AD1845JSTZ Analog Devices Inc, AD1845JSTZ Datasheet - Page 36

• Manufacturer Part Number: AD1845JSTZ
• Description: IC CODEC AUDIO 5V 16BIT 100-TQFP
• Manufacturer: Analog Devices Inc
• Type: Stereo Audior

Specifications of AD1845JSTZ

• Resolution (bits): 16 b
• Number Of Adcs / Dacs: 2 / 2
• Sigma Delta: Yes
• Dynamic Range, Adcs / Dacs (db) Typ: 81 / 82
• Voltage - Supply, Analog: 4.75 V ~ 5.25 V
• Voltage - Supply, Digital: 4.75 V ~ 5.25 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 100-TQFP, 100-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Analog Devices recommends that all digital pins be driven from
the same supply. A common technique to achieve maximum
performance is to use a +5 V regulator to power the analog side
of the codec from the PCs +12 V supply line, while the standard
PC +5 V supply line powers the entire digital side of the codec.
The separate supplies provide noise isolation for the analog side
of the codec, and maximize performance of the AD1845.
COMPATIBILITY WITH CS4231
AD1845
2. The AD1845 requires the input antialiasing filters for the
DIGITAL
GROUND
PLANE
1. The CS4231 requires a 1000 pF NPO type capacitor on
Pins 26 and 31. The AD1845 requires a 1 F capacitor on
filter Pins 26 and 31. To achieve compatibility with the
AD1845, use pad spacing that will accommodate either
1000 pF NPO capacitors for the CS4231 and the CS4248
or the 1 F capacitors for the AD1845.
ADCs (refer to Figures 27 and 28). The CS4231 can use
the same filters with no degradation in performance. For
compatibility it is suggested that the filters be added.
AD1845
PLCC
Figure 36. Recommended Ground Plane
GNDD
GNDD
44
25
R_AUX2
43
26
R_FILT
GROUND
ANALOG
PLANE
DIGITAL
GROUND
PLANE
AD1845
TQFP
NC
NC
52
24
NC
51
25
R_FILT
GROUND
ANALOG
PLANE
–36–
10. The AD1845 does not include hardware for compressing
3. The CS4231 does not require the power pins (V
4. The CS4231 does not provide software programmable
5. The CS4231 does not have the ability to mix the MIC
6. The CS4231 does not contain a Variable Sample Fre-
7. The CS4231 requires two crystal inputs, 24.575 MHz and
8. The CS4231 does not contain the INITD bit.
9. The CS4231 minimum R
45, and 54, or the ground pins (GNDD) 25, and 44. It is
suggested that the appropriate power/ground pin connec-
tions be made. This will not affect the performance of the
CS4231.
power-down modes.
input with the DAC output.
quency Generator and cannot change sample rates “on the
fly.” The CS4231 and CS4248 require entering MCE to
change the sample rate. The AD1845 can change the
sample rate without entering MCE. The AD1845’s 50,000
selectable sample rates are not available on the CS4231.
The Variable Sample Frequency Generator reduces clicks
and pops encountered in many game applications.
16.9344 MHz. The AD1845 requires only one input of
24.576 MHz or can be driven from OSC or other exter-
nal clocks.
mum input resistance is 10 k .
and decompressing ADPCM data. Analog Devices offers
Windows based software applets for using ADPCM for-
mats with the AD1845.
IN
= 20 k . The AD1845 mini-
DD
) 24,
REV. C