HT1635A/B Wearable Sports Bracelet LED Display Application
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AN0393E
HT1635A/B Wearable Sports Bracelet
LED Display Application
D/N: AN0393E
Introduction
The HT1635A and HT1635B are Holtek display data memory mapping LED driver
devices, whose driving capacity is up to 352 patterns composed of 44 rows and 8
commons. The HT1635A provides a 4-wire serial interface and the HT1635B provides an
I
2
C interface. Both interfaces are used for MCU data communication. Using the HT66F50
as the host MCU, a demo with two HT1635A devices or two HT1535B devices is taken as
an example in this application note to introduce how to use the HT1635A and HT1635B.
Each HT1635A or HT1635B device on the demo drives 8 commons and 42 rows of RGB
LEDs (8×14 RGB LEDs), showing the wearable sports bracelet LED panel display
functions.
Operating Principles
HT1635A and HT1635B Main Features
•
Operating voltage: 2.4V ~ 5.5V
•
Integrated 256kHz RC oscillator
•
Frame Rate: 100Hz
•
Maximum display capacity: 352 patterns (44 rows and 8 commons)
•
Up to 88×4 RAM display data storage
•
Supports up to 16-level PWM brightness control
•
Four blinking modes: Off, 0.5Hz, 1Hz and 2Hz
•
COM driving method selectable: NMOS open-drain or PMOS open-drain
•
HT1635A provides a 4-wire serial interface, HT1635B provides an I
2
C serial interface
•
Cascade function for extending applications
•
Package: 64-pin LQFP
