TK2051 View Datasheet(PDF) - Tripath Technology Inc.
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TK2051
Tripath Technology Inc.
TK2051 Datasheet PDF : 20 Pages
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Tripath Technology, Inc. - Technical Information
Mute Control
When a logic high signal is supplied to MUTE, both amplifier channels are muted (both high- and low-
side transistors are turned off). When a logic level low is supplied to MUTE, both amplifiers are fully
operational. There is a delay of approximately 200 milliseconds between the de-assertion of MUTE
and the un-muting of the TK2051.
To ensure proper device operation, including minimization of turn on/off transients that can result in
undesirable audio artifacts, Tripath recommends that the TK2051 device be muted prior to power up
or power down of the 5V supply. The “sensing” of the V5 supply can be easily accomplished by using
a “microcontroller supervisor” or equivalent to drive the TC2000 mute pin high when the V5 voltage is
below 4.5V. This will ensure proper operation of the TK2051 input circuitry. A micro-controller
supervisor such as the MCP101-450 from Microchip Corporation has been used by Tripath to
implement clean power up/down operation.
If turn-on and/or turn-off noise is still present with a TK2051 amplifier, the cause may be other
circuitry external to the TK2051. While the TK2051 has circuitry to suppress turn-on and turn-off
transients, the combination of power supply and other audio circuitry with the TK2051 in a particular
application may exhibit audible transients. One solution that will completely eliminate turn-on and
turn-off pops and clicks is to use a relay to connect/disconnect that amplifier from the speakers with
the appropriate timing during power on/off.
TK2051 Output Capability
The TK2051 can drive two 8 Ohm loads with 45 Watts each at less than 0.05% THD+N. The
maximum sustained amplifier output power will be determined by a number of factors including the
TC2000/TP2051 junction temperatures, the load impedance and the power supply voltage.
Tripath does not recommend driving loads below 6 Ohms single ended as the amplifier efficiency will
be reduced and the amplifier will reach it’s current limit at relatively low power output levels. With the
outputs connected in parallel, however, the TK2051 is capable of driving single channel loads down
to 4 Ohms with very high power capability. In such applications, special consideration must be give
to cooling of the TP2051 power device.
Paralleled Outputs
For stereo mode operation, the TK2051 is a dual full bridge. For parallel mode operation, the TK2051
can be configured as a single full bridge with double current capability by connecting the CONFIG pin
to the Vdd pin of the TP2051. Please refer to the Applications/Test Diagram for Parallel Operation.
Output Voltage Offset
The TK2051 does not have internal compensation for DC offset. If offset is a consideration for the
intended application, trimming of the input offset voltage will be required. Tripath has had success
with both active and passive circuits for this purpose; please consult with the Tripath applications
team for further information or review the EB-TK2051 datasheet for a full description of input
trimming.
Output Filter Design
Tripath amplifiers generally have a higher switching frequency than PWM implementations, allowing
the use of higher cutoff frequency filters and reducing the load dependent peaking/drooping in the
20kHz audio band. This is especially important for applications where the end customer may attach
any speaker to the amplifier (as opposed to a system where speakers are shipped with the amplifier),
since speakers are not purely resistive loads and the impedance they present changes over
frequency and from speaker model to speaker model. An RC network, or “Zobel” (RZ, CZ) should be
placed at the filter output to control the impedance “seen” by the TP2051 when not attached to a
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TK2051 – SB/1.0/8-02
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