TPA3111D1 www.ti.com ................................................................................................................................................................................................ SLOS618 – AUGUST 2009 10-W FILTER-FREE MONO CLASS-D AUDIO POWER AMPLIFIER with SPEAKER GUARD™ Check for Samples: TPA3111D1 FEATURES 1 • 2 • • • • • • • • • • 10-W into an 8-Ω Load at 10% THD+N From a 12-V Supply 7-W into an 4-Ω Load at 10% THD+N From a 8-V Supply 94% Efficient Class-D Operation into 8-Ω Load Eliminates Need for Heat Sinks Wide Supply Voltage Range Allows Operation from 8 to 26 V Filter-Free Operation SpeakerGuard™ Speaker Protection Includes Adjustable Power Limiter plus DC Protection Flow Through Pin Out Facilitates Easy Board Layout Robust Pin-to-Pin Short Circuit Protection and Thermal Protection with Auto-Recovery Option Excellent THD+N/ Pop Free Performance Four Selectable, Fixed Gain Settings Differential Inputs APPLICATIONS • • • Televisions Monitor/Laptop Consumer Audio Equipment DESCRIPTION The TPA3111D1 is a 10-W efficient, Class-D audio power amplifier for driving a bridge tied speaker. Advanced EMI Suppresion Technology enables the use of inexpensive ferrite bead filters at the outputs while meeting EMC requirements. SpeakerGuard™ speaker protection system includes an adjustable power limiter and a DC detection circuit. The adjustable power limiter allows the user to set a "virtual" voltage rail lower than the chip supply to limit the amount of current through the speaker. The DC detect circuit measures the frequency and amplitude of the PWM signal and shuts off the output stage if the input capacitors are damaged or shorts exist on the inputs. The TPA3111D1 can drive a mono speaker as low as 4Ω. The high efficiency of the TPA3111D1, > 90%, eliminates the need for an external heat sink when playing music. The outputs are fully protected against shorts to GND, VCC, and output-to-output. The short-circuit protection and thermal protection includes an auto-recovery feature. 1uF Audio Source OUT+ INP OUT - INN TPA3111D1 OUTP FERRITE BEAD FILTER OUTN 10W 8Ω GAIN0 GAIN1 PLIMIT Fault SD PVCC 8 to 26V Figure 1. Simplified Application Diagram 1 2 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. SpeakerGuard is a trademark 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. Copyright © 2009, Texas Instruments Incorporated TPA3111D1 SLOS618 – AUGUST 2009 ................................................................................................................................................................................................ 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 VI Interface pin voltage –0.3 V to 30 V SD, FAULT,GAIN0, GAIN1 –0.3 V to VCC + 0.3 V PLIMIT –0.3 V toGVDD + 0.3 V INN, INP –0.3 V to 6.3 V Continuous total power dissipation See Dissipation Rating Table TA Operating free-air temperature range –40°C to 85°C TJ Operating junction temperature range (2) –40°C to 150°C Tstg Storage temperature range –65°C to 150°C RL Minimum Load Resistance Electrostatic discharge (1) BTL 3.2 Human body model (3) Charged-device model (all pins) (4) ±2 kV (all pins) ±500 V Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and functional operations of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. The TPA3111D1 incorporates an exposed thermal pad on the underside of the chip. This acts as a heatsink, and it must be connected to a thermally dissipating plane for proper power dissipation. Failure to do so may result in the device going into thermal protection shutdown. See TI Technical Briefs SCBA017D and SLUA271 for more information about using the QFN thermal pad. See TI Technical Briefs SLMA002 for more information about using the HTQFP thermal pad. In accordance with JEDEC Standard 22, Test Method A114-B. In accordance with JEDEC Standard 22, Test Method C101-A (2) (3) (4) TYPICAL DISSIPATION RATINGS PACKAGE (1) 28 pin TSSOP (PWP) (1) TA ≤ 25°C DERATING FACTOR TA = 85°C θJP ψJT 4.98 W 25.1 °C/W 2.59 W 0.72 °C/W 0.45 °C/W For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI website at www.ti.com. 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 VOL Low-level output voltage FAULT, RPULLUP=100kΩ, VCC=26V 0.8 V IIH High-level input current SD, GAIN0, GAIN1, VI = 2, VCC = 18 V 50 µA IIL Low-level input current SD, GAIN0, GAIN1, VI = 0.8V, VCC = 18 V 5 µA TA Operating free-air temperature 85 °C V –40 V DC CHARACTERISTICS TA = 25°C, VCC = 24 V, RL = 8 Ω (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT | VOS | Class-D output offset voltage (measured differentially) VI = 0 V, Gain = 36 dB 1.5 ICC Quiescent supply current SD = 2 V, no load, PVcc=21V 40 mA ICC(SD) Quiescent supply current in shutdown mode SD = 0.8 V, no load, PVcc=21V 400 µA 2 Submit Documentation Feedback 15 mV Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 TPA3111D1 www.ti.com ................................................................................................................................................................................................ SLOS618 – AUGUST 2009 DC CHARACTERISTICS (continued) TA = 25°C, VCC = 24 V, RL = 8 Ω (unless otherwise noted) PARAMETER rDS(on) TEST CONDITIONS IO = 500 mA, TJ = 25°C Drain-source on-state resistance GAIN1 = 0.8 V G Gain GAIN1 = 2 V tON Turn-on time SD = 2 V tOFF Turn-off time SD = 0.8 V GVDD Gate Drive Supply IGVDD = 2mA MIN TYP MAX High Side 240 Low side 240 mΩ GAIN0 = 0.8 V 19 20 21 GAIN0 = 2 V 25 26 27 GAIN0 = 0.8 V 31 32 33 GAIN0 = 2 V 35 36 37 6.5 UNIT dB dB 10 ms 2 μs 6.9 7.3 V DC CHARACTERISTICS TA = 25°C, VCC = 12 V, RL = 8 Ω (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT | VOS | Class-D output offset voltage (measured differentially) VI = 0 V, Gain = 36 dB 1.5 ICC Quiescent supply current SD = 2 V, no load, PVcc=12V 20 mA ICC(SD) Quiescent supply current in shutdown mode SD = 0.8 V, no load, PVcc=12V 200 µA Drain-source on-state resistance IO = 500 mA, TJ = 25°C rDS(on) GAIN1 = 0.8 V G Gain GAIN1 = 2 V High Side 240 Low side 240 15 mΩ GAIN0 = 0.8 V 19 20 21 GAIN0 = 2 V 25 26 27 GAIN0 = 0.8 V 31 32 33 GAIN0 = 2 V 35 36 37 tON Turn-on time SD = 2 V tOFF Turn-off time SD = 0.8 V GVDD Gate Drive Supply IGVDD = 2mA PLIMIT Output Voltage maximum under PLIMIT control VPLIMIT=2.0 V; VI=6.0V differential mV 10 dB dB ms μs 2 6.5 6.9 7.3 V 6.75 7.90 8.75 V MAX UNIT AC CHARACTERISTICS TA = 25°C, VCC = 24 V, RL = 8 Ω (unless otherwise noted) PARAMETER TEST CONDITIONS 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 ≤ 0.1%, f = 1 kHz, VCC = 24 V THD+N Total harmonic distortion + noise VCC = 24 V, f = 1 kHz, PO = 5 W (half-power) Vn MIN TYP –70 dB 10 W <0.05 % 65 µV Output integrated noise 20 Hz to 22 kHz, A-weighted filter, Gain = 20 dB –80 dBV Crosstalk VO = 1 Vrms, Gain = 20 dB, f = 1 kHz –70 dB SNR Signal-to-noise ratio Maximum output at THD+N < 1%, f = 1 kHz, Gain = 20 dB, A-weighted 102 dB fOSC Oscillator frequency 250 Thermal trip point Thermal hysteresis 310 350 °C 15 °C Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 kHz 150 3 TPA3111D1 SLOS618 – AUGUST 2009 ................................................................................................................................................................................................ www.ti.com AC CHARACTERISTICS TA = 25°C, VCC = 12 V, RL = 8 Ω (unless otherwise noted) PARAMETER TEST CONDITIONS MIN KSVR Supply ripple rejection 200 mVPP ripple from 20 Hz–1 kHz, Gain = 20 dB, Inputs ac-coupled to AGND PO Continuous output power PO Continuous output power THD+N Total harmonic distortion + noise RL = 8 Ω, f = 1 kHz, PO = 5 W (half-power) Vn Output integrated noise 20 Hz to 22 kHz, A-weighted filter, Gain = 20 dB Crosstalk SNR Signal-to-noise ratio fOSC Oscillator frequency TYP MAX UNIT –70 dB THD+N ≤ 10%, f = 1 kHz , RL = 8Ω 10 W THD+N ≤ 0.1%, f = 1 kHz , RL = 4Ω 10 W <0.06 % 65 µV –80 dBV Po = 1 W, Gain = 20 dB, f = 1 kHz –70 dB Maximum output at THD+N < 1%, f = 1 kHz, Gain = 20 dB, A-weighted 102 dB 250 Thermal trip point Thermal hysteresis 310 350 kHz 150 °C 15 °C PWP (TSSOP) Package (Top View) SD FAULT 1 28 2 27 GND GND GAIN0 GAIN1 3 26 4 25 5 24 6 23 AVCC AGND GVDD PLIMIT 7 22 8 21 INN INP NC AVCC 9 20 10 19 11 18 12 17 13 16 14 15 PVCC PVCC BSN OUTN PGND OUTN BSN BSP OUTP PGND OUTP BSP PVCC PVCC 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. Otherwise bothe short circuit faults and dc detect faults must be reset by cycling PVCC. FAULT 2 GND 3 GND 4 GAIN0 5 I Gain select least significant bit. TTL logic levels with compliance to AVCC. GAIN1 6 I Gain select most significant bit. TTL logic levels with compliance to AVCC. AVCC 7 P Analog supply. AGND 8 GVDD 9 O High-side FET gate drive supply. Nominal voltage is 7V. May also be used as supply for PLILMIT divider. Add a 1μF cap to ground at this pin. PLIMIT 10 I Power limit level adjust. Connect directly to GVDD pin for no power limiting. Add a 1μF cap to ground at this pin. 4 Connect to local ground Connect to local ground Analog supply ground. Connect to the thermal pad. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 TPA3111D1 www.ti.com ................................................................................................................................................................................................ SLOS618 – AUGUST 2009 PIN FUNCTIONS (continued) PIN NAME Pin # I/O DESCRIPTION INN 11 I Negative audio input. Biased at 3V. INP 12 I Positive audio input. Biased at 3V. NC 13 AVCC 14 P Connect AVCC supply to this pin PVCC 15 P Power supply for H-bridge. PVCC pins are also connected internally. PVCC 16 P Power supply for H-bridge. PVCC pins are also connected internally. BSP 17 I Bootstrap I/O for positive high-side FET. OUTP 18 O Class-D H-bridge positive output. PGND 19 OUTP 20 O Class-D H-bridge positive output. BSP 21 I Bootstrap I/O for positive high-side FET. BSN 22 I Bootstrap I/O for negative high-side FET. OUTN 23 O Class-D H-bridge negative output. PGND 24 OUTN 25 BSN PVCC PVCC Not connected Power ground for the H-bridges. Power ground for the H-bridges. O Class-D H-bridge negative output. 26 I Bootstrap I/O for negative high-side FET. 27 P Power supply for H-bridge. PVCC pins are also connected internally. 28 P Power supply for H-bridge. PVCC pins are also connected internally. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 5 TPA3111D1 SLOS618 – AUGUST 2009 ................................................................................................................................................................................................ www.ti.com FUNCTIONAL BLOCK DIAGRAM GVDD PVCC BSP PVCC OUTP FB OUTP FB INP Gain Control PWM Logic PLIMIT Gate Drive OUTP INN OUTN FB PGND FAULT SD GAIN0 TTL Buffer Gain Control GAIN1 PLIMIT Reference PLIMIT GVDD AVDD AVCC PVCC BSN PVCC LDO Regulator SC Detect GVDD DC Detect GVDD Ramp Generator Biases and References Startup Protection Logic Thermal Detect Gate Drive OUTN OUTN FB UVLO/OVLO PGND AGND 6 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 TPA3111D1 www.ti.com ................................................................................................................................................................................................ SLOS618 – AUGUST 2009 TYPICAL CHARACTERISTICS (All Measurements taken at 1 kHz, unless otherwise noted. Measurements were made using the TPA3110D2 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 0.01 PO = 5 W Gain = 20 dB VCC = 24 V ZL = 8 Ω + 66 µH 1 PO = 1 W 0.1 0.01 PO = 10 W PO = 5 W PO = 2.5 W 0.001 20 100 1k 10k 0.001 20 20k 100 1k f − Frequency − Hz 10k G001 G002 Figure 2. Figure 3. TOTAL HARMONIC DISTORTION vs FREQUENCY TOTAL HARMONIC DISTORTION + NOISE vs OUTPUT POWER 10 Gain = 20 dB VCC = 12 V ZL = 4 Ω + 33 µH THD+N − Total Harmonic Distortion + Noise − % THD − Total Harmonic Distortion − % 10 1 PO = 5 W PO = 10 W 0.1 0.01 0.001 20 20k f − Frequency − Hz PO = 1 W 100 1k 10k 20k Gain = 20 dB VCC = 12 V ZL = 8 Ω + 66 µH 1 f = 1 kHz f = 20 Hz 0.1 0.01 f = 10 kHz 0.001 0.01 f − Frequency − Hz G003 Figure 4. 0.1 1 10 PO − Output Power − W 20 G004 Figure 5. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 7 TPA3111D1 SLOS618 – AUGUST 2009 ................................................................................................................................................................................................ www.ti.com TYPICAL CHARACTERISTICS (continued) (All Measurements taken at 1 kHz, unless otherwise noted. Measurements were made using the TPA3110D2 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 0.1 0.01 f = 10 kHz 0.001 0.01 0.1 1 10 PO − Output Power − W 20 0.01 f = 10 kHz 0.1 1 10 G005 Figure 6. Figure 7. MAXIMUM OUTPUT POWER vs PLIMIT VOLTAGE OUTPUT POWER vs PLIMIT VOLTAGE 20 G006 20 Gain = 20 dB VCC = 12 V ZL = 4 Ω + 33 µH Gain = 20 dB VCC = 24 V ZL = 8 Ω + 66 µH 15 15 10 10 5 5 0 0.0 0.5 1.0 1.5 2.0 2.5 VPLIMIT − PLIMIT Voltage − V 3.0 0 0.0 0.5 1.0 1.5 VPLIMIT − PLIMIT Voltage − V G007 Note: Dashed line represents thermally limited region. 2.0 G008 Note: Dashed line represents thermally limited region. Figure 8. 8 f = 20 Hz f = 1 kHz 0.1 PO − Output Power − W PO − Output Power − W PO(Max) − Maximum Output Power − W 1 0.001 0.01 25 20 Gain = 20 dB VCC = 12 V ZL = 4 Ω + 33 µH Figure 9. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 TPA3111D1 www.ti.com ................................................................................................................................................................................................ SLOS618 – AUGUST 2009 TYPICAL CHARACTERISTICS (continued) (All Measurements taken at 1 kHz, unless otherwise noted. Measurements were made using the TPA3110D2 EVM which is available at ti.com.) GAIN/PHASE vs FREQUENCY EFFICIENCY vs OUTPUT POWER 40 100 35 50 100 Phase 30 VCC = 12 V 90 80 0 VCC = 24 V −50 Phase − ° Gain − dB 25 Gain 20 −100 15 −150 CI = 1 µF Gain = 20 dB Filter = Audio Precision AUX-0025 VCC = 12 V VI = 0.1 Vrms ZL = 8 Ω + 66 µH 10 5 0 10 100 1k η − Efficiency − % 70 50 40 −200 30 −250 20 Gain = 20 dB ZL = 8 Ω + 66 µH 10 −300 100k 10k 60 0 f − Frequency − Hz 0 G009 1 2 3 4 5 6 7 8 9 PO − Output Power − W Figure 10. Figure 11. EFFICIENCY vs OUTPUT POWER SUPPLY CURRENT vs TOTAL OUTPUT POWER G012 1.2 100 Gain = 20 dB ZL = 8 Ω + 66 µH 90 1.0 ICC − Supply Current − A 80 70 η − Efficiency − % 10 60 50 40 30 0.8 VCC = 12 V 0.6 0.4 VCC = 24 V 20 0.2 Gain = 20 dB VCC = 12 V ZL = 4 Ω + 33 µH 10 0 0.0 0 1 2 3 4 5 6 7 PO − Output Power − W 8 9 10 0 1 G013 Figure 12. 2 3 4 5 6 7 8 9 PO(Tot) − Total Output Power − W 10 G014 Figure 13. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 9 TPA3111D1 SLOS618 – AUGUST 2009 ................................................................................................................................................................................................ www.ti.com TYPICAL CHARACTERISTICS (continued) (All Measurements taken at 1 kHz, unless otherwise noted. Measurements were made using the TPA3110D2 EVM which is available at ti.com.) SUPPLY CURRENT vs TOTAL OUTPUT POWER SUPPLY RIPPLE REJECTION RATIO vs FREQUENCY 0 1.2 ICC − Supply Current − A 1.0 KSVR − Supply Ripple Rejection Ratio − dB Gain = 20 dB VCC = 12 V ZL = 4 Ω + 33 µH 0.8 0.6 0.4 0.2 0.0 0 1 2 3 4 5 6 7 8 9 10 Gain = 20 dB ZL = 8 Ω + 66 µH −20 −40 −60 VCC = 12 V −80 −100 −120 20 100 1k 10k 20k f − Frequency − Hz PO(Tot) − Total Output Power − W G016 G015 Figure 14. Figure 15. DEVICE INFORMATION Gain setting via GAIN0 and GAIN1 inputs The gain of the TPA3111D1 is set by two input terminals, GAIN0 and GAIN1. The gains listed in Table 1 are realized by changing the taps on the input resistors inside the amplifier. This causes the input impedance (ZI) to be dependent on the gain setting. The actual gain settings are controlled by ratios of resistors, so the gain variation from part-to-part is small. However, the input impedance from part-to-part at the same gain may shift by ±20% due to shifts in the actual resistance of the input resistors. For design purposes, the input network (discussed in the next section) should be designed assuming an input impedance of 7.2 kΩ, which is the absolute minimum input impedance of the TPA3111D1. At the lower gain settings, the input impedance could increase as high as 72 kΩ Table 1. Gain Setting 10 AMPLIFIER GAIN (dB) INPUT IMPEDANCE (kΩ) TYP TYP 20 60 1 26 30 0 32 15 1 36 9 GAIN1 GAIN0 0 0 0 1 1 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 TPA3111D1 www.ti.com ................................................................................................................................................................................................ SLOS618 – AUGUST 2009 SD OPERATION The TPA3111D1 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. Never leave SD unconnected, because amplifier operation would be unpredictable. For the best power-off pop performance, place the amplifier in the shutdown mode prior to removing the power supply voltage. PLIMIT The voltage at pin 10 can used to limit the power to levels below that which is possible based on the supply rail. Add a resistor divider from GVDD to ground to set the voltage at the PLIMIT pin. An external reference may also be used if tighter tolerance is required. Also add a 1μF capacitor from pin 10 to ground. The PLIMIT circuit sets a limit on the output peak-to-peak voltage. This limit can be thought of as a "virtual" voltage rail which is lower than the supply connected to PVCC. This "virtual" rail is 4 times the voltage at the PLIMIT pin. This output voltage can be used to calculate the maximum output power for a given maximum input voltage and speaker impedance. Figure 16. PLIMIT Circuit Operation The PLIMIT circuits sets a limit on the output peak-to-peak voltage. The limiting is done by limiting the duty cycle to fixed maximum value. This limit can be thought of as a “virtual” voltage rail which is lower than the supply connected to PVCC. This “virtual” rail is 4 times the voltage at the PLIMIT pin. This output voltage can be used to calculate the maximum output power for a given maximum input voltage and speaker impedance. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 11 TPA3111D1 SLOS618 – AUGUST 2009 ................................................................................................................................................................................................ www.ti.com POUT ææ ö ö RL çç ç ÷ ´ VP ÷÷ 2 R R + ´ S ø è L ø =è 2 ´ RL 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. PLIMIT Typical Operation Test Conditions () PLIMIT Voltage Output Power (W) Output Voltage Amplitude (VP-P) PVCC=24V, Vin=1Vrms, RL=4Ω, Gain=20dB 1.92 10 15.0 PVCC=24V, Vin=1Vrms, RL=4Ω, Gain=20dB 1.24 5 10.0 PVCC=12V, Vin=1Vrms, RL=4Ω, Gain=20dB 1.75 10 15.3 PVCC=12V, Vin=1Vrms, RL=4Ω, Gain=20dB 1.20 5 10.3 GVDD Supply The GVDD Supply is used to power the gates of the output full bridge transistors. It can also used to supply the PLIMIT voltage divider circuit. Add a 1μF capacitor to ground at this pin. DC Detect TPA3111D1 has circuitry which will protect the speakers from DC current which might occur due to defective capacitors on the input or shorts on the printed circuit board at the inputs. A DC detect fault will be reported on the FAULT pin as a low state. The DC Detect fault will also cause the amplifier to shutdown by changing the state of the outputs to Hi-Z. To clear the DC Detect it is necessary to cycle the PVCC supply. Cycling SD will NOT clear a DC detect fault. A DC Detect Fault is issued when the output differential duty-cycle exceeds 14% (eg. +57%, -43%) for more than 420 ms at the same polarity. This feature protects the speaker from large DC currents or AC currents less than 2 Hz. To avoid nuisance faults due to the DC detect circuit, hold the SD pin low at power-up until the signals at the inputs are stable. Also, take care to match the impedance seen at the positive and negative input to avoid nuisance DC detect faults. The minimum differential input voltages required to trigger the DC detect are shown in Table Table 3. The inputs must remain at or above the voltage listed in the table for more than 420 ms to trigger the DC detect. Table 3. DC Detect Threshold 12 AV(dB) Vin (mV, differential) 20 112 26 56 32 28 36 17 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 TPA3111D1 www.ti.com ................................................................................................................................................................................................ SLOS618 – AUGUST 2009 SHORT-CIRCUIT PROTECTION AND AUTOMATIC RECOVERY FEATURE TPA3110D2 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. If automatic recovery from the short circuit protection latch is desired, connect the FAULT pin directly to the SD pin. This will allow the FAULT pin function to automatically drive the SD pin low which will clear the short circuit protection latch. THERMAL PROTECTION Thermal protection on the TPA3111D1 prevents damage to the device when the internal die temperature exceeds 150°C. There is a ±15°C tolerance on this trip point from device to device. Once the die temperature exceeds the thermal set point, the device enters into the shutdown state and the outputs are disabled. This is not a latched fault. The thermal fault is cleared once the temperature of the die is reduced by 15°C. The device begins normal operation at this point with no external system interaction. Thermal protection faults are NOT reported on the FAULT terminal. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 13 TPA3111D1 SLOS618 – AUGUST 2009 ................................................................................................................................................................................................ 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 GND BSN GND OUTN GAIN0 PGND GAIN1 OUTN AVCC BSN 10 Ω 8 TPA3111D1 AGND BSP GVDD OUTP PLIMIT PGND INN OUTP INP BSP NC PVCC 27 26 0.47 μF 25 24 FB 23 1000 pF 22 21 1000 pF 9 1 uF 10 1 uF Audio Source 11 12 1 uF 13 20 FB 19 0.47 μF 18 17 16 100 μF AVCC 14 AVCC PVCC GND 29 PowerPAD 15 0.1 μF 1000pF PVCC Figure 17. Mono Class-D Amplifier with BTL Output 14 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 TPA3111D1 www.ti.com ................................................................................................................................................................................................ SLOS618 – AUGUST 2009 CLASS-D OPERATION This section focuses on the class-D operation of the TPA3111D1. TPA3111D1 Modulation Scheme The TPA3111D1 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. The duty cycle of OUTP is greater than 50% and OUTN is less than 50% for positive output voltages. The duty cycle of OUTP is less than 50% and OUTN is greater than 50% for negative output voltages. The voltage across the load sits at 0 V throughout most of the switching period, greatly reducing the switching current, which reduces any I2R losses in the load. OUTP OUTN Differential Voltage Across Load Output = 0 V +12 V 0V -12 V Current OUTP OUTN Differential Voltage Across Load Output > 0 V +12 V 0V -12 V Current Figure 18. The TPA3111D1 Output Voltage and Current Waveforms Into an Inductive Load Ferrite Bead Filter Considerations Using the Advanced Emissions Suppression Technology in the TPA3111D1 amplifier it is possible to design a high efficiency Class-D audio amplifier while minimizing interference to surrounding circuits. it is also possible to accomplishthis with only a low-cost ferrite bead filter. In this case it is necessary to carefully select the ferrite bead used in the filter. 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 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 15 TPA3111D1 SLOS618 – AUGUST 2009 ................................................................................................................................................................................................ www.ti.com emissions limits as low as 30 MHz. It is important to use the ferrite bead filter to block radiation in the 30 MHz and above range from appearing on the speaker wires and the power supply lines which are good antennas for these signals. The impedance of the ferrite bead can be used along with a small capacitor with a value in the range of 1000 pF to reduce the frequency spectrum of the signal to an acceptable level. For best performance, the resonant frequency of the ferrite bead/ capacitor filter should be less than 10 MHz. Also, it is important that the ferrite bead is large enough to maintain its impedance at the peak currents expected for the amplifier. Some ferrite bead manufacturers specify the bead impedance at a variety of current levels. In this case it is possible to make sure the ferrite bead maintains an adequate amount of impedance at the peak current the amplifier will see. If these specifications are not available, it is also possible to estimate the bead current handling capability by measuring the resonant frequency of the filter output at very low power and at maximum power. A change of resonant frequency of less than fifty percent under this condition is desirable. Examples of ferrite beads which have been tested and work well with the TPA3110D2 include 28L0138-80R-10 and HI1812V101R-10 from Steward and the 742792510 from Wurth Electronics. A high quality ceramic capacitor is also needed for the ferrite bead filter. A low ESR capacitor with good temperature and voltage characteristics will work best. Additional EMC improvements may be obtained by adding snubber networks from each of the class D outputs to ground. Suggested values for a simple RC series snubber network would be 10 ohms in series with a 330 pF capacitor although design of the snubber network is specific to every application and must be designed taking into account the parasitic reactance of the printed circuit board as well as the audio amp. Take care to evaluate the stress on the component in the snubber network especially if the amp is running at high PVCC. Also, make sure the layout of the snubber network is tight and returns directly to the PGND or the PowerPad beneath the chip. Efficiency: LC Filter Required With the Traditional Class-D Modulation Scheme The main reason that the traditional class-D amplifier needs an output filter is that the switching waveform results in maximum current flow. This causes more loss in the load, which causes lower efficiency. The ripple current is large for the traditional modulation scheme, because the ripple current is proportional to voltage multiplied by the time at that voltage. The differential voltage swing is 2 x VCC, and the time at each voltage is half the period for the traditional modulation scheme. An ideal LC filter is needed to store the ripple current from each half cycle for the next half cycle, while any resistance causes power dissipation. The speaker is both resistive and reactive, whereas an LC filter is almost purely reactive. The TPA3111D1 modulation scheme has little loss in the load without a filter because the pulses are short and the change in voltage is VCC instead of 2 x VCC. As the output power increases, the pulses widen, making the ripple current larger. Ripple current could be filtered with an LC filter for increased efficiency, but for most applications the filter is not needed. An LC filter with a cutoff frequency less than the class-D switching frequency allows the switching current to flow through the filter instead of the load. The filter has less resistance but higher impedance at the switching frequency than the speaker, which results in less power dissipation, therefore increasing efficiency. When to Use an Output Filter for EMI Suppression The TPA3111D1 has been tested with a simple ferrite bead filter for a variety of applications including long speaker wires up to 125 cm and high power. The TPA3111D1 EVM passes FCC Class B specifications under these conditions using twisted speaker wires. The size and type of ferrite bead can be selected to meet applicaton requirements. Also, the filter capacitor can be increased if necessary with some impact on efficiency. There may be a few circuit instances where it is necessary to add a complete LC reconstruction filter. These circumstances might occur if there are nearby circuits which are very sensitive to noise. In these cases a classic second order Butterworth filter similar to those shown in the figures below can be used. 16 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 TPA3111D1 www.ti.com ................................................................................................................................................................................................ SLOS618 – AUGUST 2009 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. Typical Ferrite Chip Bead Filter (Chip Bead Example: Steward HI0805R800R-10) Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 17 TPA3111D1 SLOS618 – AUGUST 2009 ................................................................................................................................................................................................ 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. f = 1 2p Zi Ci (2) 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 the input impedance of the amplifier (ZI) form a high-pass filter with the corner frequency determined in Equation 3. -3 dB fc = 1 2p Zi Ci fc (3) The value of CI is important, as it directly affects the bass (low-frequency) performance of the circuit. Consider the example where ZI is 60 kΩ and the specification calls for a flat bass response down to 20 Hz. Equation 3 is reconfigured as Equation 4. Ci = 1 2p Zi fc (4) In this example, CI is 0.13 µF; so, one would likely choose a value of 0.15 μF as this value is commonly used. If the gain is known and is constant, use ZI from Table 1 to calculate CI. A further consideration for this capacitor is the leakage path from the input source through the input network (CI) and the feedback network to the load. This leakage current creates a dc offset voltage at the input to the amplifier that reduces useful headroom, especially in high gain applications. For this reason, a low-leakage tantalum or ceramic capacitor is the best choice. If a ceramic capacitor is used, use a high quality capacitor with good temperature and voltage coefficient. An X7R type works well and if possible use a higher voltage rating than required. This will give a better C vs voltage characteristic. When polarized capacitors are used, the positive side of the capacitor should face the amplifier input in most applications as the dc level there is held at 3 V, which is likely higher than the source dc level. Note that it is important to confirm the capacitor polarity in the application. Additionally, lead-free solder can create dc offset voltages and it is important to ensure that boards are cleaned properly. POWER SUPPLY DECOUPLING, CS The TPA3111D1 is a high-performance CMOS audio amplifier that requires adequate power supply decoupling to ensure that the output total harmonic distortion (THD) is as low as possible. Power supply decoupling also prevents oscillations for long lead lengths between the amplifier and the speaker. Optimum decoupling is achieved by using a network of capacitors of different types that target specific types of 18 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 TPA3111D1 www.ti.com ................................................................................................................................................................................................ SLOS618 – AUGUST 2009 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-series-resistance (ESR) ceramic capacitor of value between 220 pF and 1000 pF works well. This capacitor should be placed as close to the device PVCC pins and system ground (either PGND pins or PowerPad) as possible. For mid-frequency noise due to filter resonances or PWM switching transients as well as digital hash on the line, another good quality capacitor typically 0.1 mF to 1 μF placed as close as possible to the device PVCC leads works best For filtering lower frequency noise signals, a larger aluminum electrolytic capacitor of 220 mF or greater placed near the audio power amplifier is recommended. The 220 mF capacitor also serves as a local storage capacitor for supplying current during large signal transients on the amplifier outputs. The PVCC terminals provide the power to the output transistors, so a 220 μF or larger capacitor should be placed on each PVCC terminal. A 10 μF capacitor on the AVCC terminal is adequate. Also, a small decoupling resistor between AVCC and PVCC can be used to keep high frequency class D noise from entering the linear input amplifiers. BSN and BSP CAPACITORS The full H-bridge output stage uses only NMOS transistors. Therefore, they require bootstrap capacitors for the high side of each output to turn on correctly. A 220-nF ceramic capacitor, rated for at least 25 V, must be connected from each output to its corresponding bootstrap input. Specifically, one 220-nF capacitor must be connected from OUTP to BSP, and one 220-nF capacitor must be connected from OUTN to BSN. (See the application circuit diagram in Figure 1.) The bootstrap capacitors connected between the BSx pins and corresponding output function as a floating power supply for the high-side N-channel power MOSFET gate drive circuitry. During each high-side switching cycle, the bootstrap capacitors hold the gate-to-source voltage high enough to keep the high-side MOSFETs turned on. DIFFERENTIAL INPUTS The differential input stage of the amplifier cancels any noise that appears on both input lines of the channel. To use the TPA3111D1 with a differential source, connect the positive lead of the audio source to the INP input and the negative lead from the audio source to the INN input. To use the TPA3111D1 with a single-ended source, ac ground the INP or INN input through a capacitor equal in value to the input capacitor on INN or INP and apply the audio source to either input. In a single-ended input application, the unused input should be ac grounded at the audio source instead of at the device input for best noise performance. For good transient performance, the impedance seen at each of the two differential inputs should be the same. The impedance seen at the inputs should be limited to an RC time constant of 1 ms or less if possible. This is to allow the input dc blocking capacitors to become completely charged during the 14 msec power-up time. If the input capacitors are not allowed to completely charge, there will be some additional sensitivity to component matching which can result in pop if the input components are not well matched. USING LOW-ESR CAPACITORS Low-ESR capacitors are recommended throughout this application section. A real (as opposed to ideal) capacitor can be modeled simply as a resistor in series with an ideal capacitor. The voltage drop across this resistor minimizes the beneficial effects of the capacitor in the circuit. The lower the equivalent value of this resistance, the more the real capacitor behaves like an ideal capacitor. PRINTED-CIRCUIT BOARD (PCB) LAYOUT The TPA3111D1 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. • Decoupling capacitors—The high-frequency decoupling capacitors should be placed as close to the PVCC and AVCC terminals as possible. Large (220 μF or greater) bulk power supply decoupling capacitors should be placed near the TPA3111D1 on the PVCC supplies. Local, high-frequency bypass capacitors should be placed as close to the PVCC pins as possible. These caps can be connected to the thermal pad directly for an excellent ground connection. Consider adding a small, good quality low ESR ceramic capacitor between 220 pF and 1000 pF and a larger mid-freqency cap of value between 0.1mF and 1mF also of good quality to the PVCC connections at each end of the chip. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 19 TPA3111D1 SLOS618 – AUGUST 2009 ................................................................................................................................................................................................ www.ti.com • • • Keep the current loop from each of the outputs through the ferrite bead and the small filter cap and back to PGND as small and tight as possible. The size of this current loop determines its effectiveness as an antenna. Output filter—The ferrite EMI filter (Figure 32) should be placed as close to the output terminals as possible for the best EMI performance. The LC filter (Figure 30 and Figure 31) should be placed close to the outputs. The capacitors used in both the ferrite and LC filters should be grounded to power ground. Thermal Pad—The thermal pad must be soldered to the PCB for proper thermal performance and optimal reliability. The dimensions of the thermal pad and thermal land should be 6.46 mm by 2.35mm. Seven rows of solid vias (three vias per row, 0.33 mm or 13 mils diameter) should be equally spaced underneath the thermal land. The vias should connect to a solid copper plane, either on an internal layer or on the bottom layer of the PCB. The vias must be solid vias, not thermal relief or webbed vias. . See TI Application Report SLMA002 for more information about using the TSSOP thermal pad. For recommended PCB footprints, see figures at the end of this data sheet. For an example layout, see the TPA3111D1 Evaluation Module (TPA3111D1EVM) User Manual. Both the EVM user manual and the thermal pad application note are available on the TI Web site at http://www.ti.com. 20 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TPA3111D1 PACKAGE MATERIALS INFORMATION www.ti.com 9-Sep-2009 TAPE AND REEL INFORMATION *All dimensions are nominal Device TPA3111D1PWPR 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 16.0 Q1 PACKAGE MATERIALS INFORMATION www.ti.com 9-Sep-2009 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TPA3111D1PWPR HTSSOP PWP 28 2000 346.0 346.0 33.0 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. 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