Datasheet

TMC246 DATA SHEET (V2.02 / Jul. 31st, 2006) 9

Control via the SPI Interface

The SPI data word sets the current and polarity for both coils. By applying consecutive values,

describing a sine and a cosine wave, the motor can be driven in microsteps. Every microstep is

initiated by its own telegram. Please refer to the description of the analog mode for details on the

waveforms required. The SPI interface timing is described in the timing section. We recommend the

TMC428 to automatically generate the required telegrams and motor ramps for up to three motors.

Serial data word transmitted to TMC246

(MSB transmitted first)

Bit Name Function Remark

11 MDA mixed decay enable phase A “1” = mixed decay

10 CA3 current bridge A.3 MSB

9 CA2 current bridge A.2

8 CA1 current bridge A.1

7 CA0 current bridge A.0 LSB

6 PHA polarity bridge A “0” = current flow from OA1 to OA2

5 MDB mixed decay enable phase B “1” = mixed decay

4 CB3 current bridge B.3 MSB

3 CB2 current bridge B.2

2 CB1 current bridge B.1

1 CB0 current bridge B.0 LSB

0 PHB polarity bridge B “0” = current flow from OB1 to OB2

Serial data word transmitted from TMC246

(MSB transmitted first)

Bit Name Function Remark

11 LD2 load indicator bit 2 MSB

10 LD1 load indicator bit 1

9 LD0 load indicator bit 0 LSB

8 1 always “1”

7 OT overtemperature “1” = chip off due to overtemperature

6 OTPW temperature prewarning “1” = prewarning temperature exceeded

5 UV driver undervoltage “1” = undervoltage on VS

4 OCHS overcurrent high side 3 PWM cycles with overcurrent within 63 PWM cycles

3 OLB open load bridge B no PWM switch off for 14 oscillator cycles

2 OLA open load bridge A no PWM switch off for 14 oscillator cycles

1 OCB overcurrent bridge B low side 3 PWM cycles with overcurrent within 63 PWM cycles

0 OCA overcurrent bridge A low side 3 PWM cycles with overcurrent within 63 PWM cycles