Features: 40 to 85 operation
I2C serial interface
Robust CMOS-Schmitt input
CMOS/TTL compatible output
Multiple color input formats CIE XYZ, Yxy, Yu'v' and RGB
3-channel analog interface tocolor sensor X, Y and Z channels
3-channel 12-bit PWM output Red, Green, and Blue LED channels
Internal computation of calibrationdata
Internal clock generator
Internal reference voltagegenerator
Error flag output
External push-button interface
Only passive components requiredexternally
ApplicationBacklighting
General illumination
Mood/accent lighting
Color context sensitive appliancesPinout
Specifications
|
Parameter |
Symbol |
Minimum |
Maximum |
Units |
Notes |
|
Storage Temperature |
TSTG_ABS |
-65 |
150 |
°C |
|
|
DigitalSupplyVoltage,DVDDtoDVSS |
VDDD_ABS |
-0.3 |
6.0 |
V |
|
|
AnalogSupplyVoltage,AVDDtoAVSS |
VDDA_ABS |
-0.3 |
6.0 |
V |
|
|
Input Voltage |
VIN_ABS |
-0.3 |
VDDD+0.3 |
V |
All I/O pins |
|
Solder Reflow Peak Temperature |
TL_ABS |
|
260 |
°C |
|
|
Latch-Up Current |
IL_ABS |
-100 |
100 |
mA |
|
|
Human Body Model ESD Rating |
ESDHBM_ABS |
|
2 |
kV |
Allpins,human bodymodel MIL883Method 3015 |
|
Machine Model ESD Rating |
ESDMM_ABS |
|
200 |
V |
|
DescriptionThe HDJD-J822 is a CMOS mixedsignal IC designed to be theoptical feedback controller of anLED-based lighting system. Atypical system consists of anarray of red, green and blueLEDs, LED drivers, a tri-colorphotosensor that samples thelight output, and the HDJD-J822.The IC interfaces directly to thephotosensor, processes the color information and adjusts the lightoutput from the LEDs until thedesired color is achieved. Toachieve this, the IC integrates ahigh-accuracy 10-bit analog-to-digital converter front-end, acolor data processing logic core,and a high-resolution 12-bit PWMoutput generator.
By employing a feedback systemand the HDJD-J822, the lightoutput produced by the LEDarray maintains its color over
time and temperature. Inaddition, the desired color can bespecified using a standard CIEcolor space.
In addition, by incorporating astandard I2C serial interface,specifying the color of the LEDarray's light output is as simple aspicking the color coordinatesfrom the CIE color space andwriting several bytes of data to HDJD-J822. The output PWM signals areconnected directly to the LEDdrivers as enable signals. ThePWM signals control the on-timeduration of the red, green andblue LEDs. That duration iscontinually adjusted in real-timeto match the light output from theLED array to the specified,desired color.
HDJD-J822 Data Sheet
