SN3189
Nov. 2009 P0.7 SI-EN Technology
1
Audio Modulated LED Driver
Description
The SN3189 is an LED driver with an audio
synchronization mode that virtually eliminates the need
for real time software processing for LED lighting effects.
The OUT0~9 can be operated at 4 basic modes:
Audio synchronization mode, top-down scan mode,
constant current mode, combination of audio
synchronization and top-down scan mode.
Each of the OUT0~2, OUT7~9 is a constant current sink
pulse width modulated in 256 steps, featuring One Shot
Programming mode and Interface Intensity Control mode
for RGB lighting effects. The output current is user
selectable to be one of 5 levels, 17.5mA, 28.9mA,
38.9mA, 46.7mA or 66.5mA (typical). At 38.9mA the
SN3189 outputs require only 0.4V of headroom voltage.
In One Shot Programming mode, the timing
characteristics for output current - current ramping up,
holding, ramping down and off time, can be adjusted
individually so that each output can independently
maintain a pre-established pattern without requiring any
additional interface activity, thus saving valuable system
resources.
In Interface Intensity Control mode, the PWM duty cycle
of each output can be independently programmed and
controlled in 256 steps to simplify color mixing.
Applications
Cellular phones
MP3/MP4/CD/minidiskplayers
Digital picture frame/toys
Features
10 outputs each with 38.9mA at 0.4V headroom.
2 independently controlled, 6 channels of 256 steps
PWM RGB LED drivers with programmable
brightness and blinking patterns for LED’s lighting
effects
Fully programmable operating modes:
-Audio synchronization mode
-Audio synchronization +Top-down scan mode
-Top-down scan mode
-Constant current mode
-One Shot Programming mode with Gamma
correction
-Interface intensity control mode with 256 steps
current level setting for RGB lighting effects
-RGB blink/not blink with audio mode
Each outputs enable/disable individually
Programmable parameter setting:
Audio gain setting
Top-down scan mode output current setting
Top-down scan mode scan rate setting
RGB mode output current setting
Programmable Output Current Level settings
For Anode-common LEDs
VDD Range: 3.0V to 5.5V
Package: QFN-20, 3mm × 3mm
T ypical Application Circuit
Figure 1 Typical Application Circuit
SN3189
Nov. 2009 P0.7 SI-EN Technology
2
Pin Configuration
Package Pin Configurations (Top View)
QFN-20
1
2
3
4 12
13
14
15
5 11 OUT7
OUT8
OUT9
SDI
OUT0
OUT1
OUT2
VDD
SDB
CS
Pin Description
No. Pin I/O Description
1 SDB I Shutdown, pull to GND for shutdown mode.
2 VDD
-
Power supply.
3~7, 9~13 OUT0 ~ OUT9 O LED outputs.
8,17 GND
-
Ground.
14
C
S
I Chip select, active is low.
15 SDI I/O Input serial data for data shift resister.
16 SCK I Input clock for data shift on rising edge.
18 IN I Audio signal input.
19 C_FILT I Low pass filter input.
20 R_EXT I
External resistor (R
EXT
) connect pin to regulate the
output current.
Thermal Pad
-
Connect to GND.