TDA5345HT Datasheet, PDF (2/44 Pages) NXP Semiconductors – 5 V spindle & VCM driver combo

Philips Semiconductors
5 V spindle & VCM driver combo
Preliminary specification
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%.
1999 June 10
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