saa7825 NXP Semiconductors, saa7825 Datasheet - Page 3

• Manufacturer Part Number: saa7825
• Description: Cd Audio Decoder, Digital Servo And Filterless Dac With Integrated Pre-amp And Laser Control
• Manufacturer: NXP Semiconductors

Philips Semiconductors
1
2003 Aug 13
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
CD audio decoder, digital servo and filterless
DAC with integrated pre-amp and laser control
FEATURES
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2
The SAA7825 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.
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
EBU mute function which allows independent muting of
data being transmitted over the EBU interface whilst
maintaining the SPDIF frame structure.
GENERAL DESCRIPTION
Objective specification
SAA7825