Tai-1 Microelectronics www.taimec.com.tw / TMPA2155DS Preliminary www.class-d.com.tw Rev.1.0 June 27, 2006 2.7W/CH STEREO CLASS-D AUDIO POWER AMPLIFIER GENERAL DESCRIPTION FEATURES The TMPA2155DS is a stereo class-D audio power amplifier ♦ 2.5V to 6V Single Supply IC. With BTL(Bridge-Tied-Load) configuration, it delivers up ♦ Up to 2.7W / Ch at 5V, 3 ohms to 2.7W/ch(5.4W in all) into a 3 ohm load or 2.3W/ch(4.6W in all) into a 4 ohm load or 1.5W/ch(3W in all) into an 8 ohm load. ♦ Up to 85% Power Efficiency ♦ Automatic output power control (APC) No external heat-sink is required. ♦ 2.2mA / Ch Quiescent Current at 5V For multiple-input applications, independent gain control and ♦ Less Than 0.2uA / Ch Shutdown Current corner frequency can be implemented by summing the input ♦ Pop-less Power-Up, Shutdown and Recovery sources through resistor ratio and input capacitor values. ♦ Differential 250 KHz PWM Allows Bridge-Tied Load to Automatic voltage gain control makes the best use of battery. Doubles Output Power and Eliminates LC Output Filter ♦ Thermal Shutoff and Automatic Recovery Analog input signal is converted into digital output which drives directly to the speaker. High power efficiency is ♦ Compatible with earphone application ♦ Output Pin Short-Circuit Protection (Short to Other achieved due to digital output at the load. The audio information is embedded in PWM（Pulse Width Modulation）. Outputs, Short to VCC, Short to Ground) ♦ Differential Signal Processing Improves CMRR APPLICATIONS Multimedia application includes Cellular Phones, PDAs, DVD/CD players, TFT LCD TVs/Monitors, 2.1 channel/5.1 channel audio systems, USB audio. It is also ideal for other portable devices like Wireless Radios. Package TSSOP20, QFN24 Available For best performance, please refer to http://www.taimec.com.tw/English/EVM.htm http://www.class-d.com.tw/English/EVM.htm for PCB layout. REFERENCE CIRCUIT（Please refer to TMPA002.APP for application） Copyright©2005, Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com 1 www.taimec.com.tw / TMPA2155DS Preliminary Tai-1 Microelectronics www.class-d.com.tw Rev.1.0 June 27, 2006 （Please email [email protected] for complete datasheet.） Tai-1 Microelectronics reserves 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. Customers are responsible for their products and applications using Tai-1 Microelectronics components. Note that the external components or PCB layout should be designed not to generate abnormal voltages to the chip to prevent from latch up which may cause damage to the device. Typical Application VDD L1 C16 VO1+ C9 1uF(6.3V) 33uH 1uF(6.3V) JP1 J1 C1 1uF(6.3V) PHONEJACKSTEREO C14 470p(6.3V) C15 R9 470p(6.3V) 22k 1 LOUTP GND 20 2 VDD LOUTN 19 VDD 3 NC 18 4 LINP SDNB 17 LIN N AV DD 5 16 6 RINN AGND 15 7 RINP CAP14 VD D NC 8 13 9 VDD ROUTN 12 10ROUTP GND 11 C5 1uF(6.3V)(optional) R5 C6 1uF(6.3V) SDN 100 R10 10K L2 33uH 2155DS(FD) C10 1uF(6.3V) LS2 switch S1 L3 VO2- 33uH C7 1uF(6.3V)(optional) L4 C17 1uF(6.3V) VO1- C8 1uF(6.3V) VO2+ C12 1uF(6.3V) 33uH LS1 C13 470uF(6.3V) R12 0 + J3 VR C2 1uF(6.3V) C3 1uF(6.3V) C4 1uF(6.3V) R3 330 R4 330 R6 22k R7 22k R8 22k C11 1uF(6.3V) ABSOLUTE MAXIMUM RATINGS Over operating free-air temperature range unless otherwise noted(1) Supply voltage, VDD, AVDD In normal mode -0.3V to 6V V In shutdown mode -0.3V to 7V V -0.3V to VDD+0.3V V Input voltage, V I Continuous total power dissipation Operating free-air temperature, TA See package dissipation ratings 。C -20 to 85 Operating junction temperature, TJ -20 to 150 Storage temperature, Tstg -40 to 150 。C 。C (1) Stresses beyond those listed under”absolute maximum ratings” 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 under “recommended operating conditions “is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. Copyright©2005, Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com 2 www.taimec.com.tw / TMPA2155DS Preliminary Tai-1 Microelectronics www.class-d.com.tw Rev.1.0 June 27, 2006 RECOMMENDED OPERATING CONDITONS MIN Supply voltage, VDD, AVDD High-level input voltage, V IH SDNB Low-level input voltage, VIL SDNB Operating free-air temperature, TA NOM MAX UNIT 2.5 6 V 2 VDD V 0 0.8 V -20 85 。C PACKAGE DISSIPATION RATINGS PACKAGE TSSOP20 DERATING TA ≤ 25。C TA = 70。C TA = 85。C FACTOR POWER RATING POWER RATING POWER RATING 8.73 mW/。C 1.09W 698mW 567mW ELECTRICAL CHARACTERISTICS TA=25。C (unless otherwise noted) PARAMETER │VOS│ PSRR Output offset voltage TEST CONDITIONS (measured differentially) Power supply rejection ratio MIN TYP MAX UNIT VI=0V,AV=2, VDD=AVDD=2.5V to 5.5V 25 VDD=AVDD=2.5V to 5.5V -75 -55 dB -55 -50 dB VDD=AVDD=2.5V to 5.5V, mV CMRR Common mode rejection ratio │IIH│ High-level input current │IIL│ Low-level input current IQ Quiescent current / Ch VDD=AVDD=5V, no load IQ (SD) Shutdown current / Ch rDS(on) Static output resistance f(sw) Switching frequency VDD=AVDD=2.5V to 5.5V 230 280 330 *Av BTL Gain VDD=AVDD=2.5V to 5.5V, RL=8Ω 12 16 20 RSDN Resistance from shutdown to GND V(SDNB)=5V 200 kΩ ZI Input impedance RINN,RINP,LINN,LINP 15 kΩ VIC=1Vpp, RL=8Ω VDD=AVDD=5.5V, μA 30 VI=5.8V (SDNB) VDD=AVDD=5.5V, 1 μA 2.2 3 mA V( SDN )=0.8V, VDD=AVDD=2.5V to 5.5V 0.2 0.5 VDD=AVDD=5.5V 790 VI=-0.3V (SDNB) μA mΩ kHz V V *The gain of the amplifier is determined by, for VDD=VDDA =2.5V to 5.5V Gain = 320kohms Ri + 15kohms where Ri is the external serial resistance at the input pin. Copyright©2005, Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com 3 Preliminary Tai-1 Microelectronics www.taimec.com.tw / www.class-d.com.tw TMPA2155DS Rev.1.0 June 27, 2006 OPERATING CHARACTERISTICS TA=25。C, RL=8Ω speaker (unless otherwise noted) PARAMETER TEST CONDITIONS RL=8Ω Output power / Ch PO (Limited by thermal condition) RL=4Ω VDD=AVDD=5V. THD+N=10%,f=1kHz. RL=3Ω THD+N Total harmonic distortion plus noise MIN TYP MAX UNIT 1.5 W 2.3 W 2.7 W VDD=AVDD=5V, PO=0.85W, RL=8Ω, f=1kHz 0.55 VDD=AVDD=5V, PO=1.3W, RL=4Ω, f=1kHz 0.55 VDD=AVDD=5V, PO=1.5W, RL=3Ω, f=1kHz 0.64 % SNR Signal-to-noise ratio VDD=AVDD=5V, PO=1W, RL=8Ω 95 dB Crosstalk Crosstalk between outputs VDD=AVDD=5V, PO=1W RL=8Ω -68 dB TERMINAL FUNCTIONS TERMINAL I/O NAME DESCRIPTION PIN NO AGND 15 - Analog ground AVDD 16 - Analog Power supply CAP 14 I Capacitance for power up delay GND 11,20 - Digital ground LINN 5 I Negative input of left channel LINP 4 I Positive input of left channel LOUTN 19 O Negative output of left channel LOUTP 1 O Positive output of left channel 3,8 - No Connection RINN 6 I Negative input of right channel RINP 7 I Positive input of right channel ROUTN 12 O Negative output of right channel ROUTP 10 O Positive output of right channel SDNB 17 I Shutdown terminal (active low logic) 2,9,13,18 - Digital Power supply NC VDD TYPICAL CHARACTERISTICS Note 1. Input coupling 1µF capacitors are used for all measurements. 2. Differential inputs are applied and BTL outputs are measured. 3. Balanced LC filter is used for THD+N measurement and power efficiency measurement. 4. Characteristic frequency of the LC filter is set 41KHz unless otherwise specified. Copyright©2005, Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com 4 Tai-1 Microelectronics www.taimec.com.tw / Preliminary www.class-d.com.tw TMPA2155DS Rev.1.0 June 27, 2006 APPLICATION INFORMATION Copyright©2005, Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com 5 Tai-1 Microelectronics www.taimec.com.tw / Preliminary www.class-d.com.tw Copyright©2005, Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com TMPA2155DS Rev.1.0 June 27, 2006 6 Tai-1 Microelectronics www.taimec.com.tw l / Preliminary TMPA2155DS www.class-d.com.tw Rev.1.0 June 27, 2006 Input Resistors and Gain The gain of the amplifier is determined by, for VDD=VDDA =2.5V to 5.5V Gain = 320kohms where Ri is the external serial resistance at the input pin. Ri + 15kohms Note：Please refer to document 010 APP for more application examples. Copyright©2005, Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com 7 Tai-1 Microelectronics www.taimec.com.tw / Preliminary www.class-d.com.tw TMPA2155DS Rev.1.0 June 27, 2006 DETAILED DESCRIPTION Efficiency The output transistors of a class D amplifier act as switches. The power loss is mainly due to the turn on resistance of the output transistors when driving current to the load. As the turn on resistance is so small that the power loss is small and the power efficiency is high. With 8 ohm load the power efficiency can be better than 85%. Shutdown The shutdown mode reduces power consumption. A LOW at shutdown pin forces the device in shutdown mode and a HIGH forces the device in normal operating mode. Shutdown mode is useful for power saving when not in use. This function is useful when other devices like earphone amplifier on the same PCB are used but class D amplifier is not necessary. Internal circuit for shutdown is shown below. Pop-less A soft start capacitor can be added to the CAP pin. This capacitor introduces delay for the internal circuit to be stable before driving the load. The pop or click noise when power up/down or switching in between shutdown mode can be thus eliminated. The delay time is proportional to the value of the capacitance. It is about 500ms for a capacitor of 1uF at 5v. CAP Cap provides a way of soft startup delay. A 5uA current source and a half_Vcc detector are integrated in the chip. The charged capacitor is externally hooked up. For C=1uF the half_Vcc delay is T = CV / I = （1uF × 2.5V）/ 5uA = 0.5 seconds Copyright©2005, Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com 8 Tai-1 Microelectronics www.taimec.com.tw / Preliminary www.class-d.com.tw TMPA2155DS Rev.1.0 June 27, 2006 Voltage gain The voltage gain is defined in the table on page 3. For lower voltage gain one can add external input resistors to input pins. If external resistors are used they should be well matched. Well matched input resistors are also required even for single ended input configuration for low noise. Automatic output Power Control (APC) The voltage gain is self adjusted in the chip over voltage range. This means that, regardless supply voltage change, the output power keeps about the same for a given input level from VDD=5.5v to 2.5v. It allows the best use of the battery. Differential input VS single ended input Differential input offers better noise immunity over single ended input. A differential input amplifier suppresses common noise and amplifies the difference voltage at the inputs. For single ended applications just tie the negative input end of the balanced input structure to ground. If external input resistors are used, the negative input has to be grounded with a series resistor of the same value as the positive input to reduce common noise. Output filter Ferrite bead filter can be used for EMI purpose. The ferrite filter reduces EMI around 1 MHz and higher（FCC and CE only test radiated emissions greater than 30 MHz）. When selecting a ferrite bead, choose one with high impedance at high frequencies, but low impedance at low frequencies. Use an LC output filter if there are low frequency（＜1 MHz）EMI sensitive circuits and/or there are long wires from the amplifier to the speaker. EMI is also affected by PCB layout and the placement of the surrounding components. Copyright©2005, Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com 9 Preliminary Tai-1 Microelectronics www.taimec.com.tw / www.class-d.com.tw TMPA2155DS Rev.1.0 June 27, 2006 The suggested LC values for different speaker impendence are showed in following figures for reference. Typical LC Output Filter (1) 33μH Vo+ 0.47μ F 0.1μ F 33μH Vo0.1μ F Typical LC Output Filter (2) Over temperature protection A temperature sensor is built in the device to detect the temperature inside the device. When a high temperature around 145oC and above is detected the switching output signals are disabled to protect the device from over temperature. Automatic recovery circuit enables the device to come back to normal operation when the internal temperature of the device is below around 120oC. Copyright©2005, Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com 10 Tai-1 Microelectronics www.taimec.com.tw / Preliminary www.class-d.com.tw TMPA2155DS Rev.1.0 June 27, 2006 Over current protection A current detection circuit is built in the device to detect the switching current of the output stages of the device. It disables the device when the current is beyond about 3.5amps. It protects the device when there is an accident short between outputs or between output and power/gnd pins. It also protects the device when an abnormal low impedance is tied to the output. High current beyond the specification may potentially causes electron migration and permanently damage the device. Shutdown or power down is necessary to resolve the protection situation. There is no automatic recovery from over current protection. Copyright©2005, Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com 11 www.taimec.com.tw / TMPA2155DS Preliminary Tai-1 Microelectronics www.class-d.com.tw Rev.1.0 Physical Dimensions June 27, 2006 (IN MILLIMETERS) ± 7.72 TYP 4.16 TYP (1.78 TYP) 0.42 TYP 0.65 TYP LAND PATTERN TSSOP20 Copyright©2005, Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com 12 Tai-1 Microelectronics www.taimec.com.tw / Preliminary www.class-d.com.tw TMPA2155DS Rev.1.0 June 27, 2006 QFN24 Copyright©2005, Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com 13 Tai-1 Microelectronics www.taimec.com.tw / Preliminary www.class-d.com.tw TMPA2155DS Rev.1.0 June 27, 2006 IMPORTANT NOTICE Tai-1 Microelectronics Corp. reserves the right to make changes to its products and services and to discontinue any product or service without notice. Customers should obtain the latest relevant information for reference. Testing and quality control techniques are used to screen the parameters. Testing of all parameters of each product is not necessarily performed. Tai-1 Microelectronics Corp. assumes no liability for applications assistance or customer product design. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. Reproduction of information in data sheets or related documentation is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Tai-1 Microelectronics Corp. is not responsible or liable for such altered documentation. Resale of Tai-1 Microelectronics Corp. products or services with statements different from the parameters stated by Tai-1 Microelectronics Corp. for that product or service voids all express and any implied warranties. Tai-1 Microelectronics Corp. is not responsible or liable for any such statements. Copyright ©2005,Tai-1 Microelectronics Corp. Copyright©2005, Tai-1 Microelectronics Corp. PDF created with pdfFactory trial version www.pdffactory.com 14