Monthly Archives: October 2013

Give your whites goods the automotive treatment

Interface solutions designed to withstand the rigors of automotive applications are the ideal choice for white goods, too.

For the most part, people don’t usually put cars and trucks in the same category as dishwashers, refrigerators, and washer/dryers. After all, today’s automobiles are highly complex systems that weather the elements and provide safe, efficient transportation for people and things, while white goods are somewhat less complex systems that operate in temperature-controlled environments and perform specific household tasks.

But if you take a closer look at what’s expected of the electronics in the average household appliance, you might start to see how white goods and automobiles overlap. White goods and automobiles are expensive pieces of equipment that need to be durable, reliable, and efficient, so they both rely on electronic components that live up to these requirements. Also, white goods and automobiles are, by and large, operated by human beings, so they both benefit from having human interfaces that are highly interactive and easy to use.

Automobiles do, of course, present some of the most challenging environments an electronic component will ever face. In places with harsh winters, a car left outside overnight might be expected to start at temperatures below -20 °C, and depending on the situation, that same engine compartment might reach temperatures that approach 125 °C. Add to that the potential for exposure to fuel, coolants, salts, and other corrosive substances, and you’re asking quite a lot from an integrated circuit. Life inside the average household appliance is quite a bit friendlier to an IC, but white goods still put semiconductors through their paces. Having components that are tough enough to operate in a car can improve performance in white goods, too.

As it happens, NXP is the global number-one supplier of automotive-qualified logic, and offers a leading portfolio of interface ICs that support automotive operation.

AEC-Q100 interface products

Figure 1 gives a high-level block diagram of a washing machine. The AEC-Q100 qualified interface ICs, shown along the serial bus, support system-level functions like timing, LED and LCD control, and interactions with touch panels. They also make it easy to add features and implement last-minute changes. AEC-Q100 qualified interface ICs serve similar functions in other white goods, such as refrigerators, clothes dryers, and dishwashers.

White goods Figure 1

Figure 1. High-level block diagram of a typical washing machine

To ensure the reliability of our automotive electronics, we follow the Automotive Electronics Council standard AEC-Q100, which outlines a set of procedures to be followed to ensure ICs meet the quality and reliability levels that automobiles need. Every NXP product that is AEC-Q100 compliant delivers the highest robustness in harsh conditions. That includes extended temperature range, tolerating temperatures up to 95, 105, or 125 °C, depending on the device.

Our automotive-qualified products are manufactured in special TS16949-certified and VDA-approved production facilities, and are flagged as automotive lots so they get special treatment. They’re subjected to additional process-flow quality gates, stricter rules for lot handling, and undergo special tests for ruggedness.

The interface portfolio includes AEC-Q100 qualified real-time clocks, LCD drivers, LED drivers, capacitive sensors, and GPIO expanders. The rest of this article offers links to recommended products in each category.

Automotive-qualified RTCs

These RTCs, qualified for operation across extended temperature ranges, deliver very high accuracy with very low power consumption.

Device Description
PCA2129 SPI and I2C with integrated TCXO

Automotive-qualified LCD drivers

LCD displays give consumers an easy way to interface with the appliance. NXP has been a leader in LCD technology for more than 25 years, building on the reliable chip-on-glass (COG) technology used in the automotive industry. All our new LCD drivers are designed for 15 kV ESD performance, and are AEC-Q100 compliant. The AEC-Q100 qualification means a VLCD range up to 8.0 or 12.0 V. Our LCD drivers are ideally suited for driving Vertical Alignment (VA) displays, which deliver high contrast, a true-black background, and a wide viewing angle.

Device Description
PCA85162 4 x 32 segment driver
PCA85176 4 x 40 segment driver
PCA85133 4 x 80 segment driver
PCA85132 4 x 160 segment driver
PCA8536 8 x 40 segment driver with 6 PWM outputs
PCA8537 8 x 44 segment driver
PCA9620 8 x 60 segment driver with on-chip charge pump and temp sensor
PCA8538 9 x 102 segment driver

Automotive-qualified LED controllers

Compatible with the I2C bus and supporting Fm+ operation (up to 1 MHz), these LED controllers are designed for red/green/blue/amber (RGBA) color mixing, color backlighting, and sophisticated blinking and dimming functions, like those used in amusement products.

Device Description
PCA9635 16-channel LED blinker
PCA9685 16-channel LED dimmer
PCA9952 16-channel constant current LED controller with 3 address pins and /OE
PCA9955 16-channel constant current LED controller with 4 address pins

Automotive-qualified capacitive sensors

Capacitive sensors, which are also called proximity sensors, use human body capacitance as an input and can be used to detect position or displacement, humidity, fluid level, or acceleration. In terms of user interfaces, capacitive sensors enable touch-sensitive interactions, like those used with trackpads on laptop computers or touchscreens on household appliances.

The NXP PCA8886, which is AEC-Q100 compliant, is a dual-channel sensor that can be used for up to three sensors without a microcontroller. The PCA8885 is an automotive version of the PCF8885, an eight-channel sensor that requires a microcontroller. It can be configured for up to 28 sensors and, with two devices, can enable up to 80 sensors. All NXP’s capacitive sensors are available in evaluation kits, reference designs, or application boards that make it easier for engineers to get started with a design.

Automotive-qualified GPIO expanders

These sophisticated yet easy-to use features make it possible to extend the feature list or make last-minute design changes with minimal modification to the microcontroller or the PCB board.

Device Description
PCA9502 8-bit SPI/I2C Fast Mode totem-pole GPIO expander with interrupt and reset
PCA9554 8-bit I2C Fast Mode totem-pole GPIO expander with interrupt and pull-up resistors
PCA9538 8-bit I2C Fast Mode totem-pole GPIO expander with interrupt and reset
PCA9539 16-bit I2C Fast Mode totem-pole GPIO Expander with interrupt and reset
PCA9701 16-bit SPI GPI with interrupt and 18-V tolerant input
PCA9703 16-bit SPI GPI with maskable interrupt and 18-V tolerant input

Just the Beginning

Automotive-qualified components can boost performance and reliability in white goods, but they’re just one part of the design. For the rest of your system, our interface portfolio offers standard building blocks like bridges, voltage translators, temp sensors, RF solutions, and more.

Bottom line — no matter what kind of household appliance you’re designing, we have components that will help you improve performance and get to market quickly. For more ideas about white goods, explore the other areas of our website ( or contact your local NXP representative.

Let us hear from you

Are you designing a household appliance? If so, we’d like to hear about it. Leave a comment to share an experience, pass along a design trick, or ask a question.