PCA9745 16채널 정류 LED 드라이버 -SPI
(LED DRIVER 16 CLICK)
개요
- 본 제품은 PCA9745 16채널 정류 LED 드라이버 -SPI 입니다.
- PCA9745B 칩을 기반으로 디자인된 제품입니다.
- 각 LED 출력은 8비트 분해능 고정 주파수 PWM 컨트롤러(31.25kHz with an adjustable duty cycle from 0 to 100% )를 가지고 있습니다.
- 3.3V나 5V 시스템과 사용이 가능합니다.
- 채널당 최대 57mA 출력이 가능합니다.
특징
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HOW DOES IT WORK?
LED Driver 16 Click is based on the PCA9745B, a daisy-chain SPI-compatible 16-channel constant current LED driver from NXP Semiconductors. The PCA9745B provides a maximum output current of 57mA per channel (set through an onboard R6 resistor), making it suitable for dimming and blinking Red/Green/Blue/Amber (RGBA) LEDs. Each of the 16 LED outputs has its 8-bit resolution (256 steps) fixed-frequency individual PWM controller, operating at 31.25 kHz with an adjustable duty cycle. The duty cycle goes from 0% to 100%, allowing LEDs to be set to a specific brightness value; either dim or blink all LEDs with the same value.
Gradation control for all current sources is achieved through serial interface and 8-bit DACs, allowing users to ramp current automatically, without MCU intervention, and thus adjust brightness levels for each LED current source. There are four selectable gradation control groups, and each group has independently four registers to control ramp-up and ramp-down rate, step time, hold ON/OFF time, and final hold ON output current. Two gradation operation modes are available for each group: single shot mode (output pattern once) and continuous mode (output pattern repeat).
LED Driver 16 Click communicates with MCU through a register-selectable standard SPI interface that enables high clock speed up to 25MHz for optimum performance, supporting the most common SPI mode, SPI Mode 0. In addition to the SPI interface signals, this board uses several other signals from the mikroBUS™ socket. The reset pin routed on the RST pin of the mikroBUS™ socket provides the general reset ability, while the OE pin of the mikroBUS™ socket, hence, offers a switch operation (enabled/disabled) to turn ON/OFF power delivery to the PCA9745B. The OE pin can also be used as an external dimming control signal. In that case, the external clock frequency must be very high, more precisely unseen by the human eye, and the duty cycle value determines the brightness of the LEDs.
This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.
SPECIFICATIONS
Type LED Drivers Applications Can be used for dimming and blinking Red/Green/Blue/Amber (RGBA) LEDs for various consumer amusement applications, LED status signalization, and more On-board modules PCA9745B - 16-channel constant current LED driver from NXP Semiconductors Key Features Programmable outputs, gradation control for all channels, output channels can sink up to 57mA, output current adjustable through onboard resistor, protection features, SPI interface, output enable feature, and more Interface SPI Compatibility mikroBUS Click board size M (42.9 x 25.4 mm) Input Voltage 3.3V or 5V