NXP Semiconductors 74HCT4020D,652

Overview

74HCT4020D,652 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, and delivers f_max = 25 MHz at V_CC = 4.5 V for frequency division in industrial timing circuits.

For engineers reviewing the 74HCT4020D,652 datasheet, 74HCT4020D,652 pinout, 74HCT4020D,652 application, or 74HCT4020D,652 equivalent, this device serves as a low-power, temperature-stable ripple counter for clock division, time delay generation, and control sequencing where precise cascaded divide-by-2 stages are required.

Technical Context

This device implements a synchronous-cascade-free 14-bit ripple counter using static CMOS toggle flip-flops, where each stage drives the next via its Q output - resulting in cumulative propagation delay (e.g., 18 ns CP→Q0, 8 ns Q_n→Q_n+1 at 4.5 V). Its TTL-level input thresholds (V_IL = 0.8 V, V_IH = 2.0 V) ensure direct compatibility with legacy 5 V logic families without level shifting.

The MR input is asynchronous and active-HIGH, forcing all outputs LOW regardless of CP state; clamp diodes on all inputs permit safe interfacing to voltages exceeding V_CC when used with current-limiting resistors. Output drive capability is ±4.0 mA at V_CC = 4.5 V, with VOL ≤ 0.26 V and VOH ≥ 3.98 V under load.

Key Specifications

Pinout & Package

74HCT4020D,652 uses the SO16 (SOT109-1) plastic small outline package: 16-pin, 3.9 mm body width, gull-wing leads, JEDEC MS-012 compliant. Pin 1 index located at top-left corner; recommended reflow profile per J-STD-020.

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 SN74LV4020DR, the 74HCT4020D,652 uniquely balances TTL interoperability, industrial temperature resilience, and proven board-level reliability in fixed-frequency divider roles - making it optimal for retrofitting into existing 5 V control hardware.

Availability

74HCT4020D,652 is available at Aetrix Electronics and suitable for frequency division, time delay generation, control sequencing, and LED pattern control requiring stable component supply across automotive-grade thermal ranges and long-lifecycle production programs.

Supply support for 74HCT4020D,652 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 specializing in high-volume, high-reliability logic, discrete, and MOSFET solutions, with manufacturing rooted in process control and automotive-grade quality systems.

The 74HCT4020 belongs to Nexperia's industry-standard 74-series logic family, engineered specifically for robust, pin-compatible replacement of legacy TTL counters in industrial control, power management, and instrumentation applications.

FAQ

What is the maximum clock frequency supported by 74HCT4020D,652 at 5.0 V?

At V_CC = 5.0 V with C_L = 15 pF, the maximum clock frequency is 47 MHz (typical) per datasheet Table 7. This value reflects guaranteed operation under recommended conditions; actual system-level f_max may be limited by cumulative ripple delay across all 14 stages, especially when routing Q_n to Q_n+1 loads.

Can 74HCT4020D,652 be operated from a 3.3 V supply?

No - the 74HCT4020 variant is specified only for 4.5 V to 5.5 V operation (Table 5). At 3.3 V, input thresholds fall outside TTL specification (V_IH min = 2.0 V becomes marginal), and output drive degrades significantly. For 3.3 V systems, use 74LVC4020 or 74AUP4020 instead.

How does the asynchronous MR input behave during clock transitions?

The MR input overrides all clock activity: when asserted HIGH, it forces Q0–Q13 LOW immediately (t_PHL ≤ 45 ns at V_CC = 4.5 V), regardless of CP state or edge. No setup/hold timing relative to CP is required, enabling immediate, unconditional reset in fault-handling circuits.

Are unused outputs required to be terminated?

No - all outputs (Q0, Q3–Q13) are fully buffered CMOS and may be left unconnected without affecting functionality or stability. However, floating inputs (none apply here, as MR and CP must be actively driven) would require pull-up/down; outputs do not.