AP4203 Datasheet, PDF (21/28 Pages) Asahi Kasei Microsystems – 15ch 100mA LED Driver IC

[AP4203]
10.4. LED Current Setting (fixed current output)
LED current can be adjusted from 5mA to 50mA with an external resistor which is connected between the
ISET pin and GND. Since the ISET pin is easily affected by a noise, RISET layout should take a shortest
connection to avoid unstableness LED current. The ISET_R pin is used to set LEDR4~8 current, the ISET_G
pin used to set LEDG4~8 current and the ISET_B pin used to set LEDB4 ~ 8 current. An approximate formula
of ILED, that is LED current, and RISET resistor, which is connected to the ISET pin, and a relationship table
between ILED and RISET are shown below. Please confirm actual values on your board when setting.
ILED(mA)  ¹⁰⁰⁰ 　
R _ISET (k)
Table 10. Combination of ILED and R_ISET
RISET_R (kΩ)
ILEDRx (mA)
RISET_G (kΩ)
ILEDGx (mA)
RISET_B (kΩ)
ILEDBx (mA)
200.0
5.0
166.7
6.0
142.9
7.0
125.0
8.0
111.1
9.0
100.0
10.0
90.9
11.0
83.3
12.0
76.9
13.0
71.4
14.0
66.7
15.0
62.5
16.0
58.8
17.0
55.6
18.0
52.6
19.0
50.0
20.0
47.6
21.0
45.5
22.0
43.5
23.0
41.7
24.0
40.0
25.0
38.5
26.0
37.0
27.0
RISET_R (kΩ)
RISET_G (kΩ)
RISET_B (kΩ)
35.7
34.5
33.3
32.3
31.3
30.3
29.4
28.6
27.8
27.0
26.3
25.6
25.0
24.4
23.8
23.3
22.7
22.2
21.7
21.3
20.8
20.4
20.0
ILEDRx (mA)
ILEDGx (mA)
ILEDBx (mA)
28.0
29.0
30.0
31.0
32.0
33.0
34.0
35.0
36.0
37.0
38.0
39.0
40.0
41.0
42.0
43.0
44.0
45.0
46.0
47.0
48.0
49.0
50.0
015008158-E-00
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2015/09