DRV612_15 Datasheet, PDF (10/24 Pages) Texas Instruments – 2-Vrms DirectPath™ Line Driver With Programmable-Fixed Gain

DRV612
SLOS690B – DECEMBER 2010 – REVISED APRIL 2011
COMPONENT SELECTION
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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.
Gain_set RESISTOR
249 kΩ⁽¹⁾
82k5
51k1
34k8
27k4
20k5
15k4
11k5
9k09
7k5
6k19
5k11
4k22
Table 1. Gain Settings
GAIN
–2×
–1×
–1.5×
–2.3×
–2.5×
–3×
–3.5×
–4.0×
–5×
–5.6×
–6.4×
–8.3×
–10×
GAIN (dB)
6
0.0
3.5
7.2
8
9.5
10.9
12
14
15
16.1
18.4
20
INPUT RESISTANCE
37 kΩ
55 kΩ
44 kΩ
33 kΩ
31 kΩ
28 kΩ
24 kΩ
22 kΩ
18 kΩ
17 kΩ
15 kΩ
12 kΩ
10 kΩ
(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.
VDD
1.25 V
Bandgap
AMP Enable
Comparator
Internal VDD
10
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