SAA7826HL/E/M1A,55 NXP Semiconductors, SAA7826HL/E/M1A,55 Datasheet - Page 30

• Manufacturer Part Number: SAA7826HL/E/M1A,55
• Description: IC DIGITAL/CD DAC DECODER 80LQFP
• Manufacturer: NXP Semiconductors
• Type: Audio Decoderr

Specifications of SAA7826HL/E/M1A,55

• Voltage - Supply, Analog: 3 V ~ 3.6 V
• Voltage - Supply, Digital: 1.65 V ~ 1.95 V
• Mounting Type: Surface Mount
• Package / Case: 80-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Applications: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 935272863557; SAA7826HL/E/M1A; SAA7826HL/E/M1A

Philips Semiconductors
7.16.2
The digital codes retrieved from the ADCs are applied to
logic circuitry to obtain the various control signals. The
signals from the central aperture diodes are processed to
obtain a normalised focus error signal:
Where the detector set-up is assumed to be as shown in
Fig 21.
In the event of single Foucault focusing method, the signal
conditioning can be switched under software control such
that the signal processing is as follows:
The error signal, FE
Proportional Integral and Differential (PID) filter section.
A Focus OK (FOK) flag is generated by the central
aperture signal and an adjustable reference level. This
signal is used to provide extra protection for the
Track-Loss (TL) generation, the focus start-up procedure
and the dropout detection.
2003 Oct 01
FE
FE
01
(bank 1)
SHADEN BITS
CD audio decoder, digital servo and filterless
DAC with integrated pre-amp and laser control
n
n
=
=
2
D1 D2
--------------------- -
D1
S
IGNAL CONDITIONING
–
+
D1 D2
--------------------- -
D1
D2
+
–
D2
–
--------------------- -
D3
D3 D4
n
C
signal magnitude
control for diodes
R1 and R2
(LF only)
, is further processed by a
+
–
REGISTER
D4
SHADOW
ADDRESS
1100
30
The radial or tracking error signal is generated by the
satellite detector signals R1 and R2. The radial error
signal can be formulated as follows:
RE
Where the index ‘s’ indicates the automatic scaling
operation which is performed on the radial error signal.
This scaling is necessary to avoid non-optimum dynamic
range usage in the digital representation and reduces the
radial bandwidth spread. Furthermore, the radial error
signal will be made free from offset during start-up of the
disc.
The four signals from the central aperture detectors,
together with the satellite detector signals generate a
Track Position signal (TPI) which can be formulated as
follows:
TPI = sign [(D1 + D2 + D3 + D4)
Where the weighting factor sum_gain is generated
internally by the SAA7826 during initialization.
s
= (R1
DATA
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
R2)
re_gain + (R1 + R2)
VOLTAGE MODE
(mV)
100
120
150
200
270
350
450
600
720
960
20
25
30
40
60
75
(R1 + R2)
Product specification
SAA7826
re_offset.
INITIAL
reset
sum_gain]