Nexperia USA Inc. HEF4021BTT-Q100J

Overview

HEF4021BTT-Q100 from Nexperia is an AEC-Q100 Grade 1 qualified 8-bit static shift register (parallel-to-serial converter) with synchronous serial input (DS), asynchronous parallel load (PL), and buffered Q5–Q7 outputs. It operates from 3 V to 15 V, features Schmitt-trigger clock input for noise immunity, and supports automotive ambient temperatures up to +125 °C. Used in body control modules for LED multiplexing and sensor data serialization.

For engineers reviewing the HEF4021BTT-Q100 datasheet, HEF4021BTT-Q100 pinout, HEF4021BTT-Q100 application, or HEF4021BTT-Q100 equivalent, key selection criteria include parallel-load timing (tW ≥ 24 ns @ 15 V), CP-to-Qn propagation delay (40 ns min @ 15 V), output drive capability (±2.4 mA @ 15 V), and TSSOP16 thermal derating (8.5 mW/K above 91 °C).

Technical Context

The HEF4021BTT-Q100 implements eight cascaded D-type master-slave flip-flops, each with independent SD and CD inputs, enabling full asynchronous reset/set control per stage. Its dual-mode operation-parallel load (PL HIGH) and serial shift (PL LOW)-is decoupled from clock edge sensitivity, allowing deterministic data capture independent of CP state.

Schmitt-trigger action on CP ensures robust clocking with slow-rising signals (Δt/ΔV down to 0.08 μs/V at 15 V), while CMOS architecture delivers static operation with IDD ≤ 600 μA at 15 V and +125 °C. Output VOH/VOL specifications are rail-to-rail referenced (e.g., VOH = 14.95 V @ 15 V, |I_O| < 1 μA), supporting direct interface with 5 V/10 V logic families.

Key Specifications

Pinout & Package

TSSOP16 plastic thin shrink small outline package (SOT403-1); 16-pin, 4.4 mm body width; lead pitch 0.65 mm; RoHS-compliant; moisture sensitivity level MSL3.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit static shift register applications.

Compared with SN74HC165QPWRQ1 and 74LVC164APWJ, the HEF4021BTT-Q100 uniquely combines AEC-Q100 Grade 1 qualification, 3–15 V operation, per-stage SD/CD control, and three buffered mid-register outputs - making it the only option for automotive applications demanding atomic parallel load, wide voltage tolerance, and real-time internal state visibility.

Availability

HEF4021BTT-Q100 is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC I/O expansion, door module status acquisition, and diagnostic data loggers requiring stable component supply across extended temperature and voltage ranges.

Supply support for HEF4021BTT-Q100 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 delivering high-performance logic, discrete, and MOSFET solutions optimized for automotive, industrial, and mobile applications with emphasis on reliability and energy efficiency.

The HEF4021BTT-Q100 belongs to Nexperia's automotive-qualified logic portfolio, designed specifically for robust serial data conversion in harsh environments where wide supply range, AEC-Q100 compliance, and noise-immune clocking are mandatory.

FAQ

What is the minimum pulse width required on the PL pin for reliable parallel load operation?

The HEF4021BTT-Q100 requires a minimum PL HIGH pulse width (tW) of 24 ns at VDD = 15 V and +125 °C, per Table 7. This ensures complete asynchronous loading of all eight D0–D7 bits into the register regardless of CP or DS state. At lower voltages or temperatures, the requirement relaxes to 35 ns at 10 V and 70 ns at 5 V, enabling flexible timing margin allocation in microcontroller-driven systems.

Can unused inputs be left floating in automotive designs?

No - all unused inputs must be externally tied to VDD, VSS, or another driven input, as specified in Section 1 of the datasheet. Floating CMOS inputs cause increased supply current, unpredictable logic states, and potential latch-up in high-noise automotive environments. This requirement is enforced in AEC-Q100 stress testing and applies to SD, CD, DS, CP, and PL when not actively used.

How does the Schmitt-trigger clock input improve system-level noise immunity?

The Schmitt-trigger on CP provides hysteresis of typically 1.5 V at 5 V supply, meaning the rising threshold is ~3.5 V and falling threshold is ~2.0 V. This prevents multiple clock edges from slow-rising noise transients and allows direct interface with unconditioned signals from switches, sensors, or RC oscillators - reducing BOM cost and PCB area versus adding external hysteresis circuitry.

What thermal derating applies to the TSSOP16 package at elevated ambient temperatures?

The SOT403-1 (TSSOP16) package has a total power dissipation (Ptot) derating slope of 8.5 mW/K above +91 °C, per Table 4 footnote [1]. At +125 °C ambient, Ptot is reduced by (125 − 91) × 8.5 = 289 mW from its 500 mW rating at +110 °C, resulting in a maximum allowable Ptot of 211 mW. Designers must verify dynamic power (PD) using the formula PD = 12000 × fi + Σ(fo × CL) × VDD² at worst-case VDD = 15 V and fi/f_o.