a Mono 1.5 W/Stereo 250 mW Power Amplifier SSM2250 PIN CONFIGURATIONS 10-Lead MSOP (RM Suffix) FEATURES Part of SoundMax® Audio Solution for Desktop Computers Mono 1.5 W Differential or Stereo 250 mW Output Single-Supply Operation: 2.7 V to 6 V Low Shutdown Current = 60 A PC 99 Compliant Low Distortion: 0.2% THD at 1.5 W Wide Bandwidth: 4 MHz Unity-Gain Stable APPLICATIONS Desktop, Portable or Palmtop Computers Sound Cards Communication Headsets 2-Way Communications Handheld Games The SSM2250 is specified over the industrial (–40°C to +85°C) temperature range. It is available in 14-lead TSSOP and 10-lead MSOP surface mount packages. 10 LEFT OUT/BTL– SHUTDOWN 2 9 SSM2250 VDD SE/BTL 3 8 BTL+ GND 4 7 BYPASS RIGHT IN 5 6 RIGHT OUT NC LEFT IN SHUTDOWN SE/BTL 1GND RIGHT IN NC The SSM2250 is intended for use in desktop computers that have basic audio functions. It is also ideal for any audio system that needs to provide both an internal monaural speaker and a stereo line or headphone output. Combined with an AC’97 Codec it provides a PC audio system that meets the PC 99 requirements. The SSM2250 is compact and requires a minimum of external components. The SSM2250 can automatically switch between an internal mono speaker and external headphones. The device can run from a single supply, ranging from 2.7 V to 6 V, with an active supply current of 9␣ mA typical. The ability to shut down the amplifiers, (60 µA shutdown current) makes the SSM2250 an ideal speaker amplifier for battery-powered applications. 1 14-Lead TSSOP (RU Suffix) GENERAL DESCRIPTION The SSM2250 features an audio amplifier capable of delivering 1.5 W of low distortion power into a mono 4 Ω bridged-tied load (BTL) or 2 ⫻ 90 mW into stereo 32 Ω single-ended load (SE) headphones. Both amplifiers provide rail-to-rail outputs for maximum dynamic range from a single supply. The balanced output provides maximum output from 5 V supply and eliminates the need for a coupling capacitor. LEFT IN 1 NC LEFT OUT/BTL VDD BTL1 BYPASS RIGHT OUT NC 14 SSM2250 7 8 NC = NO CONNECT VDD LEFT IN LEFT SE/ MONO BTL OUT– A1 BYPASS CAP MONO BTL OUT+ A2 VDD RIGHT IN RIGHT SE OUT A3 SWITCHING CIRCUITRY VDD GND CLICK AND POP REDUCTION BIAS BTL/SE SELECT SHUTDOWN Figure 1. Functional Block Diagram SoundMax is a registered trademark of Analog Devices, Inc. REV. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 World Wide Web Site: http://www.analog.com Fax: 781/326-8703 © Analog Devices, Inc., 1999 SSM2250–SPECIFICATIONS ELECTRICAL CHARACTERISTICS (V S = 5.0 V, VCM = 2.5 V, TA = 25ⴗC unless otherwise noted) Parameter Symbol Conditions DEVICE CHARACTERISTICS␣ Output Offset Voltage Large Signal Voltage Gain Output Power VOS AVO POUT BTL Mode; AV = 2; BTL+ to BTL– RL = 2 kΩ SE Mode: RL = 32 Ω, THD < 1% BTL Mode: RL = 8 Ω, THD < 1% Output Impedance Min Typ Max 4 100 2 90 1,000 0.1 ZOUT Unit mV V/mV mW mW Ω SHUTDOWN INPUT Input Voltage High Input Voltage Low VIH VIL IS < 100 µA IS > 1 mA POWER SUPPLY␣ Supply Current IS BTL Mode SE Mode 6.4 6.4 60 mA mA µA Supply Current/Amplifier 2.0 0.8 IS V V DYNAMIC PERFORMANCE␣ Slew Rate Gain Bandwidth Product Phase Margin SR GBP Φo RL = 100 kΩ, CL = 50 pF 4 4 84 V/µs MHz Degrees NOISE PERFORMANCE␣ Voltage Noise Density en f = 1 kHz 45 nV/√Hz Specifications subject to change without notice. ELECTRICAL CHARACTERISTICS (V S = 2.7 V, VCM = 1.35 V, TA = 25ⴗC unless otherwise noted) Parameter Symbol Conditions DEVICE CHARACTERISTICS␣ Output Offset Voltage Large Signal Voltage Gain Output Power VOS AVO POUT BTL Mode; AV = 2; BTL+ to BTL– RL = 2 kΩ SE Mode: RL = 32 Ω, THD < 1% BTL Mode: RL = 8 Ω, THD < 1% Output Impedance Min ZOUT Typ Max Unit 4 2 25 300 0.1 100 mV V/mV mW mW Ω SHUTDOWN INPUT Input Voltage High Input Voltage Low VIH VIL IS < 100 µA IS > 1 mA POWER SUPPLY␣ Supply Current IS BTL Mode SE Mode 6.4 6.4 32 mA mA µA Supply Current/Amplifier IS 2.0 0.8 V V DYNAMIC PERFORMANCE␣ Slew Rate Gain Bandwidth Product Phase Margin SR GBP Φo RL = 100 kΩ, CL = 50 pF 4 4 84 V/µs MHz Degrees NOISE PERFORMANCE␣ Voltage Noise Density en f = 1 kHz 45 nV/√Hz Specifications subject to change without notice. –2– REV. 0 SSM2250 ABSOLUTE MAXIMUM RATINGS 1 Supply Voltage . . . . . . . .2. . . . . . . . . . . . . . . . . . . . . . . . . . 6 V Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . ±5 V Common-Mode Input Voltage . . . . . . . . . . . . . . . . . . . . ±6 V ESD Susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2000 V Storage Temperature Range RM, RU Packages . . . . . . . . . . . . . . . . . . –65°C to +150°C Operating Temperature Range SSM2250 . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C Junction Temperature Range RM, RU Packages . . . . . . . . . . . . . . . . . . –65°C to +165°C Lead Temperature Range (Soldering, 60 sec) . . . . . . . . 300°C Package Type JA1 JC Unit 10-Lead MSOP (RM) 14-Lead TSSOP (RU) 200 180 44 35 °C/W °C/W NOTE 1 θ JA is specified for worst-case conditions, i.e., θ JA is specified for device soldered in circuit board for surface mount packages. ORDERING GUIDE NOTES 1 Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those listed in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. 2 Differential Input Voltage or ± VS, whichever is lower. Model Temperature Range Package Description SSM2250RM SSM2250RU –40°C to +85°C –40°C to +85°C 10-Lead MSOP RM-10 14-Lead TSSOP RU-14 CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the SSM2250 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. REV. 0 –3– Package Option WARNING! ESD SENSITIVE DEVICE SSM2250 1 VS = 5V BTL MODE RL = 8V CB = 1mF POUT = 1W AV = 2 1 0.1 VS = 5V SE MODE RL = 32V CB = 1mF POUT = 60mW AV = 1 TOTAL HARMONIC DISTORTION – % TOTAL HARMONIC DISTORTION – % 10 0.1 0.01 20 100 1k FREQUENCY – Hz 10k 20k 10k 20k VS = 2.7V SE MODE RL = 32V CB = 1mF POUT = 15mW AV = 1 TOTAL HARMONIC DISTORTION – % TOTAL HARMONIC DISTORTION – % VS = 2.7V BTL MODE RL = 8V CB = 1mF POUT = 0.25W AV = 2 1 0.1 0.01 20 100 1k FREQUENCY – Hz 10k 20k 20 10 3.3V 1 5V 0.1 10m SE MODE RL = 32V CB = 1mF VIN = 1kHz 2.7V TOTAL HARMONIC DISTORTION – % VS = VARIES BTL MODE RL = 8V CB = 1mF VIN = 1kHz AV = 2 100m OUTPUT POWER – W 1 100 1k FREQUENCY – Hz 10k 20k Figure 6. SE Out THD + N vs. Frequency Figure 3. BTL Out THD + N vs. Frequency TOTAL HARMONIC DISTORTION – % 1k FREQUENCY – Hz 1 10 10 100 Figure 5. SE Out THD + N vs. Frequency Figure 2. BTL Out THD + N vs. Frequency 0.1 20 3.3V 5V 1 0.1 0.01 2 2.7V 10 100 200 OUTPUT POWER – mW Figure 7. BTL Out THD + N vs. Output Power Figure 4. THD + N vs. Output Power –4– REV. 0 SSM2250 10 VS = 5V BTL MODE RL = 8V CB = 1mF VIN = 20Hz AV = 2 TOTAL HARMONIC DISTORTION – % TOTAL HARMONIC DISTORTION – % 10 1 0.1 10m 100m OUTPUT POWER – W 1 TOTAL HARMONIC DISTORTION – % TOTAL HARMONIC DISTORTION – % 10 1 100m OUTPUT POWER – W 1 100 200 VS = 5V SE MODE RL = 8V CB = 1mF VIN = 20kHz AV = 1 1 0.1 0.01 2 10 100 200 OUTPUT POWER – mW Figure 9. BTL Out THD + N vs. Output Power at 20 kHz REV. 0 10 Figure 10. SE Out THD + N vs. Output Power at 20 Hz VS = 5V BTL MODE RL = 8V CB = 1mF VIN = 20kHz AV = 2 0.1 10m 0.1 OUTPUT POWER – mW Figure 8. BTL Out THD + N vs. Output Power at 20 Hz 10 1 0.01 2 VS = 5V SE MODE RL = 32V CB = 1mF VIN = 20Hz AV = 1 Figure 11. SE Out THD + N vs. Output Power at 20 kHz –5– SSM2250 In BTL Mode, the SSM2250 can achieve 1␣ W continuous output into 8␣ Ω at ambient temperatures up to 40°C. The power derating curve shown in Figure 15 should be observed for proper operation at higher ambient temperatures. For a standard 14-lead TSSOP package, typical junction-to-ambient temperature thermal resistance (θJA) is 180°C/W on a 2-layer board, and 140°C/W on a 4-layer board. PRODUCT OVERVIEW The SSM2250 is a low distortion power amplifier that can drive a set of stereo headphones or a single 8 Ω loudspeaker. It contains three rail-to-rail output op amps, click and pop reduction biasing, and all necessary switching circuitry. In SE (Single-Ended) Mode, the device automatically mutes the internal 8 Ω speaker. In BTL (Bridge-Tied Load) Mode, the internal speaker is activated. Internal Speaker/External Headphones Automatic Switching The SSM2250 can operate from a 2.7 V to 5.5 V single supply. The rail-to-rail outputs can be driven to within 400 mV of either supply rail while supplying a sustained output current of 350 mA into 8 Ω. The device is unity-gain stable and requires no external compensation capacitors. The SSM2250 can be configured for gains of up to 40␣ dB. Pin 4 on the SSM2250 controls the switching between BTL and SE Modes. Logic low to Pin 4 activates BTL Mode, while logic high activates SE Mode. The configuration shown in Figure 12 provides the appropriate logic voltages to Pin 4, muting the internal speaker when headphones are plugged into the jack. A stereo headphone jack with a normalizing pin is required for the application. With no plug inserted, a mechanical spring connects the normalizing pin to the output pin in the jack. Once a plug is inserted, this connection is broken. TYPICAL APPLICATION In SE Mode, the device operates similar to a high current output, dual op amp. A1 and A3 are independent amplifiers with a gain of –R2/R1. The outputs of A1 and A3 are used to drive the external headphones plugged into the headphone jack. Amplifier A2 is shut down to a high output impedance state. This prevents current from flowing through the 8 Ω internal speaker, thereby muting it. Referring to Figure 12, Pin 4 of the SSM2250 is connected to the normalizing pin for the right channel output. This is the pin in the headphone jack that will hit the ring on the headphone plug. A 100 kΩ pull-up resistor to 5 V is also connected at this point. Although the gains of A1 and A3 can be set independently, it is recommended that the feedback and feedforward resistor around both amplifiers be equal. This will prevent one channel from becoming louder than the other. With a headphone plug inserted, the normalizing pin disconnects from the output pin, and Pin 4 is pulled up to 5 V, activating SE Mode on the SSM2250. This mutes the internal speaker while driving the stereo headphones. In BTL mode, the current into the Right In pin is directed to the input of A1. This effectively sums the Left and Right In audio signals. The A2 amplifier is activated and configured with a fixed gain of AV ␣ =␣ –1. This produces a balanced output configuration that drives the internal speaker. Because the BTL output voltages swing opposite to each other, the gain to the speaker in BTL mode is twice the gain of SE mode. The voltage across the internal speaker can be written: Once the headphone plug is removed, the normalizing pin connects to the output pin. This drives the voltage at Pin 4 to 50 mV, as this point is pulled low by the 1 kΩ resistor now connected to the node. The SSM2250 goes into BTL mode, deactivating the right SE amplifier to prevent the occurrence of any false mode switching. ( ) VSPEAKER = VLEFT + VRIGHT × 2 × R2 R1 It is important to connect Pin 4 and the 100 kΩ pull up resistor to the normalizing pin for the right output in the headphone jack. Connecting them to the left output normalizing pin will result in improper operation from the device. The normalizing pin to the left output in the headphone jack should be left open. (1) The bridged output configuration offers the advantage of a more efficient power transfer from the input to the speaker. Because both outputs are symmetric, the dc voltage bias across the 8 Ω internal speaker is zero. This eliminates the need for a coupling capacitor at the output. In BTL mode, the A3 amplifier is shut down to conserve power. Coupling Capacitors Output coupling capacitors are not required to drive the internal speaker from the BTL outputs. However, coupling capacitors are required between the amplifier’s SE outputs and the headphone jack to drive external headphones. This prevents dc current from flowing through the headphone speakers, whose resistances are typically on the order of 80 Ω. R2 20kV R1 20kV NC LEFT IN 1 14 2 13 NC 220mF + 1mF – SHUTDOWN 3 12 R1 20kV RIGHT IN 4 11 5 10 6 9 7 8 1mF NC 10mF 1kV BTL OUT 5V SSM2250 NC + 220mF + 1kV NC 5V R2 20kV 100kV NC = NO CONNECT Figure 12. Typical Application –6– REV. 0 SSM2250 The output coupling capacitor creates a high-pass filter with a cutoff frequency of: f −3dB = 1 2πRL CC PDISS , MAX = (2) CC is the output coupling capacitor. 0.35 POWER DISSIPATION – W 0.3 (3) 0.25 0.2 RL = 8V 0.15 0.1 RL = 16V 0.05 Using the values shown in Figure 2, where R1␣ =␣ 20 kΩ and C1␣ =␣ 1 µF, will create a corner frequency of 8 Hz. This is acceptable, as the PC 99 audio requirement specifies the computer audio system bandwidth to be 20 Hz to 20 kHz. 0 0 0.1 0.2 OUTPUT POWER – W PDISS , MAX = VDD 2 2π 2 RL (5) Because the SSM2250 is designed to drive two single-ended loads simultaneously, the worst-case maximum power dissipation in SE Mode is twice the value of Equation␣ 5. Power Dissipation An important advantage in using a bridged output configuration is the fact that bridged output amplifiers are more efficient than single-ended amplifiers in delivering power to a load. A thorough mathematical explanation behind Equation␣ 4 and Equation␣ 5 is given in the SSM2211 data sheet, which can be downloaded at http://www.analog.com. Example: Given worst-case stereo headphone loads of 32 Ω, the maximum power dissipation of the SSM2250 in SE Mode with a 5 V supply would be: 1.5 VDD = 5V RL = 4V PDISS , 1.0 MAX = (5 V )2 2π 2 32 Ω = 79 mW (6) With an 8 Ω internal speaker attached, the maximum power dissipation in BTL mode is (from Equation 4): 0.75 RL = 8V 0.5 2 × (5 V ) 2 RL = 16V PDISS , 0.25 0 0.25 0.5 0.75 1.0 OUTPUT POWER – W 1.25 MAX = π2 8 Ω = 633 mW (7) It can be easily seen that power dissipation from BTL Mode operation is of greater concern than SE Mode. 1.5 Solving for Maximum Ambient Temperature Figure 13. Power Dissipation vs. Output Power in BTL Mode REV. 0 0.4 The maximum power dissipation for a single-ended output is: The SSM2250 has excellent phase margin and is stable even under heavy loading. Therefore, a feedback capacitor in parallel with R2 is not required, as it is in some competitors’ products. 0 0.3 Figure 14. Power Dissipation vs. Single-Ended Output Power (VDD␣ = 5␣ V) Pin 10 on the SSM2250 provides the proper bias voltage for the amplifiers. A 0.1 µF capacitor should be connected here to reduce sensitivity to noise on the power supply. A larger capacitor can be used should more rejection from power supply noise be required. POWER DISSIPATION – W RL = 4V VDD = 5V An input coupling capacitor should be used to remove dc bias from the inputs to the SSM2250. Again, the input coupling capacitor in combination with the input resistor will create a high-pass filter with a corner frequency of: 1.25 (4) π 2 RL The power dissipation for a single-ended output application where an output coupling capacitor is used is shown in Figure 14. Although a majority of headphones have around 80 Ω of resistance, this resistance can vary between models and manufacturers. Headphone resistances are commonly between 32 Ω to 600 Ω. Using a 220 µF capacitor as shown in Figure 12, the worst-case –3 dB corner frequency would be 22 Hz, with a 32 Ω headphone load. Smaller output capacitors could be used at the expense of low frequency response to the headphones. 1 2πR1C1 2 Using Equation 4 and the power derating curve in Figure 15, the maximum ambient temperature can be easily found. This ensures that the SSM2250 will not exceed its maximum junction temperature of 150°C. Where, RL is the resistance of the headphone, and f −3dB = 2VDD To protect the SSM2250 against thermal damage, the junction temperature of the die should not exceed 150°C. The maximum allowable ambient temperature of the application can be easily found by solving for the expected maximum power dissipation in Equation␣ 4 and Equation␣ 5, and using Equation␣ 8. –7– SSM2250 Continuing from the previous example, the θJA of the SSM2250 14-lead TSSOP package on a 4-layer board is 140°C/W. To ensure the SSM2250 die junction temperature stays below 150°C, the maximum ambient temperature can be solved using Equation 8. TAMB, MAX = +150°C − θ JA × PDISS, MAX (8) So the maximum ambient temperature must remain below 61°C to protect the device against thermal damage. Another method for finding the maximum allowable ambient temperature is to use the power derating curve in Figure 15. The y-axis corresponds to the expected maximum power dissipation, and the x-axis is the corresponding maximum ambient temperature. Either method will return the same answer. POWER DISSIPATION – W 1.0 0.8 14-LEAD TSSOP uJA = 1408C/W 0.6 10-LEAD MSOP uJA = 1808C/W TJ,MAX = 1508C/W FREE AIR NO HEAT SINK 75 RL = 32V 50 RL = 64V 25 RL = 128V 0 1.5 2.0 2.5 3.0 3.5 4.0 SUPPLY VOLTAGE – V 4.5 5.0 Figure 17. Maximum SE Output Power vs. VS Example: An application requires only 500␣ mW to be output in BTL Mode into an 8␣ Ω speaker. By inspection, the minimum supply voltage required is 3.3␣ V. 0.4 Speaker Efficiency and Loudness 0.2 0 100 MAXIMUM OUTPUT @ THD 1% – mW = +150°C − (140°C/W × 0.633 W ) = +61°C The output power in SE mode is exactly one-fourth the equivalent output power in BTL mode. This is because twice the voltage swing across the two BTL outputs results in 4⫻ the power delivered to the load. Figure 17 shows the maximum output power in SE mode vs. supply voltage for various headphone loads. 0 25 50 75 AMBIENT TEMPERATURE – 8C 100 Figure 15. Maximum Power Dissipation vs. Ambient Temperature The effective loudness of 1 W of power delivered into an 8 Ω speaker is a function of the efficiency of the speaker. The efficiency of a speaker is typically rated at the sound pressure level (SPL) at 1 meter in front of the speaker with 1 W of power applied to the speaker. Most speakers are between 85 dB and 95 dB SPL at one meter at 1 W of power. Table I shows a comparison of the relative loudness of different sounds. Maximum Output Power The maximum amount of power that can be delivered to a speaker is a function of the supply voltage and the resistance of the speaker. Figure 15 shows the maximum BTL output power possible from the SSM2250. Maximum output power is defined as the point at which the output has greater than 1% distortion. MAXIMUM OUTPUT @ THD 1% – W 1.6 1.4 RL = 4V 1.2 1.0 Source of Sound dB SPL Threshold of Pain Heavy Street Traffic Cabin of Jet Aircraft Average Conversation Average Home at Night Quiet Recording Studio Threshold of Hearing 120 95 80 65 50 30 0 It can be easily seen that 1␣ W of power into a speaker can produce quite a bit of acoustic energy. 0.8 RL = 8V Shutdown Feature 0.6 The SSM2250 can be put into a low power consumption shutdown mode by connecting Pin␣ 3 to VDD. In shutdown mode, the SSM2250 has low supply current of 60 µA. 0.4 RL = 16V 0.2 0 1.5 Table I. Typical Sound Pressure Levels 2.0 2.5 3.0 3.5 4.0 SUPPLY VOLTAGE – V 4.5 5.0 Figure 16. Maximum BTL Output Power vs. VS To find the minimum supply voltage needed to achieve a specified maximum undistorted output power, simply use Figure 16. Pin␣ 3 should be connected to ground for normal operation. Connecting Pin␣ 3 to VDD will shut down all amplifiers and put all outputs into a high impedance state, effectively muting the SSM2250. A pull-up or pull-down resistor is not required. Pin 3 should never be left floating as this could produce unpredictable results. PC 99 Compliant Computer Audio Reference Design The schematic shown in Figure 18 is a reference design for a complete audio system in a computer. The design is compliant with the PC 99 standard for computer audio. –8– REV. 0 SSM2250 The AD1881 is an AC’97 Ver. 2.1 audio codec available from Analog Devices. The stereo output from the AD1881 is coupled into the SSM2250, which is used to drive a mono internal speaker and stereo headphones. The internal speaker switching is controlled by the SSM2250 through the normalizing pin on the headphone jack. The AD1881 controls the shutdown pin on the SSM2250, and is activated through the power management software drivers installed on the computer. For more information on the AD1881, the data sheet can be downloaded from the Analog Devices web site at http://www.analog.com. R1 20kV TO SPEAKER2 AVDD = 5V R2 100kV SSM2250 NC TO SPEAKER+ 1 14 2 13 3 12 C1 100mF + NC R3 1kV AVDD = 5V NC C2 10mF C7 0.1mF NC C8 22pF 48 NC NC NC NC 47 46 45 44 43 NC NC NC 42 41 40 39 37 36 2 35 3 34 R8 47V 4 33 5 32 9 28 SYNC 10 27 RST# 11 26 12 AUX LEFT 25 R11 1kV 14 15 16 17 NC NC 18 19 20 21 22 23 24 270pF C21 0.1mF C16 10mF C17 C19 0.1mF AVDD = 5V R9 2kV C24 1mF NC LINE IN RIGHT C25 1mF LINE IN LEFT C27 1mF MIC IN C29 1mF R12 4.7kV C30 1mF C32 1mF C31 1mF R16 4.7kV C28 0.001mF R13 4.7kV CD RIGHT R14 4.7kV AUX IN C16 1mF C26 1mF MONO PHONE 0.047mF C15 270pF 13 C23 0.1mF C14 1mF 29 C22 1mF C13 31 8 PCBEEP LINE OUT LEFT C12 AD1881 30 R10 10kV LINE OUT RIGHT C10 0.1mF 7 SDATA IN 0 R4 1kV NC R7 20kV 1mF 6 C20 27pF R6 20kV 1mF BITCLK 8 MONO OUT 38 1 SDATA OUT 9 7 C5 100mF + C3 0.1mF C9 Y1 24.576MHz SMT 10 6 R15 4.7kV CD GND R17 4.7kV C33 1mF R18 4.7kV CD LEFT R19 4.7kV NC = NO CONNECT Figure 18. PC 99 Compliant Audio System Reference Design REV. 0 NC R5 20kV AC CLK C11 22pF 11 5 AVDD = 5V AVDD = 5V C6 10mF 4 C4 10mF + –9– SSM2250 OUTLINE DIMENSIONS Dimensions shown in inches and (mm). C3729–2.5–10/99 10-Lead MSOP (RM Suffix) 0.124 (3.15) 0.112 (2.84) 10 6 0.124 (3.15) 0.112 (2.84) 0.199 (5.05) 0.187 (4.75) 1 5 PIN 1 0.0197 (0.50) BSC 0.122 (3.10) 0.110 (2.79) 0.038 (0.97) 0.030 (0.76) 0.120 (3.05) 0.112 (2.84) 0.043 (1.09) 0.037 (0.94) 0.006 (0.15) 0.002 (0.05) 68 SEATING 08 0.011 (0.28) PLANE 0.003 (0.08) 0.016 (0.41) 0.006 (0.15) 0.022 (0.56) 0.021 (0.53) 14-Lead TSSOP (RU Suffix) 0.201 (5.10) 0.193 (4.90) 8 1 7 0.256 (6.50) 0.246 (6.25) 0.177 (4.50) 0.169 (4.30) 14 PIN 1 0.006 (0.15) 0.002 (0.05) 0.0256 (0.65) BSC 0.0118 (0.30) 0.0075 (0.19) 0.0079 (0.20) 0.0035 (0.090) 88 08 0.028 (0.70) 0.020 (0.50) PRINTED IN U.S.A. SEATING PLANE 0.0433 (1.10) MAX –10– REV. 0