TAS5622ADDVR datasheet(30/44 Pages) TI2

30 / 44 page

TAS5622A

SLAS845A – MAY 2012 – REVISED MARCH 2015

www.ti.com

9 Power Supply Recommendations

To facilitate system design, the TAS5622A needs only a 12-V supply in addition to the (typical) 32.5-V power-

stage supply. An internal voltage regulator provides suitable voltage levels for the digital and low-voltage analog

circuitry. Additionally, all circuitry requiring a floating voltage supply, that is, the high-side gate drive, is

accommodated by built-in bootstrap circuitry requiring only an external capacitor for each half-bridge.

To provide outstanding electrical and acoustical characteristics, the PWM signal path including gate drive and

output stage is designed as identical, independent half-bridges. For this reason, each half-bridge has separate

bootstrap pins (BST_X) and each full-bridge has separate power stage supply (PVDD_X) and gate supply

(GVDD_X) pins. Although supplied from the same 12-V source, it is highly recommended to separate GVDD_AB,

GVDD_CD, and VDD on the printed-circuit board (PCB) by RC filters (see application diagram for details). These

RC filters provide the recommended high-frequency isolation. Special attention should be paid to placing all

decoupling capacitors as close to their associated pins as possible. In general, inductance between the power

supply pins and decoupling capacitors must be avoided. (See reference board documentation for additional

information.)

Special attention should be paid to the power-stage power supply; this includes component selection, PCB

placement, and routing. As indicated, each full-bridge has independent power-stage supply pins (PVDD_X). For

optimal electrical performance, EMI compliance, and system reliability, it is important that each PVDD_X

connection is decoupled with minimum 2x 220 nF ceramic capacitors placed as close as possible to each supply

pin. It is recommended to follow the PCB layout of the TAS5622A reference design. For additional information on

recommended power supply and required components, see the application diagrams in this data sheet.

The 12-V supply should be from a low-noise, low-output-impedance voltage regulator. Likewise, the 32.5-V

power-stage supply is assumed to have low output impedance and low noise. The power-supply sequence is not

critical as facilitated by the internal power-on-reset circuit. Moreover, the TAS5622A is fully protected against

erroneous power-stage turn on due to parasitic gate charging when power supplies are applied. Thus, voltage-

supply ramp rates (dV/dt) are noncritical within the specified range (see the Recommended Operating Conditions

table of this data sheet).

9.1 Boot Strap Supply

For a properly functioning bootstrap circuit, a small ceramic capacitor must be connected from each bootstrap pin

(BST_X) to the power-stage output pin (OUT_X). When the power-stage output is low, the bootstrap capacitor is

charged through an internal diode connected between the gate-drive power-supply pin (GVDD_X) and the

bootstrap pin. When the power-stage output is high, the bootstrap capacitor potential is shifted above the output

potential and thus provides a suitable voltage supply for the high-side gate driver. In an application with PWM

switching frequencies in the range from 300 kHz to 400 kHz, it is recommended to use 33-nF ceramic capacitors,

size 0603 or 0805, for the bootstrap supply. These 33-nF capacitors ensure sufficient energy storage, even

during minimal PWM duty cycles, to keep the high-side power stage FET (LDMOS) fully turned on during the

remaining part of the PWM cycle.

10 Layout

10.1 Layout Guidelines

A rising-edge transition on reset input allows the device to execute the start-up sequence and starts switching.

Apply audio only according to the timing information for start-up and shutdown sequence. That will start and stop

the amplifier without audible artifacts in the output transducers.

The CLIP signal indicates that the output is approaching clipping (when output PWM starts skipping pulses due

to loop filter saturation). The signal can be used to initiate an audio volume decrease or to adjust the power

supply rail.

The device inverts the audio signal from input to output.

The DVDD and AVDD pins are not recommended to be used as a voltage source for external circuitry.

Submit Documentation Feedback

Product Folder Links: TAS5622A

TAS5622ADDVR Datasheet(PDF) 30 Page - Texas Instruments

TAS5622ADDVR Datasheet(HTML) 30 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44

Datasheet Download

Link URL