Understanding the Figure 7 of STEVAL-IPMM15B Schematic

[yeewei]

Hi,

I recently purchased the STEVAL-IPMM15B motor control board and am studying its schematic (Figure 7 as attached). However, I am having trouble understanding the role of certain resistors in the circuit.

From my analysis:

R44, R45, and R46 appear to be pull-up resistors.
R47, R48, and R49 seem to function as current-limiting resistors.
R50, R51, and R52—their purpose is unclear to me.

I have the following questions:

1. If SW13, SW14, and SW15 are open (disconnected) and H1/A+ of J5 provides a HIGH signal (+5V), will M_phase_A output a HIGH signal (+5V)?

2. If SW13, SW14, and SW15 are closed (connected) and H1/A+ of J5 provides a HIGH signal (+5V), will M_phase_A still output a HIGH signal (+3.4V)?

3. Can R50, R51, and R52 be considered a voltage divider circuit along with R47, R48, and R49 (i.e., R47 in series with R50, R48 in series with R51, and R49 in series with R52)? or R50, R51 and R52 serve as another purposes?

I appreciate any clarification on how these components interact.

Thanks you.

Regards
YW

[Peter BENSCH]

Welcome @yeewei, to the community!

Your assumption is correct, they are switchable voltage dividers if a 5V type is connected as an encoder.

Regards
/Peter