Tripath Technology, Inc. - Preliminary Information
External Components Description (Refer to the Application/Test Circuit)
Components Description
RI
RF
CI
Inverting input resistance to provide AC gain in conjunction with RF. This input is
biased at the BIASCAP voltage (approximately 2.5VDC).
Feedback resistor to set AC gain in conjunction with RI. Please refer to the Amplifier
Gain paragraph, in the Application Information section.
AC input coupling capacitor which, in conjunction with RI, forms a high-pass filter at
.
fC = 1 (2πRICI)
RFBA
RFBB
RFBC
Feedback divider resistor connected to V5. This value of this resistor depends on
the supply voltage setting and helps set the TDA1400 gain in conjunction with RI, RF,
RFBA, and RFBC. Please see the Modulator Feedback Design paragraphs in the
Application Information Section.
Feedback divider resistor connected to AGND. This value of this resistor depends
on the supply voltage setting and helps set the TDA1400 gain in conjunction with RI,
RF, RFBA, and RFBC. Please see the Modulator Feedback Design paragraphs in the
Application Information Section.
Feedback resistor connected from either the OUTP to FBK_POS or OUTN to
FBK_NEG. The value of this resistor depends on the supply voltage setting and
helps set the TDA1400 gain in conjunction with RI, RF, RFBA,, and RFBB. It should be
noted that RFBC must have a power rating of greater than
.
)
P
= VPP2 (2RFBC
Please see the Modulator Feedback Design paragraphs inDtIhSSe Application
Information Section.
CFB
Feedback delay capacitor that both lowers the idle switching frequency and filters
very high frequency noise from the feedback signal, which improves amplifier
performance. The same value CFB should be used for each side and located directly
at FBK_POS and FBK_NEG. Please refer to the Application / Test Circuit.
Potentiometer used to manually trim the DC offset on the output of the TDA1400.
Resistor that limits the DC offset trim range and allows for precise adjustment.
Capacitor that filters the manual DC offset trim voltage.
ROFA
ROFB
COF
RREF
Bias resistor. Locate close to pin 34 and ground to plane with a low impedance
connection to pins 41 and 42.
RBBMSET
Bias current setting resistor for the BBM setting. Locate close to pin 7 and ground
directly to pin 5. See Application Information on how to determine the value for
RBBM
.
CA
CS
BIASCAP decoupling capacitor. Locate close to pin 3 and ground to plane with a
low impedance connection to pins 41 and 42.
Supply decoupling capacitor for the power pins. For optimum performance, these
components should be located close to the TDA1400 and returned to their
respective ground as shown in the Application Circuit.
RVNN1
RVNN2
RVPP1
Main overvoltage and undervoltage sense resistor for the negative supply (VNN).
Please refer to the Electrical Characteristics Section for the trip points as well as the
hysteresis band. Also, please refer to the Over / Under-voltage Protection section in
the Application Information for a detailed discussion of the internal circuit operation
and external component selection. When using a single power supply, this circuit
can be defeated by connecting a 16KΩ resistor to AGND.
Secondary overvoltage and undervoltage sense resistor for the negative supply
(VNN). This resistor accounts for the internal VNNSENSE bias of 1.25V. Nominal
resistor value should be three times that of RVNN1. Please refer to the Over / Under-
voltage Protection section in the Application Information for a detailed discussion of
the internal circuit operation and external component selection. When using a single
power supply, omit RVNN2
.
Main overvoltage and undervoltage sense resistor for the positive supply (VPP).
Please refer to the Electrical Characteristics Section for the trip points as well as the
hysteresis band. Also, please refer to the Over / Under-voltage Protection section in
the Application Information for a detailed discussion of the internal circuit operation
and external component selection.
RVPP2
Secondary overvoltage and undervoltage sense resistor for the positive supply
9
TDA1400 – Rev. 0.65/KLi/02.06
TRIPATH [ TRIPATH TECHNOLOGY INC. ]
