TDA5145TS Datasheet, PDF (13/20 Pages) NXP Semiconductors – Brushless DC motor drive circuit

Philips Semiconductors
Brushless DC motor drive circuit
Product specification
TDA5145TS
handbook, full pagewidth
VMOT ₁
voltage
on CAP-TI
MGH318
If the chosen value of CAP-TI is too small oscillations can occur in certain positions of a blocked rotor. If the chosen value is too large, then it is possible
that the motor may run in the reverse direction (synchronously with little torque).
Fig.9 Typical CAP-TI and V_MOT1 voltage waveforms in normal running mode.
Other design aspects
There are other design aspects concerning the application
of the TDA5145TS besides the commutation function.
They are:
• Direction function
• Brake function
• Reliability.
DIRECTION FUNCTION
If the voltage at pin 9 is less than 0.8 V, the motor is
running in one direction (depending on the motor
connections). If the voltage at pin 9 is greater than 2.0 V,
the motor is running in the opposite direction.
RESET FUNCTION
If the voltage at pin 18 is greater than 2.0 V, the output
states are shown in Table 2.
Table 2 Output states if V_RESET > 2.0 V
DRIVER OUTPUT
STATE⁽¹⁾
MOT1
Z
MOT2
L
MOT3
H
Note
1. Z = high-impedance OFF-state; L = LOW state;
H = HIGH state.
BRAKE FUNCTION
If the voltage at pin 8 is greater than 2.0 V, the motor
brakes. In that condition, the 3 outputs MOT1, MOT2 and
MOT3 are forced to a LOW voltage level and the current
limitation is performed internally by the sink drivers.
1998 Oct 27
13