STPM01_11 STMICROELECTRONICS [STMicroelectronics], STPM01_11 Datasheet - Page 30

• Manufacturer Part Number: STPM01_11
• Description: Programmable single phase energy metering IC with tamper detection
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Theory of operation
Figure 21. Positive energy stepper driving signals
Figure 22. Negative energy stepper driving signals
8.16
30/60
When a no-load condition is detected MOP and MON are held low.
Using STPM01 in microcontroller based meter (peripheral)
The higher flexibility of STPM01 allows its use in very high end microcontroller based energy
meters. In this case the STPM01 must be programmed to work in peripheral mode, all the
SPI pins (SCS, SCLNCL, SDATD, SYN) are used only for communication purposes allowing
the microcontroller to write and read the internal STPM01 registers. The peripheral mode
has two further different configuration modes according to the status of the APL
configuration bit. The APL bit status changes the function of MOP, MON and LED pins
according to the description below.
APL = 0:
In the MOP pin, the ZCR signal is available (see paragraph 3 for details about ZCR signal);
The pin MON provides the DOG signal. The DOG signal generates a 16 ms long positive
pulse every 1.6 seconds. Generation of these pulses can be suspended if data are read in
intervals shorter than 1.6 s. The DOG signal is actually a watchdog reset signal which can
be used to control an operation of an on-board microcontroller. It is set to high whenever the
V
DDA
voltage is below 2.5 V, but after V
Hi
Lo
Hi
Lo
Hi
Lo
Hi
Lo
Doc ID 10853 Rev 8
DDA
goes above 2.5 V this signal starts to run.
MON
MON
MOP
MOP
STPM01