, timing, drive strength, and control architecture. The inversion behavior is fixed per device and cannot be configured; selection depends strictly on system-level logic polarity requirements. 29F52SPC maintains signal polarity across registers, making it suitable for applications where data integrity and sign preservation are critical.

Does 29F52SPC support operation at 3.3 V supply voltage?

No, 29F52SPC is specified only for +4.5 V to +5.5 V operation per its DC Electrical Characteristics table. It does not meet VIH/VIL thresholds or output drive specifications at 3.3 V, and applying 3.3 V to VCC may result in undefined logic states or insufficient output swing. For 3.3 V systems, designers should consider modern registered transceivers such as the SN74LVCH16245A or similar LVCMOS-compatible alternatives-not 29F52SPC.

What is the maximum capacitive load supported by 29F52SPC outputs?

The 29F52SPC AC Electrical Characteristics are tested at CL = 50 pF, and its propagation delay (tPLH/tPHL) and output enable timing (tPZH/tPZL) are guaranteed only under that condition. While the device can drive higher capacitance, timing margins degrade linearly beyond 50 pF. For reliable operation above 50 pF, derating analysis per application-specific trace length and termination is required. 29F52SPC is not characterized for >100 pF loads in official documentation.

Can OEA and OEB be tied together for simultaneous 3-STATE control of both registers?

Yes, OEA and OEB may be connected to a single control signal to disable both A- and B-register outputs concurrently. This configuration is electrically valid and commonly used in bus arbitration schemes where full bidirectional isolation is needed. However, doing so forfeits independent directional control-e.g., holding A→B active while disabling B→A-which is a core capability of 29F52SPC. Use tied enables only when symmetric bus release is acceptable.

Is 29F52SPC RoHS compliant?

The original 29F52SPC was manufactured prior to RoHS enforcement and uses leaded PDIP packaging (JEDEC MS-001). It is not RoHS compliant. No lead-free version was released by Fairchild. For RoHS-compliant alternatives, engineers should evaluate newer-generation registered transceivers such as the TI SN74ALVCH16245 or NXP 74LVC16245A, which offer compatible functionality in green-compliant packages-but these are not drop-in replacements for 29F52SPC.