Nexperia USA Inc. 74HCT4020D,653

Overview

74HCT4020D,653 from Nexperia is a 14-stage asynchronous binary ripple counter IC with TTL-compatible inputs, 12 buffered outputs (Q0, Q3–Q13), master reset (MR) active HIGH, and clock input (CP) triggered on HIGH-to-LOW transition. It operates from 4.5 V to 5.5 V, supports -40 °C to +125 °C, and delivers f_max = 25 MHz at V_CC = 4.5 V with CL = 50 pF - used in precision frequency division and timing delay circuits for industrial control logic.

For engineers reviewing the 74HCT4020D,653 datasheet, 74HCT4020D,653 pinout, 74HCT4020D,653 application, or 74HCT4020D,653 equivalent, this page provides verified functional identity, SO16 package mapping, CP/MR timing behavior, output stage count, and direct substitution guidance - all confirmed against Nexperia's Rev. 9 (27 March 2024) product data sheet.

Technical Context

This device implements a cascaded chain of 14 static toggle flip-flops, advancing only on the falling edge of CP. Each stage drives the next via internal ripple propagation, resulting in cumulative delay per stage (e.g., 8 ns typical Qn→Qn+1 at V_CC = 4.5 V). MR overrides all stages asynchronously, forcing Q0–Q13 LOW regardless of CP state.

No internal synchronization or carry lookahead is present; output transitions are inherently non-simultaneous. Input clamp diodes enable safe interfacing to voltages exceeding V_CC, and TTL-level input thresholds (VIH = 2.0 V min, VIL = 0.8 V max at V_CC = 5 V) ensure compatibility with legacy 5 V logic families.

Key Specifications

Pinout & Package

74HCT4020D,653 is housed in a plastic small outline package (SO16, SOT109-1) with 16 leads, 3.9 mm body width, and gull-wing lead form. Pin 1 index is marked by a bevelled corner or notch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HC4020D,653 and CD4020BE, the 74HCT4020D,653 uniquely bridges TTL input compatibility with 25 MHz operation and industrial temperature range - making it the only choice for reliable 5 V legacy system integration requiring both speed and noise resilience.

Availability

74HCT4020D,653 is available at Aetrix Electronics and suitable for frequency division, time delay generation, control sequence logic, and serial data rate reduction requiring stable component supply across automotive-grade temperature ranges and long-lifecycle industrial programs.

Supply support for 74HCT4020D,653 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 devices optimized for reliability and manufacturability.

The 74HCT4020 belongs to Nexperia's industry-standard 74-series logic family, engineered specifically for drop-in replacement of legacy TTL counters while maintaining pinout and electrical compatibility across wide temperature and supply ranges.

FAQ

What is the maximum clock frequency supported by 74HCT4020D,653?

The maximum operating frequency is 25 MHz at V_CC = 4.5 V with 50 pF load, as specified in Table 7 of the Nexperia Rev. 9 datasheet. At V_CC = 5.0 V and CL = 15 pF, f_max increases to 52 MHz. Performance degrades above 125 °C due to Ptot derating (12.4 mW/K above 110 °C for SO16).

Can 74HCT4020D,653 be used with a 3.3 V microcontroller clock output?

No - the 74HCT4020 requires TTL-level inputs (VIH ≥ 2.0 V, VIL ≤ 0.8 V at V_CC = 5 V), but its V_CC must be 4.5–5.5 V. A 3.3 V clock signal falls below the guaranteed VIH threshold; use a level shifter or select the 74HC4020 variant with CMOS inputs if 3.3 V supply is mandatory.

How does the asynchronous MR pin behave during clock activity?

MR is fully asynchronous and overrides all internal states immediately upon going HIGH, forcing Q0–Q13 LOW within t_PHL(MR→Qn) ≤ 68 ns (max at V_CC = 5 V). This occurs independently of CP state or edge timing - no clock cycle is required for reset assertion or release.

Are all 14 counter stages accessible at the pins?

No - only 12 outputs are externally available: Q0 and Q3 through Q13. Q1 and Q2 are internal-only and not bonded out. The counter advances through all 14 stages, but only the listed outputs are buffered and routed to package pins per Figure 1 and Table 2.