Datasheet

INR+
INR-
INL+
INL-
AGND
SGND
OUTR
HPVSS
CPP CPN
SW
HPVDD
OUTL
2.2 Fm
Vbat
CODEC
OUTR+
OUTR-
OUTL+
OUTL-
1mF
GAIN
EN
EN
AVDD
GAIN
nHcoil
FM Tuner
2.2 Hm
2.2 Fm
TPA6141A2
TPA6141A2
SLOS634A –MARCH 2009–REVISED AUGUST 2009.................................................................................................................................................... www.ti.com
INDUCTOR SELECTION
The TPA6141A2 requires one inductor for its DC/DC converter. The following table lists recommended inductors.
Inductors not shown on this table can be used if they have similar performance characteristics.
When selecting an inductor observe the following rules:
• Lower DCR increases DC/DC converter efficiency.
• The minimum working inductance should never be below 1 μH.
• Include temperature and aging derating factors into the inductor value calculations.
MANUFACTURER PART NUMBER
TOKO MDT2012-CH2R2A
LQM21PN2R2MC0D
Murata
LQH2MCN2R2M02L
BRL2012T2R2M
Taiyo Yuden
BRC1608T2R2M
GAIN CONTROL
The TPA6141A2 has two gain settings which are controlled with the GAIN pin. The following table gives an
overview of the gain function.
GAIN VOLTAGE AMPLIFIER GAIN
≤0.6 V 0 dB
≥1.3 V 6 dB
GROUND SENSE FUNCTION
The ground sense pin, SGND, reduces ground-loop noise when the audio output jack is connected to a different
ground reference than codec and amplifier ground. Always connect the SGND pin to the headphone jack. This
reduces output offset voltage and eliminates turn-on pop. Figure 27 shows how to connect SGND when an FM
radio antenna function is implemented on the headphone wire. The nH coil and capacitor separate the RF signal
from the audio GND signal. In this case, SGND is used to eliminate the offset voltage that is generated from the
audio signal current and the RF coil low-frequency impedance.
The voltage difference between SGND and AGND cannot be greater than ±300 mV. The amplifier performance
degrades if the voltage difference between SGND and AGND is greater than ±300 mV.
Figure 27. Sense Ground
12 Copyright © 2009, Texas Instruments Incorporated
Product Folder Link(s): TPA6141A2