BIGTREETECH SKR 3, User Manual

Page: 11 / 39

Shenzhen Big Tree Technology CO.,LTD .
BIG TREE TECH
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Chips:
MS1 MS2 MS3
microstep Excitation Mode
A4988
16
microstep
max
35V 2A
L L L Full Step 2 Phase
H L L 1/2 1-2 Phase
L H L 1/4 W1-2 Phase
H H L 1/8 2W1-2 Phase
H H H 1/16 4W1-2 Phase
Current
𝐑
𝑆
=0.1Ω
𝐈
𝐓𝐫𝐢𝐩𝐌𝐀𝐗
=
𝐕
𝐑𝐄𝐅
𝟖 ∗ 𝐑
𝑆
Driver chips
MODE2 MODE1 MODE0
Microsteps Excitation Mode
DRV8825
Maximum
32
microsteps
8.2V-45V 2.5A at
24V T=25℃
L L L Full Step 2 Phase
L L H 1/2 1-2 Phase
L H L 1/4 W1-2 Phase
L H H 1/8
H L L 1/16
H L H 1/32
H H L 1/32
H H H 1/32
Current
𝐑
𝐼𝑆𝐸𝑁𝑆𝐸
=0.1Ω
𝐈
𝐂𝐇𝐎𝐏
=
𝐕
(𝐱𝐑𝐄𝐅)
𝟓 ∗ 𝐑
𝐼𝑆𝐸𝑁𝑆𝐸
Driver chips
MD3 MD2 MD1
Microsteps
Excitation Mode
LV8729
Maximum
128 microsteps
36V 1.8A
L L L Full Step 2 Phase
L L H 1/2 1-2 Phase
L H L 1/4 W1-2 Phase
L H H 1/8 2W1-2 Phase
H L L 1/16 4W1-2 Phase
H L H 1/32 8W1-2 Phase
H H L 1/64 16W1-2 Phase
H H H 1/128 32W1-2 Phase
Current
RF1=0.22
Ω
𝐈
OUT
= (
𝐕
𝐑𝐄𝐅
/ 5 ) / RF1
Driver chips MS3 MS2 MS1 Microsteps
ST820
Maximum
256 microsteps
45V 1.5A
L L L Full Step
L L H 1/2
L H L 1/4
L H H 1/8
H L L 1/16
H L H 1/32
H H L 1/128
H H H 1/256
Current
Rs=0.15
Ω
𝐈
𝐩𝐞𝐚𝐤
=
𝐕
𝐑𝐄𝐅∗
𝐕
𝐃𝐃
𝟓 ∗ 𝐑
𝐒