MAX14 Microphone Amplifier ith AGC an LoNoise …

1 Click here to ask an associate for production status of specific part numbers. Microphone Amplifier with AGC and MAX9814. Low-Noise Microphone Bias General Description Features The MAX9814 is a low-cost, high-quality Microphone Automatic Gain Control (AGC). Amplifier with automatic gain control (AGC) and Three Gain Settings (40dB, 50dB, 60dB). low-noise Microphone bias. The device features a low-noise preamplifier, variable gain Amplifier (VGA), output Programmable Attack Time Amplifier , Microphone -bias-voltage generator, and AGC Programmable Attack and Release Ratio control circuitry. to Supply Voltage Range The low-noise preamplifier has a fixed 12dB gain, while Low Input-Referred Noise Density of 30nV/ Hz the VGA gain automatically adjusts from 20dB to 0dB, Low THD: (typ). depending on the output voltage and the AGC threshold. The output Amplifier offers selectable gains of 8dB, 18dB, Low-Power Shutdown Mode and 28dB. With no compression, the cascade of the Internal Low-Noise Microphone Bias, 2V.

2 Amplifiers results in an overall gain of 40dB, 50dB, or 60dB. Available in the Space-Saving, 14-Pin TDFN. A trilevel digital input programs the output Amplifier gain. An (3mm x 3mm) Package external resistive divider controls the AGC threshold and a single capacitor programs the attack/release times. A -40 C to +85 C Extended Temperature Range trilevel digital input programs the ratio of attack-to-release time. The hold time of the AGC is fixed at 30ms. The low- noise Microphone -bias-voltage generator can bias most electret microphones. Ordering Information appears at end of data sheet. The MAX9814 is available in the space-saving, 14-pin TDFN package. This device is specified over the -40 C to +85 C extended temperature range. Simplified Block Diagram Applications Digital Still Cameras TO Digital Video Cameras PDAs SHDN VDD. MICBIAS LOW-NOISE MAX9814. Bluetooth Headsets RMICBIAS. REFERENCE AGC. Entertainment Systems ( , Karaoke). CIN COUT. MICIN GAIN. LNA VGA MICOUT.

3 +8/+18/. +12dB +20dB/0dB. +28dB. Two-Way Communicators GND. High-Quality Portable Recorders IP Phones/Telephone Conferencing 19-0764; Rev 4; 2/20. 2022 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. One Analog Way, Wilmington, MA 01887 | Tel: | 2022 Analog Devices, Inc. All rights reserved. MAX9814 Microphone Amplifier with AGC and Low-Noise Microphone Bias Absolute Maximum Ratings VDD to to +6V Continuous Power Dissipation (TA = +70 C). All Other Pins to to (VDD + ) 14-Pin TDFN-EP. Output Short-Circuit (derate C above +70 C).. Continuous Current (MICOUT, MICBIAS).. 100mA Operating Temperature -40 C to +85 C. All Other 20mA Junction +150 C. Lead Temperature (soldering, 10s).. +300 C. Bump Temperature (soldering) +235 C. 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 in the operational sections of the specifications is not implied.

4 Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Electrical Characteristics (VDD = , SHDN = VDD, CCT = 470nF, CCG = 2 F, GAIN = VDD, TA = TMIN to TMAX, unless otherwise specified. Typical values are at TA = +25 C.) (Note 1). PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS. GENERAL. Operating Voltage VDD Guaranteed by PSRR test V. Supply Current IDD 6 mA. Shutdown Supply Current ISHDN 1 A. Input-Referred Noise Density en BW = 20kHz, all gain settings 30 nV/ Hz Output Noise BW = 20kHz 430 VRMS. BW = 22Hz to 22kHz 61. Signal-to-Noise Ratio SNR (500mVRMS output signal) dB. A-weighted 64. Dynamic Range DR (Note 2) 60 dB. fIN = 1kHz, BW = 20Hz to 20kHz, RL = 10k , VTH = 1V (threshold = 2VP-P), Total Harmonic Distortion Plus VIN = , VCT = 0V. THD+N %. Noise fIN = 1kHz, BW = 20Hz to 20kHz, RL = 10k , VTH = (threshold = 200mVP-P), VIN = 30mVRMS, VCT = 2V. Amplifier Input BIAS VIN V. Maximum Input Voltage VIN_MAX 1% THD 100 mVP-P.

5 Input Impedance ZIN 100 k . GAIN = VDD 40 Maximum Gain A GAIN = GND 50 dB. GAIN = unconnected 60 GAIN = VDD 20 Minimum Gain GAIN = GND 30 dB. GAIN = unconnected 40 Maximum Output Level VOUT_RMS 1% THD+N, VTH = MICBIAS VRMS. Regulated Output Level AGC enabled, VTH = VP-P. AGC Attack Time tATTACK CCT = 470nF (Note 3) ms A/R = GND 1:500. Attack/Release Ratio A/R A/R = VDD 1:2000 ms/ms A/R = unconnected 1:4000. Analog Devices 2. MAX9814 Microphone Amplifier with AGC and Low-Noise Microphone Bias Electrical Characteristics (continued). (VDD = , SHDN = VDD, CCT = 470nF, CCG = 2 F, GAIN = VDD, TA = TMIN to TMAX, unless otherwise specified. Typical values are at TA = +25 C.) (Note 1). PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS. MICOUT High Output Voltage VOH IOUT sourcing 1mA V. MICOUT Low Output Voltage VOL IOUT sinking 1mA 3 mV. MICOUT Bias MICOUT unconnected V. Output Impedance ZOUT 50 . Minimum Resistive Load RLOAD_MIN 5 k . Maximum Capacitive Drive CLOAD_MAX 200 pF.

6 Maximum Output Current I OUT_MAX 1% THD, RL = 500 1 2 mA. Output Short-Circuit Current ISC 3 8 mA. AGC mode; VDD = to (Note 4) 35 50. f = 217Hz, VRIPPLE = 100mVP-P (Note 5) 55. Power-Supply Rejection Ratio PSRR dB. f = 1kHz, VRIPPLE = 100mVP-P (Note 5) f = 10kHz, VRIPPLE = 100mVP-P (Note 5) 43. Microphone BIAS. Microphone Bias Voltage VMICBIAS IMICBIAS = V. Output Resistance RMICBIAS IMICBIAS = 1mA 1 . Output Noise Voltage VMICBIAS_NOISE IMICBIAS = , BW = 22Hz to 22kHz VRMS. DC, VDD = to 70 80. Power-Supply Rejection Ratio PSRR IMICBIAS = , VRIPPLE = 100mVP-P, dB. 71. fIN = 1kHz TRILEVEL INPUTS (A/R, GAIN). A/R or GAIN = VDD. / 180k / 100k / 50k . Trilevel Input Leakage Current mA. A/R or GAIN = GND. / 180k / 100k / 50k . Input High Voltage VIH VDD x V. Input Low Voltage VIL VDD x V. Shutdown Enable Time tON 60 ms Shutdown Disable Time tOFF 40 ms DIGITAL INPUT (SHDN). SHDN Input Leakage Current -1 +1 A. Input High Voltage VIH V. Input Low Voltage VIL V. AGC THRESHOLD INPUT (TH).

7 TH Input Leakage Current -1 +1 A. Note 1: Devices are production tested at TA = +25 C. Limits over temperature are guaranteed by design. Note 2: Dynamic range is calculated using the EIAJ method. The input is applied at -60dBFS ( VRMS), fIN = 1kHz. Note 3: Attack time measured as time from AGC trigger to gain reaching 90% of its final value. Note 4: CG is connected to an external DC voltage source, and adjusted until VMICOUT = Note 5: CG connected to GND with F. Analog Devices 3. MAX9814 Microphone Amplifier with AGC and Low-Noise Microphone Bias Typical Operating Characteristics (VDD = 5V, CCT = 470nF, CCG = F, VTH = VMICBIAS x , GAIN = VDD (40dB), AGC disabled, no load, RL = 10k , COUT = 1 F, TA = +25 C, unless otherwise noted.). POWER-SUPPLY REJECTION RATIO MICBIAS POWER-SUPPLY REJECTION RATIO. GAIN vs. FREQUENCY vs. FREQUENCY vs. FREQUENCY. 80 0 -30. MAX9814 toc01. MAX9814 toc02. MAX9814 toc03. 70 GAIN = UNCONNECTED -10 -40. 60 -20 -50. 50 -30 -60. PSRR (dB).

8 PSRR (dB). GAIN (dB). 40 -40 -70. 30 GAIN = 0 -50 -80. GAIN = 1. 20 -60 -90. 10 -70 -100. VRIPPLE = 200mVP-P VRIPPLE = 200mVP-P. 0 -80 -110. 10 100 1k 10k 100k 10 100 1k 10k 100k 10 100 1k 10k 100k FREQUENCY (Hz) FREQUENCY (Hz) FREQUENCY (Hz). SUPPLY CURRENT SHUTDOWN CURRENT Microphone BIAS VOLTAGE. vs. SUPPLY VOLTAGE vs. SUPPLY VOLTAGE vs. Microphone BIAS SOURCE CURRENT. MAX9814 toc06. MAX9814 toc04. MAX9814 toc05. SHUTDOWN CURRENT (nA). SUPPLY CURRENT (mA). VMICBIAS VOLTAGE (V). 0 0. 0 5 10 15 20 25 30. SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) IMICBIAS (mA). TOTAL HARMONIC DISTORTION PLUS NOISE TOTAL HARMONIC DISTORTION PLUS NOISE INPUT-REFERRED NOISE. vs. FREQUENCY vs. OUTPUT VOLTAGE vs. FREQUENCY. 10 10 1000. MAX9814 toc09. MAX9814 toc08. MAX9814 toc07. VOUT = 800mVRMS MICIN AC-COUPLED. INPUT-REFERRED NOISE ( VRMS/Hz). TO GND. fIN = 300Hz, 1kHz, 1 1 and 3kHz 100. THD+N (%). THD+N (%). 10. fIN = 10kHz 1. 10 100 1k 10k 100k 0 1 10 100. FREQUENCY (Hz) OUTPUT VOLTAGE (VRMS) FREQUENCY (kHz).

9 Analog Devices 4. MAX9814 Microphone Amplifier with AGC and Low-Noise Microphone Bias Typical Operating Characteristics (continued). (VDD = 5V, CCT = 470nF, CCG = F, VTH = VMICBIAS x , GAIN = VDD (40dB), AGC disabled, no load, RL = 10k , COUT = 1 F, TA = +25 C, unless otherwise noted.). MICBIAS NOISE vs. FREQUENCY SMALL-SIGNAL PULSE RESPONSE TURN-ON RESPONSE. 10,000. MAX9814 toc10. MAX9814 toc11. MAX9814 toc12. VMICIN VSHDN. 10mV/div 5V/div MICBIAS NOISE (nVRMS/Hz). 0V 0V. 1000. VMICBIAS. VMICOUT 2V/div 500mV/div 0V. 100. VMICOUT. 1V/div 0V 0V. CL = 10pF. 10. 10 100 1k 10k 100k 200 s/div 20 s/div FREQUENCY (Hz). VOUT vs. VIN VOUT vs. VIN VOUT vs. VIN. MAX9814 toc13. MAX9814 toc14. MAX9814 toc15. VTH = 1V VTH = 1V VTH = 1V. VOUT (VRMS). VOUT (VRMS). VOUT (VRMS). VTH = VTH = VTH = VTH = VTH = VTH = AGC ENABLED. AGC ENABLED AGC ENABLED. GAIN = 1 GAIN = 0 GAIN = UNCONNECTED. 0 0 0. 0 50 100 150 0 10 20 30 40 0 5 10 15. VIN (mVRMS) VIN (mVRMS) VIN (mVRMS). ATTACK TIME ATTACK TIME HOLD AND RELEASE TIME.

10 MAX9814 toc16. MAX9814 toc17. MAX9814 toc18. VMICOUT VMICOUT. 500mV/div VMICOUT. 500mV/div 500mV/div 0V 0V 0V. CCT = 47nF. CCT = 47nF CCT = 100nF A/R = GND. 200 s/div 200 s/div 20ms/div Analog Devices 5. MAX9814 Microphone Amplifier with AGC and Low-Noise Microphone Bias Typical Operating Characteristics (continued). (VDD = 5V, CCT = 470nF, CCG = F, VTH = VMICBIAS x , GAIN = VDD (40dB), AGC disabled, no load, RL = 10k , COUT = 1 F, TA = +25 C, unless otherwise noted.). HOLD AND RELEASE TIME HOLD AND RELEASE TIME. MAX9814 toc19. MAX9814 toc20. VMICOUT VMICOUT. 500mV/div 500mV/div 0V 0V. CCT = 47nF CCT = 47nF. A/R = VDD A/R = UNCONNECTED. 40ms/div 100ms/div Analog Devices 6. MAX9814 Microphone Amplifier with AGC and Low-Noise Microphone Bias Pin Configuration TOP VIEW. MICBIAS. MICIN. GAIN. BIAS. A/R. TH. 14 13 12 11 10 9 8. MAX9814. *EP. +. 1 2 3 4 5 6 7. CT. SHDN. CG. VDD. MICOUT. GND. TDFN. Pin Description PIN. NAME FUNCTION. TDFN. Timing Capacitor Connection.