Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsLinear IC - Audio amplifier 1-channel (mono) Class D HTSSOP 28

INP

INN

SDSD

FaultFault

PLIMITPLIMIT

PVCC 8to26V

1uF

OUTN

FERRITE

BEAD

FILTER

OUTP

25W

8Ω

OUTN

FERRITE

BEAD

FILTER

FERRITE

BEAD

FILTER

OUTP

8Ω

OUT+

OUT

Audio

Source

TPA3112D1

GAIN0

GAIN1GAIN1

TPA3112D1

www.ti.com

SLOS654C –SEPTEMBER 2009–REVISED JULY 2012

25-W FILTER-FREE MONO CLASS-D AUDIO POWER AMPLIFIER with SPEAKER GUARD™

Check for Samples: TPA3112D1

FEATURES

DESCRIPTION

• 25-W into an 8-Ω Load at < 0.1% THD+N From

The TPA3112D1 is a 25-W efficient, Class-D audio

a 24-V Supply

power amplifier for driving a bridge tied speaker.

• 20-W into an 4-Ω Load at 10% THD+N From a

Advanced EMI Suppression Technology enables the

12-V Supply

use of inexpensive ferrite bead filters at the outputs

• 94% Efficient Class-D Operation into 8-Ω Load

while meeting EMC requirements. SpeakerGuard™

speaker protection system includes an adjustable

Eliminates Need for Heat Sinks

power limiter and a DC detection circuit. The

• Wide Supply Voltage Range Allows Operation

adjustable power limiter allows the user to set a

from 8 to 26 V

"virtual" voltage rail lower than the chip supply to limit

• Filter-Free Operation

the amount of current through the speaker. The DC

detect circuit measures the frequency and amplitude

• SpeakerGuard™ Speaker Protection Includes

of the PWM signal and shuts off the output stage if

Adjustable Power Limiter plus DC Protection

the input capacitors are damaged or shorts exist on

• Flow Through Pin Out Facilitates Easy Board

the inputs.

Layout

The TPA3112D1 can drive a mono speaker as low as

• Robust Pin-to-Pin Short Circuit Protection and

4Ω. The high efficiency of the TPA3112D1, > 90%,

Thermal Protection with Auto-Recovery Option

eliminates the need for an external heat sink when

• Excellent THD+N/ Pop Free Performance

playing music.

• Four Selectable, Fixed Gain Settings

The outputs are fully protected against shorts to

• Differential Inputs

GND, V

, and output-to-output. The short-circuit

protection and thermal protection includes an auto-

APPLICATIONS

recovery feature.

• Televisions

• Consumer Audio Equipment

Figure 1. Simplified Application Diagram

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2SpeakerGuard, PowerPad are trademarks of Texas Instruments.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (27 pages)

PAGE 1
TPA3112D1 www.ti.com SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 25-W FILTER-FREE MONO CLASS-D AUDIO POWER AMPLIFIER with SPEAKER GUARD™ Check for Samples: TPA3112D1 FEATURES 1 • 2 • • • • • • • • • • 25-W into an 8-Ω Load at < 0.
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TPA3112D1 SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 www.ti.com These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range (unless otherwise noted) (1) UNIT VCC Supply voltage AVCC, PVCC –0.3 V to 30 V SD, FAULT,GAIN0, GAIN1, AVCC (Pin 14) VI Interface pin voltage PLIMIT –0.
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TPA3112D1 www.ti.com SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 RECOMMENDED OPERATING CONDITIONS over operating free-air temperature range (unless otherwise noted) PARAMETER TEST CONDITIONS MIN MAX 26 UNIT VCC Supply voltage PVCC, AVCC 8 VIH High-level input voltage SD, GAIN0, GAIN1 2 V VIL Low-level input voltage SD, GAIN0, GAIN1 0.8 V VOL Low-level output voltage FAULT, RPULLUP=100kΩ, VCC=26V 0.
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TPA3112D1 SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 www.ti.com AC CHARACTERISTICS TA = 25°C, VCC = 24 V, RL = 8 Ω (unless otherwise noted) PARAMETER TEST CONDITIONS MIN KSVR Power Supply ripple rejection 200 mVPP ripple from 20 Hz–1 kHz, Gain = 20 dB, Inputs ac-coupled to AGND PO Continuous output power THD+N ≤ 0.
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TPA3112D1 www.ti.com SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 PIN FUNCTIONS PIN NAME SD Pin # 1 I/O DESCRIPTION I Shutdown logic input for audio amp(LOW = outputs Hi-Z, HIGH = outputs enabled). TTL logic levels with compliance to AVCC. O Open drain output used to display short circuit or dc detect fault status. Voltage compliant to AVCC. Short circuit faults can be set to auto-recovery by connecting FAULT pin to SD pin.
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TPA3112D1 SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 www.ti.
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TPA3112D1 www.ti.com SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 TYPICAL CHARACTERISTICS (All Measurements taken at 1 kHz, unless otherwise noted. Measurements were made using the TPA3112D2 EVM which is available at ti.com.) TOTAL HARMONIC DISTORTION vs FREQUENCY TOTAL HARMONIC DISTORTION vs FREQUENCY 10 Gain = 20 dB VCC = 12 V ZL = 8 Ω + 66 µH THD − Total Harmonic Distortion − % THD − Total Harmonic Distortion − % 10 1 0.1 PO = 1 W 0.
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TPA3112D1 SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 www.ti.com TYPICAL CHARACTERISTICS (continued) (All Measurements taken at 1 kHz, unless otherwise noted. Measurements were made using the TPA3112D2 EVM which is available at ti.com.) TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT POWER TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT POWER 10 Gain = 20 dB VCC = 24 V ZL = 8 Ω + 66 µH THD+N − Total Harmonic Distortion + Noise − % THD+N − Total Harmonic Distortion + Noise − % 10 1 f = 1 kHz f = 20 Hz 0.
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TPA3112D1 www.ti.com SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 TYPICAL CHARACTERISTICS (continued) (All Measurements taken at 1 kHz, unless otherwise noted. Measurements were made using the TPA3112D2 EVM which is available at ti.com.) GAIN/PHASE vs FREQUENCY EFFICIENCY vs OUTPUT POWER 40 100 35 50 100 90 Phase VCC = 24 V 80 30 0 25 −50 20 −100 15 −150 CI = 1 µF Gain = 20 dB Filter = Audio Precision AUX-0025 VCC = 12 V VI = 0.
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TPA3112D1 SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 www.ti.com TYPICAL CHARACTERISTICS (continued) (All Measurements taken at 1 kHz, unless otherwise noted. Measurements were made using the TPA3112D2 EVM which is available at ti.com.) SUPPLY CURRENT vs TOTAL OUTPUT POWER SUPPLY RIPPLE REJECTION RATIO vs FREQUENCY 0 1.8 1.6 KSVR − Supply Ripple Rejection Ratio − dB Gain = 20 dB VCC = 12 V ZL = 4 Ω + 33 µH ICC − Supply Current − A 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.
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TPA3112D1 www.ti.com SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 SD OPERATION The TPA3112D1 employs a shutdown mode of operation designed to reduce supply current (ICC) to the absolute minimum level during periods of nonuse for power conservation. The SD input terminal should be held high (see specification table for trip point) during normal operation when the amplifier is in use. Pulling SD low causes the outputs to mute and the amplifier to enter a low-current state.
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TPA3112D1 SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 POUT ææ ö ö RL çç ç ÷ ´ VP ÷÷ è RL + 2 ´ RS ø ø =è 2 ´ RL www.ti.com 2 for unclipped power (1) Where: RS is the total series resistance including RDS(on), and any resistance in the output filter. RL is the load resistance. VP is the peak amplitude of the output possible within the supply rail. VP = 4 × PLIMIT voltage if PLIMIT < 4 × VP POUT(10%THD) = 1.25 × POUT(unclipped) Table 2.
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TPA3112D1 www.ti.com SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 SHORT-CIRCUIT PROTECTION AND AUTOMATIC RECOVERY FEATURE TPA3112D2 has protection from over-current conditions caused by a short circuit on the output stage. The short circuit protection fault is reported on the FAULT pin as a low state. The amplifier outputs are switched to a Hi-Z state when the short circuit protection latch is engaged. The latch can be cleared by cycling the SD pin through the low state.
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TPA3112D1 SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 www.ti.com APPLICATION INFORMATION PVCC 100 μF 0.1 μF 1000pF 100k Ω Control System 1 SD PVCC FAULT PVCC 28 1 kΩ 2 3 4 5 6 AVCC PVCC 7 10 Ω 1 uF 8 GND BSN GND OUTN GAIN0 PGND GAIN1 OUTN BSN AVCC TPA3112D1 AGND BSP GVDD OUTP PLIMIT PGND INN OUTP INP BSP NC PVCC AVCC PVCC 27 26 0.47 μF 25 24 FB 23 1000 pF 22 21 1000 pF 9 1 uF 10 11 1 uF Audio Source 12 1 uF AVCC 100 kW 13 (1) 20 FB 19 0.
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TPA3112D1 www.ti.com SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 CLASS-D OPERATION This section focuses on the class-D operation of the TPA3112D1. TPA3112D1 Modulation Scheme The TPA3112D1 uses a modulation scheme that allows operation without the classic LC reconstruction filter when the amp is driving an inductive load. Each output is switching from 0 volts to the supply voltage. The OUTP and OUTN are in phase with each other with no input so that there is little or no current in the speaker.
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TPA3112D1 SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 www.ti.com One important aspect of the ferrite bead selection is the type of material used in the ferrite bead. Not all ferrite material is alike, so it is important to select a material that is effective in the 10 to 100 MHz range which is key to the operation of the Class D amplifier. Many of the specifications regulating consumer electronics have emissions limits as low as 30 MHz.
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TPA3112D1 www.ti.com SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 33 mH OUTP L1 C2 1 mF 33 mH OUTN L2 C3 1 mF Figure 19. Typical LC Output Filter, Cutoff Frequency of 27 kHz, Speaker Impedance = 8 Ω 15 mH OUTP L1 C2 2.2 mF 15 mH OUTN L2 C3 2.2 mF Figure 20. Typical LC Output Filter, Cutoff Frequency of 27 kHz, Speaker Impedance = 4 Ω Ferrite Chip Bead OUTP 1 nF Ferrite Chip Bead OUTN 1 nF Figure 21.
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TPA3112D1 SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 www.ti.com INPUT RESISTANCE Changing the gain setting can vary the input resistance of the amplifier from its smallest value, 9 kΩ ±20%, to the largest value, 60 kΩ ±20%. As a result, if a single capacitor is used in the input high-pass filter, the -3 dB or cutoff frequency may change when changing gain steps. Zf Ci IN Input Signal Zi The -3-dB frequency can be calculated using Equation 2. Use the ZI values given in Table 1.
PAGE 19
TPA3112D1 www.ti.com SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 Optimum decoupling is achieved by using a network of capacitors of different types that target specific types of noise on the power supply leads. For higher frequency transients due to parasitic circuit elements such as bond wire and copper trace inductances as well as lead frame capacitance, a good quality low equivalent-seriesresistance (ESR) ceramic capacitor of value between 220 pF and 1000 pF works well.
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TPA3112D1 SLOS654C – SEPTEMBER 2009 – REVISED JULY 2012 www.ti.com PRINTED-CIRCUIT BOARD (PCB) LAYOUT The TPA3112D1 can be used with a small, inexpensive ferrite bead output filter for most applications. However, since the Class-D switching edges are very fast, it is necessary to take care when planning the layout of the printed circuit board. The following suggestions will help to meet EMC requirements.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device TPA3112D1PWPR Package Package Pins Type Drawing SPQ HTSSOP 2000 PWP 28 Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 330.0 16.4 Pack Materials-Page 1 6.9 B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 10.2 1.8 12.0 16.
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PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TPA3112D1PWPR HTSSOP PWP 28 2000 367.0 367.0 38.
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