Nexperia USA Inc. 74HCT4020BQ,115

Overview

74HCT4020BQ,115 from Nexperia is a 14-stage binary ripple counter IC with TTL-compatible inputs, asynchronous master reset (MR), and 12 buffered outputs (Q0, Q3–Q13). It advances on the HIGH-to-LOW clock edge, operates from 4.5 V to 5.5 V, supports -40 °C to +125 °C ambient range, and delivers 25 MHz max frequency at VCC = 4.5 V - used in precision timing division for industrial control logic.

For engineers reviewing the 74HCT4020BQ,115 datasheet, 74HCT4020BQ,115 pinout, 74HCT4020BQ,115 application, or 74HCT4020BQ,115 equivalent, this device serves as a low-power, high-noise-immunity ripple counter for frequency division, time delay generation, and sequential control where deterministic propagation delay stacking and TTL-level input compatibility are required.

Technical Context

The 74HCT4020BQ,115 implements a cascaded chain of 14 static toggle flip-flops, each triggered by the falling edge of the preceding stage's output - resulting in cumulative propagation delays across Q0→Q13. Its MR input forces all outputs LOW asynchronously, independent of CP state, enabling immediate system-wide reset.

Input thresholds are fixed at VIH = 2.0 V (min) and VIL = 0.8 V (max) under 4.5–5.5 V supply, ensuring robust interfacing with legacy TTL logic families. Output drive capability is ±4.0 mA at VOH ≥ 3.98 V and VOL ≤ 0.26 V, supporting direct fan-out to multiple 74HCT inputs without buffering.

Key Specifications

Pinout & Package

DHVQFN16 (SOT763-1) package: 2.5 × 3.5 × 0.85 mm body, no leads, exposed thermal pad (non-soldered or floating), 16 terminals in quad arrangement with terminal 1 index area.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 14-stage binary ripple counter applications.

Compared with 74HC4020BQ,115 and CD4020BE, the 74HCT4020BQ,115 uniquely bridges TTL logic families and modern low-power CMOS systems - offering guaranteed 5 V TTL input recognition, 25 MHz operation, and industrial temperature support in a thermally enhanced QFN package.

Availability

74HCT4020BQ,115 is available at Aetrix Electronics and suitable for frequency division, time delay generation, control counters, and LED sequencers requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for 74HCT4020BQ,115 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, high-reliability logic, analog, and discrete components.

The 74HCT4020BQ,115 belongs to Nexperia's 74HCT logic family, engineered for seamless TTL-to-CMOS interfacing in industrial automation, power management, and embedded control systems where robustness and timing predictability are critical.

FAQ

What is the function of the MR pin on the 74HCT4020BQ,115?

The MR (Master Reset) pin is an asynchronous active-HIGH input that forces all 14 counter stages to zero and drives all outputs (Q0, Q3–Q13) LOW regardless of the CP state or clock edge. It requires no clock cycle to take effect and overrides ongoing counting immediately - making it ideal for emergency system reset or initialization sequences.

Can the 74HCT4020BQ,115 operate at 3.3 V supply?

No - the 74HCT4020BQ,115 is specified only for 4.5 V to 5.5 V operation. At 3.3 V, input thresholds (VIH ≥ 2.0 V) may not be reliably met, and output drive strength degrades significantly. For 3.3 V systems, use the 74LVC4020 or 74AUP4020, which are explicitly characterized at 3.3 V with compatible logic levels.

Why does the DHVQFN16 package include an exposed pad with "no electrical requirement"?

The exposed thermal pad in the SOT763-1 (DHVQFN16) package improves thermal dissipation but has no electrical function. Nexperia specifies it may remain floating or connect to VCC - never to GND - to avoid unintended ground loops or parasitic capacitance that could degrade high-speed timing margins in ripple counters.

How does propagation delay accumulate across Q0 to Q13?

Each stage adds its own tpd (e.g., 15 ns typ from Qn to Qn+1 at VCC = 4.5 V), so total delay from CP to Q13 is the sum of 13 inter-stage delays plus CP→Q0 delay - approximately 210 ns max. This cumulative delay defines the minimum usable clock period and limits maximum cascade depth before timing violations occur.