Appliance products integrate microcontrollers, displays, Wi-Fi and Ethernet connectivity. The type and function of an appliance mandate the requirements for displays, indicator lamps and application circuitry. Power management solutions are required for display backlight and bias, LED indicator lamp control, power switching and buck and boost converters.
Buck and Boost Converters
Appliances and their control boards use AC/DC supplies or AC/DC adapters and do not always provide specific voltage rails needed by application circuits. Appliances need high efficiency power conversion to create regulated voltage rails from their power source.
Point of load voltage regulators provide a local supply rail with high efficiency
Single output high efficiency DC/DC switching regulators can provide either a step-up or step-down voltage output.
Kinetic Technologies’ EMI/ESD Suppression technology is the industry’s first and is used to improve EMC performance in Ethernet applications. What used to present as a design challenge is solved by this unique solution that offers EMC compliance for Ethernet connected devices. The physical interface of the PD data path to the outside environment is through the PHY. The PHY is also subject to ESD and surge events when an Ethernet cable is inserted. CM emissions are typically filtered by large passive devices located between the PHY and the LAN isolation magnetics. Kinetic Technologies offers the world’s first active ESD and EMI suppressor IC, a 4-channel device in which each channel connects to one wire of the two twisted pair sets. ESD performance, EFT-B and surge immunity, and CM emissions equal or exceed passive techniques while occupying a much smaller footprint.
The Kinetic Technologies EMI/ESD Suppression technology enables system designers to comply with:
CISPR22 and FCC Part 15, Class B requirements for Radiated and Conducted Emissions
IEC 61000-4-3/6 requirements for Radiated and Conducted Immunity, Level 3 or higher
Quad Channel Active EMI & ESD Suppressor for Ethernet Applications
LCD Backlight LED Drivers
Appliance LCD display panels use white LED backlight drivers to boost input voltage supply rails to the levels needed to drive a backlight LED string along with providing a means of LED brightness control by the system microcontroller.
Panel size and resolution determine the number of white LEDs (WLED) required to produce the necessary screen brightness
Dimming techniques to control the brightness can range from simple linear LED brightness control to sophisticated high efficiency PWM control to achieve contrast ratios of typically 20,000:1
High accuracy current sinks to provide uniform backlight across larger panel sizes
High efficiency boost power conversion required to minimize demands on battery power consumption and maximize the battery life between charge cycles
Multiple series/parallel strings of WLED drivers to match the display panel needs
Multiple programming options from simple PWM signal control to full-featured I2C interfaces.
Advanced design, low drop-out current sinks with tight linearity characteristics to maintain constant LED current accuracy over all battery voltage extremes
High efficiency boost converters with integrated protection against LED open and short-circuit conditions
2-Channel LCD Panel Bias Supply with Single Inductor
Overvoltage and Surge Protection ICs
Appliance controllers and displays are AC/DC line powered or AC/DC adaptor powered. Input DC power ports are subject to voltage surge conditions that can potentially damage the device and therefore in need of protection. Appliances voltage rail switching is used to reduce standby power consumption or to enable/disable specific function circuits while the device is operating.
Over-voltage, and surge protected load switches protect internal circuit boards, by breaking the connection between the power source and the internal circuitry. During the event the device is disconnected from the faulty power source or abnormal stress condition.
Programmable and fixed over-voltage protection (OVP) shutdown thresholds.
Wrong adapter up to +40V
Reverse voltage down to -6V
Transient voltage protection up to 200V, compliant to IEC61000-4-2 (Level 4)
ESD protection compliant to ±8kV contact, ±15kV air gap and ±2kV human body model.
Single or dual devices with Uni or Bi-directional blocking
Integrated load switches provide internal power switching and are controlled by simple GPIO logic.
Eliminate the need for bias and level shift circuits associated with discrete MOSFET switches
Provides slew-rate limited turn-on with reverse current blocking and output discharge mode to de-select functions when not required to extend battery life.
Appliance controllers use multicolor RGB LEDs for function indicator lamps. Indicator lamps show power on/off or function status. Implementing indicator lamp LED control circuits to interface LED control switching to microcontroller logic is a tedious design process and requires multiple discrete components.
RGB LED drivers allow simplified programmable control of LED color and brightness
3-channel RGB LED drivers permit custom color control
4-channel RGBW devices allow for driving a white LED in addition to the RGB LED
I2C to ease integration with a wide variety of processors and operating systems
Wide range of ramp up/down timing for slow fade in/out effects and complex repeating patterns