TAS5110A_16 Datasheet, PDF (8/20 Pages) Texas Instruments – PurePath Digital AMPLIFIER TAS5110A 50-W DIGITAL AMPLIFIER POWER STAGE

TAS5110A
SLES079A – APRIL 2003 – REVISED MAY 2003
www.ti.com
DEVICE OPERATION
Power Sequences
System Power-up/Power-down Sequencing
The recommended power-up/power-down sequence is shown in Figure 3. For proper operation the RESET signal
should be kept low when both DVDD and output power (PVDDA1, PVDDA2, PVDDB1, and PVDDB2) are being
applied. The RESET signal should remain low for at least 1 ms after output power is applied.
DVDD(1)
PWDN
PVDDA2
PVDDB2
≥ 1 ms
PVDDA1
PVDDB1
RESET
u 100 µs
u 100 µs
u 1 ms
(1) _{For most applications, it is recommended that the PWDN pin be connected directly to the DVDD pin.}
Figure 3. Power-Up/Power-Down Sequence
RESET Function
The device is put into a reset condition when the (active low) RESET signal is asserted. While in the reset state, the
input H-bridge control signals consisting of PWM_AP, PWM_AM, PWM_BP, and PWM_BM are ignored, and the
H-bridge MOSFETs are placed in a state where OUTPUTA and OUTPUTB are both low. Asserting the RESET signal
low also causes the short circuit protection latch to be reset. The RESET signal is normally connected to the VALID
signal from the TAS50xx.
Reinitialization Sequence
Proper initial conditions for this device include asserting the RESET signal until the reset operation has completed
(1 ms). Additionally, when using this device with the TAS50xx controller, this function can be accomplished by
asserting the reset pin on the TAS50xx during the reset sequence (see Figure 3).
Audio Application Considerations
Optimal Power Transfer For H-Bridge
The TAS5110A is a power H-bridge that is designed to deliver a maximum of 50 W RMS into a 6-Ω load. In order
to achieve 50 W into 6 Ω, the system designer must provide an adequate thermal design. See the Thermal
Methodology for the 32-Pin DAD Package 50 W, 6-Ω Test section for a discussion of possible thermal solutions.
Careful attention must be given to the value of the high-voltage power supply level for a given load resistance. See
recommended operating conditions. See the Maximum Available Power at Common Load Impedances for DAD
Packages section.
reconstruction output filter
An output reconstruction filter is required between the H-bridge outputs and the loudspeaker load. This second-order
low-pass filter passes the audio information to the loudspeaker, while filtering out the high-frequency out-of-band
information contained in the H-bridge output PWM pulses. The values of the L and C components selected are
dependent on the loudspeaker load impedance.
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