LMV1089RLEVAL National Semiconductor, LMV1089RLEVAL Datasheet - Page 8

• Manufacturer Part Number: LMV1089RLEVAL
• Description: BOARD EVALUATION LMV1089
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LMV1089RLEVAL

• Main Purpose: Audio, Microphone Amp
• Embedded: No
• Utilized Ic / Part: LMV1089
• Primary Attributes: Dual Input, Single Output
• Secondary Attributes: Graphical User Interface, I²C Interface
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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Measuring Characteristics of the
LMV1089
Important:
Whenever the LMV1089 part calibration data is stored into the
EEPROM, some parameters like Gain will differ from the
measured data in the datasheet. This is due to the nature of
the calibration system which equalizes the gain between the
two microphone channels. To measure the characteristics of
the part as described in the data sheet tables, the part should
not be calibrated. The part can be set in 'un-calibrated state'
via the I
(see Figure 7) in the graphical user interface of the program
that is available from National.
Connecting to an Audio Tester
For measuring the performance of the part as described in the
data sheet tables, there will be no header placed on J11 and
2
C interface by operating the Default setting button
FIGURE 8. Audio tester connections
8
J16 (see Figure 8), while J21 and J25 (see Figure 4) must be
shorted to supply and enable the part and the headers J18
and J19 (see Figure 8) that are used for automatic calibration
are open.
The outputs of the generator are connected differentially to
J11 and J16 where the (+) and (-) signals are applied to pin 3
and 4 and where pin 5 and 6 on J11 and J16 are ground con-
nection for shielding.
In a similar way the differential outputs of the LMV1089 can
be connected to the differential inputs of a tester via J14 and
J24 (see Figure 8). Pin 2 of the header must be connected to
the (+) and (-) inputs of the tester. Pin 1 of these headers are
ground pins that can be used for shielding. Optionally the
tester can also be connected via the 3.5mm jack at J27 (see
Figure 8).
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