SAA7824 Datasheet, PDF (3/89 Pages) NXP Semiconductors – CD audio decoder, digital servo and filterless DAC with integrated pre-amp and laser control (PhonIC)

Philips Semiconductors
CD audio decoder, digital servo and filterless
DAC with integrated pre-amp and laser control
Product specification
SAA7824
1 FEATURES
• Decoder and servo parts are based upon the SAA732X
design (the original features are maintained)
• Software compatibility is maintained with the SAA732X
by using a similar register structure (new features are
controlled from new shadow registers)
• 1×, 2× and 4× speed
• LF (servo) signals converted to digital representations
by 6 oversampling bitstream ADCs
• HF part summed from signals D1 to D4 and converted
into a digital signal by a data slicer
• On-chip buffering and filtering of the diode signals from
the mechanism for signal optimization
• Selectable DC offset cancellation of quiescent
mechanism voltages and dark currents
• On-chip laser power control (up to 120 mA)
• Laser on/off control, including ‘soft’ start control (zero to
nominal power in 1 ms)
• Monitor control and feedback circuit to maintain nominal
output power throughout laser life
• Dynamic element matching DAC with minimum external
components
• DAC performance of −80 dB Total Harmonic
Distortion + Noise (THD + N) and 90 dB Signal-to-Noise
Ratio (S/N) A-weighted
• Separate left and right channel digital silence detection
available on the KILL pins
• Digital silence detection on internal data and loopback
(external) data
• 5 versatile pins, 2 inputs and 3 outputs
• Integrated CD text decoder with separate
microcontroller interface
• Dedicated 4 MHz or 12 MHz clock output for
microcontroller (configurable)
• Configured for N-sub monitor diode
• On-chip clock multiplier allows the use of an
8.4672 MHz crystal or ceramic resonator
• The M1 version has an EBU mute function which allows
independent muting of data being transmitted over the
EBU interface whilst maintaining the SPDIF frame
structure.
2 GENERAL DESCRIPTION
This document covers versions M0 and M1 of the CD
audio decoder IC.
The SAA7824 is a CD audio decoder IC which combines
the function of the SAA732X IC with the pre-amplifier and
laser control functions previously found in the TZA102X
IC. The design is intended to reduce the external
component count and hence the Bill Of Material (BOM).
Supply of this Compact Disc IC does not convey an
implied license under any patent right to use this IC in any
Compact Disc application.
2003 Oct 01
3