TDA5341 Datasheet, PDF (7/28 Pages) NXP Semiconductors – Brushless DC motor and VCM drive circuit with speed control

Philips Semiconductors
Brushless DC motor and VCM drive circuit
with speed control
Product specification
TDA5341
FUNCTIONAL DESCRIPTION
The TDA5341 offers a sensorless three-phase motor
full-wave drive function. The device also offers protected
outputs capable of handling high currents and can be used
with star or delta connected motors.
The TDA5341 can easily be adapted for different motors
and applications.
The TDA5341 offers the following features:
• Sensorless commutation by using the motor EMF
• Built-in start-up circuit
• Optimum commutation, independent of motor type or
motor loading
• Built-in flyback diodes
• Three-phase full-wave drive
• High output current (1.3 A)
• Low MOS R_DSon (1 Ω)
• Outputs protected by current limitation and thermal
protection of each output transistor
• Low current consumption
• Additional uncommitted operational amplifier
• H-bridge actuator driver current controlled with an
external series sense resistor
• Automatic retract procedure
• Adjustable park voltage
• Sleep mode
• Automatic brake (after park) procedure
• Speed control based on FLL technique
• Serial port DATAIN (24 bits)
• Friction reduction prior to spin-up.
TDA5341 modes description
The TDA5341 can be used in two main modes, depending
on whether they are controlled or not.
The ‘controlled modes’ (user commands) are executed by
the TDA5341 without delay or priority treatment, either by
software via the serial port or by hardware. BRAKE is a
hardware command whereas RETRACT can be controlled
in both ways. If it is preferable to control the heads parking
via the serial bus, the equivalent pin can be left
open-circuit.
The sleep mode is controlled by software only; it results
from the combination of the spindle and actuator being
disabled. The spindle is turned off by bit SPINDLE
DISABLE, whereas the actuator is disabled towards bit
VCM DISABLE of the serial port (see Section “Serial
port”). In addition, a special spin-up mode can be activated
in the event of high head stiction
The ‘uncontrolled modes’ only result from different failures
caused by either a too high internal temperature or an
abnormally low power voltage, which will cause the
actuator to retract and, after the spindle, to brake.
The output signals mainly affected by those failures are
RESETOUT, MOT1, 2 and 3, VCM+ and VCM−. This is
summarised in Tables 1 and 2.
Table 1 Summary of controlled modes
HARDWARE/
SOFTWARE
Software
Software
Hardware
Software/
hardware
Hardware
MODE
spindle disable
VCM disable
brake
retract
friction reduction
MOT1, 2 AND 3
high impedance
not affected
LOW
not affected
−
VCM+ AND
VCM−
high impedance
high impedance
not affected
VCM− = 0.65 V;
VCM+ = 0 V
not affected
RESETOUT
HIGH
HIGH
HIGH
HIGH
HIGH
EFFECT
spindle off
spindle on; VCM off
spindle coils ground
heads parked
heads in vibration
1997 Jul 10
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