Point of Sale (POS) terminals in wide use today have an array of power management requirements from display backlighting, function indicator lamps and power port protection to load switching, and buck and boost converters. These products typically operate from line driven AC/DC adaptor supplies with voltage rails that need power distribution control and regulation at the point of load.
Buck and Boost Converters
POS terminal AC/DC power adaptor supplies do not always provide specific voltage rails needed by application circuits. Buck/boost converters regulate to allow the adaptor-supplied voltage rail to be stepped up or down at the point of load for specific application circuits.
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.
POS terminals often have large displays that require LED backlighting. White LEDs are used for color LCD displays and lower cost terminals use monochrome displays with either white or other fixed color LEDs. Backlight LED strings are configured in series or series/parallel configurations that often require the supply voltage to be boosted from the power supply source. Multiple current sink drivers connect to long serial strings of WLEDs and therefore require a compliance voltage significantly higher than the battery voltage.
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
High Efficiency 4-CH LED Backlight Driver with Dual LCD Bias Power
Overvoltage and Surge Protection ICs
POS terminals have input power ports that are subject to voltage surge conditions that can potentially damage the device. POS terminal also need internal voltage rail switching to reduce standby power consumption or to enable/disable specific function circuits while the device is operating. Input power port protection is desirable to guard against unreliable power sources.
Over-voltage, and surge protected load switches protect battery charge management and operating handset circuits, by breaking the connection between the power source and the internal circuitry, in the event the device is connected to a faulty power source or subjected to an 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.
Applications requiring PoE typically need high efficiency power conversion, small PCB area and reduced component count. Kinetic Technologies offers a product solution which integrate the PD physical interface and DC/DC controller functions into a single package. Supporting solutions from a few watts up to the maximum allowed, Kinetic Technologies provides a high efficiency power solution for nearly every PoE PD application.
The KTA1137A targets both Type 1 and Type 2 PDs. It is a highly integrated CMOS solution for PoE PDs requiring input power up to 30 watts. The KTA1137A integrates input Surge Protection, a digital PD controller, and a low-emission DC/DC controller onto a single die. The KTA1137A implements the physical layer PD functionality as required by IEEE® 802.3af and IEEE® 802.3at. This includes 2-event classification, a Type 2 PSE detection indicator (ATDET) in addition to PD detection, under-voltage lockout, and hot-swap FET integration.
POS terminals use multicolor RGB LEDs for function indicator lamps. Indicator lamps show power on or function status. Implementing indicator lamp LED control circuits to interface LED control switching to microcontroller logic is a tedious process that 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