TDA5345HT datasheet(2/44 Pages) PHILIPS

2 / 44 page

1999 June 10

Philips Semiconductors

Preliminary speciﬁcation

5 V spindle & VCM driver combo

TDA5345HT

FEATURES

• Single chip voice coil and spindle motor drivers:

• Complementary outputs (Nmos & Pmos): No step-up converter needed

• On-chip isolation switch to allow synchronous rectification at power-down

• Suited for ramp load operation

• Register based architecture: on-chip serial interface

• Temperature shut down protection

• Linear 3.3 V regulator using one external NPN transistor

• Power monitor circuitrymonitoring the 5 V supply

• 1 axis shock sensor amplifier

• Switched capacitor regulator (-3 V) using 2 external capacitors and 2 external shottky diodes

• All main internal functions can be independently put in Sleep mode

• Small low profile package: TQFP64 (1.2 mm high).

Spindle motor driver:

• High efficiency drivers: 1.5 Ω Max

• 0.62 Amp capability, full wave (bipolar) drive

• Internal current mirrors to measure the motor curren

• Controlled fly-back pulse slopes, programmable through the serial interface

• Active fly-back pulse limitation, using the Power MOS instead of diodes

• Internal digital timing to control the commutations by back-EMF sensing (Start-up & running)

• Internal speed loop combining FLL and PLL

• Start-up current control by an internal 6-bit DAC (shared with the VCM loop).

Voice coil motor (VCM) driver:

• High efficiency drivers: 1.5 Ω Max (without the external sense resistor); 0.4 Amp capability

• External sense resistor to accurately control the VCM current

• True AB Class linear amplifier with no crossover distortion

• Internal 12-bit DAC to control the VCM transconductance input voltage

• Internal 6-bit DAC to cancel the VCM loop offsets

• Active fly-back pulse limitation, using the Power transistors instead of diodes

• 3-step programmable retract function activated by either the serial port or the power monitor circuitry

• Back-EMF amplifier to monitor the actuator speed when ramp loading.

Power Monitor:

• Monitors the 5 V power supply

• Power fault output (battery too low); threshold = 4.2 V

• Power on Reset output; threshold = 4.1 V (Vdd5)

• Threshold accuracy: +/-3%.

TDA5345HT Datasheet(PDF) 2 Page - NXP Semiconductors