STLED316SMTR STMicroelectronics, STLED316SMTR Datasheet - Page 17

• Manufacturer Part Number: STLED316SMTR
• Description: IC LED CTLR SERIAL 6DIGIT SO-24
• Manufacturer: STMicroelectronics

Specifications of STLED316SMTR

• Applications: LED Controller with Keyscan, 6-Digit
• Interface: Serial
• Voltage - Supply: 4.5 V ~ 5.5 V
• Package / Case: 24-SOIC (7.5mm Width)
• Mounting Type: Surface Mount
• Number Of Digits: 6
• Number Of Segments: 48
• Operating Supply Voltage: 4.5 V to 5.5 V
• Maximum Supply Current: 15000 uA
• Maximum Power Dissipation: 1200 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• For Use With: 497-8417 - BOARD DEMO FRONT PANEL STLED316S497-8399 - BOARD EVAL ST7LITE49M/STLED316S497-8432 - BOARD LED CTLR/DVR STLED316S
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6925-2; STLED316SMTR

STLED316S
6
Key-scan & display cycle
The display RAM stores the data transmitted from an external device to the STLED316S
through the serial interface. Refer to
for a pictorial representation.
The grid and segment outputs are controlled by the display output module. The entire grid
will be turned off on channel 1/16 and 16/16 meaning that the first channel and last channel
are off. This is referred to as blanking time.
During the keyscan time (first cycle from timing generator), the entire grid is turned off and
only the segments are enabled one by one (seg0 to seg7). The segment on time is 64 µs.
During the LED discrete time (second cycle), the data present on the internal LED buffer is
checked. If the data is present, then the brightness setting of each LED in the brightness
control register is checked. Then each segment will be enabled or disabled based on the
register value. In this duration, the grids 1 to 6 are turned off. The grid corresponding to LED
digit is turned on. The LED on duty cycle is 14/16. If the LED/seg1 brightness is 12/16, it
means that the segment1 OFF time is 12/16 and on time is 2/16.
During 7-segment display time (3
it is ON or OFF. If display is ON, then the dimming settings are checked from the
configuration register for the grid (it may be common dimming setting or individual dimming
setting for each digit). The minimum turn on time is 1/16 and maximum turn on time is 14/16.
The blanking time is valid before the turning on and turning off of the grid. The blanking
interval is 32 µs. This will continue until the maximum number of digits configured in the
register. Once the full cycle is complete, the keyscan cycle will start again.
If the display is not turned on, then the timing generation will immediately go to the key scan
mode.
Initial:
All the segments and grids are turned off.
During operation:
1.
2.
3.
Turn on segment (keyscan) one by one. On time duration is 64 µs.
Check the data present in LED register. If data is present, turn on the respective LED
grid and segments.
Check the display on. If display is turned on, then enable the grid one by one from grid
1 to grid 6 (maximum) and turn on segments.
rd
cycle to 8
Section 9: Key-scanning and display timing on page 25
th
cycle), the display status is checked whether
Key-scan & display cycle
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