fc +

1

2p R

I

C

I

Gain +

2 x 150 kW

R

I

V

V

TPA2006D1

SLOS498B – SEPTEMBER 2006 – REVISED SEPTEMBER 2015

www.ti.com

10.2.2 Detailed Design Procedure

10.2.2.1 Component Selection

Figure 35 shows the TPA2006D1 device typical schematic with differential inputs and Figure 38 shows the

TPA2006D1 device with differential inputs and input capacitors, and Figure 39 shows the TPA2006D1 device

with single-ended inputs. Differential inputs should be used whenever possible because the single-ended inputs

are much more susceptible to noise.

Table 2. Typical Component Values

REF DES

VALUE

EIA SIZE

MANUFACTURER

PART NUMBER

150 k

Ω (±0.5%)

0402

Panasonic

ERJ2RHD154V

1

μF (+22%, -80%)

0402

Murata

GRP155F50J105Z

(1)

3.3 nF (±10%)

0201

Murata

GRP033B10J332K

(1)

(20)

Resistor matching is important in fully differential amplifiers. The balance of the output on the reference voltage

depends on matched ratios of the resistors. CMRR, PSRR, and cancellation of the second harmonic distortion

diminish if resistor mismatch occurs. Therefore, it is recommended to use 1% tolerance resistors or better to

keep the performance optimized. Matching is more important than overall tolerance. Resistor arrays with 1%

matching can be used with a tolerance greater than 1%.

Place the input resistors close to the TPA2006D1 device to limit noise injection on the high-impedance nodes.

For optimal performance the gain must be set to 2 V/V or lower. Lower gain allows the TPA2006D1 device to

operate at its best and keeps a high voltage at the input making the inputs less susceptible to noise.

The TPA2006D1 device is a high-performance class-D audio amplifier that requires adequate power supply

decoupling to ensure the efficiency is high and total harmonic distortion (THD) is low. For higher frequency

transients, spikes, or digital hash on the line, a good low equivalent-series-resistance (ESR) ceramic capacitor,

typically 1

close to the device is important for the efficiency of the class-D amplifier, because any resistance or inductance

in the trace between the device and the capacitor can cause a loss in efficiency. 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.

The TPA2006D1 device does not require input coupling capacitors if the design uses a differential source that is

common-mode input range, if needing to use the input as a high pass filter (shown in Figure 38), or if using a

single-ended source (shown in Figure 39), input coupling capacitors are required.

Equation 21.

(21)

The value of the input capacitor is important to consider as it directly affects the bass (low frequency)

performance of the circuit. Speakers in wireless phones cannot usually respond well to low frequencies, so the

corner frequency can be set to block low frequencies in this application.

20

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