VDD

Internal VDD

AMP Enable

1.25 V

Bandgap

Comparator

DRV612

SLOS690B

– DECEMBER 2010 – REVISED APRIL 2011

www.ti.com

COMPONENT SELECTION

Charge Pump Flying Capacitor and VSS Capacitor

The charge-pump flying capacitor serves to transfer charge during the generation of the negative supply voltage.

The VSS 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 1

μF is typical.

Decoupling Capacitors

The DRV612 is a DirectPath line-driver amplifier that requires 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 1

μF, placed as close as possible to the device VDD lead works best. Placing this decoupling

capacitor close to the DRV612 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 also helps, but it is not required

in most applications because of the high PSRR of this device.

Gain-Setting

The gain setting is programmed with the GAIN pin. Gain setting is latched durning power on. Table 1 lists the

gain settings.

NOTE: If gain pin is left unconnected (open) default gain of

–2× is selected.

Table 1. Gain Settings

Gain_set RESISTOR

GAIN

GAIN (dB)

INPUT RESISTANCE

249 k

–2×

6

37 k

Ω

82k5

–1×

0.0

55 k

Ω

51k1

–1.5×

3.5

44 k

Ω

34k8

–2.3×

7.2

33 k

Ω

27k4

–2.5×

8

31 k

Ω

20k5

–3×

9.5

28 k

Ω

15k4

–3.5×

10.9

24 k

Ω

11k5

–4.0×

12

22 k

Ω

9k09

–5×

14

18 k

Ω

7k5

–5.6×

15

17 k

Ω

6k19

–6.4×

16.1

15 k

Ω

5k11

–8.3×

18.4

12 k

Ω

4k22

–10×

20

10 k

Ω

(1)

or higher

Internal Undervoltage Detection

The DRV612 contains an internal precision band-gap reference voltage and a comparator used to monitor the

supply voltage, VDD. The internal VDD monitor is set at 2.8 V with 200-mV hysteresis.

10

Submit Documentation Feedback

Copyright

© 2010–2011, Texas Instruments Incorporated

Product Folder Link(s) :DRV612