BIGTREETECH SKR 3 User Manual

Shenzhen Big Tree Technology CO.,LTD .
BIG TREE TECH
11 / 39
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
32microsteps
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
128microsteps
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=0.22Ω
𝐈
OUT
= (𝐕
𝐑𝐄𝐅
/ 5 ) / RF1
Driver chips
MS3
MS2
MS1
Microsteps
ST820
Maximum
256microsteps
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=0.15Ω
𝐈
𝐩𝐞𝐚𝐤
=
𝐕
𝐑𝐄𝐅∗
𝐕
𝐃𝐃
𝟓 ∗ 𝐑
𝐒

BIGTREETECH SKR 3 Specifications

General

Frequency	480 MHz
Driver Interface	SPI/UART
Logic Voltage	3.3V
Heated Bed Output	1
Fan Outputs	3
Endstop Inputs	6
Stepper Motor Connectors	6
USB Port	1 x USB Type-C
Display Support	Yes
BLTouch Connector	Yes
Dimensions	110mm x 85mm
Motor Driver Support	TMC5160, TMC2209
Input Voltage	12-24V DC
Operating Voltage	12-24V DC
Communication Interface	USB, CAN, UART
Firmware	Marlin, Klipper
Heater Output	2
Fan Connectors	3
Heater Connectors	3
SD Card Slot	Yes
Display Connector	EXP1, EXP2
Thermistor Inputs	5