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
B
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 TK2070. 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.
For proper operation for the TPS1035, the Fault pin (pin 8) must tied to the Bypass
pin (pin 7) through a 27kohm resistor.
9
TK2070 – MC/2.1/10-03
TRIPATH [ TRIPATH TECHNOLOGY INC. ]
