Tr i path Technol ogy, I nc. - Techni cal I nfor m ati on
C
B
D
S
R
VPP1
R
VPP2
R
VNN
C
A
R
HMUTE
D
CH
Q
1
Q
2
R
BASE
R
C
R
OFF
D
P
D
Z
R
BIAS1
R
BIAS2
R
D
D
C
D
BOOT2
R
OUT1
R
OUT2
R
B
C
OUT
Bypass capacitor for the internal regulator that powers the gate drive circuitry.
MOSFET protection diode. This diode absorbs any high frequency overshoots or
undershoots caused by the output inductor L
O
during high output current conditions.
In order for this diode to be effective it must be connected directly to the drain of the
topside MOSFET (pin 2) and the output (pin 3) and source of bottom side MOSFET
(pin 4) and the output (pin 3). An ultra fast recovery diode that can sustain the entire
VCC voltage should be used here. Thus a 50V or greater diode must be used.
Overvoltage and undervoltage sense resistor for the positive supply (VDD). 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.
Secondary overvoltage and undervoltage sense resistor for the positive supply
(VDD). This resistor accounts for the internal V
PPSENSE
bias of 2.5V. Nominal
resistor value should be equal to that of R
VPP1
. 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.
Not used on TK2019. Connect this pin to AGND through a 10kΩ resistor.
BIASCAP decoupling capacitor. Should be located close to pin 1 of the TC2001 and
grounded at pin 20 of the TC2001.
Base resistor to limit the current output from the HMUTE pin.
Diode to keep the Bypass pin (pin 7) of the TPS1035 charged to 5V while HMUTE is
high. This diode should be a Schottky diode.
PNP transistor to keep the Bypass pin (pin 7) of the TPS1035 charged to 5V
whenever the HMUTE is high.
PNP transistor to keep HMUTE high and mute the amplifier if the 5V supply is
turned off before the 24V supply. If the amplifier is not muted and the 5V supply is
turned off before the 24V supply, the amplifier will have an audible pop.
Base resistor for limiting the current entering the base for Q2.
Pull down resistor to pull the collector of Q2 to ground if both the 5V supply and the
24V supply is on and Q2 is off.
Resistor that limits the current from the 24V supply going into the 5.1V zener diode
(D
Z
).
Diode in series with the collector of Q2 to pull HMUTE high if the 5V supply is turned
off before the 24V supply.
5.1V zener diode to keep the emitter of Q2 to 5.1V so that when Q2 is on the
HMUTE pin will not exceed 5V.
Bias resistor to bias the FBKGND pins (pins 2 and 8 on TC2001) to 2.5V. Typically
used value is 4.64kΩ.
Second bias resistor to bias the FBKGND pins (pins 2 and 8 on TC2001) to 2.5V.
The value of R
BIAS2
when placed in parallel with R
FBB
and R
FBC
should have
equivalent resistance to R
BIAS1
. Please see the Modulator Feedback Design
paragraphs in the Application Information Section. An equivalent equation would be
R
BIAS1
= 1/ (R
FBB
+ R
FBC
) + 1/ R
BIAS2
.
Resistor to limit the current flowing into diode D
C
.
Diode to connect the VBOOT pin (pin 5 of the TPS1035) to the 24V supply so that
the VBOOT pin is charged up while the TPS1035 is muted. This helps prevent
clicks and pops while the sleep is disabled on the TPS1035.
Protection diode for the VBOOT pin (pin 5 of the TPS1035) so that the VBOOT pin
will never exceed 6.2V.
Bias resistor to keep the output capacitor C
OUT
charged to VDD/2. Typically used
value is 8.45kΩ.
Bias resistor used in conjunction with R
OUT1
to keep the output capacitor C
OUT
charged to VDD/2. Typically used value is 20kΩ.
For proper operation of the TPS1035, the Fault pin (pin 8) must be connected to the
Bypass pin (pin 7) through a 27kohm resistor.
Output capacitor in series with the output to block DC current to flow to the output
load. This capacitor will form a high pass filter with output load with a cutoff
frequency at
f
C
=
1 (2
π
R
I
C
I
)
. Where R is the resistive value of the output load.
TK2019 – MC/2.1/10-03
9
TRIPATH [ TRIPATH TECHNOLOGY INC. ]
