Datasheet

5 Layout Recommendations
5.1 SGND and PGND Connections
6 DRV603EVM Performance
Layout Recommendations www.ti.com
Figure 3 uses the component references also used in the FilterPro software. Various recommendation for
filter and gain settings are listed in Table 3 .
Table 3. DRV603EVM Filter Specifications
C23, C27, C24, C26, R23, R24, R22, R27, R25, R26,
EVM Reference Designators
C28, C32 C25, C30 C29, C31 R29, R30 R28, R33 R31, R32
Gain High Pass Low Pass C1 C2 C3 R1 R2 R3
–1 V/V 1.6 Hz 40 kHz 100 pF 680 pF 10 µ F 10 k Ω 10 k Ω 24 k Ω
–1.5 V/V 1.3 Hz 40 kHz 68 pF 680 pF 15 µ F 8.2 k Ω 12 k Ω 30 k Ω
–2 V/V 1.6 Hz 40 kHz 33 pF 150 pF 6.8 µ F 15 k Ω 30 k Ω 47 k Ω
–2 V/V 1.6 Hz 30 kHz 47 pF 470 pF 6.8 µ F 15 k Ω 30 k Ω 43 k Ω
–3.33 V/V 1.2 Hz 40 kHz 33 pF 470 pF 10 µ F 13 k Ω 43 k Ω 43 k Ω
–10 V/V 0.6 Hz 30 kHz 22 pF 1 nF 22 µ F 4.7 k Ω 47k Ω 27 k Ω
The resistor values should be low value to achieve low noise, but should be of high enough value to
obtain a small size ac-coupling capacitor.
The MFB topology demands a unity-gain stable op amp. If this condition can be relaxed for a specific
application, a capacitor from the inverting input to GND of the same value as C
1
can be used. This
alternate configuration increases the high-frequency gain to 2.
The SGND and GND pins of the DRV603 must be routed separately back to the decoupling capacitor in
order to facilitate proper device operation. If the SGND pins are connected directly to each other, the
device functions without risk of failure, but noise and THD performance can be reduced.
On the DRV603EVM, a star ground routing pattern is used; the star point is located directly below the
DRV603 device itself.
This section discusses the DRV603EVM overall performance in key parametric areas. Table 4 through
Table 8 summarize the EVM specifications.
Note: All electrical and audio specifications are typical values.
Table 4. General Test Conditions
(1)
General Test Conditions Notes
Supply voltage 7.0 V
Load impedance 2.5 k Ω
Input signal 1 kHz sine Digital audio TOSLINK S/PDIF
Measurement filter AES17
(1)
These test conditions are used for all tests, unless otherwise specified.
DRV603EVM 6 SLOU252A – December 2008 – Revised January 2009
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