Working with Surface Mount Components

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.

Altium Designer : PCB Planes Pullback implementation

There are many ways to implement polygon planes pullback in Altium. One of my prefer way is utilizing design rules as below.

Alternatively, we can make use of keep-out layer to define polygon pullback.

If you believe in 20H rules and to implement for Internal plane pull back, Layer Stack Manager can be used which is only for internal planes.

WORKMANSHIP STANDARD FOR POLYMERIC APPLICATION ON ELECTRONIC ASSEMBLIES

 Reference : NASA-STD-8739.1B – 2016-06-30

This is a good refereence standard for staking, conformal coating, bonding and encapsulation of PCB.

STAKING: Staking usually be performed prior to conformal coating and stamking material should be free from contamination. 

Default Staking for Horizontally-Mounted Sleeved or Sleeveless Cylindrical Part

Single Wire Staking

Staking for Radial Lead Components

Staking for Radial Multi-lead Rectangular Components

Default Staking of a Single Vertically-Mounted Rectangular Part

Default Staking for an Array of Vertically-Mounted Rectangular Parts

Wire Bundle Staking

Fastener Staking , Locking of Screws and Bolts with Nuts

Thread Locking of Blind Screw

Torque Striping Methods

CONFORMAL COATING, Spray Application

CONFORMAL COATING, Bubbles

CONFORMAL COATING, Scratches

CONFORMAL COATING, Liftting and Peeling

CONFORMAL COATING,Coverage Defects

COMPONENT BONDING, Excess Bonding Material

ENCAPSULATION, Encapsulating Wires at Connector

ENCAPSULATION, Modules

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/

What is the difference between lux and lumens?

 It is good to know the difference between Lux and Lumens if you are designing lighting products.

The core difference can be summarized as follows:

- Lux is a measure of illuminance, the total amount of light that falls on a surface

- Lumens is a measure of luminous flux, the total amount of light emitted in all directions.

Information Reference: 

Voltage controlled Current Source Circuit

 

This circuit control the output current flow effectively. Reference voltage V1 can be set to desire output current, for instance V1=700 mV is setting output current to 670 mA.

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.