Matrix LED Display Driver

16

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DIGIT 1

ROW 1

DIGIT 1

ROW 2

DIGIT 1

ROW 3

DIGIT 1

ROW 4

DIGIT 1

ROW 5

DIGIT 1

ROW 6

DIGIT 1

ROW 7

DIGIT 3

ROW 1

DIGIT 3

ROW 2

DIGIT 3

ROW 3

DIGIT 3

ROW 4

DIGIT 3

ROW 5

DIGIT 3

ROW 6

DIGIT 3

ROW 7

DIGIT 1

ROW 1

COLUMN DRIVER

PINS O19-O23

DIGIT 0

ROW 1

DIGIT 0

ROW 2

DIGIT 0

ROW 3

DIGIT 0

ROW 4

DIGIT 0

ROW 5

DIGIT 0

ROW 6

DIGIT 0

ROW 7

DIGIT 2

ROW 1

DIGIT 2

ROW 2

DIGIT 2

ROW 3

DIGIT 2

ROW 4

DIGIT 2

ROW 5

DIGIT 2

ROW 6

DIGIT 2

ROW 7

DIGIT 0

ROW 1

COLUMN DRIVER

PINS O14-O18

DIGIT 1 ROW 1's 100µs MULTIPLEX TIMESLOT

CURRENT SOURCE

1/16TH

2/16TH

(MIN ON)

3/16TH

4/16TH

5/16TH

6/16TH

7/16TH

8/16TH

9/16TH

10/16TH

11/16TH

12/16TH

13/16TH

14/16TH

15/16TH

16/16TH

(MAX ON)

CURRENT SOURCE

CURRENT SOURCE

CURRENT SOURCE

CURRENT SOURCE

CURRENT SOURCE

CURRENT SOURCE

CURRENT SOURCE

CURRENT SOURCE

CURRENT SOURCE

CURRENT SOURCE

CURRENT SOURCE

CURRENT SOURCE

CURRENT SOURCE

CURRENT SOURCE

CURRENT SOURCE

ONE COMPLETE 1.4ms MULTIPLEX CYCLE AROUND 14 ROWS

100µs

DIGIT 1 COLUMN

DRIVER OUTPUTS

PINS O19-O23

HIGH-Z

HIGH-Z

HIGH-Z

HIGH-Z

HIGH-Z

HIGH-Z

HIGH-Z

HIGH-Z

HIGH-Z

HIGH-Z

HIGH-Z

HIGH-Z

HIGH-Z

HIGH-Z

HIGH-Z

HIGH-Z

DIGITS 0 AND 1

ROW OUTPUTS

PINS O0–06

HIGH-Z

LOW

DIGITS 2 AND 3

ROW OUTPUTS

PINS O7–O13

HIGH-Z

HIGH-Z

HIGH-Z

MINIMUM 6.25µs INTERDIGIT BLANKING INTERVAL

START OF

NEXT CYCLE

Figure 10. Multiplex Timing Diagram (OSC = 4MHz)