Rainbow Electronics MAX6963 - Manual (Page 23)

arithmetic (off, 1/3, 2/3, full) or geometric (off, 1/4, 1/2,
full). The setting is made on a digit-by-digit basis, so
each color on an RGY or RGB panel can use the most
appropriate graduation type.
Digit Intensity Control
The digit intensity registers (Tables 25 and 26) set the
fractions of the panel intensity PWM value that are
applied to the two display digits. The PWM for each
digit is calculated as n/256th of the panel intensity
value, where n is the value in the digit’s digit intensity
register. The digit intensity registers enable configuring
relative adjustments in digit intensity, while the display
panel is still controlled as a whole by the panel intensity.
These adjustments are typically used to calibrate out
luminosity differences between LEDs from different
batches. They can also be used to color balance RGY
displays so that, for example, full panel intensity of a
red-green panel is a consistent orange hue.
Panel Intensity Control
Digital control of panel display brightness is provided
by an internal pulse-width modulator, which is con-
trolled by the panel intensity register (Table 27). The
modulator scales the average segment current in 253
steps from a maximum of 255/256 down to 2/256 of the
peak current. The maximum effective PWM duty cycle
for a digit is therefore 254/256, given by the maximum
MAX6960–MAX6963
4-Wire Serially Interfaced
8 x 8 Matrix Graphic LED Drivers
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REGISTER DATA
REGISTER
ADDRESS
CODE (HEX) D7 D6 D5 D4 D3 D2 D1 D0
0/256 0x03 0 0 0 0 0 0 0 0
1/256 0x03 0 0 0 0 0 0 0 1
2/256 0x03 0 0 0 0 0 0 1 0
3/256 0x03 0 0 0 0 0 0 1 1
4/256 0x03 0 0 0 0 0 1 0 0
— 0x03 — — — — — — — —
251/256 0x03 1 1 1 1 1 0 1 1
252/256 0x03 1 1 1 1 1 1 0 0
253/256 0x03 1 1 1 1 1 1 0 1
254/256 0x03 1 1 1 1 1 1 1 0
255/256 (max on) 0x03 1 1 1 1 1 1 1 1
Table 25. Digit 0 Intensity Register Format
REGISTER DATA
REGISTER
ADDRESS CODE
(HEX) D7 D6 D5 D4 D3 D2 D1 D0
0/256 0x04 0 0 0 0 0 0 0 0
1/256 0x04 0 0 0 0 0 0 0 1
2/256 0x04 0 0 0 0 0 0 1 0
3/256 0x04 0 0 0 0 0 0 1 1
4/256 0x04 0 0 0 0 0 1 0 0
— 0x04 — — — — — — — —
251/256 0x04 1 1 1 1 1 0 1 1
252/256 0x04 1 1 1 1 1 1 0 0
253/256 0x04 1 1 1 1 1 1 0 1
254/256 0x04 1 1 1 1 1 1 1 0
255/256 (max on) 0x04 1 1 1 1 1 1 1 1
Table 26. Digit 1 Intensity Register Format