CS4245-DQZR Cirrus Logic Inc, CS4245-DQZR Datasheet - Page 33

• Manufacturer Part Number: CS4245-DQZR
• Description: IC,Soundcard Circuits,QFP,48PIN,PLASTIC
• Manufacturer: Cirrus Logic Inc
• Type: Stereo Audior

Specifications of CS4245-DQZR

• Data Interface: Serial
• Resolution (bits): 24 b
• Number Of Adcs / Dacs: 2 / 2
• Sigma Delta: Yes
• Dynamic Range, Adcs / Dacs (db) Typ: 104 / 104
• Voltage - Supply, Analog: 3.13 V ~ 5.25 V
• Voltage - Supply, Digital: 3.13 V ~ 5.25 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 48-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 598-1501 - BOARD EVAL FOR CS4245 CODEC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DS656F2
4.4
4.5
4.6
Analog Input Multiplexer, PGA, and Mic Gain
The CS4245 contains a stereo 6-to-1 analog input multiplexer followed by a programmable gain amplifier
(PGA). The input multiplexer can select one of six possible stereo analog input sources and route it to the
PGA. Analog inputs 4A and 4B are able to insert a +32 dB gain stage before the input multiplexer, allowing
them to be used for microphone-level signals without the need for any external gain. The PGA stage pro-
vides ±12 dB of gain or attenuation in 0.5 dB steps.
er, PGA, and microphone gain stages.
The
multiplexer and mic gain.
- Address 08h” on page 46
level input 1 is selected, and the PGA is set to 0 dB.
Input Connections
The analog modulator samples the input at 6.144 MHz (MCLK=12.288 MHz). The digital filter will reject sig-
nals within the stopband of the filter. However, there is no rejection for input signals which are
(n
for the recommended analog input circuit that will attenuate noise energy at 6.144 MHz. The use of capac-
itors which have a large voltage coefficient (such as general-purpose ceramics) must be avoided since
these can degrade signal linearity. Any unused analog input pairs should be left unconnected.
Output Connections
The CS4245 DACs implement a switched-capacitor filter, followed by a continuous time low-pass filter. Its
response, combined with that of the digital interpolator, is shown in
page
The CS4245 DAC does not include phase or amplitude compensation for an external filter. Therefore, the
DAC system phase and amplitude response is dependent on the external analog circuitry.
×
““Analog Input Selection (Bits 2:0)” on page
6.144 MHz) the digital passband frequency, where n=0,1,2,... Refer to the Typical Connection Diagram
52”. The recommended external analog circuitry is shown in the Typical Connection Diagram.
AIN4A/MICIN1
AIN4B/MICIN2
“Channel B PGA Control - Address 07h” on page 46
AIN1A
AIN2A
AIN3A
AIN5A
AIN6A
AIN1B
AIN2B
AIN3B
AIN5B
AIN6B
outline the register settings necessary to control the PGA. By default, line-
Figure 14. Analog Input Architecture
+32 dB
+32 dB
Selection Bits
Analog Input
MUX
MUX
47” outlines the bit settings necessary to control the input
Figure 14
PGA Gain Bits
PGA Gain Bits
Channel A
Channel B
PGA
PGA
shows the architecture of the input multiplex-
Out to ADC
Channel B
Out to ADC
Channel A
Section 8. “DAC Filter Plots” on
and
“Channel A PGA Control
CS4245
33