A2211 AITSEMI | Alldatasheet
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AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 1 - DESCRIPTION FEATURES The A2211 is a mono fully-differential audio power amplifier designed for portable communication device applications. The A2211 operates from 2.2V to 5.5V, is capable of delivering 1.25W of continuous average power to an 8Ω BTL load w ith less than 1% distortion (THD+N) from a 5V supply. A2211 features like -86dB PSRR at 217Hz, improved RF-rectification immunity, small PCB area, a fast startup with minimal pop & click circuitry makes the A2211 idea for PDA, smartphone applications; and low power shutdown mode suitable for wireless handsets. The A2211 is unity -gain stable, and the gain can be configured by external input resistors and internal feedback resistors. The A2211 is available in MSOP8 package 1.25W into 8Ω from a 5V Supply at THD=1% (Typ) Wide Supply Voltage: 2.2V to 5.5V Ultra low shutdown current: 0.01uA (Typ) Fast Startup With Minimal POP Fully differential design reduce RF rectification Improved PSRR -86dB at 217Hz (VDD>3.0V) Improved pop & click circuitry eliminates Noise During Turn-on and Turn-off Transitions Thermal overload protection circuitry No output coupling capacitors, bootstrap capacitors required Unity-gain stable External gain configuration capability Available in MSOP8 package APPLICATION GPS, Wireless Handsets Portable Audio Devices PDA, Handheld Computer RF Audio Application TYPICAL APPLICATION
ORDERING INFORMATION
SPQ: 4,000pcs/Reel MS8 A2211MS8R A2211MS8VR Note V: Halogen free Package R: Tape & Reel AiT provides all RoHS products
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 2 - PIN DESCRIPTION Top View Pin # Symbol Type Functions
1 SHD I Shutdown Pin, Active Low
2 BP I
Common Mode Voltage. Connect a Bypass Capacitor to GND for Common Mode Voltage Filtering. The Bypass Capacitor is Optional.
3 IN+ I Positive Differential Input
4 IN- I Negative Differential Input
5 VOUT1 O Positive Differential Output
6 VDD I Power Supply
7 GND I Ground
8 VOUT2 O Negative Differential Output
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 3 - ABSOLUTE MAXIMUM RATINGS VDD, Supply Voltage -0.3V~+6.0V Input Voltage -0.3V~VDD+0.3V Power DissipationNOTE1 Internally Limited ESD Parameter ESD Protection (HBM, 1.5kΩ and 100pF in Series) 2000V ESD Protection (MM, 200pF, no Resistor) 200V θJA, Thermal Resistance 190°C/W θJC, Thermal Resistance 56°C/W TJ, Junction Temperature -40°C ~+150°C TA, Environment Temperature 140°C Ts, Storage Temperature Range -65°C ~150°C Lead Temperature (soldiering, 10 seconds) 300°C Stresses above may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the Electrical Characteristics is not implied. Exposure to absolute m aximum rating conditions for extended periods may affect device reliability. NOTE1: The Maximum Power Dissipation must be de -rated at elevated temperatures and is dictated by TJMAX, θJA, and the ambient temperature TA. The maximum allowable power dissipation is: PDMAX = (TJMAX - TA) / θJA or the number given in Absolute Maximum Ratings, whatever is lower. OPERATING CONDITIONS Parameter Symbol Min Typ Max Unit Power Supply Voltage VDD 2.2 - 5.5 V Operating Temperature Range TA -40 - 85 °C
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 4 -
ELECTRICAL CHARACTERISTICS
Test Condition: 1. VDD=5V, 8Ω load, AV=1V/V, TA=25°C, unless otherwise noted. Symbol Parameter Conditions Min. Typ. Max. Unit IDD Quiescent Power Supply Current VIN=0V, no Load - 2.5 5 mA VIN=0V, RL=8Ω - 4 8 ISD Shutdown Current VSHUTDOWN=GND - 0.01 1 µA Po Output Power THD+N=1%, f=1kHz - 1.25 - W THD+N Total Harmonic Distortion +Noise Po=0.6Wrms, f=1kHz - 0.02 - % PSRR Power Supply Rejection Ratio VRIPPLE=200mV sine p-p dB f=217HzNOTE1 - -88 - f=1kHzNOTE1 - -83 - f=217HzNOTE2 - -83 - f=1kHzNOTE2 - -83 - CMRR Common Mode Rejection Ratio f=217Hz VCM=200mVpp - -78 - dB VOS Output Offset VIN=0V - 2 8 mV VSDIH Shutdown Voltage Input High 1.5 - - V VSDIL Shutdown Voltage Input Low - - 0.5 V AV Closed Loop Gain 36kΩ RI 40kΩ RI 44kΩ RI V / V Test Condition: 2. VDD=3.6V, 8Ω load, AV=1V/V, TA=25oC, unless otherwise noted. Symbol Parameter Conditions Min. Typ. Max. Unit IDD Quiescent Power Supply Current VIN=0V, no Load - 2 4.5 mA VIN=0V, RL=8Ω - 3.5 7.5 ISD Shutdown Current VSHUTDOWN=GND - 0.01 1 µA Po Output Power THD+N=1%, f=1kHz - 0.6 - W THD+N Total Harmonic Distortion +Noise Po=0.4Wrms, f=1kHz - 0.02 - % PSRR Power Supply Rejection Ratio VRIPPLE=200mV sine p-p dB f=217HzNOTE1 - -86 - f=1kHzNOTE1 - -83 - f=217HzNOTE2 - -83 - f=1kHzNOTE2 - -83 - CMRR Common Mode Rejection Ratio f=217Hz, VCM=200mVpp - -76 - dB VOS Output Offset VIN=0V - 2 8 mV VSDIH Shutdown Voltage Input High 1.5 - - V VSDIL Shutdown Voltage Input Low - - 0.5 V Gain Closed Loop Gain 36kΩ RI 40kΩ RI 44kΩ RI V / V NOTE 1: Unterminated Input NOTE 2: 10Ω Terminated Input
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 5 - 1. Output Power vs. Supply Voltage, RL=8Ω 2. Power Dissipation vs. Output Power 3. Power Dissipation vs. Output Power 4. Power Derating Curve 5. THD+N vs. Frequency VDD=5V, RL=8Ω, Po=600mW 6. THD+N vs. Frequency VDD=3.6V, RL=8Ω, Po=400mW TYPICAL PERFORMANCE CHARACTERISTICS
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 6 - 7. THD+N vs. Frequency VDD=2.5V, RL=8Ω, Po=150mW 8. THD+N vs. Output Power VDD=5V, RL=8Ω 9. THD+N vs. Output Power VDD=3.6V, RL=8Ω 10. THD+N vs. Output Power VDD=2.5V, RL=8Ω 11. PSRR vs. Frequency VDD=5.0V, RL=8Ω, Input 10Ω Terminated 12. PSRR vs. Frequency VDD=3.6V, RL=8Ω, Input 10Ω Terminated
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 7 - 13. PSRR vs. Common Mode Voltage VDD=5.0V, RL=8Ω, 217Hz, 200mVPP 14. PSRR vs. Common Mode Voltage VDD=3.6V, RL=8Ω, 217Hz, 200mVPP 15. Open Loop Frequency Response 16. Closed Loop Frequency Response
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 8 - BLOCK DIAGRAM
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 9 - DETAILED INFORMATION Fully Differential Amplifier . The A2211 is a fully differential amplifier with differential inputs and outputs. The fully differential amplifier consists of a differential amplifier and a common mode amplifier. The differential amplifier ensures that the amplifier outputs a differential voltage that is equal to the differential input times the gain. The common mode feedback ensures that the common-mode voltage at the output is biased around VDD/2 regardless of the common-mode voltage at the input. Bridge – Tied - Load, BTL. The A2211 provides a “bridged mode” output configuration (bridge-tied-load, BTL). This means the output signals at VOUT1 and V OUT2 that at 180 oC out of phase with respect to each other. Bridged mode operation is different from the single-ended output configuration that connects the load between the amplifier output and ground. A bridged amplifier design has distinct ad vantages over the single-ended output configuration: A2211 provides differential drive to the load, thus doubling maximum possible output swing for a specific supply voltage. Four times the output power is possible compared with a single-ended output confi guration under the same conditions. T his increase in attainable output power assumes that the amplifier is not current limited or clipped. CMRR. Input and output coupling capacitor not required: A fully differential amplifier with good CMRR, the A2211 allows the input signal to be biased at voltage other than mid -supply of the A2211, the common-mode feedback circuit adjust for it, and the outputs are still biased at mid-supply of the A2211. Bypass Capacitor. Mid-supply bypass capacitor, CBYPASS not required: The fully differential amplifier does not require a bypass capacitor. It is because any shift in t he mid -supply affects both positive and negative channels equally and cancels the differential output. However, removing the bypass capacitor slightly worsens power supply rejection ration, but a slightly decrease of PSRR may be acceptable when an additional component can be eliminated. Better RF-Immunity. GSM handsets save power by turning on and shutting off the RF transmitter at a rate of 217Hz. The transmitted signal is picked-up on input and output traces. The fully differential amplifier reduces the RF rectification much better than the typical audio amplifier. See Fig 1, Fig 2 and Fig 3 show application schematics for differential and single-ended inputs.
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 10 - Fig. 1 Typical Differential Input Application Fig. 2 Differential Input Application with Input Capacitors
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 11 - Fig. 3 Single-Ended Input Application Input Resistor (RI) The input (R I) and internal feedback resistor s, R F=40kΩ, set the gain of the a mplifier according to the following (E1): Gain = 40kΩ / RI In order to optimize the THD+N and SNR performance, the A2211 should be used in low closed -loop gain configuration. R I should be in range f rom 1kΩ to 100 kΩ. Resistor matching is very important for fully differential amplifiers. The balance of the output on the common mode voltage depends on matched ratios of the resistors. CMRR, PSRR, and the second harmonic distortion is increased if resistor is not matched. Therefore, it is recommended to use 1% tolerance resistors or better to keep the performance optimized.
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 12 - Input Capacitor (CI) The input coupling capacitor blocks the input DC voltage. The A2211 does not require input coupling capacitors if using a differential input source that is bias ed from 0.5V to VDD-0.8V. Use 1% tolerance or better resistors if not using input coupling capacitors. In the single -ended input application an input capacitor, C I, is required to allow the amplifier to bias the input signal to the proper DC level. The CI and RI from a high-pass filter with the corner frequency determined as below (E2): fC = 1 / 2πRICI Special care should be taken to th e value of the value of C I because it directly affects the low frequency performance of the system. For example assuming R I is 20kΩ and the specification calls for a flat response A further consideration for CI is the leakage path from the input source through the input network (R I, CI) and the feedback resistor (R F) to the load. The leakage current creates a DC offset voltage that reduces useful headroom, especially in high gain applications. For this reason, a ceramic capacitor is the best choice. Bypass capacitor (CB) and Start-Up Time Connecting a capacitor to BP pin filters any noise into this pin and increases the PSRR performance. CB also determines the rise time of VOUT1 and VOUT2, the larger the capacitor, the slower the rise time, the A2211 start to work after the CB voltage reaches the mid-supply voltage. This capacitor can also minimize the pop & click noise during turn -on and turn -off transitions, the larger the capacitor, the smaller the pop & click noise, 1uF capacitor is recommended for CB.
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 13 - Decoupling Capacitor (CS) Power supply decoupling is critical for low TH D+N and high PSRR perfor mance. A low equivalent-series-resistance (ESR) ceramic capacitor, typically 0.1uF to 1uF, placed as close as possible to VDD pin make the device works better. For filtering lower frequency noise signals, a 10uF or greater capacitor placed near the audio p ower amplifier also helps, but it is not required in most applications because of the high PSRR of this device. LOW-ESR Capacitors LOW-ESR capacitors are recommended. A real capacitor can be modeled simply as a resistor in s eries 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. Power Dissipation Power dissipation is a major concern when designing a successful amplifier, whether the amplif ier is bridged or single -ended. Below (E3) states, the maximum power dissipation point for a single -ended amplifier operating at a given supply voltage and driving a specified output load. Single-Ended (E3): PDMAX = (VDD)2 / (2π2RL) However, a direct consequence of the increased power delivered to the load by a bridge amplifier is an increase in internal power dissipation versus a single -ended amplifier operating at the same conditions. Bridge-Ended (E4): PDMAX = 4 x (VDD)2 / (2π2RL) Since the A2211 has bridged outputs, the maximum internal power dissipation is 4 times tha t of a single-ended amplifier. Even with this substantial increasing in power dissipation, the A2211 does not require additional heat-sinking under most operating conditions and output loading. From the above (E4), assuming a 5V power supply and an 8Ω load, the maximum power dissipation point is 625mW. The maximum power dissipation point obtained from above (E4) must not be greater than the power dissipation results from the follows (E5): PDMAX = ( TJMAX – TA ) / θJA Depending on the ambient temperature (T A) of the system surroundings, above can be used to find the
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 14 - maximum internal power dissipation supported by the IC p ackaging. If the result of Bridge-Ended (E4) is greater than that of (E5), then either the supply voltage must be decreased, the load impedance increased, the ambient temperature reduced, or the θJA reduced with heat-sinking. In many cases, larger traces near the output, V DD, and GND pins can be used to lower the θJA. The larger areas of copper provide a form of heat-sinking allowing higher power dissipation. Recall that internal power dissipation is a function of output power. If the typical operation is n ot around the maximum power dissipation point, the A2211 can operate at higher ambient temperatures. Shutdown Function The A2211 contains shutdown circuitry that is used to turn off the amplifier ’s bias circuitry, in order to reduce power consumption while not in use. The shutdown pin should be tied to a definite voltage to avoid unwanted state changes. In many applications, a microcontroller or microprocessor output is used to control the shutdown circuitry, which provides a quick, smooth transition to shu tdown. Another solution is to use a single-throw switch in conjunction with a n external pull -down resistor. This scheme guarantees that the shutdown pin will not float, thus preventing unwanted state changes. PCB Layout The residual resistance of the PCB trace between the amplifier output pins and the speaker causes a voltage drop, which results in power dissipated in the PCB trace and not in the speaker as desired. Therefore, to maintain the highest speaker power dissipation and widest output voltage swing, PCB trace that connects the amplifier output pins to the speaker must be as wide as possible. Poor power supply regulation adversel y affects maximum output power. A poorly regulated supply ’s output voltage decreases with increasing load current. Reduced supply voltage causes decrease headroom, output signal clipping, and reduced output power. Even with tightly regulated supplies, power supply trace resistance creates the same effects as poor supply regulation. Therefore, be making the power supply tra ce as wide as possible helps to maintain full output voltage swing. It’s very important to keep the A2211 external components very close to the A2211 to limit noise pickup.
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 15 -
PACKAGE INFORMATION
Dimension in MSOP8 (Unit: mm) Land Pattern Recommendation
AiT Semiconductor Inc. www.ait-ic.com A2211 A UDIO AMPLIFIER CLASS AB 1.25W MONO FULL Y-DIFFERENTIAL A UDIO POWER AMPLIFIER WITH INTERNAL FEEDB ACK RESISTORS REV1.3 - AUG 2006 RELEASED, FEB 2020 UPDATED - - 16 - IMPORTANT NOTICE AiT Semiconductor Inc. (AiT) reserves the right to make changes to any its pr oduct, specifications, to discontinue any integrated circuit product or service w ithout notice, and advises its customers to obt ain the latest version of relevant information to verify, before placing orders, that the information being relied on is current. AiT Semiconductor Inc. 's integrated circuit products are not designed, intended, authorized, or warranted to be suitable for use in life support applications, devices or systems or other critical applications. Use of AiT products in such applications is understood to be fully at the risk of the customer. As used herein may involve potential risks of death, personal injury, o r servere property, or environmental damage. In order to minimize risks associated with the customer's applications, the customer should provide adequate design and operating safeguards. AiT Semiconductor Inc. assumes to no liability to customer produc t design or application support. AiT warrants the performance of its products of the specifications applicable at the time of sale.