Bipolar transistors

Diodes

ESD protection, TVS, filtering and signal conditioning

MOSFETs

SiC MOSFETs

GaN FETs

IGBTs

Analog & Logic ICs

Automotive qualified products (AEC-Q100/Q101)

HEF4521BT

24-stage frequency divider and oscillator

The HEF4521B consists of a chain of 24 toggle flip-flops with an overriding asynchronous master reset input (MR), and an input circuit that allows three modes of operation. The single inverting stage (A2 to Y2) functions as: a crystal oscillator, an input buffer for an external oscillator or in combination with A1 as an RC oscillator. The crystal oscillator operates in Low-power mode when pins VSS1 and VDD1 are supplied via external resistors.

Each flip-flop divides the frequency of the previous flip-flop by two, consequently the HEF4521B counts up to 224 = 16777216. The counting advances on the HIGH-to-LOW transition of the clock (A2). The outputs from each of the last seven stages (218 to 224) are available for additional flexibility.

It operates over a recommended VDD power supply range of 3 V to 15 V referenced to VSS (usually ground). Unused inputs must be connected to VDD, VSS, or another input.

Alternatives

Features and benefits

  • Wide supply voltage range from 3.0 V to 15.0 V

  • CMOS low power dissipation

  • High noise immunity

  • Low power crystal oscillator operation

  • Fully static operation

  • 5 V, 10 V, and 15 V parametric ratings

  • Standardized symmetrical output characteristics

  • Complies with JEDEC standard JESD 13-B

  • ESD protection:

    • HBM: ANSI/ESDA/JEDEC JS-001 class 2 exceeds 2000 V

    • CDM: ANSI/ESDA/JEDEC JS-002 class C3 exceeds 1000 V

  • Specified from -40 °C to +85 °C

Parametrics

Type number VCC (V) Output drive capability (mA) Logic switching levels tpd (ns) Power dissipation considerations Tamb (°C) Rth(j-a) (K/W) Ψth(j-top) (K/W) Rth(j-c) (K/W) Package name
HEF4521BT 3.0 - 15 ± 2.4 CMOS 220 medium -40~85 65 1 22.8 SO16

PCB Symbol, Footprint and 3D Model

Model Name Description

Package

Type number Orderable part number, (Ordering code (12NC)) Status Marking Package Package information Reflow-/Wave soldering Packing
HEF4521BT HEF4521BT,653
(933406770653)		 Active HEF4521BT SOT109-1
SO16
(SOT109-1) 		SOT109-1 SO-SOJ-REFLOW
SO-SOJ-WAVE
WAVE_BG-BD-1
Not available

All type numbers in the table below are discontinued.

Type number Orderable part number, (Ordering code (12NC)) Status Marking Package Package information Reflow-/Wave soldering Packing
HEF4521BT HEF4521BT,652
(933406770652)		 Withdrawn / End-of-life HEF4521BT SOT109-1
SO16
(SOT109-1) 		SOT109-1 SO-SOJ-REFLOW
SO-SOJ-WAVE
WAVE_BG-BD-1
SOT109-1_652

Environmental information

Type number Orderable part number Chemical content RoHS RHF-indicator
HEF4521BT HEF4521BT,653 HEF4521BT rohs rhf rhf

All type numbers in the table below are discontinued.

Type number Orderable part number Chemical content RoHS RHF-indicator
HEF4521BT HEF4521BT,652 HEF4521BT rohs rhf rhf
Quality and reliability disclaimer

Series

Documentation (10)

File name Title Type Date
HEF4521B 24-stage frequency divider and oscillator Data sheet 2024-08-19
AN11051 Pin FMEA HEF4000 family Application note 2019-01-09
SOT109-1 3D model for products with SOT109-1 package Design support 2020-01-22
Nexperia_package_poster Nexperia package poster Leaflet 2020-05-15
SO16_SOT109-1_mk plastic, small outline package; 16 leads; 1.27 mm pitch; 9.9 mm x 3.9 mm x 1.35 mm body Marcom graphics 2017-01-28
SOT109-1 plastic, small outline package; 16 leads; 1.27 mm pitch; 9.9 mm x 3.9 mm x 1.75 mm body Package information 2023-11-07
HEF4521BT_Nexperia_Product_Reliability HEF4521BT Nexperia Product Reliability Quality document 2024-06-16
SO-SOJ-REFLOW Footprint for reflow soldering Reflow soldering 2009-10-08
SO-SOJ-WAVE Footprint for wave soldering Wave soldering 2009-10-08
WAVE_BG-BD-1 Wave soldering profile Wave soldering 2021-09-08

Support

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Models

File name Title Type Date
SOT109-1 3D model for products with SOT109-1 package Design support 2020-01-22

PCB Symbol, Footprint and 3D Model

Model Name Description

Ordering, pricing & availability

Type number Orderable part number Ordering code (12NC) Status Packing Packing Quantity Buy online
HEF4521BT HEF4521BT,653 933406770653 Active Not available 2,500 Order product

Sample

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If you do not have a direct account with Nexperia our network of global and regional distributors is available and equipped to support you with Nexperia samples. Check out the list of official distributors.

How does it work?

The interactive datasheets are based on the Nexperia MOSFET precision electrothermal models. With our interactive datasheets you can simply specify your own conditions interactively. Start by changing the values of the conditions. You can do this by using the sliders in the condition fields. By dragging the sliders you will see how the MOSFET will perform at the new conditions set.

Interactive datasheet

Orderable parts

Type number Orderable part number Ordering code (12NC) Package Buy from distributors
HEF4521BT HEF4521BT,653 933406770653 SOT109-1 Order product