ST STEVAL-ISC004V1, Руководство пользователя

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RA =
R2 ∙ 1.22
VOUT − 1.22
= 200 ∙ 1.22
5 − 1.22 = 64550Ω
(1)
To limit the error propagation, the resistor computation should start from the highest voltage to the lowest one by
integrating the previous computation at each step.
R3 =
R2 ∙ 1.22
VOUT − 1.22
(2)
R4 =
R2 ∙ 1.22
VOUT − 1.22
− R3
(3)
R5 =
R2 ∙ 1.22
VOUT − 1.22
− R3 − R4 (4)
R6 =
R2 ∙ 1.22
VOUT − 1.22
− R3 − R4 − R5
(5)
R7 =
R2 ∙ 1.22
VOUT − 1.22
− R3 − R4 − R5 − R6 (6)
Table 2. STEVAL-ISC004V1 default resistors
Vbus (V)
Theoretical value (Ω)
R =
R2 ∙ 1.22
VOUT − 1.22
Real resistor value in 1% series
R
A
R
B
R
C
R
D
R
E
R
3
R
4
R
5
R
6
R
7
5 64550 13k0 4k7 4k87 8k66 33k0
9 31362 13k0 4k7 4k87 8k66
12 22634 13k0 4k7 4k87
15 17707 13k0 4k7
20 12992 13k0
UM2293
Voltage output trimming
UM2293 - Rev 2
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