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Nexperia USA Inc. HEF4021BTTJ
- Part No.:
- HEF4021BTTJ
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Shift Registers
- Package:
- 16-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
HEF4021BTTJ.pdf
- Description:
- IC SHIFT REGISTER 8BIT
- Quantity:
- Payment:
- Shipping:
Inventory:624
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Product details
Overview
HEF4021BTT from Nexperia is an 8-bit static shift register (parallel-to-serial converter) with asynchronous parallel load (PL), synchronous serial data input (DS), LOW-to-HIGH edge-triggered clock (CP), and buffered outputs Q5–Q7. It operates from 3 V to 15 V, supports -40 °C to +125 °C ambient range, and features Schmitt-trigger CP input for noise immunity. Used in industrial control logic, LED matrix drivers, and legacy microcontroller I/O expansion.
For engineers reviewing the HEF4021BTT datasheet, HEF4021BTT pinout, HEF4021BTT application, or HEF4021BTT equivalent, key selection criteria include its wide VDD range (3–15 V), asynchronous parallel load capability, static CMOS operation, and TSSOP16 package compatibility with high-density PCB layouts.
Technical Context
The HEF4021BTT implements eight cascaded D-type master-slave flip-flops, each with direct set (SD) and clear (CD) inputs. Parallel loading occurs asynchronously when PL = HIGH, independent of CP or DS state. Serial shifting advances data rightward on each CP LOW-to-HIGH transition while PL = LOW.
Schmitt-trigger action on CP enables robust timing with slow-rising signals; propagation delays scale with load capacitance (e.g., tPHL = 32 ns + 0.16 ns/pF × CL at VDD = 15 V). Static operation ensures zero dynamic power when idle, and output drive strength is specified across 5 V/10 V/15 V rails with guaranteed VOH/VOL over full temperature range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VDD Range | 3 V to 15 V - Enables single-supply operation across 5 V, 10 V, and 15 V logic systems without level-shifting. |
| Operating Temp | -40 °C to +125 °C - Qualified for extended industrial environments including motor control and power supply monitoring. |
| Max Clock Freq | 40 MHz at VDD = 15 V - Supports high-speed serial data streaming in real-time I/O expansion applications. |
| Propagation Delay | 40 ns (max) at VDD = 15 V, CL = 50 pF - Ensures predictable timing margins in synchronous control chains. |
| Input Hysteresis | Schmitt-trigger CP input - Tolerates >1 V of noise on clock line without false triggering. |
| ESD Rating | HBM >2000 V, CDM >1000 V - Robust handling during board assembly and field service. |
| Output Drive | IOL = 2.4 mA / IOH = −2.4 mA at VDD = 15 V - Sufficient to directly drive LEDs or TTL-compatible inputs. |
Pinout & Package
TSSOP16 plastic thin shrink small outline package (SOT403-1); 16-pin, 4.4 mm body width, 0.65 mm lead pitch; RoHS-compliant, moisture sensitivity level MSL3.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | D7 | Parallel data input bit 7 - Loaded simultaneously with D0–D6 when PL = HIGH. |
| 2 | Q5 | Buffered output from stage 5 - Provides access to intermediate shift register content for feedback or daisy-chaining. |
| 3 | Q7 | Buffered output from stage 7 - Final-stage output used for serial stream termination or status indication. |
| 4 | D3 | Parallel data input bit 3 - Part of 8-bit parallel bus aligned to standard byte ordering. |
| 5 | D2 | Parallel data input bit 2 - Enables fast parallel capture of sensor or bus data without clock dependency. |
| 6 | D1 | Parallel data input bit 1 - Used in conjunction with D0–D7 for latch-and-shift operations in control registers. |
| 7 | D0 | Parallel data input bit 0 - LSB of parallel load word; critical for alignment-sensitive interfaces like 7-segment decoders. |
| 8 | VSS | Ground reference - Must be low-impedance connection; unused inputs tied here meet CMOS input bias requirements. |
| 9 | PL | Asynchronous parallel load enable - Active HIGH; overrides clocking to inject new data instantly into all stages. |
| 10 | CP | Clock input - LOW-to-HIGH edge-triggered; Schmitt-triggered for noise rejection on long traces or noisy environments. |
| 11 | DS | Serial data input - Shifts into first stage (D0-equivalent position) on each CP rising edge when PL = LOW. |
| 12 | Q6 | Buffered output from stage 6 - Mid-register tap used for pipeline inspection or multi-phase timing generation. |
| 13 | D4 | Parallel data input bit 4 - Supports byte-wide configuration loading in programmable logic controllers. |
| 14 | D5 | Parallel data input bit 5 - Enables rapid reconfiguration of display buffers or I/O port mappings. |
| 15 | D6 | Parallel data input bit 6 - Used with D7 for upper nibble loading in 8-bit microcontroller peripheral emulation. |
| 16 | VDD | Positive supply - Decoupling capacitor (100 nF) required within 10 mm for stable switching performance. |
Key Features
| Feature | Design Value |
|---|---|
| Wide VDD range (3–15 V) | Eliminates need for separate voltage regulators in mixed-voltage systems such as industrial HMIs with 5 V MCU and 12 V actuator interfaces. |
| Asynchronous parallel load (PL) | Enables immediate register update without waiting for clock edges - essential for emergency reset or configuration reload in safety-critical logic. |
| Schmitt-trigger clock input | Accepts slow or noisy clock sources (e.g., RC oscillators, mechanical switch debouncing) without external conditioning circuitry. |
| Static CMOS operation | Zero quiescent current at standby - extends battery life in portable instrumentation using periodic shift-register polling. |
| JEDEC JESD13-B compliance | Ensures interoperability with legacy 4000-series logic families and simplifies migration from older HEF4021 variants. |
Applications
| Industrial PLC I/O Expansion | LED Matrix Row Driver |
|---|---|
|
Use Scenario: Adding 8-bit parallel input capability to a microcontroller with limited GPIO, using shift-in for sensor status or switch states. IC Role / Device Role / Timing Role: Parallel-to-serial converter capturing real-time hardware states on PL assertion, then streaming via DS/CP to MCU SPI interface. Use Value: Reduces MCU pin count by 8 while maintaining deterministic latency (<40 ns per bit at 15 V), enabling cost-effective scaling of distributed I/O nodes. |
Use Scenario: Driving 8 rows of a multiplexed LED display where row selection must be updated rapidly and synchronously. IC Role / Device Role / Timing Role: Static shift register holding active-row pattern; Q5–Q7 feed decoder logic while full 8-bit content controls row enable timing. Use Value: Eliminates software-based row scanning overhead; parallel load allows instantaneous row change (no clock cycles needed), improving display flicker immunity. |
| Microcontroller Peripheral Emulation | Legacy Bus Interface Adapter |
|
Use Scenario: Emulating an 8-bit parallel port on an ARM Cortex-M0+ with only UART and GPIO available. IC Role / Device Role / Timing Role: Latching host commands via PL, then shifting out control bits to discrete actuators or relays synchronized to CP. Use Value: Achieves cycle-accurate timing for stepper motor step/direction signals without DMA or timer peripherals - reducing firmware complexity. |
Use Scenario: Interfacing modern microcontrollers to vintage 4000-series logic subsystems requiring parallel data handshaking. IC Role / Device Role / Timing Role: Bidirectional bridge: accepts parallel writes from legacy bus, shifts out serially to MCU; reverse path uses DS/CP for command injection. Use Value: Maintains electrical and timing compatibility with ±1 V noise margin and 15 V tolerance - avoids level translators or custom ASICs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8-bit static shift register applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CD4021BE | Same logic function but non-Schmitt CP input; max VDD = 18 V; wider temp range (-55 °C to +125 °C); DIP-16 only. | Lacks noise immunity on clock line; requires external RC filtering for noisy environments; incompatible with surface-mount-only designs. | Select when legacy through-hole assembly or extreme cold operation is required, and clock signal integrity is assured. |
| 74HC165PW | 8-bit parallel-load shift register with complementary outputs; 2–6 V VDD range; faster max clock (100 MHz @ 6 V); TSSOP16 package. | Higher speed but narrower voltage range; no Q5–Q7 buffered taps; lacks direct SD/CD per stage. | Select for high-throughput serial acquisition where 5 V operation suffices and mid-register taps are unnecessary. |
Compared with CD4021BE and 74HC165PW, the HEF4021BTT uniquely combines Schmitt-trigger clock tolerance, 3–15 V flexibility, and dedicated buffered mid-tap outputs - making it optimal for industrial retrofit and mixed-voltage embedded control where reliability trumps raw speed.
Availability
HEF4021BTT is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, LED matrix row driving, and microcontroller peripheral emulation requiring stable component supply across extended temperature and voltage ranges.
Supply support for HEF4021BTT 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, analog, and MOSFET solutions optimized for efficiency, reliability, and manufacturability in industrial, automotive, and consumer applications.
The HEF4021BTT belongs to Nexperia's legacy-compatible 4000-series logic family, designed specifically for drop-in replacement and long-lifecycle support in industrial control, instrumentation, and retrofitted electronic systems.
FAQ
What is the minimum pulse width required for the PL (parallel load) input?
The minimum PL HIGH pulse width is 24 ns at VDD = 15 V and 70 ns at VDD = 5 V, as specified in Table 7. This ensures reliable asynchronous capture of D0–D7 values across the full operating voltage and temperature range. Shorter pulses may result in incomplete or metastable loading.
Can unused inputs be left floating?
No. Unused inputs must be connected to VDD, VSS, or another driven input to prevent CMOS input instability and excessive supply current. Floating inputs risk oscillation, increased power dissipation, and potential device latch-up due to undefined threshold crossing.
Does the HEF4021BTT support hot insertion or live swapping?
No. The HEF4021BTT is not designed for hot-swap operation. Applying VDD before establishing proper VSS connection, or connecting inputs before supply stabilization, may exceed absolute maximum ratings (e.g., VI < –0.5 V or > VDD + 0.5 V) and cause permanent damage.
How does the Schmitt-trigger clock input improve system robustness?
The Schmitt-trigger on CP provides hysteresis (~1 V typical at VDD = 10 V), allowing reliable edge detection even with slow rise/fall times (e.g., from RC networks or long PCB traces). This eliminates need for external debouncing or sharpening circuits in electromechanical or noisy industrial environments.
HEF4021BTTJ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- 4000B
- Package/Case:
- 16-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Logic Type:
- Shift Register
- Output Type:
- Push-Pull
- Number of Elements:
- 1
- Number of Bits per Element:
- 8
- Function:
- Parallel or Serial to Serial
- Voltage - Supply:
- 3V ~ 15V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-TSSOP
HEF4021BTTJ FAQ
1.How can I place an order for HEF4021BTTJ through Aetrix?
Please submit a Request for Quotation (RFQ) for HEF4021BTTJ on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for HEF4021BTTJ reliable?
The price and inventory of HEF4021BTTJ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for HEF4021BTTJ is usually 5 days.
3.What payment methods are accepted for HEF4021BTTJ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for HEF4021BTTJ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for HEF4021BTTJ?
HEF4021BTTJ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your HEF4021BTTJ order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for HEF4021BTTJ?
For technical support, including HEF4021BTTJ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your HEF4021BTTJ requirements.
6.How does Aetrix verify that HEF4021BTTJ is sourced from the original manufacturer or authorized distributors?
All HEF4021BTTJ products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that HEF4021BTTJ meets industry standards.
7.What is the process for return or replacement of HEF4021BTTJ?
All HEF4021BTTJ units undergo pre-shipment inspection (PSI). If there is an issue with HEF4021BTTJ, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The HEF4021BTTJ part is unused and in its original packaging.
Return procedure for HEF4021BTTJ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
HEF4021BTTJ Tags
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74HC165D,653
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