GENERAL DESCRIPTION

The TDA1301T is a fully digital servo processor which has been designed to provide all servo functions, except the spindle motor control, in two-stage three-spot compact disc systems. The device offers a high degree of

integration, combined with the low additional cost of external components. The servo characteristics have a

wide range of adjustment via a three-line serial interface. This offers an enormous flexibility with respect to

applications for different CD mechanisms. The circuit is optimized for low-power low-voltage applications.

FEATURES

The DSIC2 realizes the following servo functions:

• Diode signal preprocessing

• Focus servo loop

• Radial servo loop

• Sledge motor servo loop

• Three-line serial interface via the microcontroller The other features include:

• Full digital signal processing

• Low power consumption, down to 30 mW

• Low voltage supply 3 to 5.5 V

• Integrated analog-to-digital converters and digital servo loop filters

• Double speed possible

• Easy application

– Single supply voltage

– Small number of external components; only 6 decoupling capacitors

– Flexible system oscillator circuitry

– Usable for single/double Foucault and astigmatic focus

– Full automatic radial error signal initialization offset control and level initialization for track position indicator

– No external adjustments required; no component ageing

– Wide range of adjustable servo characteristics

– Simple 3-line serial command interface

– 28-pin SO package

– Great flexibility towards different CD mechanisms

– Full and transparent application information

• High robustness/shock insensitivity

– Sophisticated track-loss (TL) detection mechanism

– Fast focus restart procedure

– Extended radial error signal

– Adjustable radial shock detector

– Defect drop-out detector

• Fully automatic jump procedure for radial servo

• Automatic focus start-up procedure and built-in FOK (Focus OK)

• Fast radial jump or access procedure

• Self-operational servo-control without continuous communication via the microcontroller

• Direct communication to photodiode optics; no external preprocessing.