ISSI IS31FL3731 User Manual

IS31FL3731 Audio Modulated Matrix LED Driver Evaluation Board Guide

Integrated Silicon Solution, Inc. – www.issi.com

1

R1.0, 07/12/2012

Description

The IS31FL3731 is a compact LED driver for 144 single
LEDs. The device can be programmed via an I2C
compatible interface. Additionally each of the 144 LEDs
can be dimmed individually with 8-bit allowing 256
steps of linear dimming.

To reduce CPU usage up to 8 frames can be stored
with individual time delays between frames to play
small animations automatically. LED frames can be
modulated with audio signal.

Features

• Supply voltage range from 2.7V to 5.5V

• 8 frames memory for animations

• Picture mode and animation mode

• Auto intensity breathing during the switching of

different frames

• LED frames displayed can be modulated with
audio signal intensity

• LED light intensity can be modulated with audio
signal intensity

• QFN-28 (4mm × 4mm) package

Quick Start

Recommended Equipment

• 5.0V, 2A power supply

• Audio source( i.e. MP3 player, Notebook PC, etc)

• 8Ω speaker

Absolute Maximum Ratings

• ≤ 5.5V power supply

Caution: Do not exceed the conditions listed above, otherwise
the board will be damaged.

Procedure

The IS31FL3731 evaluation board is fully assembled
and tested. Follow the steps listed below to verify
board operation.

Caution: Do not turn on the power supply until all connections
are completed.

1) Connect an 8Ω speaker to the “SPK” connector.

2) Connect the audio source to the “AUDIO IN”
connector.

3) Connect the DC power to the connector (DC IN).

4) Turn on the power supply and pay attention to the
supply current. If the current exceeds 1A, please
check for circuit fault.

5) Turn on the audio signal.

6) Modulation of the audio signal utilized to obtain
better sound output performance

Figure 1: Photo of IS31FL3731 Evaluation Board

Evaluation Board Ordering Information

Part No. IC Package

IS31FL3731-QFLS2-EB QFN-28, Lead-free

Table1: Ordering Information

For pricing, delivery, and ordering information, please contacts ISSI’s analog marketing
team at [e-mail] or [phone].

IS31FL3731 Audio Modulated Matrix LED Driver Evaluation Board Guide

Integrated Silicon Solution, Inc. – www.issi.com

2

R1.0, 07/12/2012

Evaluation Board Operation

The IS31FL3199 evaluation board has eight display
modes. Press MODE button to switch configurations.

1)

Firework animation

2)

Lighting animation

3)

Power-on animation

4)

Water drop animation

5)

Static graphics breathe dimming effect

6)

Triangular music bar effect: more triangular music
bars are displayed with stronger music.

7)

Equalizer bar effect: EQ bars move up and down
with music.

8)

Multiple graphics display: different graphics
change with music rhythm.

*Note:

IS31FL3731 solely controls the FxLED function on the
evaluation board.

Software Control

JP1 default setting is close circuit. If it is set to open,
the on-board MCU will stop working. The I2C pins
are set to High Impedance. External I2C signals can
be connected to TP3 to control the IS31FL3731 LED
driver.

Please refer to the datasheet to get more information about
IS31FL3731.

IS31FL3731 Audio Modulated Matrix LED Driver Evaluation Board Guide

Integrated Silicon Solution, Inc. – www.issi.com

3

R1.0, 07/12/2012

CA9

1

VCC

2

SDB

3

INTB

4

GND

5

REXT

6

CB1

7

CB2

8

CB3

9

CB4

10

CB5

11

CB6

12

CB7

13

CB8

14

CB9

15

C_fILT

16

IN

17

AD

18

SDA

19

SCL

20

CA1

21

CA2

22

CA3

23

CA4

24

CA5

25

CA6

26

CA7

27

CA8

28

IS31FL3731

U1

Y1

12MHZ

C7
33p

C8
33p

C6
1uF

VCC

10K

R7

4.7K

R3

20K

R1 C3

0.1uF

C4

0.22uF

C2
1uF

1
2
3

RST

4

RXD

5
6

TXD

7

INT0

8

INT1

9
10
11

12

13

XTAL2

14

XTAL115GND

16

1718192021

22

23

24

25

26

27

28

29

30

31

32

33

343536

37

VDD

38

39

P1.040P1.141P1.2

42

43

P1.4

44

STC12C5A60S2

U2

INTB

SDA

SCL

SDB

VCC

100K

R6

MODE

K1

1uF

C5 VCC

SDA

SCL

SDB

INTB

100K

R4

VCC

JP1

OPEN=EXT CTRL

SDA

SDB
SCL

GND

Audio In

1

2

3

4

5

TP3

INTB

1

2

3

4

5

TP4

ISP

VCC
TXD
RXD
GND
GND

CA1

CA2

CA3

CA4

CA5

CA6

CA7

CA8

CA9

CB1

CB2

CB3

CB4

CB5

CB6

CB7

CB8

CB9

D129

D113

D97

D81

D65

D49

D33

D17

D1

D144

D128

D112

D96

D80

D64

D48

D32

D16

CA1
CA2
CA3
CA4
CA5
CA6
CA7
CA8
CA9

CB1
CB2
CB3
CB4
CB5
CB6
CB7
CB8
CB9

VCC

C1
10uF

CON1
DC IN

TP1

TP2

VCC

C11
1uF

C10
1uF

C9

0.22uF
CON3
SPK

SD

1

IN+

3

VDD

6

IN-

4

VO1

5

GND

7

VO2

8

BYPASS

2

U3

IS31AP4991

Audio In

CON2
AUDIO IN

4.7K

R2

4.7K

R5

20K

R8

39K

R9

TXD

RXD

Figure 2:IS31FL3731 Application Schematic