Ver 1.0
RGB/Matrix/Audio EQ/16Level LED Driver
Description
BCT3286 is a LED matrix driver with SPI control
interface, which features with Mono or RGB LED
dot matrix display and audio frequency equalizer
(EQ) to produce amazing visual effects.
It has the function of mono LED/ RGB LED
blinking, breathing, single shift or rotate shift,
music equalizer, …etc, realized by only one single
instruction, thus save MCU software resources.
It has less than 2uA shut down current and save
battery life.
BCT3268 is available in QFN-28(4mm × 4mm). It
operates from 2.7V to 5.5V over the temperature
range of of -40°C to +85°C
Features
Programmable 10×10, 11×9, 12×8 matrix
LED driver
Each column has 16 brightness level
programmable by SPI interface.
Max 40mA current for each row and can be
changed by external Rext
RGB numbers can be 4n ( n= 1,..8), thus
support max 32 RGB LEDs
16 colures can be selected in RGB mode.
Audio frequency EQ display of 8 column,
and sync with music
Audio input gain can be programmable or
automatic control.
Auto blink or breath functions, and
brightness level and frequency can be
programmed.
Internal RAM
Single shift or rotate shift, direction and
speed can be selected
Applications
Mobile phones and other hand-held devices
for LED displays.
Audio frequency equalizer display
Toys or home appliance devices
Pin Configuration (Top View)
www.broadchip.com
1
Ver 1.0
Ordering Information
Order Number
BCT3286EGI-TR
Package Type
QFN-28
Operating
Temperature Range
-40°C to +85°C
Marking
3286
QTY/Reel
3000
Pin Description
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
Pin
SCLK
CS
DIN
SDB
AU-IN
REXT
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
R11/C10
R12/C9
C8
C7
VDD
C6
C5
C4
C3
C2
C1
NC
GND
Description
SPI CLK
SPI CS
SPI DATA
Reset
Audio input.
current setting
Constant current row output1
Constant current row output2
Constant current row output3
Constant current row output4
Constant current row output5
Constant current row output6
Constant current row output7
Constant current row output8
Constant current row output9
Constant current row output10
Constant current row output11 or column10 Scan output
Constant current row output12 or column9 Scan output
column8 Scan output
column7 Scan output
Power supply.
column6 Scan output
column5 Scan output
column4 Scan output
column3 Scan output
column2 Scan output
column1 Scan output
Ground.
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2
Ver 1.0
Absolute Maximum Ratings
Supply voltage, V
DD
-----------------------------------------------------------------------------
-0.3
V ~ +5.5V
Outx current, IO--------------------------------------------------------------------------------------------- 40mA
Voltage at any input pin VI ----------------------------------------------------------------
-0.3V
~ V
DD
+0.3V
Working temperature, T
A
---------------------------------------------------------------------
-40
°C to +150°C
Junction temperature, T
JMAX
-------------------------------------------------------------------------------- 150°C
Storage temperature, Tstg-----------------------------------------------------------------------55 °C to +150°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.
These are stress ratings only and functional operation of the device at these or any other condition beyond those
indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
Electrical Characteristics
Test condition : Vin =
2.7V
~ 5.5V, T
A
= 25°C, unless otherwise noted.
Parameter
Supply voltage
Quiescent current
Shutdown current
Output current accuracy
Symbol
VDD
IVDD
ISHUT
IO
REXT=4K,R1~ R12 Open,VDD=5.5V
Shutdown mode,VDD=5.5V
REXT=2K，Vdropout=1V
REXT=4K，Vdropout=1V
REXT=2K,Vdropout=1VIO=40mA
REXT=4K,Vdropout=1V,IO=20mA
Vdrop
VIH
VIL
VDD=3.3V，IO=40mA
VDD=3.3V，IO=20mA
1.5
0.8
35
18
40
20
±1
±1
400
300
Condition
Min.
2.7
1.6
Typ.
Max.
5.5
2
2
45
22
±3
±3
500
500
V
V
mV
%
Unit
V
mA
uA
mA
Output current match
Dropout Voltage
Logic “H” input voltage
Logic “L” input voltage
Serial (SPI) interface
Serial (SPI) interface is for receiving the control signals sent from controller, then decode the received
command and send it to the corresponding register and control module. It has three pin: CS, SCLK and
DIN.
Pin Name
SPICK
SPIDATA
SPICS
Attribute
Rising edge
Level
Active Low
Direction
MCU->BCT3286
MCU->BCT3286
MCU->BCT3286
Description
Serial bus clock
Serial data
SPI bus chipselection
Serial (SPI) interface can only do write operation form MCU to BCT3286, it is not readable. The fixed
data width is 16 bits
www.broadchip.com
3
Ver 1.0
Figure 2 shows the timing diagram of this serial interface. When no data transmit, SPICK is forced to
LOW and SPICS is forced to HIGH. Once the data need to be send form controller to BCT3286,
SPICS is pulled LOW to enable the transmission. At rising edge of the CLK, data is latched. SPICS
keep LOW for the duration of the transmission. First 8 bits of DIN will be the register address and
following 8 bits will be the data of the register.
Figure 2: SPI timing
Serial Port Interface Timing
Figure 3. SPI Interface Timing Diagram
Symbol
Ts
Th
Parameter
SPIDATA to SPICK setup time
SPIDATA to SPICK hold time
Min
4
20
Tye
Max
Unit
ns
ns
The maximum output current per row is set by a single external resistor REXT, which is
between the REXT pin and GND pin. The maximum channel output current can be calculated
as:
IO(max) = 80
/Rext
(mA)
The max output current REXT values
REXT(K
Ω)
IOmax(mA)
2
3
4
5
40
27
20
16
If
N column are used, the Max current for each LED is
IO(max)/N.
www.broadchip.com
4
Ver 1.0
Registers Definition
1. Data register
00H
Column 1 data register
MSB
Bit
Name
Default
D7 : D4
D3 : D0
LSB
row8-row5/RGB3
0000
row12-row9/RGB4
0000
01H
Column 1 data and brightness register
MSB
Bit
Name
Default
D7 : D4
D3 : D0
LSB
Brightness/RGB1
0000
Row4-row1/RGB2
0000
02H
Column 2 data register
MSB
Bit
Name
Default
D7 : D4
D3 : D0
LSB
row8-row5/RGB3
0000
row12-row9/RGB4
0000
03H
Column 2 data and brightness register
MSB
Bit
Name
Default
D7 : D4
D3 : D0
LSB
Brightness/RGB1
0000
Row4-row1/RGB2
0000
04H
Column 3 data register
MSB
Bit
Name
Default
D7 : D4
D3 : D0
LSB
row8-row5/RGB3
0000
row12-row9/RGB4
0000
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5
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