MAX9867EWV+T Maxim Integrated Products, MAX9867EWV+T Datasheet - Page 40

• Manufacturer Part Number: MAX9867EWV+T
• Description: IC STEREO AUD CODEC LP 30WLP
• Manufacturer: Maxim Integrated Products
• Type: Stereo Audior

Specifications of MAX9867EWV+T

• Data Interface: I²C, Serial
• Resolution (bits): 18 b
• Number Of Adcs / Dacs: 2 / 2
• Sigma Delta: Yes
• Dynamic Range, Adcs / Dacs (db) Typ: 85 / 90
• Voltage - Supply, Analog: 1.65 V ~ 1.95 V
• Voltage - Supply, Digital: 1.65 V ~ 1.95 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 30-WLP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: MAX9867EWV+T; MAX9867EWV+TTR

Ultra-Low Power Stereo Audio Codec
The MAX9867 includes two 16-bit ADCs. The first ADC
is used to record left-channel microphone and line-input
audio signals. The second ADC can be used to record
right-channel microphone and line-input signals, or it
can be configured to accurately measure DC voltages.
When measuring DC voltages, both the left and right
ADCs must be enabled by setting ADLEN and ADREN
in register 0x17. The input to the second ADC is JACK-
SNS/AUX and the output is reported in AUX (registers
0x02 and 0x03). Since the audio ADC is used to per-
form the measurement, the digital audio interface must
be properly configured. If the left ADC is being used to
convert audio, the DC measurement is performed at the
same sample rate. When not using the left ADC, config-
ure the digital interface for a 48kHz sample rate to
ensure the fastest possible settling time.
To ensure accurate results, the MAX9867 includes two
calibration routines. Calibrate the ADC each time the
MAX9867 is powered on. Calibration settings are not
lost if the MAX9867 is placed in shutdown. When mak-
ing a measurement, set AUXCAP to 1 to prevent AUX
from changing while reading the registers.
1) Ensure a valid MCLK signal is provided and config-
2) Choose a clocking mode. The following options are
3) Ensure JACKSNS is disabled.
4) Enable the left and right ADC; take the MAX9867 out
Perform the following steps before the first DC mea-
surement is taken after applying power to the
MAX9867:
40
• Slave mode with LRCLK and BCLK signals pro-
• Slave mode with no LRCLK and BCLK signals
• Master mode with audio. Configure the device in
• Master mode without audio. Configure the
ure PSCLK appropriately.
possible:
of shutdown.
______________________________________________________________________________________
vided. The measurement sample rate is deter-
mined by the external clocks.
provided. Configure the device for normal clock
mode using the NI ratio. Select f
for the fastest settling times.
normal mode using the NI ratio or exact integer
mode using FREQ as required by the audio signal.
device in normal mode using the NI ratio. Select f
= 48kHz to allow for the fastest settling times.
Offset Calibration Procedure
S
Setup Procedure
= 48kHz to allow
ADC
S
1) Enable the AUX input (AUXEN = 1).
2) Enable the offset calibration (AUXCAL = 1).
3) Wait the appropriate time (see Table 13).
4) Complete calibration (AUXCAL = 0).
Perform the following steps the first time a DC measure-
ment is taken after applying power to the MAX9867 or if
the temperature changes significantly:
1) Enable the AUX input (AUXEN = 1).
2) Start gain calibration (AUXGAIN = 1).
3) Wait the appropriate time (see Table 13).
4) Freeze the measurement results (AUXCAP = 1).
5) Read AUX and store the value in memory to correct
6) Complete calibration (AUXGAIN = AUXCAP = 0).
Perform the following steps after offset and gain cali-
bration are complete:
1) Enable the AUX input (AUXEN = 1).
2) Wait the appropriate time (see Table 13).
3) Freeze the measurement results (AUXCAP = 1).
4) Read AUX and correct with the gain calibration
5) Complete measurement (AUXCAP = 0).
Table 13. AUX ADC Wait Times
all future measurements (k = AUX[15:0], k is typical-
ly 19500).
value:
LRCLK (kHz)
11.025
22.05
44.1
V
48
32
24
16
12
8
AUX
=
0 738
.
WAIT TIMES
DC Measurement Procedure
⎛
⎜
⎝
Gain Calibration Procedure
AUX
[
k
15 0
WAIT TIME (ms)
: ]
⎞
⎟
⎠
120
160
175
240
40
44
60
80
90