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Diotec keeps its product portfolio close to the market demands with know-how, research and passion.


Temperature Monitoring - An Overview of Three Cost-optimized Solutions

Temperature Monitoring

Ambient and component temperature have a decisive impact on the performance and lifetime of electronic equipment.

This Application Note introduces three accurate and cost-effective solutions for a wide range of temperature sensing applications.

Shunt Regulator and Voltage Reference with Reduced Regulation Current


The MMTL431B extends our family of Shunt Regulators and Precision Voltage References. It offers a reduced minimum regulation current I_K(min) of typically 30 µA, and maximum 300 µA. This makes it ideally suited for secondary side control of flyback converters, used in offline power supplies and battery chargers, but also replacement of low voltage Zener diodes (< 10 V). Especially in latter case it is often desired to have a temperature compensated, stabilized voltage at low current consumption. With just few external components, the MMTL431B allows for exactly such function.


Parts in Glass Package Become Totally Lead-Free

lead-free parts

Though the RoHS directive still allows usage of lead (Pb) under exemption 7(c)-I, our devices in glass package will be switched from January 2022 onwards to totally lead-free versions. Through this we address the increasing number of customer requests for such "green" devices. Package outlines include SOD-106 (MicroMelf), SOD-80C (Glass-MiniMelf), DO-213AB (Glass-Melf) and DO-35 (Axial lead). Since there is no change in form, fit nor function, a PCN is not required. Our family of totally lead-free parts further includes these plastic case outlines: 0603, 1608, SOD-882, SOT-883, SOD-523, SOD-323(F), SOD-123(F), SOT-323, SOT-363, SOT-23.

NEW: Diotec Selection Guides for Diodes & Rectifiers and Transistors & Regulators

selection guides

Our Selection Guide has been completely reworked and is now divided into two separate editions: One for Diodes & Rectifiers and the second for Transistors & Regulators.

They provide a quick overview about our entire product range and are thus a useful tool for selecting components according to their main parameters and to look for potential alternatives. For the first time, we use 3D images for the package outlines, which allow a fast recognition of the parts. The main sizes and also case outline standards are anyway provided. Standardized symbols help to easily differentiate between e. g. uni- and bidirectional TVS diodes or to recognize the configuration of dual and multiple devices. You can either download the single pages from our website or order the two printed versions here orderconfirmation@diotec.com.

High Voltage Diodes For Smart Meter, LED Street Lamps and 4G/5G Base Stations


Ubiquity is more than ever a very important item. 4G and 5G base stations are placed in exposed positions in order to cover wide areas with sending and receiving signals. As such they are often subject to lightning strikes, which can easily damage its sensitive electronic circuits. The exposed position makes any repair difficult and expensive; therefore, robust devices are required for a long lasting, reliable operation. Similar issues are valid for smart meters and LED street lamps, which are directly connected to the land lines and are widely spread over big areas.

The SM2000GP is one of the latest members of Diotec's dedicated family of high voltage rectifiers for exactly these applications. It features a maximum DC blocking voltage of 1600 V, a reverse repetitive voltage of 2000 V and offers low reverse leakage currents even at higher temperatures. Its forward surge current rating is at 35 A (50 Hz/10 ms) respectively 39 A (60 Hz/8.3 ms). The part comes in DO-213AB/Plastic Melf package for low thermal resistance and high surge current capability. It is typically used at the input rectifier stage in a B6 three-phase bridge configuration.

Dual Automotive MOSFET with Protected Gate


The MMFTN620KDW-AQ is a dual MOSFET in SOT-363 package. The two N channel types offer a continuous drain current of up to 350 mA at 25°C, a drain-source voltage of max 60 V and an on-state resistance of less than 2 Ohm at 4.5 V gate voltage applied. As a special feature, their Gate is protected against ESD voltages of up to +/- 2 kV, which makes them ideally suited for applications with high risk of ESD impacts.

This includes power management for touch screens, control and display lighting, driver stages for small DC motors and actuator coils and much more. Due to their low Gate threshold voltage and input capacitance, these MOSFETs can be controlled directly from logic outputs. Parts are fully qualified according to AEC-Q101. All in all a small yet anyway important contribution to any trip by car, e. g. into holidays.


Rectifying in a Three-phase Power Supply System - Modular or Discrete?

three-phase bridges

Luckily, Diotec offers both:

Three-phase bridges in through-hole version for soldering, screw mounting types with fast-on connectors,
or, alternatively, six discrete semiconductors in the space saving SMD package.
Here the advantages of all these types:

-    Solderable on the PCB
-    Isolated case outline, screwable on the heatsink or easily to be clamped on it

-    High performance
-    Isolated, metallic base plate to be screwed onto the heatsink

-    SMD outline DO-214AB/SMC for automatic assembly onto the PCB
-    Best price/performance ratio

Blocking Diodes for Photovoltaic Systems and High Voltage Battery Storage


The P2500Y by Diotec is an ideal blocking diode to be used in photovoltaic systems and high voltage battery storage. It offers a DC blocking voltage of 1600 V, a repetitive reverse voltage of 2000 V and an avalanche rating of 25 mJ, for robustness against short transients. The nominal average forward is 25 A; since ambient temperature in those applications is high and cooling often a problem, the typical DC current load is limited to about 10 A.

A way to reduce thermal resistance from junction to lead to lowest possible value is shown in the data sheet and the above picture. As a special service, Diotec can offer to provide the leads already bent according to that drawing. Please contact your local Diotec sales office for that service.

Cordless Power Tools - An Overview of the Electronic Equipment in Power Tool Products

cordless power tools

Human creativity and skill are the basic components of any product and can only be amplified by the use of the right tools.

Check out our latest application note to learn how Diotec helps increase efficiency, power and battery lifetime of your cordless power tool project.

Device Simulation a Step Closer to Real Life - Spice Models Offer Additional Thermal Characteristics


Software tools like Spice are widely used in electronics design and useful for simulation and optimization of circuits. Often the theoretical behaviour is, however, not matching to the later on real life testing, which requires in worst case a time consuming re-design. One reason for such mismatch is the lack of comprehensive thermal characteristics in Spice models, as offered by many suppliers. While e. g. the temperature behaviour of forward voltage and reverse leakage of semiconductor diodes are part of almost every Spice model, it is seldom provided for the voltage drift of Zener and TVS diodes, or the presumed constant current of CLDs (Current Limiting Diodes). And exactly that can cause an issue, when later the device is operated in the real circuit and gets unavoidable warm under load.

The Spice models provided by Diotec for its Zener and TVS diodes, CLDs but of course also all rectifiers are made with additional temperature characterisation.

Provided that Spice simulation is done with different temperature presettings, one can see the behaviour under real junction conditions and can adjust the circuit where necessary. The picture shows as an example the temperature behaviour of an uncompensated and a compensated CLD.

Spice models for Diotec products are accessible via www.diotec.com using simply the part search function.
Here just three examples for your testing:

ZMY18 [https://diotec.com/tl_files/diotec/files/spice/zmy18.zip]
P4SMAJ30A [https://diotec.com/tl_files/diotec/files/spice/p4smaj30a.zip]
CL10MD [https://diotec.com/tl_files/diotec/files/spice/cl10md.zip]