MA710 – 12-BIT, DIGITAL ANGLE SENSOR WITH ABZ & PWM OUTPUTS

MA710 Rev. 1.0

www.MonolithicPower.com

22

9/27/2017

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To read the MGL and MGH flags by SPI send

the 8-bit command write into register 27:

command

reg. address

MSB

value

LSB

0

1

0

1 1 0 1 1

0 0 0 0 0 0 0 0

The MA710 answers with the register 27

content in the next transmission:

R[7:0]

MGH MGL

x

x

x

x

x

x

ABZ Incremental Encoder Output

The MA710 ABZ output emulates a 10-bit

incremental

encoder

(such

as

an

optical

encoder) providing logic pulses in quadrature

(see Figure 25). Compared to signal A, signal B

is shifted by a quarter of the pulse period. Over

one revolution, signal A pulses N times, where

N is programmable from 1 to 256 pulses per

revolution. The number of pulses per channel

per revolution is programmed by setting the

parameter PPT, which consists of 8 bits split

between registers 0x4 and 0x5 (see Table 7).

The factory default value is 256. Table 17

describes how to program PPT(7:0) to set the

required resolution.

Table 17: PPT

PPT(7:0)

Pulses per

Turn

Edges per

Turn

00000000

1

4

MIN

00000001

2

8

00000010

3

12

00000011

4

16

…

…

…

…

11111100

253

1012

11111101

254

1016

11111110

255

1020

11111111

256

1024

MAX

For example, to set 120 pulses per revolution

(i.e. 480 edges), set PPT to 120 - 1 = 119. In

binary: 01110111. Thus the registers 4 and 5

must be set as shown in Table 18.

Table 18: Example PPT Setting for 120 Pulses

B7

B6

B5

B4

B3

B2

B1

B0

R4

1

1

0

0

0

0

0

0

R5

0

0

0

1

1

1

0

1

Figure 25: Timing of the ABZ Output

Signal Z (zero or index) raises only once per

turn at the zero-angle position.

The position and length of the Z pulse is

programmable via bits ILIP(3:0) in register 0x5

(see Figure 26).

Figure 26: ILIP Parameter Effect on Index Shape

By default, the ILIP parameter is 0000. The

index rising edge is aligned with the channel B

falling edge. The index length is half the A or B

pulse length.

ABZ Hysteresis

A hysteresis larger than the output noise is

introduced on the ABZ output to avoid any

spurious transitions (see Figure 27).

Figure 27: Hysteresis of the Incremental Output