Nexperia USA Inc. 74HCT4520DB,118

Overview

74HCT4520DB,118 from Nexperia is a dual 4-bit synchronous binary counter IC with two independent clock inputs (nCP0 and nCP1), asynchronous master reset (nMR), and buffered outputs (nQ0–nQ3 per counter). It operates at 4.5 V to 5.5 V, supports TTL-level inputs, delivers propagation delays as low as 24 ns (VCC = 5.0 V, CL = 15 pF), and functions across –40 °C to +125 °C for industrial timing applications such as multistage frequency division.

For engineers reviewing the 74HCT4520DB,118 datasheet, 74HCT4520DB,118 pinout, 74HCT4520DB,118 application, or 74HCT4520DB,118 equivalent, this device offers dual-edge-triggered counting logic, precise setup/pulse width timing constraints, and SO16 package compatibility - critical for deterministic digital control in programmable logic and state-machine designs.

Technical Context

The 74HCT4520DB,118 implements two independent 4-bit synchronous binary counters sharing no internal coupling - each advances on either the LOW-to-HIGH transition of nCP0 (when nCP1 = HIGH) or the HIGH-to-LOW transition of nCP1 (when nCP0 = LOW). Its asynchronous nMR input forces all eight outputs (1Q0–1Q3, 2Q0–2Q3) LOW regardless of clock state.

Input thresholds are TTL-compatible (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 4.5–5.5 V), output drive capability is ±4.0 mA (VOH ≥ 3.98 V, VOL ≤ 0.26 V), and dynamic performance is characterized up to 64 MHz (VCC = 5.0 V, CL = 15 pF), with power dissipation capacitance CPD = 24 pF.

Key Specifications

Pinout & Package

74HCT4520DB,118 is housed in a plastic small outline package (SO16, SOT109-1) with 16 leads, 3.9 mm body width, and standard 1.27 mm lead pitch - compatible with automated PCB assembly and IPC-7351B land patterns.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HC4520DB,118 and SN74LS4520N, the 74HCT4520DB,118 uniquely balances TTL input compatibility, industrial temperature support, and low-power CMOS efficiency - making it the optimal choice for new 5 V embedded timing designs requiring reliability and interoperability.

Availability

74HCT4520DB,118 is available at Aetrix Electronics and suitable for industrial motor control, programmable logic timing, and frequency division applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74HCT4520DB,118 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 discrete components with rigorous quality and reliability standards.

The 74HCT4520 belongs to Nexperia's high-speed TTL-compatible logic family, engineered specifically for robust 5 V digital control in industrial, automotive, and computing infrastructure where signal integrity and thermal resilience are critical.

FAQ

Can 74HCT4520DB,118 operate at 3.3 V supply?

No. The 74HCT4520DB,118 is specified only for 4.5 V to 5.5 V operation per its recommended conditions. At 3.3 V, input thresholds (VIH ≥ 2.0 V) may still be met, but VOH drops below 2.4 V and propagation delay exceeds 100 ns - violating functional and timing specifications. Use 74HC4520DB,118 instead for 2.0–6.0 V flexibility.

What is the maximum clock frequency when cascading both counters?

When cascading (e.g., feeding 1Q3 to 2CP0), the maximum input clock is limited by the sum of tpd(1CP0→1Q3) + tsu(2CP0) = 80 ns (VCC = 4.5 V), yielding ≤12.5 MHz. This accounts for worst-case propagation plus setup margin - not the standalone 64 MHz fmax of a single counter.

Is the SO16 package RoHS compliant and lead-free?

Yes. The SOT109-1 package used for 74HCT4520DB,118 is RoHS-compliant and lead-free per Nexperia's product compliance documentation (reference: "Lead-free and RoHS compliance statement" document number 98APA00111). Terminal finish is matte tin, with peak reflow temperature rated to 260 °C.

How does the dual-clock architecture prevent race conditions?

Race conditions are avoided because each counter advances only when one clock is active (edge-triggered) and the other is held at the required static level (HIGH for nCP0, LOW for nCP1). The function table explicitly defines "no change" states for invalid clock combinations, ensuring deterministic behavior regardless of skew between nCP0 and nCP1.