AS5040

Data Sheet

www.austriamicrosystems.com

Revision 2.10

18 - 33

Figure 16: OTP Programming Connection of AS5040 (shown with AS5040 demoboard)

Incremental Mode Programming

Three different incremental output modes are available.

Mode: Md1=0 / Md0=1 sets the AS5040 in quadrature mode.

Mode: Md1=1 / Md0=0 sets the AS5040 in step / direction mode (see Table 1)

In both modes, the incremental resolution may be reduced from 10 bit down to 9, 8 or 7 bit using the divider OTP bits

Div1 and Div0. (see Table 6 below ).

Mode: Md1=1 / Md0=1 sets the AS5040 in brushless DC motor commutation mode with an additional LSB

incremental signal at pin 12 (PWM_LSB).

To allow programming of all bits, the default factory setting is all bits = 0. This mode is equal to mode 1:0 (quadrature

A/B, 1LSB index width, 256ppr).

The absolute angular output value, by default, increases with clockwise rotation of the magnet (top view).

Setting the CCW-bit (see Figure 14) allows reversing the indicated direction, e.g. when the magnet is placed

underneath the IC:

CCW = 0 – angular value increases clockwise;

CCW = 1 – angular value increases counterclockwise.

By default, the zero / index position pulse is one LSB wide. It can be increased to a three LSB wide pulse by setting

the Index-bit of the OTP register.

Further programming options (commutation modes) are available for brushless DC motor-control.

Md1 = Md0 = 1 changes the incremental output pins 3, 4 and 6 to a 3-phase commutation signal. Div1 defines the

number of pulses per revolution for either a two-pole (Div1=0) or four-pole (Div1=1) rotor.

In addition, the LSB is available at pin 12 (the LSB signal replaces the PWM signal), which allows for high rotational

speed measurement of up to 30,000 rpm.