CMAMP110

CMAMP110 Microphone Amplifier Features • • • • • • • • • • Microsoft PC99 & PC2001 compliant Differential and Single-ended Microphone Inputs Internally frequency compensated for unity gain 20dB DC voltage gain (maximum) Buffered DC bias voltage for external microphone Very low supply current (< 3.0 mA) 20KΩ minimum input impedance Low Total Harmonic Distortion (0.03% at 1 KHz typical) Small MSOP package Lead-free version available Product Description The CMAMP110 Microphone Amplifier selects (via MIC_SELECT) between and amplifies Internal and External Microphone input signals. The device is designed to be compliant with Microsoft PC99 and PC2001 specifications. The CMAMP110 contains the equivalent of 7 operational amplifiers and 19 precision resistors, and is intended for use in PC audio applications. The Internal Microphone input is differential, but it can also be used single-ended by simply grounding one of the inputs through a capacitor. The External Microphone input is single-ended. A logic high level on the MIC_SELECT pin selects the external microphone input. Since the chip supplies the DC bias for the external microphone (EXT_MIC_BIAS), both dynamic and electret type microphones may be used. The output amplifier is unity gain stable and is capable of driving a resistive load in excess of 10KΩ. The CMAMP110 Microphone Amplifier is housed in a space saving MSOP-8 package and is optionally available with lead-free finishing. Applications • • • • • • Computers Mobile Phones PDA's MP3 Players Digital Cameras Video Tape Recorders Electrical Schematic V+ 4 500K 2.5K VREF SW1 RBIAS 3 EXT_MIC_BIAS EXT_MIC_IN 8 500K 2 500K 500K VOUT INT_MIC+ INT_MIC− 6 5 SW2 500K 500K 7 1 V− MIC_SELECT © 2004 California Micro Devices Corp. All rights reserved. 01/09/04 430 McCarthy Blvd., Milpitas, California 95035L Tel: (408) 263-3214 L Fax: (408) 263-7846 L www.calmicro.com 1 CMAMP110 PACKAGE / PINOUT DIAGRAM Top View MIC_SELECT VOUT EXT_MIC_BIAS V+ 1 2 3 4 8 7 6 5 EXT_MIC_IN V− INT_MIC+ INT_MIC− Note: This drawing is not to scale. 8-pin MSOP PIN DESCRIPTIONS PIN 1 NAME MIC_SELECT DESCRIPTION Microphone Select logic input control. The external microphone input is selected when the MIC_SELECT signal (pin 1) is at Logic "1" (> 3.5 volts), and the internal microphone inputs are selected by applying Logic "0" to the pin (< 1.5V). Amplifier output pin. External microphone bias output. Positive supply pin. Inverting internal microphone differential input. Can be operated as a single-ended input by connecting a 0.22µF (or greater) capacitor between pin 6 and V−. Non-inverting internal microphone differential input. Can be operated as a single-ended input by connecting a 0.22µF (or greater) capacitor between pin 5 and V−. Negative supply pin. External microphone signal input. 2 3 4 5 6 7 8 VOUT EXT_MIC_BIAS V+ INT_MIC− INT_MIC+ V− EXT_MIC_IN Ordering Information PART NUMBERING INFORMATION Standard Finish Pins 8 Package MSOP-8 Ordering Part Number1 CMAMP110M Part Marking A110 Lead-free Finish Ordering Part Number1 CMAMP110MR Part Marking R110 Note 1: Parts are shipped in Tape & Reel form unless otherwise specified. © 2004 California Micro Devices Corp. All rights reserved. 2 430 McCarthy Blvd., Milpitas, California 95035 L Tel: (408) 263-3214 L Fax: (408) 263-7846 L www.calmicro.com 01/09/04 CMAMP110 Specifications ABSOLUTE MAXIMUM RATINGS(SEE NOTE 1) PARAMETER ESD Protection (HBM, Note 2) Differential Input Voltage Voltage at any Input/Output Pin Storage Temperature Range Junction Operating Temperature Lead Soldering Temperature (10 seconds) Supply Voltage [(V+) - (V−)] Current at Input Pin Current at Output Pin (Note 3) Current at Power Supply Pin RATING +2000 +/− Supply Voltage [(V−) - 0.3] to [(V+) + 0.3] -40 to +150 +125 +260 7.5 5 15 15 UNITS V V V °C °C °C V mA mA mA Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. For guaranteed specifications and the test conditions, see the Electrical Operating Characteristics. Note 2: Human Body Model, 1.5KΩ in series with 100pF (MIL-STD-883, Method 3015). Note 3: Continuous short circuit operation at elevated ambient temperatures can result in exceeding the maximum allowed junction temperature of 150°C. STANDARD OPERATING CONDITIONS(SEE NOTE 1) PARAMETER Maximum Power Dissipation Ambient Operating Temperature Range Supply Voltage RATING 200 0 to +70 3.3 to 5.5 UNITS mW °C V Note 1: Operating conditions indicate ratings for which the device is intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Operating Characteristics. © 2004 California Micro Devices Corp. All rights reserved. 01/09/04 430 McCarthy Blvd., Milpitas, California 95035L Tel: (408) 263-3214 L Fax: (408) 263-7846 L www.calmicro.com 3 CMAMP110 Specifications (cont’d) ELECTRICAL OPERATING CHARACTERISTICS(SEE NOTE 1) SYMBOL RIN AV VMIC_IN VOUT VEXT_MIC_BIAS PARAMETER Input Impedance AC Voltage Gain Microphone Input Signal Level Output Signal Level External Microphone Bias Voltage No Load ISOURCE = 0.8mA RBIAS GBW SR T.H.D. VIH VIL tSW ISUP ISC RL Microphone Bias Resistor Gain Bandwidth Product Slew Rate Total Harmonic Distortion MIC_SELECT Logic High Voltage MIC_SELECT Logic Low Voltage Microphone Switching Time Supply Current Output Short Circuit Current Load Impedance Applied to VOUT VOUT = 0V 10 2 1.5 15 3.0 RL=10KΩ RL=10KΩ f = 1KHz, VIN = 100mV rms, RL=10KΩ 3.5 1.5 2.0 2.0 4.6 2.6 2.5 2.0 1.3 0.03 V V KΩ MHz V/µs % V V RL=10KΩ CONDITIONS All Inputs VIN = 100 mV rms, RL=10KΩ MIN 20 TYP 40 18 20 110 1 MAX UNITS KΩ dB mV rms V rms µs mA mA KΩ Note 1: All tests at 25°C, V+ = +5V, V- = 0V unless otherwise noted. © 2004 California Micro Devices Corp. All rights reserved. 4 430 McCarthy Blvd., Milpitas, California 95035 L Tel: (408) 263-3214 L Fax: (408) 263-7846 L www.calmicro.com 01/09/04 CMAMP110 Application Information CMAMP110 Design Considerations 1. General Overview The CMAMP110 is very straightforward to apply, but a few precautions are worth noting. It is recommended that the power supply pin, V+ (pin 4), be bypassed with a parallel combination of a 4.7µF and a 0.1µF capacitor to minimize noise and hum pickup. In addition, a 100Ω resistor may be inserted in series to form a RC filter between the the power supply feed and the V+ pin to the CMAMP110. Also, in that regard, lead dress for the microphone inputs on the PCB should either be shielded from or spaced from noise sources. The V− input on the device (pin 7) should be connected to the “clean analog ground”. Where: VBMIC = 4.6 volts RBIAS = 2.5 KΩ VB = Desired Microphone Bias Voltage IB = Microphone Bias Current For example, an electret condenser microphone that operates on 1.5V and 0.5mA, REXT should be selected to be 3.9KΩ (nearest standard value). 4. Microphone Select The CMAMP110 has provisions for the selection of either the internal microphone and external microphone inputs. The external microphone is selected when the MIC_SELECT signal (pin 1) is at Logic "1" (> 3.5 volts), and the internal microphone is selected by applying Logic "0" to the pin (< 1.5V). The switching time is approximately 2 ms. For static applications where only one input is used, pin 1 can simply be strapped to either V− or V+. 2. Passive Component Selection Selection of the microphone input coupling capacitors can be made using the following equation: 1 C = ---------------------------------2 π ⋅ R IN ⋅ f MIN Where: 5. Internal Microphone The CMAMP110 provides for a differential (floating) input for the Internal microphone where INT_MIC+ (pin 6) is the “non-inverting” input and INT_MIC− (pin 5) is the “inverting” input. The CMAMP110 may be operated single-ended by connecting a 0.22µF (or greater) capacitor between either pin 5 or pin 6 and V−. RIN = Microphone Input Impedance (40KΩ typical) ƒMIN = Minimum Input Frequency For example, for ƒMIN = 20Hz, C should be selected for 0.22µF (or greater). The above equation may also be used to select the output coupling capacitor. 6. Start Up 3. Microphone Bias The CMAMP110 provides a nominal 4.6 volt stable reference and 2.5KΩ resistor to bias the microphone. For a bias current of 800µA, a 2.6 volt bias voltage results. However, if other voltages are desired, a resistor can be inserted in series with the microphone bias output (pin 3) whose value, REXT , can be chosen using the following equation: Application of the CMAMP110 requires AC coupling the inputs and outputs (see Passive Component Selection). Both the Internal Microphone inputs (INT_MIC+ and INT_MIC−) and the External Microphone input (EXT_MIC_IN) are DC biased at half the supply voltage with an equivalent impedance of about 500KΩ. As a result, a start up transient will occur as the capacitors charge to half of the rail. The time for the amplifier inputs and outputs to settle is given by: VBMIC – ( I B ⋅ R BIAS ) – V B R EXT = ------------------------------------------------------------IB © 2004 California Micro Devices Corp. All rights reserved. 01/09/04 430 McCarthy Blvd., Milpitas, California 95035L Tel: (408) 263-3214 L Fax: (408) 263-7846 L www.calmicro.com 5 CMAMP110 Application Information (cont’d) 7. Evaluation Board An evaluation board, part number CMAMP110-20EV, is available to facilitate easy and rapid checkout of the CMAMP110. The board is about the size of a business card, and samples of it may obtained by calling the factory at (800) 325-4966 or (408) 263-3214 or from your local representative. Ask the operator to be connected to Applications Engineering. Otherwise, you may request samples on our website at www.calmicro.com by navigating to the ’Contact Us’ page, click on the ’Literature & Samples Request’ button and request the above part number. V SUP t = RC IN ⋅ ln  ------------------  = 0.69 RC IN  VSUP ⁄ 2 For an input capacitance of 0.22µF, the turn on transient is about 76ms. V+ 4.7µF 0.1µF 4 V+ EXT MIC INPUT 0.22µF 3 8 EXT_MIC_BIAS VOUT EXT_MIC_IN 2 0.22µF CMAMP110 CODEC 1 6 MIC_SELECT MIC_SELECT INT_MIC+ 0.22µF INT_MIC+ INT_MICV− 5 0.22µF 7 Figure 1. CMAMP110 Typical Application Circuit (single-ended input configuration shown for differential INT_MIC inputs). © 2004 California Micro Devices Corp. All rights reserved. 6 430 McCarthy Blvd., Milpitas, California 95035 L Tel: (408) 263-3214 L Fax: (408) 263-7846 L www.calmicro.com 01/09/04 CMAMP110 Mechanical Details MSOP Mechanical Specifications: CMAMP110 devices are packaged in 8-pin MSOP packages. Dimensions are presented below. For complete information on the MSOP-8 package, see the California Micro Devices MSOP Package Information document. Mechanical Package Diagrams TOP VIEW D 8 7 6 5 PACKAGE DIMENSIONS Package Pins Dimensions A A1 B C D E e H L # per tube # per tape and reel 2.90 2.90 4.78 0.52 Millimeters Min 0.87 0.05 0.18 3.10 3.10 4.98 0.54 0.114 0.114 0.188 0.017 Max 1.17 0.25 Min 0.034 0.002 MSOP 8 Inches Max 0.046 0.010 SIDE VIEW 1 2 3 4 H Pin 1 Marking E 0.30 (typ) 0.012 (typ) 0.007 0.122 0.122 0.196 0.025 SEATING PLANE A A1 B e END VIEW 0.65 BSC 0.025 BSC 80 pieces* 4000 pieces Controlling dimension: inches C L * This is an approximate number which may vary. Package Dimensions for MSOP-8 © 2004 California Micro Devices Corp. All rights reserved. 01/09/04 430 McCarthy Blvd., Milpitas, California 95035L Tel: (408) 263-3214 L Fax: (408) 263-7846 L www.calmicro.com 7