DD233 Datasheet, PDF (4/10 Pages) Silicon Touch Technology Inc. – 4-CHANNEL CONSTANT CURRENT LED DRIVERS

點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
DD233
Electrical Characteristics (Typ:VDD = 3.3 V, Ta = 25°C unless otherwise noted)
CHARACTERISTIC SYMBOL
CONDITION
MIN.
TYP.
Output Current (Bit-Bit)
IOL1
IOL2
VOUT = 1 V
REXT = 12kΩ
VOUT = 0.5
REXT = 60kΩ

±1.5

±1.5
Output Current (Chip-Chip)
IOL3
IOL4
VOUT = 1.0V, REXT = 12kΩ
VOUT = 0.5V, REXT = 60kΩ
26.3
29.2
4.8
5.31
MAX.
±3
±3
32.1
5.8
UNIT
%
%
mA
mA
Detailed Description
1) Constant Current Output Value Setting
The output current is determined by the resistance connected between REXT pin and GND. The
approximate relation between the resistance value and the base current value is shown in Fig1,
the approximate equation presented in (Eq.1).
Iout-Rext
35.00
30.00
25.00
20.00
15.00
10.00
5.00
0.00
0
10
20
30
40
50
60
70
80
Rext (kΩ)
Fig 1
I_{out â‰} 350.4/R_ext
(Eq.1)
2) Constant Current Output Value and Output Voltage
In order to obtain a good constant current output, a suitable output voltage is necessary. Users
can get related information about the minimum output voltage from Fig 2.
4-CHANNEL CONSTANT CURRENT LED DRIVERS Version: A.010
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