NXP Semiconductors 74HC4520D,112

Overview

74HC4520D,112 from Nexperia is a dual 4-bit synchronous binary counter IC with two independent clock inputs (1CP0/1CP1 and 2CP0/2CP1), asynchronous master reset (1MR/2MR), and buffered Q0–Q3 outputs per counter. It operates from 2.0 V to 6.0 V, supports dual-edge clocking (LOW-to-HIGH on CP0 when CP1 = HIGH; HIGH-to-LOW on CP1 when CP0 = LOW), and is rated for -40 °C to +125 °C. It is used in multistage synchronous counting and frequency division circuits.

For engineers reviewing the 74HC4520D,112 datasheet, 74HC4520D,112 pinout, 74HC4520D,112 application, or 74HC4520D,112 equivalent, this device serves as a precise, low-power, CMOS-compatible binary counter for timing control, clock division, and digital state sequencing where dual independent 4-bit counting with flexible edge-triggered clocks is required.

Technical Context

The 74HC4520D implements two identical, internally synchronous 4-bit binary counters sharing no internal signal paths-each has dedicated clock inputs (CP0/CP1), reset (MR), and outputs (Q0–Q3). Clocking logic enables either CP0 or CP1 to serve as primary clock while the other acts as enable, supporting both rising- and falling-edge triggered operation within the same package.

Its static and dynamic behavior is defined across supply voltages (2.0–6.0 V) and temperature (-40 °C to +125 °C), with propagation delays as low as 22 ns (VCC = 6.0 V, CL = 50 pF) and maximum operating frequency up to 69 MHz (VCC = 6.0 V, 74HC variant). Input clamping diodes allow safe interfacing to voltages exceeding VCC when used with current-limiting resistors.

Key Specifications

Pinout & Package

74HC4520D,112 is housed in a 16-pin SO16 (SOT109-1) plastic small outline package, 3.9 mm body width, with standard 1.27 mm pitch and gull-wing leads. Pin 1 is marked by a notch or dot; pin numbering follows counter-clockwise convention from top-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual 4-bit synchronous counter applications.

Compared with 74HCT4520D,112, the HC version offers lower static power and wider voltage tolerance but requires CMOS-level drive; versus SN74LV4040DR, the 74HC4520D provides deterministic synchronous timing and dual-channel isolation at the cost of smaller modulus per channel.

Availability

74HC4520D,112 is available at Aetrix Electronics and suitable for industrial automation controllers, digital instrumentation, test equipment frequency synthesis, and microcontroller timing extension requiring stable component supply across extended temperature ranges.

Supply support for 74HC4520D,112 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 logic, discrete, and MOSFET components for automotive, industrial, and consumer applications.

The 74HC4520 belongs to Nexperia's 74HC logic family - engineered for low-power, wide-voltage-operation digital building blocks targeting industrial control, instrumentation, and timing-critical embedded systems.

FAQ

Can 74HC4520D,112 operate reliably at 3.3 V?

Yes. The 74HC4520D,112 is fully specified from 2.0 V to 6.0 V, including 3.3 V operation. At VCC = 3.3 V, VIH = 2.31 V (70% of VCC) and VIL = 0.99 V (30% of VCC) ensure robust noise margins. Propagation delay is 36 ns (typical) and fmax reaches 45 MHz - sufficient for most 3.3 V microcontroller timing extensions.

What is the purpose of the dual clock inputs (CP0 and CP1)?

CP0 and CP1 provide flexible edge-triggered clocking: the counter advances on CP0's rising edge only when CP1 is HIGH, or on CP1's falling edge only when CP0 is LOW. This allows either pin to serve as clock while the other acts as enable - enabling gated counting, phase-selectable division, or dual-signal synchronization without external logic.

Is the 74HC4520D,112 pin-compatible with the 74HC4040?

No. The 74HC4520D,112 uses a 16-pin SO16 package with dual counters, separate CP0/CP1 inputs, and individual MR pins. The 74HC4040 is a 12-bit ripple counter in 16-pin SO16 but has only one clock and one reset. Pin functions differ completely - e.g., pins 1/2 are CP0/CP1 on 4520 but CLK/NC on 4040 - making them not interchangeable.

How does the asynchronous master reset (MR) behave during clock transitions?

The MR input is asynchronous and active HIGH: asserting MR forces all Q outputs LOW immediately, overriding any ongoing clock activity. This occurs within tPHL (max 45 ns at VCC = 4.5 V) regardless of CP0/CP1 state. Release of MR returns the counter to its prior state only if clocks are held stable - no race conditions occur due to internal synchronizer-free design.