TDA5146T Datasheet, PDF (15/18 Pages) NXP Semiconductors – Brushless DC motor drive circuit

Philips Semiconductors
Brushless DC motor drive circuit
Product specification
TDA5146T
R = ((V_P – 0.4) .10^e4) /6
TEST
V_P
Figure 10.
RESET function
If the voltage on pin 8 is higher than 2.0V, the output states are:
• MOT 1 – Float
• MOT 2 – Low
• MOT 3 – High
SL01524
SWITCHING SEQUENCE AFTER A RESET PULSE
DIR
RESET
MOT1
MOT2
H
H
F
L
H
L
F
L
H
L
H
L
H
L
H
F
H
L
F
H
H
L
L
H
H
L
L
F
L
H
H
L
L
L
H
L
L
L
F
L
L
L
L
F
L
L
L
H
L
L
F
H
L
L
H
F
MOT3
H
H
F
L
L
F
H
F
F
H
H
F
L
L
FUNCTION
Reset
Normal direction mode sequence
Reset
Reverse direction mode sequence
PRIORITY OF FUNCTION
BRAKE
L
L
L
L
H
H
H
H
TEST
L
L
H
H
L
L
H
H
RESET
L
H
L
H
L
H
L
H
FUNCTION
Normal
Reset
Test
Test
Brake
Brake
Brake
Brake
RELIABILITY
It is necessary to protect high current circuits and the output stages are protected in two ways:
• Current limiting of the ’lower’ output transistors. The ’upper’ output transistors use the same base current as the conducting ’lower’ transistor
(+15% ). This means that the current to and from the output stages is limited.
• Thermal protection of the six output transistors is achieved by each transistor having a thermal sensor that is active when the transistor is
switched on. The transistors are switched off when the local temperature becomes too high.
1994 May 18
15