DM114
DM115
Version :
A.002
Issue Date :
2005/03/18
File Name :
sp-
DM1145-A.002
Total Pages :
17
8-Bit CONSTANT CURRENT LED DRIVERS with
3.3v ~ 5v supply voltage
9 7 1
SILICON TOUCH TECHNOLOGY INC.
9-7F-1, Prosperity Road I, Science Based Industrial Park,
Hsin-Chu, Taiwan 300, R.O.C.
Tel886-3-5645656 Fax886-3-5645626
DM114
DM115
SILICON TOUCH TECHNOLOGY INC.
8-BIT CONSTANT CURRENT LED DRIVERS with 3.3V~5V supply voltage
Version:A.002
Page 1
Preliminary
DM114
DM115
8-Bit CONSTANT CURRENT LED DRIVERS with
3.3v ~ 5v Supply Voltage
General Description
The DM114DM115 is the constant current driver specifically designed for LED display
applications. The value of constant current can be varied using an external resistor. The devices
include an 8-bit shift register, latches, and constant current drivers on a single Silicon CMOS chip.
Features
Maximum Output Voltage: 17V
Maximum Clock Frequency: 25MHz (Cascade Operation)
Power Supply Voltage:
3.3V to 5.0V
CMOS Compatible Input
Package:
PDIP16,
SOP16,
SSOP16
Package and Pin Layout:
Pin layout and functionality are similar to those of the ST2221A.
(Each characteristic value is different.)
Constant Current Matching: (Ta = 25
CV
DD
= 5.0V)
Chip-to-Chip:
10.0%
DM114:
Bit-to-Bit:
4.0% @ I
OUT
= 30 ~ 90mA
6.0% @ I
OUT
= 20 ~ 30mA
DM115:
Bit-to-Bit:
4.0% @ I
OUT
= 20 ~ 60mA
6.0% @ I
OUT
= 5 ~ 20mA
DM114
DM115
SILICON TOUCH TECHNOLOGY INC.
8-BIT CONSTANT CURRENT LED DRIVERS with 3.3V~5V supply voltage
Version:A.002
Page 2
Preliminary
Pin Connection
(Top view)
Block Diagram
GND
SERIAL-IN
SERIAL-OUT
CLOCK
OUT0
OUT1
OUT2
OUT3
OUT4
OUT5
OUT6
OUT7
R-EXT
V
DD
8
7
6
5
4
3
2
1
9
10
11
12
13
14
15
16
ENABLE
LATCH
CK
CK
D
D
Q
Q
D
ST
Q
CLOCK
CK
D
Q
I-REG.
SERIAL-IN
LATCH
ENABLE
R-EXT
SERIAL-OUT
OUT7
OUT1
OUT0
D
D
ST
ST
Q
Q
Delay Unit
Delay Unit
Delay Unit
DM114
DM115
SILICON TOUCH TECHNOLOGY INC.
8-BIT CONSTANT CURRENT LED DRIVERS with 3.3V~5V supply voltage
Version:A.002
Page 3
Preliminary
Timing Diagram
(Note) Latches are level sensitive (not edge triggered).
LATCH-terminal = H level, latches become transparent; LATCH-terminal = L level, latches hold data.
ENABLE-terminal = H level, all outputs (OUT0~7) are off.
An external resistor is connected between R-EXT and GND for setting up the value of constant current.
SERIAL-OUT changes state on the rising edges of clock.
Pin Description
PIN No.
PIN NAME
FUNCTION
1 GND
GND
terminal
2
SERIAL-IN
Input terminal of a data shift register
3
CLOCK
Input terminal of a clock for shift register
4
LATCH
Input terminal for data strobe
5~12 OUT0~7
Output
terminals
13
ENABLE
Input terminal for output enable (active low)
14
SERIAL-OUT Output terminal of a data shift register
15
R-EXT
Input terminal of an external resistor
16 V
DD
3.3/5V Supply voltage terminal
OUT7
SERIAL-OUT
OUT2
OUT1
OUT0
LATCH
0V
3.3/5V
0V
3.3/5V
SERIAL IN
CLOCK
0V
3.3/5V
Off
0V
Off
On
Off
On
Off
0V
3.3/5V
3.3/5V
ENABLE
DM114
DM115
SILICON TOUCH TECHNOLOGY INC.
8-BIT CONSTANT CURRENT LED DRIVERS with 3.3V~5V supply voltage
Version:A.002
Page 4
Preliminary
Equivalent Circuit of Inputs and Outputs
1.
ENABLE
terminal
2.
LATCH
terminal
3. CLOCK, SERIAL-IN terminal
4.
SERIAL-OUT
terminal
INPUT
VDD
GND
RIN
(up)
INPUT
VDD
GND
RIN
(down)
INPUT
VDD
GND
SERIAL_OUT
VDD
GND
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