Datasheet

Theory of operation STPMC1
36/77 Doc ID 15728 Rev 7
From signal P
Σ
(3-ph active energy), stepper motor driving signals MA and MB (see
Figure 12 ) are generated by means of internal divider, mono-flop and decoder and brought
to MOP and MON pins.
The numbers of pulses per kWh on MOP and MON outputs (CM) is related to the number of
pulses on LED pin (C, see par.
9.11 ) following the table below.
The mono-flop limits the length of the pulses according to the LVS
bit value.
The decoder distributes the pulses to
MA and MB alternatively, which means that each of
them has only a half of selected frequency.
When a no-load condition is detected (
BIL =1) MOP and MON are held low because
integration of power is suspended.
The LED pin provides 3-phase active energy pulses according to the table below:
Figure 12. Stepper driving signals
MON
Hi
Hi
Low
Low
MOP
MON
Hi
Hi
Low
Low
MOP
Table 20. Configuration of MOP and MON driving signals with APL = 1, 2, 3
LVS (1 bit) KMOT (2 bits) Pulses Length Freq. CM
0
0
31.25 ms
C/64
1 C/128
2C/32
3 C/256
1
0
156.25 ms
C/640
1 C/1280
2 C/320
3 C/2560