Simple Capacitive Touch Sensor Controller

 If you need a simple capacitive touch sensor to our project, Microchip's CAP1203 is a good choice. It is a multiple channel capacitive touch sensor controller with calibrated to compensate for system parasitic capacitance and automatically recalibrated to compensate for gradual environmental changes. The best thing about this chip is low power consumption at deep sleep mode. It can be used as a touch slider and worked under 6 mm thickness of plastic or wood or almost any materials.

PCB pad Design as below.

Sparkfun has remade module to try.

Open LED Protection for LED Strings

 LEDs are fragile solid-state devices. An LED is essentially a diode, structured as a P-N junction that emits light when forward biased. One of the major causes of an electrical open in an LED is thermomechanical stress on the wire bonds. Other causes of LED open circuits are electrostatic discharge (ESD) events or surges induced by nearby lightning events. These threats are especially high in outdoor applications. Devices such as MOVs, fuses, and TVS diodes are essential components of a circuit protection strategy, because they can prevent transients and surges from damaging delicate LEDs. However, none of these traditional circuit protection devices can prevent an entire string of LEDs from going out if a single LED fails.  

An open LED protector is  can be connected in parallel with each LED in a string; it will shunt current around an openfailed LED to keep the rest of the string lit. When LED fails open-Circuit, the open LED protector goes into conduction, limiting its voltage drop to about 1.3V and keeping the rest of the string operating.

Voltage-Tracking LDO With 4-mV Tracking Tolerance

 Voltage-tracking low dropout regulator (LDO) is widely used in automotive off-board sensors and small current off-board modules for its off-board protection and high voltage-tracking accuracy advantages.The output of the device is accurately regulated by a reference voltage at the ADJ pin.

To get accurate sensor readings, power supply is required to be stable and accurate. To provide an accurate power supply to the off-board modules, this device offers a 4-mV ultralow tracking

tolerance between the ADJ and FB pins across temperature. Recommend PCB layout sample by TI as below.

Altium Designer : Solving the Component Management Challenge with Alticve BOM

 

ActiveBOM is a powerful Bill of Materials management editor that brings comprehensive BOM management tools together with Altium's powerful part-information aggregation technologies, helping you manage the component selection challenge.

Component Cross Reference Search

 Nowadays, component supply chain issue is quite common and designers need to do component cross referencing from different suppliers. Here are a list of cross reference component search websites from manufacture and others.

If you guys have more useful links, please leave it in comment session.

Component Manufacturers

https://www.analog.com/cpsearch/crossreferencesearch.aspx

https://www.diodes.com/design/tools/manufacturer-part-number-cross-reference/

https://www.nxp.com/products/cross-reference:CROSS-REFERENCE

https://www.amphenol-cs.com/crossreference

https://www.kingbrightusa.com/crossreference.asp

https://www.richtek.com/en/Design%20Support/Cross%20Reference?Keyword=20A

https://www.infineon.com/cms/en/product/search/cross-reference/

https://www.semtech.com/design-support/cross-reference-search

https://www.littelfuse.com/competitor-cross-reference

https://crossreferencetool.cooperbussmann.com/

https://www.maximintegrated.com/en/design/cross-reference-search.html

https://www.onsemi.com/products/product-services/competitor-cross-reference

https://www.genesicsemi.com/sic-mosfet/competitor-cross-reference/

https://www.molex.com/molex/crossref/ShowXrefSearch

https://www.murata.com/en-global/search/crossreference?cate=cgInductorscrossreference

https://www.te.com/commerce/pcr/

https://www.ti.com/cross-reference-search

https://www.nexperia.com/cross-multiple-parts.html

https://tools.rubycon.co.jp/cross-reference/

https://product.tdk.com/en/search/cross_reference

https://www.vishay.com/crossreference/

https://www.we-online.com/web/en/electronic_components/produkte_pb/toolbox_pbs/Cross_Reference_1.php

Other Sites

https://octopart.com/?gclid=EAIaIQobChMI6OKQw5y49wIVcZNmAh1mqwCpEAAYASAAEgLvivD_BwE

https://partcross.com/semiconductor-manufacturers/Atmel/

http://ebook.pldworld.com/_Semiconductors/Atmel/Databook%20CDROM/Atmel/xref2.htm

https://gct.co/connector-cross-reference

http://www.cross-parts.com/news/shortcut/shortcut-data/L23.html

https://alltransistors.com/

https://www.findchips.com/

https://clockworks.microchip.com/microchip/crossref

http://www.cross-parts.com/news/M_search.php?nWord=NEC

https://www.we-online.com/web/en/electronic_components/produkte_pb/toolbox_pbs/Cross_Reference_1.php

https://www.ultralibrarian.com/

Basics of eFuses

 eFuses are integrated power path protection devices that are used to limit circuit currents, voltages to safe levels during fault conditions. eFuses offer many benefits to the system and can include protection features that are often difficult to implement with discrete components. Discrete solutions are bulky, inefficient, do not incorporate thermal protection, need more components and occupy more board space. More components also raise concerns on protection-circuit robustness and reliability.

Different types of eFuses are available in the market. Here is one of my favorite eFuses, TPS259271 from TI.

This chip is a robust defence against overloads, shorts circuits, voltage surges, excessive inrush current, and reverse current. It also offers Controlled Power Down, Over Temperature Protection, Health Monitoring and Reporting.

Low cost temperature sensor

Low cost temperature sensor can be achieved by using diode or transistor (by shorting Base and Collector). When constant current passes through the base-emitter junction it produces a voltage between the base and emitter (Vbe) that is a linear function of the absolute temperature. 

The overall forward voltage drop has a temperature coefficient of approximately 2 mV/°C. The semiconductor junction sensor’s voltage versus temperature is much more linear than that of a thermocouple or resistive temperature device (RTD). 

Implementing Ship Mode to Your Product

As the presence of global manufacturing and distribution increases, many original equipment manufacturers are looking for creative ways to extend battery life during shipping and shelf life at big-box warehouses. Keeping the battery sufficiently charged during shipment enables a consistent out-of-box experience for the end-user. A solution that has gained popularity is the use of a ship mode feature that keeps devices in a low-power state during shipment and while on the shelf. Here is my solution using a load switch from TI, TPS22915B.

This is how the circuit works. Before the button is pressed, the solution is in ship mode, meaning that the system is not powered and theTPS22915B load switch is turned off. When the button is pressed, the voltage from the battery is passed through the PMOS to the ON pin of the TPS22915B. The voltage enables the TPS22915B, brings VOUT high, turns off the PMOS, and powers the system. The ON pin is pulled up to VOUT, which keeps the load switch enabled even after the button is released.