sx1508bevk Semtech Corporation, sx1508bevk Datasheet - Page 19

• Manufacturer Part Number: sx1508bevk
• Manufacturer: Semtech Corporation

ADVANCED COMMUNICATIONS & SENSING
Each IO[X] has its own set of programmable registers (Cf §5 for more detailed information):
Please note that the LED driver mode is selectable for each IO bank between linear and logarithmic. (Cf §4.9.5)
All the figures assume normal IO polarity, for inverse polarity RegData control must be inverted (does not invert
the polarity of the IO signal itself).
4.9.2
Only mode available for non blinking capable IOs (with Off intensity = 0), else invoked when TOnX = 0.
If the I/O doesn’t support fading the LED intensity will step directly to the IOnX/IOffX value.
4.9.3
Invoked when TOnX != 0 and TOffX = 0.
If the I/O doesn’t support fading the LED intensity will step directly to the IOnX/IOffX value.
Rev 3 – 9
RegData(X)
IOLED(X) level
RegTOnX (blinking capable I/Os only): TOnX, ON time of IO[X]
RegIOnX (all I/Os): IOnX, ON intensity of IO[X]
RegOffX (blinking capable I/Os only): TOffX and IOffX, OFF time and intensity of IO[X]
RegTRiseX(breathing capable I/Os only): TRiseX, fade in time of IO[X]
RegTFallX(breathing capable I/Os only): TFallX, fade out time of IO[X]
Static Mode
Single Shot Mode
100%
RegData[X]
IO[X] Intensity (PWM value)
IOnX
IOffX
th
0
1
0
Sept. 2010
Fade In
Off intensity(min) determined by
On intensity(max) determined by
TRiseX
register RegIOffX
register RegIOnX
ON
TOnX
Figure 17 – LED Driver Static Mode
Figure 16 – LED Driver Overview
Fade in rate determined by
register RegTRiseX
Fade Out
TFallX
19
World’s Lowest Voltage Level Shifting GPIO
Fade out rate determined
by register RegTFallX
SX1507B/SX1508B/SX1509B
OFF
TOffX
with LED Driver and Keypad Engine
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