Philips Semiconductors
Product specification
Digital servo processor (DSIC2)
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
QUICK REFERENCE DATA
SYMBOL
V
DDD
V
DDA
I
DDD
I
DDA
I
DDD(q)
I
i(cd)
I
i(sd)
P
tot
T
amb
Note
1. f
sys
= 4.2336 MHz; V
RL
= 0 V; V
RH
= 2.5 V (externally applied).
March 1994
2
PARAMETER
digital supply voltage
analog supply voltage
digital supply current
analog supply current
digital quiescent supply current
central diode input currents (D1 to D4)
satellite diode input currents (R1 and R2)
total power dissipation
operating ambient temperature
note 1
note 1
CONDITIONS
MIN.
3.0
3.0
−
−
−
−
−
−
−40
−
−
5
5
−
−
−
50
−
TYP.
– 28-pin SO package
TDA1301T
– 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.
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.
MAX.
5.5
5.5
−
−
10
15.8
7.9
−
+85
UNIT
V
V
mA
mA
µA
µA
µA
mW
°C
PHILIPS [ NXP SEMICONDUCTORS ]
