TPA6132A2_17 Datasheet, PDF (13/28 Pages) Texas Instruments – 25-mW DirectPath Stereo Headphone Amplifier With Pop Suppression

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TPA6132A2
SLOS597A – DECEMBER 2008 – REVISED OCTOBER 2014
Feature Description (continued)
8.3.3 RF and Power Supply Noise Immunity
The TPA6132A2 employs a new differential amplifier architecture to achieve high power supply noise rejection
and RF noise rejection. RF and power supply noise are common in modern electronics. Although RF frequencies
are much higher than the 20 kHz audio band, signal modulation often falls in-band. This, in turn, modulates the
supply voltage, allowing a coupling path into the audio amplifier. A common example is the 217 Hz GSM frame-
rate buzz often heard from an active speaker when a cell phone is placed nearby during a phone call.
The TPA6132A2 has excellent rejection of power supply and RF noise, preventing audio signal degradation.
8.3.4 Constant Maximum Output Power and Acoustic Shock Prevention
Typically the output power increases with increasing supply voltage on an unregulated headphone amplifier. The
TPA6132A2 maintains a constant output power independent of the supply voltage. Thus the design for
prevention of acoustic shock (hearing damage due to exposure to a loud sound) is simplified since the output
power will remain constant, independent of the supply voltage. This feature allows maximizing the audio signal at
the lowest supply voltage.
8.4 Device Functional Modes
8.4.1 Gain Control
The TPA6132A2 has four gain settings which are controlled with pins G0 and G1. Table 1 gives an overview of
the gain function.
G0 VOLTAGE
≤ 0.5 V
≥ 1.3 V
≤ 0.5 V
≥ 1.3 V
G1 VOLTAGE
≤ 0.5 V
≤ 0.5 V
≥ 1.3 V
≥ 1.3 V
AMPLIFIER GAIN
–6 dB
0 dB
3 dB
6 dB
Table 1. Windows Vista™ Premium Mobile Mode Specifications
Device Type
Requirement
Analog Speaker Line Jack
(R_L = 10 kΩ, FS = 0.707
Vrms)
THD+N
Dynamic Range with Signal
Present
Line Output Crosstalk
Analog Headphone Out Jack
(R_L = 32Ω, FS = 0.300
Vrms)
THD+N
Dynamic Range with Signal
Present
Headphone Output Crosstalk
Windows Premium Mobile Vista
Specifications
≤ –65 dB FS [20 Hz, 20 kHz]
≤ –80 dB FS A-Weight
≤ –60 dB [20 Hz, 20 kHz]
≤ –45 dB FS [20 Hz, 20 kHz]
≤ –80 dB FS A-Weight
≤ –60 dB [20 Hz, 20 kHz]
TPA6132A2 Typical Performance
–75 dB FS[20 Hz, 20 kHz]
–100 dB FS A-Weight
–90 dB [20 Hz, 20 kHz]
–65 dB FS [20 Hz, 20 kHz]
–94 dB FS A-Weight
–90 dB [20 Hz, 20 kHz]
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