AN2009 datasheet(17/39 Pages) STMICROELECTRONICS

Part #	AN2009

Description	PWM MANAGEMENT FOR 3-PHASE BLDC MOTOR DRIVES USING THE ST7MC

PDF	39 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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PWM MANAGEMENT FOR 3-PHASE BLDC MOTOR DRIVES USING THE ST7MC

Table 1. Frequency selection

PWM REGISTER (MPWME)

Read/Write

Reset Value: 0000 0000 (00h)

The current reference is provided to the comparator by Phase U, V or W of the PWM Gener-

ator (up to 12-bit accuracy) and the signal from the three compare registers U, V or W can be

output by setting the PWMU, PWMV or PWMW bits.

Bits 3:0 = OT[3:0]: Off Time selection

These bits are used to select the OFF time in sensorless current mode as shown in the fol-

lowing table

SA3

SA2

SA1

SA0

Sampling Frequency

50.0 KHz

40.0 KHz

33.33 KHz

25.0 KHz

20.0 KHz

18.1 KHz

15.4 KHz

12.5 KHz

10 KHz

6.25 KHz

3.13 KHz

1.56 KHz

1.25 KHz

961 Hz

625 Hz

390 Hz

PWMW PWMV PWMU

OT3

OT2

OT1

OT0

AN2009 Datasheet(PDF) 17 Page - STMicroelectronics