AS5040

Data Sheet

www.austriamicrosystems.com

Revision 2.10

16 - 33

Figure 12: U, V and V-signals for BLDC Motor Commutation (Div1=0, Div0=0)

U

V

W

Position:

0

171

341

512

683

853

0

Angle:

0.0

60.12

119.88

180.0

240.12

299.88

360.0

Width: 512 Steps

Width: 512 Steps

CW Direction

Figure 13: U, V and W-signals for 2-pole BLDC Motor Commutation (Div1=1; Div0=0)

U

V

W

Position:

0

85

171

256

341

427

512

597

683

768

853

939

0

Angle:

0.0

29.88

60.12

90.0

119.88

150.12

180.0

209.88

240.12

270.00

299.88

330.12

360.0

Width: 256 Steps

Width: 256 Steps

CW Direction

12 Programming the AS5040

After power-on, programming the AS5040 is enabled with the rising edge of CSn with Prog = high and CLK = low. 16

bit configuration data must be serially shifted into the OTP register via the Prog-pin. The first “CCW” bit is followed by

the zero position data (MSB first) and the incremental mode setting as shown in Table 6. Data must be valid at the

rising edge of CLK (see Figure 14).

After writing data into the OTP register it can be permanently programmed by rising the Prog pin to the programming

mode, the chip must be reset by a power-on-reset. The programmed data is available after the next power-up.

Note: During the programming process, the transitions in the programming current may cause high voltage spikes

generated by the inductance of the connection cable. To avoid these spikes and possible damage to the IC, the

connection wires, especially the signals Prog and VSS must be kept as short as possible. The maximum wire length

suppress eventual voltage spikes, a 10nF ceramic capacitor should be connected close to pins Prog and VSS. This

capacitor is only required for programming, it is not required for normal operation.

(see Figure 14). Additionally, the programming supply voltage should be buffered with a 10µF capacitor mounted

close to the switching transistor. This capacitor aids in providing peak currents during programming.

The specified programming voltage at pin Prog is 7.3 – 7.5V (see section 0). To compensate for the voltage drop

Figure 16).