Tripath Technology, Inc. - Technical Information
10THD+N versus Frequency versus Gate Resistance
10 THD+N versus Frequency versus Gate Resistance
RL = 6Ω
RL = 8Ω
5
5
Pout = 25W /Channel
FET's = FQP13N10
f = 1kHz
Pout = 20W /Channel
FET's = FQP13N10
2
2
1
f = 1kHz
1
BBM = 40nS
BBM = 40nS
VS = +40V
BW = 22Hz - 22kHz
V S = +40V
0.5
0.5
BW = 22Hz - 22kHz
RG = 22 Ω
RG = 33 Ω
RG = 22 Ω
RG = 33 Ω
RG = 46.4 Ω
0.2
0.1
0.2
0.1
%
%
RG = 46.4 Ω
0.05
0.05
0.02
0.01
0.02
0.01
0.005
0.005
0.002
0.001
0.002
0.001
20
50
100
200
500
1k
2k
5k
10k 20k
20
50
100
200
500
Hz
1k
2k
5k
10k 20k
6 ohm and 8 ohm plots of THD+N versus Frequency for variousHzgate resistor values
6 ohms 8 ohms
22 ohms
33 ohms
18mA
20mA
18mA
20mA
80mA
46.4 ohms 80mA
Table 2: Idle current draw for VPP with various gate resistor values
Application Information – Recommended MOSFETs
Part Number Recommended Max
Supply Voltage
Typical Load at
Maximum Supply
8 ohm SE
Recommended
Gate Resistor
22 ohms
Other applications
IRF520N
FQP13N10
+/-45V
+/-45V
Only for 8 ohm SE Loads
6 ohm SE
33 ohms
6 ohm BR at +/25V
8 ohm BR at +/-33V
6 ohm BR at +/-25V
8 ohm BR at +/-33V
6 ohm BR at +/-33V
4 ohm BR at +/-33V
4 ohm BR at +/-35V
STP14NF10
+/-45V
6 ohm SE
33 ohms
IRF530N
BUK7575-100A
STP24NF10
+/-45V
+/-45V
+/-45V
4 ohm SE / 8 ohm BR
4 ohm SE / 6 ohm BR
4 ohm SE / 6 ohm BR
15 ohms
15 ohms
10 ohms
SE stands for Single Ended Outputs and BR stands for Bridged Output
MOSFETs Under Evaluation
The following MOSFETs appear to be suitable for use with the TK2150, and we are waiting for
samples to evaluate. Most of these devices come from the same “family” or generation, as other
recommended MOSFETs. However, experience tells us that we cannot recommend any devices
until we have received samples and fully tested them.
Device Information – MOSFETs Under Evaluation
Part Number
FQP14N15
FQP16N15
FDP2572
Manufacturer
BVDSS (V)
150
ID (A)
14.4
16.4
29
Qg (nC)
18
23
27
18.5
RDS(on) Ω
(
)
PD (W)
104
108
135
95
Package
T0220
TO220
TO247
TO220
Fairchild Semiconductor
Fairchild Semiconductor
Fairchild Semiconductor
Fairchild Semiconductor
.164
0.123
0.045
0.032
150
150
100
FDP3682
32
Note: The devices are listed in ascending current capability not in order of recommendation.
Output Filter Design
One advantage of Tripath amplifiers over PWM solutions is the ability to use higher-cutoff-
frequency filters. This means load-dependent peaking/droop in the 20kHz audio band potentially
caused by the filter can be made negligible. This is especially important for applications where
the user may select a 6-Ohm or 8-Ohm speaker. Furthermore, speakers are not purely resistive
27
TK2150 – Rev. 1.0/12.02
TRIPATH [ TRIPATH TECHNOLOGY INC. ]
