DRV602 Datasheet, PDF (7/12 Pages) Texas Instruments – DIRECTPATH™, 2Vrms Line Driver with Adjustable gain

DRV602
www.ti.com ........................................................................................................................................................................................... SLOS572 – DECEMBER 2008
Charge Pump Flying Capacitor and PVSS Capacitor
The charge pump flying capacitor serves to transfer charge during the generation of the negative supply voltage.
The PVSS capacitor must be at least equal to the charge pump capacitor in order to allow maximum charge
transfer. Low ESR capacitors are an ideal selection, and a value of 1µF is typical. Capacitor values that are
smaller than 1µF can be used, but the maximum output voltage may be reduced and the device may not operate
to specifications.
Decoupling Capacitors
The DRV602 is a DirectPath Line Driver amplifier that require adequate power supply decoupling to ensure that
the noise and total harmonic distortion (THD) are low. A good low equivalent-series-resistance (ESR) ceramic
capacitor, typically 1µF, placed as close as possible to the device V_DD lead works best. Placing this decoupling
capacitor close to the DRV602 is important for the performance of the amplifier. For filtering lower frequency
noise signals, a 10-µF or greater capacitor placed near the audio power amplifier would also help, but it is not
required in most applications because of the high PSRR of this device.
Gain setting resistors ranges
The gain setting resistors, R_IN and R_fb, must be chosen so that noise, stability and input capacitor size of the
DRV602 is kept within acceptable limits. Voltage gain is defined as R_fb divided by R_IN.
Selecting values that are too low demands a large input ac-coupling capacitor, C_IN . Selecting values that are too
high increases the noise of the amplifier. Table 1 lists the recommended resistor values for different gain
settings.
INPUT RESISTOR
VALUE, R_IN
22 kΩ
15 kΩ
33 kΩ
10 kΩ
Table 1. Recommended Resistor Values
FEEDBACK RESISTOR
VALUE, R_fb
22 kΩ
30 kΩ
68 kΩ
100 kΩ
DIFFERENTIAL INPUT
GAIN
1.0 V/V
1.5 V/V
2.1 V/V
10.0 V/V
INVERTING INPUT GAIN
–1.0 V/V
–1.5 V/V
–2.1 V/V
–10.0 V/V
NON INVERTING INPUT
GAIN
2.0 V/V
2.5 V/V
3.1 V/V
11.0 V/V
C_IN
R_IN
-In
Differential
Input
R_fb
-
+
C_IN
R_IN
-In
Inverting
R_fb
-
+
+In
C_IN
R_IN
R_fb
Figure 6. Differential Input
Cx
R_IN
Non
Inverting
R_fb
-
+
Figure 7. Inverting
+In
C_IN
Rx
Figure 8. Non-Inverting
Copyright © 2008, Texas Instruments Incorporated
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