tda5140at-c1 NXP Semiconductors, tda5140at-c1 Datasheet - Page 15

• Manufacturer Part Number: tda5140at-c1
• Description: Brushless Dc Motor Drive Circuit
• Manufacturer: NXP Semiconductors

Philips Semiconductors
The special PG pulse is derived from the negative-going
zero-crossing from the MOT3 output (pin 16). The external
PG signal (PG IN on pin 5) must sense a positive-going
voltage ( 80 mV) within 1.5 to 7.5 commutation periods
before the negative-going zero-crossing in MOT3
(see Fig.10).
The voltage requirements of the PG IN input are such that
an inexpensive pick-up coil can be used as a sensor
(see Fig.11).
Example: If p = 6, then one revolution contains 6
commutations. The tolerance is 6 periods, that is 60
degrees (mechanically) or 6.67 ms at 1500 rpm.
If a PG sensor is not used, the PG IN input must be
grounded, this will result in a 50% duty factor FG signal.
April 1994
Brushless DC motor drive circuit
Fig.10 Timing and the FG and PG IN signals.
6 = 36
15
Fig.11 Pick-up coil as PG sensor.
2.2 k
22 nF
MBD696
Product specification
PG IN
GND2
TDA5140A