Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsLinear IC - Audio amplifier 1-channel (mono) Class AB SOIC 8

www.ti.com

FEATURES

SHUTDOWN

BYPASS

IN+

IN–

GND

D PACKAGE

(TOP VIEW)

DESCRIPTION

Audio

Input

Bias

Control

1 W

IN+

IN–

BYPASS

SHUTDOWN

–

GND

TPA4861

SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004

1-W MONO AUDIO POWER AMPLIFIER

• 1-W BTL Output (5 V, 0.11 % THD+N)

• 3.3-V and 5-V Operation

• No Output Coupling Capacitors Required

• Shutdown Control (I

= 0.6 µA)

• Uncompensated Gains of 2 to 20 (BTL Mode)

• Surface-Mount Packaging

• Thermal and Short-Circuit Protection

• High Supply Ripple Rejection Ratio (56 dB at

1 kHz)

• LM4861 Drop-In Compatible

The TPA4861 is a bridge-tied load (BTL) audio power amplifier capable of delivering 1 W of continuous average

power into an 8-Ω load at 0.2% THD+N from a 5-V power supply in voiceband frequencies (f < 5 kHz). A BTL

configuration eliminates the need for external coupling capacitors on the output in most applications. Gain is

externally configured by means of two resistors and does not require compensation for settings of 2 to 20.

Features of the amplifier are a shutdown function for power-sensitive applications as well as internal thermal and

short-circuit protection. The TPA4861 works seamlessly with TI's TPA4860 in stereo applications. The amplifier

is available in an 8-pin SOIC surface-mount package that reduces board space and facilitates automated

assembly.

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.

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 (26 pages)

PAGE 1
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 1-W MONO AUDIO POWER AMPLIFIER FEATURES • • • • • • • • • D PACKAGE (TOP VIEW) 1-W BTL Output (5 V, 0.11 % THD+N) 3.3-V and 5-V Operation No Output Coupling Capacitors Required Shutdown Control (IDD = 0.
PAGE 2
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 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. AVAILABLE OPTIONS PACKAGED DEVICE TA SMALL OUTLINE (1) (D) –40°C to 85°C (1) TPA4861D The D package is available tape and reeled. To order a tape and reeled part, add the suffix R to the part number (e.g., TPA4861DR).
PAGE 3
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 ELECTRICAL CHARACTERISTICS at specified free-air temperature, VDD = 3.3 V (unless otherwise noted) PARAMETER VOO Output offset voltage See (1) PSRR Power supply rejection ratio (∆VDD/∆VOO) VDD = 3.2 V to 3.4 V IDD IDD(SD) (1) TPA4861 TEST CONDITIONS MIN TYP MAX 20 UNIT mV 75 dB Supply current 2.5 mA Supply current, shutdown 0.6 µA At 3 V < VDD < 5 V the dc output voltage is approximately VDD/2.
PAGE 4
TPA4861 www.ti.
PAGE 5
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 SUPPLY CURRENT DISTRIBUTION vs FREE-AIR TEMPERATURE SUPPLY CURRENT DISTRIBUTION vs FREE-AIR TEMPERATURE 3.5 5 VDD = 5 V VDD = 3.3 V 3 4 I DD − Supply Current − mA I DD − Supply Current − mA 4.5 3.5 3 Typical 2.5 2 1.5 2.5 2 1 0.5 1 0.5 0 −40 25 85 −40 25 85 TA − Free-Air Temperature − °C Figure 3. Figure 4.
PAGE 6
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 10 VDD = 5 V PO = 1 W AV = −20 V/V RL = 8 Ω CB = 0.1 µF 1 CB = 1 µF 0.1 0.01 20 100 1k TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY THD+N − Total Harmonic Distortion Plus Noise − % THD+N − Total Harmonic Distortion Plus Noise − % TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY 10 k 20 k 10 VDD = 5 V PO = 0.5 W AV = −2 V/V RL = 8 Ω 1 CB = 0.1 µF 0.1 CB = 1 µF 0.01 20 100 Figure 8.
PAGE 7
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT POWER 10 THD+N − Total Harmonic Distortion Plus Noise − % THD+N − Total Harmonic Distortion Plus Noise − % TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY VDD = 5 V AV = −10 V/V Single Ended 1 0.1 0.01 20 RL = 8 Ω PO = 250 mW RL = 32 Ω PO = 60 mW 100 1k 10 k 20 k 10 VDD = 5 V AV = −2 V/V RL = 8 Ω f = 20 Hz 1 CB = 0.1 µF CB = 1 µF 0.1 0.01 0.02 1 Figure 11. Figure 12.
PAGE 8
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 10 VDD = 3.3 V PO = 350 mW RL = 8 Ω AV = −2 V/V 1 CB = 0.1 µF 0.1 CB = 1 µF 0.01 20 100 TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY THD+N − Total Harmonic Distortion Plus Noise − % THD+N − Total Harmonic Distortion Plus Noise − % TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY 1k 10 k 20 k 10 VDD = 3.3 V PO = 350 mW RL = 8 Ω AV = −10 V/V 1 CB = 0.1 µF 0.1 CB = 1 µF 0.
PAGE 9
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT POWER THD+N − Total Harmonic Distortion Plus Noise − % 10 VDD = 3.3 V AV = −2 V/V RL = 8 Ω f = 20 Hz 1 CB = 0.1 µF 0.1 CB = 1.0 µF 0.01 0.02 0.1 1 2 10 VDD = 3.3 V AV = −2 V/V RL = 8 Ω f = 1 kHz 1 CB = 0.1 µF CB = 1 µF 0.1 0.01 0.02 0.1 1 PO − Output Power − W PO − Output Power − W Figure 19. Figure 20.
PAGE 10
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 OUTPUT NOISE VOLTAGE vs FREQUENCY OUTPUT NOISE VOLTAGE vs FREQUENCY 103 103 VDD = 3.3 V Vn − Output Noise Voltage − µ V Vn − Output Noise Voltage − µ V VDD = 5 V 102 V01 +V02 V02 101 V01 1 20 100 1k 102 V01 +V02 V02 101 V01 1 20 10 k 20 k 100 f − Frequency − Hz 1k 10 k 20 k f − Frequency − Hz Figure 23. Figure 24. MAXIMUM PACKAGE POWER DISSIPATION vs FREE-AIR TEMPERATURE POWER DISSIPATION vs OUTPUT POWER 0.
PAGE 11
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 POWER DISSIPATION vs OUTPUT POWER MAXIMUM OUTPUT POWER vs FREE-AIR TEMPERATURE 0.5 160 VDD = 3.3 V 140 TA − Free-Air Temperature − °C PD − Power Dissipation − W 0.4 RL = 8 Ω 0.3 0.2 RL = 16 Ω 0.1 120 RL = 16 Ω 100 80 60 RL = 8 Ω 40 20 0 0 0 0.1 0.2 0.3 PO − Output Power − W 0.4 0.5 0 0.5 0.75 Figure 27. Figure 28. OUTPUT POWER vs LOAD RESISTANCE OUTPUT POWER vs SUPPLY VOLTAGE 2 AV = −2 V/V f = 1 kHz CB = 0.
PAGE 12
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 OPEN-LOOP GAIN vs FREQUENCY SUPPLY RIPPLE REJECTION RATIO vs FREQUENCY 45° VDD = 5 V RL = 8 Ω CB = 0.1 µF 0° −45° 60 Phase 40 −90° Gain 20 −135° 0 −20 10 Phase Open-Loop Gain − dB 80 0 k SVR − Supply Ripple Rejection Ratio − dB 100 −180° 100 1k 10 k 1M 100 k −225° 10 M VDD = 5 V RL = 8 Ω Bridge-Tied Load −10 −20 −30 −40 CB = 0.
PAGE 13
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 APPLICATION INFORMATION BRIDGED-TIED LOAD VERSUS SINGLE-ENDED MODE Figure 34 shows a linear audio power amplifier (APA) in a bridge-tied load (BTL) configuration. A BTL amplifier actually consists of two linear amplifiers driving both ends of the load. There are several potential benefits to this differential drive configuration, but initially, let us consider power to the load.
PAGE 14
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 APPLICATION INFORMATION (continued) VDD VO(PP) CC RL VO(PP) Figure 35. Single-Ended Configuration Increasing power to the load does carry a penalty of increased internal power dissipation. The increased dissipation is understandable considering that the BTL configuration produces 4 times the output power of the SE configuration. Internal dissipation versus output power is discussed further in the thermal considerations section.
PAGE 15
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 APPLICATION INFORMATION (continued) P Efficiency Where: P L SUP V L RMS PL R L 2 Vp 2 2R L V V P L RMS 2 P SUP VDD I DD RMS I DD RMS V DD 2VP RL 2V P RL (3) Efficiency of a BTL configuration VP 2V DD PLR 1 2 L 2 2V DD (4) Table 1 employs Equation 4 to calculate efficiencies for four different output power levels.
PAGE 16
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 SELECTION OF COMPONENTS Figure 37 is a schematic diagram of a typical notebook computer application circuit. 50 kΩ CF 50 kΩ VDD 6 RF VDD = 5 V CS VDD/2 Audio Input RI 4 IN − 3 IN + CI CB VO1 5 − + 46 kΩ 1-W Internal Speaker 46 kΩ 2 BYPASS 1 SHUTDOWN (see Note A) VO2 8 − + Bias Control 7 NOTE A: SHUTDOWN must be held low for normal operation and asserted high for shutdown mode. Figure 37.
PAGE 17
TPA4861 www.ti.com f co(lowpass) SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 1 2 R F CF (7) For example if RF is 100 kΩ and CF is 5 pF, then fco is 318 kHz, which is well outside of the audio range. Input Capacitor, CI In the typical application, an input capacitor, CI, is required to allow the amplifier to bias the input signal to the proper dc level for optimum operation. In this case, CI and RI form a high-pass filter with the corner frequency determined in Equation 8.
PAGE 18
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 SINGLE-ENDED OPERATION Figure 38 is a schematic diagram of the recommended SE configuration. In SE mode configurations, the load should be driven from the primary amplifier output (VO1, terminal 5). VDD 6 RF VDD VDD/2 CS Audio Input RI 4 IN − CI 3 IN + 2 BYPASS − + VO1 5 − + VO2 8 CC 250-mW External Speaker CB RSE = 50 Ω CSE = 0.1 µF Figure 38.
PAGE 19
TPA4861 www.ti.com SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 Table 2. Common Load Impedances vs Low-Frequency Output Characteristics in SE Mode RL CC LOWEST FREQUENCY 8Ω 68 µF 293 Hz 32Ω 68 µF 73 Hz 47,000 Ω 68 µF 0.05 Hz As Table 2 indicates, most of the bass response is attenuated into 8-Ω loads, while headphone response is adequate and drive into line level inputs (a home stereo for example) is good.
PAGE 20
TPA4861 SLOS163C – SEPTEMBER 1996 – REVISED JUNE 2004 www.ti.com 5-V VERSUS 3.3-V OPERATION The TPA4861 was designed for operation over a supply range of 2.7 V to 5.5 V. This data sheet provides full specifications for 5-V and 3.3-V operation, as these are considered to be the two most common standard voltages. There are no special considerations for 3.3-V versus 5-V operation as far as supply bypassing, gain setting, or stability. Supply current is slightly reduced from 3.5 mA (typical) to 2.
PAGE 21
PACKAGE OPTION ADDENDUM www.ti.
PAGE 22
PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device TPA4861DR Package Package Pins Type Drawing SOIC D 8 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 2500 330.0 12.4 Pack Materials-Page 1 6.4 B0 (mm) K0 (mm) P1 (mm) 5.2 2.1 8.0 W Pin1 (mm) Quadrant 12.
PAGE 23
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) TPA4861DR SOIC D 8 2500 367.0 367.0 35.
PAGE 24
PAGE 25
PAGE 26
IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46C and to discontinue any product or service per JESD48B. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.