ISSI IS31FL3238 User manual

18-CHANNEL LED DRIVER EVALUATION BOARD GUIDE
Integrated Silicon Solution, Inc. – ams.issi.com 1
Rev. B, 12/28/2018
DESCRIPTION
IS31FL3238 is an LED driver with 18 constant current
channels. Each channel can be pulse width modulated
(PWM) by 16 bits for smooth LED brightness control.
In addition, each channel has an 8-bit output current
control register which allows fine tuning the current for
rich RGB color mixing, e.g., a pure white color LED
application. The maximum output current of each
channel is designed to be 76mA, which can be
adjusted by one 8-bit global control register.
Proprietary programmable algorithms are used in
IS31FL3238 to minimize audible noise caused by the
MLCC decoupling capacitor. All registers can be
programmed via a high speed I2C (1MHz).
FEATURES
2.7V to 5.5V VCC supply
Modulate LED brightness with
256/1024/4096/65536 steps PWM method
Modulate LED DC current with 256 steps method
Global 256 steps analog global current control
PWM frequency selectable
Open short detect function
Spread spectrum
QFN-28 (5mm×5mm) packages
QUICK START
Figure 1: Photo of IS31FL3238-QWLS4 Evaluation Board
RECOMMENDED EQUIPMENT
5.0V, 2A power supply
ABSOLUTE MAXIMUM RATINGS
≤5.5V power supply
Caution: Do not exceed the conditions listed above, otherwise
the board will be damaged.
PROCEDURE
The IS31FL3238 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) If using external DC power supply connect the
ground terminal of the power supply to the
evaluation board's GND pin and the positive
terminal to the VCC pin. The evaluation board can
also be powered via the Micro USB connector.
2) Short JP1 to disable external control.
3) Turn on the power supply/Plug in the Micro USB
and pay attention to the supply current. If the
current exceeds 1A, please check for circuit fault.
4) Enter the desired mode of display by toggling the
MODE button (K1).
ORDERING INFORMATION
Part No. Temperature Range Package
IS31FL3238-QFLS4-EB -40°C to +125°C (Industrial) QFN-28, Lead-free
Table 1: Ordering Information
For pricing, delivery, and ordering information, please contacts ISSI’s analog marketing team at
[email protected] or [phone].

18-CHANNEL LED DRIVER EVALUATION BOARD GUIDE
Integrated Silicon Solution, Inc. – ams.issi.com 2
Rev. B, 12/28/2018
EVALUATION BOARD OPERATION
The IS31FL3238 evaluation board has six display
modes. Press MODE button to switch configurations.
1) (Default mode) Two groups single color LEDs
chasing each other-A.
2) Two groups single color LEDs chasing each
other-B.
3) There groups single color LEDs chasing after
each other.
4) Chasing cycle.
5) RGB LEDs (RGB1-RGB6) are breathing effect
A-mixed color.
6) RGB LEDs (RGB1-RGB6) are breathing effect B.
Note: IS31FL3238 solely controls the FxLED function on the
evaluation board.
SOFTWARE SUPPORT
JP1 default setting is close circuit. If it is set to open,
the on-board MCU will stop working. The I2C pins and
SDB pin are set to High Impedance. External I2C and
SDB signals can be connected to TP4 to control the
IS31FL3238 LED driver. During external control mode,
toggling the MODE button (K1) can switch the power of
single blue color LED and power of RGB LED.
GND
SDA
SCL
SDB
VCC
Figure 2: Photo of Arduino UNO connected to Evaluation
Board
The steps listed below are an example using the
Arduino for external control.
The Arduino hardware consists of an Atmel
microcontroller with a bootloader allowing quick
firmware updates. First download the latest Arduino
Integrated Development Environment IDE (1.6.12 or
greater) from www.arduino.cc/en/Main/Software. Also
download the Wire.h library from
www.arduino.cc/en/reference/wire and verify that
pgmspace.h is in the directory …program
Files(x86)/Arduino/hardware/tools/avr/avr/include/avr
/. Then download the latest IS31FL3238 test firmware
(sketch) from the ISSI website
http://ams.issi.com/US/product-analog-fxled-driver.shtml.
1) Open JP1.
2) Connect the 5 pins from Arduino board to
IS31FL3238 EVB:
a) Arduino 5V pin to IS31FL3238 EVB VCC.
b) Arduino GND to IS31FL3238 EVB GND.
c) Arduino SDA (A4) to IS31FL3238 EVB SDA.
d) Arduino SCL (A5) to IS31FL3238 EVB SCL.
e) If Arduino use 3.3V MCU VCC, connect
3.3V to IS31FL3238 EVB SDB, if Arduino
use 5.0V MCU VCC, connect 5.0V or 3.3V
to EVB SDB.
(Arduino UNO MCU VCC is 5V, so SDB can
be 5V or 3.3V)
3) Use the test code in appendix Ⅰor download
the test firmware (sketch) from the ISSI website,
a .txt file and copy the code to Arduino IDE,
compile and upload to Arduino.
4) Run the Arduino code and the initial mode will
change the Blue LED brightness every second.
5) During external control mode, toggling the MODE
button (K1) can switch the power of single color
LEDs and power of RGB LEDs.
Please refer to the datasheet to get more information about
IS31FL3238.

18-CHANNEL LED DRIVER EVALUATION BOARD GUIDE
Integrated Silicon Solution, Inc. – ams.issi.com 3
Rev. B, 12/28/2018
VDD
3
SCL
7SDA
6
SDB
1
R-EXT
5
GND
4
OUT1 8
OUT2 9
OUT3 10
OUT4 12
OUT5 13
OUT6 14
OUT7 15
OUT8 16
OUT9 17
OUT10 19
OUT11 20
OUT12 21
OUT13 22
OUT14 23
OUT15 24
OUT16 26
OUT17 27
OUT18 28
AD
2
GND
11
GND
18
GND
25
TPAD
29
U1
IS31FL3238
SDA
SCL
VCC
Vdd
1
GND
2
EN
3
Vout 5
BP 4
U3
LDO
VDD
DS1
VCC
VCC
VCC
GND
VDD
SDA
SCL
INTB
DIO
GND
VDD
GND
CLK
VDD
K1
VDD
SDB
VDD
33P
C8
33P
C7
OSCO
OSCI
OSCI
OSCO
VBAT
1
PC13-ANTI_TAMP
2
PC14-OSC32_IN
3
PC15-OSC32_OUT
4
OSC_IN
5
OSC_OUT
6
NRST
7
VSSA
8
VDDA
9
PA0-WKUP/ADC_IN0/TIM2_CH1_ETR
10
PA1/ADC_IN1/TIM2_CH2
11
PA2/USART2_TX/ADC_IN2/TIM2_CH3
12
PA3/USART2_RX/ADC_IN3/TIM2_CH4
13
PA4/SPI1_NSS/ADC_IN4
14
PA5/SPI1_SCK/ADC_IN5
15
PA6/SPI1_MISO/ADC_IN6/TIM3_CH1
16
PA7/SPI1_MOSI/ADC_IN7/TIM3_CH2
17
PB0/ADC_IN8/TIM3_CH3
18
PB1/ADC_IN9/TIM3_CH4
19
PB2/BOOT1
20
PB10/I2C2_SCL/USART3_TX
21
PB11/I2C2_SDA/ USART3_RX
22
VSS_1
23
VDD_1
24 PB12/SPI2_NSS/TIM1_BKIN 25
PB13/SPI2_SCK/TIM1_CH1N 26
PB14/SPI2_MISO/TIM1_CH2N 27
PB15/SPI2_MOSI/TIM1_CH3N 28
PA8/TIM1_CH1/MCO 29
PA9/USART1_TX/TIM1_CH2 30
PA10/USART1_RX/TIM1_CH3 31
PA11/CANRX/USBDM/TIM1_CH4 32
PA12/CANTX/USBDP/TIM1_ETR 33
PA13/JTMS/SWDIO 34
VSS_2 35
VDD_2 36
PA14/JTCK/SWCLK 37
PA15/JTDI 38
PB3/JTDO 39
PB4/JNTRST 40
PB5 41
PB6/I2C1_SCL/TIM4_CH1 42
PB7/I2C1_SDA/TIM4_CH2 43
BOOT0 44
PB8/TIM4_CH3 45
PB9/TIM4_CH4 46
VSS_3 47
VDD_3 48
U2
STM32F103C8T6
1
2
3
4
TP3
Header 4 GND
SDA
SCL
SDB
GND
VDD
CLK
DIO
VRGB
VBlue
VCC
BIT1
BIT2
SDB
VUSB
1
2
TP1
1
2
TP2
1
2
JP1
GND
GND
GND
PA0
PA0
OUT01
OUT02
OUT03
OUT04
OUT05
OUT06
OUT07
OUT08
OUT09
OUT10
OUT11
OUT12
OUT13
OUT14
OUT15
OUT16
OUT17
OUT18
OUT01
OUT02
OUT03
OUT04
OUT05
OUT06
OUT07
OUT08
OUT09
OUT10
OUT11
OUT12
OUT13
OUT14
OUT15
OUT16
OUT17
OUT18
VRGBVBlue
OSCO
2
OSCI 4 GND
1
GND 3
Y1 8M
OUT01
OUT02
OUT03
OUT04
OUT05
OUT06
OUT07
OUT08
OUT09
OUT10
OUT11
OUT12
OUT13
OUT14
OUT15
OUT16
OUT17
OUT18
SCL
SDA
GND
VCC
MISO
13V3 2
MOSI
35V 4
SCK
5SCL 6
CS
7SDA 8
SDB
9GND 10
CON2
VCC
MISO
MOSI
SCK
CS
S1
1
G1
2
S2
3
G2
4D2 5
D2 6
D1 7
D1 8
U4
APM4953
R6
100K
R7
100K
R1
2K R3 2K
R5
3.3K
R2 100K
R4
100K
D1
D2
C5
1uF
C6
10nF
C4
1uF
C3
10uF
C1
100nF
C2
100nF
ISSI
GND
VCC
VCC
+5V 1
D- 2
D+ 3
ID 4
GND 5
CON1
USB-5P
BIT2
BIT1
R9 1K
R8 100K VDD
PA0
CS
SCK
MISO
MOSI
LEDR
LEDB
INTB
D19
LED-RGB-SIDE
D20
LED-RGB-SIDE
D21
LED-RGB-SIDE
D22
LED-RGB-SIDE
D23
LED-RGB-SIDE
D24
LED-RGB-SIDE
R1022R
R1122R
R121.5K
D-
D+
D-
D+
USB_DM
USB_DP
USB_DM
USB_DP
VDD
1
2
3
JP1
1
2
3
JP2
1
2
3
JP3
1
2
3
JP4
1
2
3
JP5
1
2
3
JP6
OUT01
OUT02
OUT03
OUT04
OUT05
OUT06
OUT07
OUT08
OUT09
OUT10
OUT11
OUT12
OUT13
OUT14
OUT15
OUT16
OUT17
OUT18
D3
D4
D5
D6
D7
D8
D9
D10
D11
D12
D13
D14
D15
D16
D17
D18
Figure 3: IS31FL3238 Application Schematic

18-CHANNEL LED DRIVER EVALUATION BOARD GUIDE
Integrated Silicon Solution, Inc. – ams.issi.com 4
Rev. B, 12/28/2018
BILL OF MATERIALS
Name Symbol Description Qty Supplier Part No.
LED Driver U1 18CH FxLED Driver 1 ISSI IS31FL3238
MCU U2 Microcontroller 1 STM STM32F103C8T6
LDO U3 3.0V LDO 1 SGMICRO SGM2019-3.0YN5G
PMOS U4 Dual PMOS 1 ANPEC APM4953
Crystal Y1 Crystal, 8MHz 1 HLX HC-49S
Diode D1~D18 Diode, LED Blue, SMD 18 Everlight 19-217/BHC-AN1P2/3T
Diode D19~D24 Diode, LED RGB, SMD 6 ROHM SMLV56RGB1W1
Diode DS1 Diode, SMD 1 DIODES DFLS240
Resistor R1,R3 RES,2k,1/10W,±5%,SMD 1 Yageo RC0603JR-072KL
Resistor R2,R4,R6,
R7,R8 RES,100k,1/10W,±5%,SMD 5 Yageo RC0603JR-07100KL
Resistor R5 RES,3.3k,1/10W,±5%,SMD 1 Yageo RC0603JR-073K3L
Resistor R9 RES,1k,1/10W,±5%,SMD 1 Yageo RC0603JR-071KL
Resistor R10, R11 RES,22R,1/10W,±5%,SMD 1 Yageo RC0603JR-0722RL
Resistor R12 RES,1.5k,1/10W,±5%,SMD 1 Yageo RC0603JR-071K5L
Capacitor C1,C2 CAP,100nF,16V,±20%,SMD 2 Yageo CC0603MRX7R7BB104
Capacitor C3 CAP,10µF,16V,±20%,SMD 1 Yageo CC0603MRX5R7BB106
Capacitor C4,C5 CAP, 1µF,16V,±10%,SMD 2 Yageo CC0603KRX7R7BB105
Capacitor C6 CAP,10nF,16V,±10%,SMD 1 Yageo CC0603KPX7R7BB103
Capacitor C7, C8 CAP,33pF,50V,±5%,SMD 2 Yageo CQ0603JRNPO9BN360
Button K1 Button SMD 1
Bill of Materials, refer to Figure 3 above.

18-CHANNEL LED DRIVER EVALUATION BOARD GUIDE
Integrated Silicon Solution, Inc. – ams.issi.com 5
Rev. B, 12/28/2018
0
0 0
0
8
6
4
2
10
1
3
5
7
9
2
1
2
1
1 2 3 4
0
00
0
11
2
1
Figure 4: Board Component Placement Guide - Top Layer
0
0 0
0
8
6
4
2
10
1
3
5
7
9
2
1
2
1
2 1
2
1
2
1
2
1
2
1
2
12
1
2
1
2
1
21
2
1
2
1
2
1
2
1
2
1
2
1
12
2
1
2
1
1 2 3 4
29
0
00
0
11
2
1
Figure 5: Board PCB Layout - Top Layer

18-CHANNEL LED DRIVER EVALUATION BOARD GUIDE
Integrated Silicon Solution, Inc. – ams.issi.com 6
Rev. B, 12/28/2018
0
0 0
0
8
6
4
2
10
1
3
5
7
9
2
1
2
1
1234
0
00
0
11
2
1
Figure 6: Board Component Placement Guide - Bottom Layer
0
0 0
0
1
2
8
6
4
2
10
1
3
5
7
9
1
2
1
2 1
2
8
7
6
5
1
2
3
4
1
2
1 2
1
2
1
2
1
2
1
21
2
2
1
2
1
1
2
3
4
2
1
21
1234
2
1
12
0
00
0
11
2 1
12
12
321321321321321
12
12
1 2
321
2
1
Figure 7: Board PCB Layout - Bottom Layer
Copyright©2018IntegratedSiliconSolution,Inc.Allrightsreserved.ISSIreservesthe righttomakechangestothisspecificationanditsproductsatany
timewithoutnotice.ISSIassumesnoliabilityarisingoutoftheapplicationoruseofanyinformation,productsorservicesdescribedherein.Customersare
advisedtoobtainthelatestversionofthisdevicespecificationbeforerelyingonanypublishedinformationandbeforeplacingordersforproducts.
IntegratedSiliconSolution,Inc.doesnotrecommendtheuseofanyofitsproductsinlifesupportapplicationswherethefailureormalfunctionofthe
productcanreasonablybeexpectedtocausefailureofthelifesupportsystemortosignificantlyaffectitssafetyoreffectiveness.Productsarenot
authorizedforuseinsuchapplicationsunlessIntegratedSiliconSolution,Inc.receiveswrittenassurancetoitssatisfaction,that:
a.)theriskofinjuryordamagehasbeenminimized;
b.)theuserassumeallsuchrisks;and
c.)potentialliabilityofIntegratedSiliconSolution,Incisadequatelyprotectedunderthecircumstances

18-CHANNEL LED DRIVER EVALUATION BOARD GUIDE
Integrated Silicon Solution, Inc. – ams.issi.com 7
Rev. B, 12/28/2018
REVISION HISTORY
Revision Detail Information Data
A Initial Release 2018.09.17
B Update schematic and PCB layout 2018.12.28

18-CHANNEL LED DRIVER EVALUATION BOARD GUIDE
Integrated Silicon Solution, Inc. – ams.issi.com 8
Rev. B, 12/28/2018
APPENDIX Ⅰ: IS31FL3238 Arduino Test Code V01A
#include<Wire.h>
#include<avr/pgmspace.h>
#define Addr_GND 0x68
//7 bit format is 0x3F
byte PWM_Gamma64[64]=
{
0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,
0x08,0x09,0x0b,0x0d,0x0f,0x11,0x13,0x16,
0x1a,0x1c,0x1d,0x1f,0x22,0x25,0x28,0x2e,
0x34,0x38,0x3c,0x40,0x44,0x48,0x4b,0x4f,
0x55,0x5a,0x5f,0x64,0x69,0x6d,0x72,0x77,
0x7d,0x80,0x88,0x8d,0x94,0x9a,0xa0,0xa7,
0xac,0xb0,0xb9,0xbf,0xc6,0xcb,0xcf,0xd6,
0xe1,0xe9,0xed,0xf1,0xf6,0xfa,0xfe,0xff
};
void setup() {
// put your setup code here, to run once:
Wire.begin();
Wire.setClock(400000);//I2C 400kHz
// pinMode(4,OUTPUT);//SDB
// digitalWrite(4,HIGH);//SDB_HIGH
//delay(100); //keep 0.5s
Init_FL3238();
}
void loop() {
// put your main code here, to run repeatedly:
// delay(50);
Init_FL3238();
IS31FL3238_mode1();//breath mode
}
void IS_IIC_WriteByte(uint8_t Dev_Add,uint8_t Reg_Add,uint8_t Reg_Dat)
{
Wire.beginTransmission(Dev_Add/2);
Wire.write(Reg_Add); // sends regaddress
Wire.write(Reg_Dat); // sends regaddress
Wire.endTransmission(); // stop transmitting
}
void Init_FL3238(void)
{
uint8_t i = 0;
for(i=0x4A;i<=0x6D;i++)
{
IS_IIC_WriteByte(Addr_GND,i,0xFF);//write all scaling
}
IS_IIC_WriteByte(Addr_GND,0x6e,0xff);//GCC
IS_IIC_WriteByte(Addr_GND,0x49,0x00);//update PWM & congtrol registers
IS_IIC_WriteByte(Addr_GND,0x00,0x01);//normal operation
}
void IS31FL3238_mode1(void)//white LED
{
int i=0,j=0;
for(j=0;j<=63;j++)
{
for(i=0x01;i<=0x47;i=i+2)
{
IS_IIC_WriteByte(Addr_GND,i, PWM_Gamma64[j]);//write all PWM set 0x80
IS_IIC_WriteByte(Addr_GND,0x49,0x00);//update PWM & congtrol registers
}
delay(10); //keep 0.5s
}
for(j=63;j>=0;j--)
{
for(i=0x01;i<=0x47;i=i+2)
{

18-CHANNEL LED DRIVER EVALUATION BOARD GUIDE
Integrated Silicon Solution, Inc. – ams.issi.com 9
Rev. B, 12/28/2018
IS_IIC_WriteByte(Addr_GND,i, PWM_Gamma64[j]);//write all PWM set 0x80
IS_IIC_WriteByte(Addr_GND,0x49,0x00);//update PWM & congtrol registers
}
delay(10); //keep 0.5s
}
}