Overview

The TMC2208 (TMC2208-LA) is an advanced 2-phase stepper motor driver IC manufactured by Trinamic (Analog Devices), widely used as a drop-in SilentStepStick breakout module for 3D printers (Ender 3, Prusa, Marlin/Klipper mainboards), CNC machines, and precision motion control robotics.

Equipped with Trinamic's patented StealthChop2 silent chopper technology, the TMC2208 eliminates audible stepper motor hum and high-pitched whining during standstill and slow movements. It supports motor supply voltages from 4.75V to 36V DC, continuous phase currents up to 1.2A RMS (2.0A2.0\text{A} peak), MicroPlyer 1/256-microstep interpolation, and a single-wire UART interface for software-based current scaling, microstep setting, and diagnostic monitoring.

Quick reference

Motor Supply Voltage (VM)4.75 V to 36 V DC
Logic Supply Voltage (VIO)3.0 V to 5.25 V DC (3.3V and 5V compatible)
Phase Current Rating1.2 ARMS1.2\text{ A}_{\text{RMS}} continuous (2.0 A2.0\text{ A} peak)
Microstep Resolutions1, 1/2, 1/4, 1/8, 1/16 (Interpolated to 1/256 via MicroPlyer)
Chopper ModesStealthChop2 (Silent PWM) & SpreadCycle (High dynamic torque)
Configuration ModesStandalone OTP/MS1/MS2 pins OR Single-Wire UART Interface
Current ControlInternal VREF Potentiometer OR UART Digital Scaling
Package28-pin QFN (5×5 mm5 \times 5\text{ mm}) / SilentStepStick 16-pin Module

Pinout (SilentStepStick 16-Pin Breakout Header)

text
                       ┌─────────────┐
                 [EN] 1│ 1        16│ [VM] (Motor Power 4.75-36V)
                [MS1] 2│            │15 [GND] (Motor Power GND)
                [MS2] 3│  TMC2208   │14 [2B] (Motor Phase B)
                [PDN] 4│ SilentStep │13 [2A] (Motor Phase B)
               [UART] 5│   Stick    │12 [1A] (Motor Phase A)
                [NC]  6│            │11 [1B] (Motor Phase A)
               [STEP] 7│            │10 [VIO] (Logic Power 3.3/5V)
                [DIR] 8│            │9  [GND] (Logic Power GND)
                       └─────────────┘
PinNameTypeDescription
1ENInputEnable Motor Driver (Low = Enable outputs; High = Disable)
2MS1InputMicrostep Select Pin 1 (Pullup/Pulldown to GND/VIO)
3MS2InputMicrostep Select Pin 2 (Pullup/Pulldown to GND/VIO)
4/5PDN_UARTI/OSingle-Wire UART Pin / Power Down Input
7STEPInputStep Pulse Input (Rising edge triggers microstep)
8DIRInputDirection Input (High/Low sets rotation direction)
10VIOPowerLogic Power Supply (+3.0V to +5.25V DC)
11–141B, 1A, 2A, 2BOutputMotor Phase Connections (Phase A: 1A/1B, Phase B: 2A/2B)
15GNDPowerPower Ground
16VMPowerMotor Power Supply (+4.75V to +36V DC)

Specifications

ParameterSymbolMinTypMaxUnitConditions
Motor Supply VoltageVMV_M4.7524.036.0VDC
Logic Supply VoltageVIOV_{IO}3.03.3/5.05.25VDC
Continuous Current per PhaseIRMSI_{RMS}—1.21.4ATA=25∘CT_A = 25^\circ\text{C} with cooling
Peak Output CurrentIPEAKI_{PEAK}——2.0AShort peak duration
RDS(on) MOSFET SwitchRDS(on)R_{DS(on)}—280320mΩVVM=24V,TJ=25∘CV_{VM} = 24\text{V}, T_J = 25^\circ\text{C}
Step FrequencyfSTEPf_{STEP}——500kHzSTEP input pin

Current Adjustment via VREFV_{REF} Potentiometer

In standalone mode, the maximum phase current IRMSI_{RMS} is set via the small onboard potentiometer (VREFV_{REF}):

IRMS=VREF1.414×0.71≈VREF×0.5 (Amps)I_{RMS} = \frac{V_{REF}}{1.414} \times 0.71 \approx V_{REF} \times 0.5 \text{ (Amps)}

For example, setting VREF=1.6V  ⟹  IRMS≈0.8A.\text{For example, setting } V_{REF} = 1.6\text{V} \implies I_{RMS} \approx 0.8\text{A}.

Common mistakes

  • Disconnecting motor while driver is powered: Disconnecting a stepper motor connector while VMV_M power is applied creates inductive back-EMF spikes that destroy the internal MOSFETs.
  • Forgetting motor bulk decoupling capacitor: Always place a 100 μF100\ \mu\text{F} electrolytic capacitor between VMV_M and GNDGND directly near the driver module pins to absorb voltage spikes.
  • Overheating without a heatsink: Running currents above 0.8A0.8\text{A} without attaching an aluminum heatsink and cooling fan will trigger thermal shutdown (150∘C150^\circ\text{C}).

Notes

  • TMC2208 vs A4988 vs TMC2209: A4988 is loud with 1/16 microstepping; TMC2208 adds silent StealthChop2 and 1/256 interpolation; TMC2209 adds StallGuard4 sensorless homing and higher continuous current capability (1.7A1.7\text{A} RMS).

Assets & downloads