19-2408; Rev 1; 1/03 Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown The MAX4060/MAX4062 are capable of switching their output between the differential input and a singleended auxiliary microphone amplifier input. In addition, the MAX4060/MAX4062 have a low-noise microphone bias generator. The differential gain of the MAX4061/MAX4062 is set with a single resistor. The MAX4060 has a fixed gain of 10V/V and is PC99/2001 compliant. The MAX4061 includes a complete shutdown mode. In shutdown, the supply current is reduced to 0.3µA and the current to the microphone bias is cut off for ultimate power savings. The MAX4060 operates from a 4.5V to 5.5V single supply and the MAX4061/MAX4062 operate from 2.4V to 5.5V. All devices are specified over the extended operating temperature range, -40°C to +85°C. The MAX4060/MAX4061 are available in tiny 8-pin thin QFN (3mm x 3mm x 0.8mm) and 8-pin µMAX packages. The MAX4062 is available in a 10-pin µMAX package. Features ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ 2.4V to 5.5V Single-Supply Operation Adjustable Gain or Fixed-Gain Options High PSRR (86dB at 1kHz) High CMRR (70dB at 1kHz) Low Input-Referred Noise Integrated Microphone Bias 750µA Supply Current 0.3µA Shutdown Current ±4kV ESD Protection (AUX_IN) Rail-to-Rail® Outputs THD+N: 0.04% at 1kHz Available in Space-Saving Packages 8-Pin Thin QFN (MAX4060/MAX4061) 8-Pin µMAX (MAX4060/MAX4061) 10-Pin µMAX (MAX4062) Typical Operating Circuit 2.4V TO 5.5V Applications Notebook Audio Systems BIAS 4 VCC USB Audio Peripherals Tablet PCs PDA Audio Systems AES-42-Compliant Microphones MAX4060 Signal Conditioning 8 AUX_IN x10 INT/AUX 1 Ordering Information PART TEMP RANGE PINPACKAGE BIAS TOP MARK MAX4060ETA -40°C to +85°C 8 Thin QFN-EP* ABY MAX4060EUA -40°C to +85°C 8 µMAX MAX4061ETA -40°C to +85°C 8 Thin QFN-EP* MAX4061EUA -40°C to +85°C 8 µMAX — MAX4062EUB -40°C to +85°C 10 µMAX — OUT 2 5 IN+ — ABZ x10 6 IN- BIAS BIAS 3 VBIAS *EP = Exposed paddle. GND Pin Configurations and Selector Guide appear at end of data sheet. 7 Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX4060/MAX4061/MAX4062 General Description The MAX4060/MAX4061/MAX4062 are differential-input microphone preamplifiers optimized for notebook and PDA audio systems. These devices feature adjustable gain with excellent power-supply rejection and common-mode rejection ratios, making them ideal for lownoise applications in portable audio systems. MAX4060/MAX4061/MAX4062 Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC to GND). .................................-0.3V to +6V Any Other Pin to GND ................................-0.3V to (VCC + 0.3V) Duration of Short Circuit to GND or VCC ....................Continuous Continuous Input Current (any pin) ................................ ±10mA Continuous Power Dissipation (TA = +70°C) 8-Pin Thin QFN (derate 4.7mW/°C above +70°C) ......379mW 8-Pin µMAX (derate 4.1mW/°C above +70°C) ............330mW 10-Pin µMAX (derate 5.6mW/°C above +70°C) .........444mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°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. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V CC = 3V for MAX4061/MAX4062, V CC = 5V for MAX4060, GND = 0V, SHDN = V CC , INT/AUX = 0V, R G = 11.11kΩ, RL = 100kΩ to 1.5V, RBIAS = ∞, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Notes 1, 2) PARAMETER Supply Voltage Range Supply Current Output Common-Mode Voltage Slew Rate Supply Current in Shutdown Output Short-Circuit Current SYMBOL VCC CONDITIONS Inferred from PSRR test MIN 5.5 MAX4060 4.5 5.5 ICC I SHDN ISC MAX 2.4 VOCM SR TYP MAX4061/MAX4062 1.25 0.75 1.2 1.5 1.75 ±1 AV = 10V/V V SHDN = 0V, MAX4061 0.001 To GND 30 To VCC 30 UNITS V mA V V/µs 1 µA mA DIFFERENTIAL INPUT (INT/AUX = 0V for MAX4060/MAX4062, default for MAX4061) Input Offset Voltage VOS Common-Mode Input Voltage Range VCM Maximum Differential Input Voltage Small-Signal Bandwidth Input Resistance Input Resistance Match Input Noise-Voltage Density RMS Output Noise Voltage 2 VDIFFMAX ±0.1 1 AV = 1V/V, MAX4061/MAX4062 BW-3dB RIN Either differential input RMATCH en VNRMS ±5 mV 2 V 1 V 600 kHz 100 kΩ 1 % AV = 10V/V, f = 1kHz 100 AV = 100V/V, f = 1kHz, MAX4061/MAX4062 only 20 AV = 10V/V, BW = 22Hz to 22kHz 125 nV/√Hz _______________________________________________________________________________________ µVRMS Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown (V CC = 3V for MAX4061/MAX4062, V CC = 5V for MAX4060, GND = 0V, SHDN = V CC , INT/AUX = 0V, R G = 11.11kΩ, RL = 100kΩ to 1.5V, RBIAS = ∞, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Notes 1, 2) PARAMETER SYMBOL Total Harmonic Distortion Plus Noise THD+N Differential Gain AVDIFF Common-Mode Rejection Ratio CMRR CONDITIONS 1V < VCM < 2V, VOUT = 0.7VRMS, MAX4061/MAX4062 RG = open PSRR TYP MAX 0.04 1 1.13 1.3 9.6 10 10.4 RG = 1.01kΩ 96 100 104 9.6 10.0 10.4 VCM = 500mVP-P, f = 1kHz 70 TA = +25°C 72 TA = TMIN to TMAX 60 VCC = 5V ±100mV, f = 1kHz UNITS % RG = 11.11kΩ 1V < VCM < 2V, VOUT = 0.7VRMS, MAX4060 Power-Supply Rejection Ratio MIN AV = 10V/V, f = 1kHz, VOUT = 0.7VRMS, BW = 22Hz to 22kHz V/V dB 89 dB 86 AUXILIARY INPUT (MAX4060/MAX4062, INT/AUX = VCC) Small-Signal Bandwidth BW-3dB Input Resistance RIN Input Noise-Voltage Density en RMS Output Noise Voltage Total Harmonic Distortion Plus Noise 200 kHz 100 kΩ f = 1kHz 45 nV/√Hz VNRMS BW = 22Hz to 22kHz 385 µVRMS THD+N f = 1kHz, BW = 22Hz to 22kHz 0.05 % Power-Supply Rejection Ratio PSRR Voltage Gain AVAUX TA = +25°C 65 90 TA = TMIN - TMAX 50 VOUT = 0.7VRMS -10.7 -10 IBIAS = 0.8mA to GND, MAX4060 2 2.2 IBIAS = 0.5mA to GND, MAX4062 2 2.2 IBIAS = 0.8mA to GND, MAX4060 2 2.5 dB -9.3 V/V BIAS OUTPUT (MAX4060/MAX4062) Output Voltage VOUT Output Resistance ROUT Output Noise Voltage VNRMS IBIAS = 0.5mA to GND, MAX4062 22 IBIAS = 0.8mA to GND, BW = 22Hz to 22kHz, MAX4060 50 IBIAS = 0.5mA to GND, BW = 22Hz to 22kHz, MAX4062 20 V kΩ 40 Ω µVRMS _______________________________________________________________________________________ 3 MAX4060/MAX4061/MAX4062 ELECTRICAL CHARACTERISTICS (continued) MAX4060/MAX4061/MAX4062 Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown ELECTRICAL CHARACTERISTICS (continued) (V CC = 3V for MAX4061/MAX4062, V CC = 5V for MAX4060, GND = 0V, SHDN = V CC , INT/AUX = 0V, R G = 11.11kΩ, RL = 100kΩ to 1.5V, RBIAS = ∞, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Notes 1, 2) PARAMETER SYMBOL CONDITIONS MAX4060 Power-Supply Rejection Ratio IBIAS = 0.8mA to GND, VCC = 4.5V to 5.5V MIN TYP 50 80 IBIAS = 0.8mA, VCC = 5V + 100mVP-P, f = 1kHz PSRR MAX4062 IBIAS = 0.5mA to GND, VCC = 2.4V to 5.5V MAX UNITS 70 dB 50 IBIAS = 0.5mA, VCC = 3V + 100mVP-P, f = 1kHz 74 71 DIGITAL INPUTS (SHDN for MAX4061 and INT/AUX for MAX4060/MAX4062) Input Leakage Current IIN Input Voltage High VINH Input Voltage Low VINL ±1 VIN = 0V or VCC 0.7 ✿ VCC µA V 0.3 ✿ VCC V Shutdown Enable Time tON MAX4061 10 µs Shutdown Disable Time tOFF MAX4061 10 µs Note 1: All specifications are 100% tested at TA = +25°C. Specification limits over temperature (TA = TMIN to TMAX) are guaranteed by design, not production tested. Note 2: MAX4062 requires a 1µF capacitor from BIAS to ground. 4 _______________________________________________________________________________________ Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown GAIN vs. FREQUENCY (NO LOAD) POWER-SUPPLY REJECTION RATIO vs. FREQUENCY (DIFF INPUT) SUPPLY CURRENT vs. TEMPERATURE -60 -80 -9 -15 100 1k 10k 100k 1M 0 10 100 1k 10k 100k FREQUENCY (Hz) FREQUENCY (Hz) SUPPLY CURRENT vs. SUPPLY VOLTAGE SHUTDOWN SUPPLY CURRENT vs. TEMPERATURE 0.6 0.5 0.4 0.3 0.2 AV = 10V/V NO LOAD 10 80 VOH vs. TEMPERATURE VOH = VCC - VOUT ILOAD = 2.5mA 1 0.1 10 0.01 3.5 4.0 4.5 5.0 1 -40 5.5 -15 10 35 60 85 -40 MAX4060 toc07 VOH = VCC - VOUT 150 250 200 VOL (mV) VOH (mV) VOL (mV) 100 75 50 25 0 35 TEMPERATURE (°C) 60 85 VCC = 3V 150 100 50 1 85 300 100 ILOAD = 50µA 60 VCC = 3V 125 10 35 VOL vs. LOAD CURRENT 175 ILOAD = 2.5mA 10 TEMPERATURE (°C) VOH vs. LOAD CURRENT VOL vs. TEMPERATURE 1000 10 -15 TEMPERATURE (°C) MAX4060 toc08 3.0 -15 65 100 SUPPLY VOLTAGE (V) -40 50 1000 0.001 2.5 35 ILOAD = 50µA 0 2.0 20 MAX4060 toc09 0.1 5 VOH (mV) 0.7 -40 -25 -10 MAX4060 toc05 0.8 1M TEMPERATURE (°C) 100 SHUTDOWN SUPPLY CURRENT (nA) MAX4060 toc04 0.9 0.4 AV = 100V/V -120 10 VCC = 3V 0.6 0.2 -100 -12 SUPPLY CURRENT (mA) AV = 10V/V VCC = 5V MAX4060 toc06 -6 0.8 SUPPLY CURRENT (mA) PSRR (dB) GAIN (dB) -40 MAX4060 toc03 -20 0 -3 1.0 MAX4060 toc02 MAX4060 toc01 VCC = 5V 3 0 0 0 1 2 3 LOAD CURRENT (mA) 4 5 0 1 2 3 4 5 LOAD CURRENT (mA) _______________________________________________________________________________________ 5 MAX4060/MAX4061/MAX4062 Typical Operating Characteristics (VCC = 3V (MAX4061/MAX4062), VCC = 5V for MAX4060, AV = 10V/V, RL ≥ 100kΩ to 1.5V, SHDN = VCC (MAX4061 only), TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VCC = 3V (MAX4061/MAX4062), VCC = 5V for MAX4060, AV = 10V/V, RL ≥ 100kΩ to 1.5V, SHDN = VCC (MAX4061 only), TA = +25°C, unless otherwise noted.) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (DIFF INPUT) IBIAS = 800µA 2.275 VOUT = 2.26VP-P 1 MAX4060 toc12 1 MAX4060 toc10 2.300 TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY (AUX INPUT) MAX4060 toc11 MAX4060 MIC BIAS VOLTAGE vs. TEMPERATURE VOUT = 2.26VP-P VCC = 3V 0.1 THD+N (%) 2.225 2.200 2.175 VCC = 3V 0.1 THD+N (%) MIC BIAS VOLTAGE (V) 2.250 VCC = 5V VCC = 5V 0.01 0.01 2.150 2.125 0.001 2.100 -40 -15 10 35 60 100 1k 10k 100k 10 100 1k 10k FREQUENCY (Hz) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT AMPLITUDE (DIFF INPUT, VCC = 3V) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT AMPLITUDE (DIFF INPUT, VCC = 5V) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT AMPLITUDE (AUX INPUT, VCC = 3V) f = 1kHz THD+N (%) f = 1kHz 0.1 BW = 22kHz 1 THD+N (%) 1 10 MAX4060 toc15 BW = 22kHz MAX4060 toc14 MAX4060 toc13 10 1 0.1 0.1 f = 1kHz f = 10kHz f = 10kHz f = 10kHz 0.01 0.01 0.01 0.001 0.001 0 0.5 1.0 1.5 2.0 2.5 0.001 0 3.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 0 0.5 1.0 1.5 2.0 2.5 OUTPUT VOLTAGE (VP-P) OUTPUT VOLTAGE (VP-P) OUTPUT VOLTAGE (VP-P) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT AMPLITUDE (AUX INPUT, VCC = 5V) INPUT-REFERRED NOISE vs. FREQUENCY (DIFF INPUT) MAX4060 MIC BIAS OUTPUT NOISE MAX4060 toc17 BW = 22kHz 3.0 MAX4060 toc18 800 MAX4060 toc16 10 700 VCC = 5V BW = 22Hz TO 22kHz 600 (nV/√Hz) 1 f = 1kHz 0.1 500 400 5µV/div 300 f = 10kHz 0.01 200 100 0 0.001 0 0.5 1.0 1.5 2.0 2.5 OUTPUT VOLTAGE (VP-P) 6 100k FREQUENCY (Hz) BW = 22kHz THD+N (%) 0.001 10 85 TEMPERATURE (°C) 10 THD+N (%) MAX4060/MAX4061/MAX4062 Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown 3.0 3.5 10 100 1k 10k 100k 100ms/div FREQUENCY (Hz) _______________________________________________________________________________________ Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown MAX4062 MIC BIAS OUTPUT NOISE SMALL-SIGNAL TRANSIENT RESPONSE FOR DIFF INPUT MAX4060 toc19 MAX4060 toc20 VCC = 5V BW = 22Hz TO 22kHz INPUT 5mV/div 5µV/div OUTPUT 50mV/div 100ms/div 10µs/div LARGE-SIGNAL TRANSIENT RESPONSE FOR DIFF INPUT SMALL-SIGNAL TRANSIENT RESPONSE FOR AUX INPUT MAX4060 toc22 MAX4060 toc21 INPUT 100mV/div INPUT 5mV/div OUTPUT 1V/div OUTPUT 50mV/div 10µs/div 10µs/div LARGE-SIGNAL TRANSIENT RESPONSE FOR AUX INPUT OUTPUT OVERDRIVEN MAX4060 toc23 MAX4060 toc24 INPUT 200mV/div DIFFERENTIAL INPUT INPUT 500mV/div OUTPUT 1V/div 10µs/div OUTPUT 1V/div 10µs/div _______________________________________________________________________________________ 7 MAX4060/MAX4061/MAX4062 Typical Operating Characteristics (continued) (VCC = 3V (MAX4061/MAX4062), VCC = 5V for MAX4060, AV = 10V/V, RL ≥ 100kΩ to 1.5V, SHDN = VCC (MAX4061 only), TA = +25°C, unless otherwise noted.) Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown MAX4060/MAX4061/MAX4062 Pin Description PIN NAME FUNCTION 2 INT/AUX Internal (Differential) or Auxiliary (Single-Ended) Input Select. Drive INT/AUX low to select internal or high to select auxiliary microphone input. 3 3 OUT Amplifier Output. OUT is high impedance when in shutdown mode. 3 — — BIAS External Electret Microphone Capsule Bias Output. BIAS has a greater than 2kΩ output impedance. 4 4 5 VCC Power Supply. Bypass the VCC to GND with a 0.1µF capacitor. 5 5 6 IN+ Noninverting Differential Amplifier Input. AC-couple the audio signal into IN+. 6 6 7 IN- Inverting Differential Amplifier Input. AC-couple the audio signal into IN-. 7 7 8 GND MAX4060 MAX4061 MAX4062 1 — 2 Ground 8 — 9 AUX_IN Single-Ended Input for Auxiliary Microphone. AC-couple the audio signal into AUX_IN. — 1 1 G2 Gain-Selectable Input. Connect an external resistor between G1 and G2 to set the gain for the differential amplifier. (See Adjustable Differential-Gain Setting section.) — 2 — SHDN Shutdown Input. Drive SHDN high for normal operation. Drive SHDN low for shutdown mode. — — 4 BIAS External Electret Microphone Capsule Bias Output Bypass BIAS with 1µF Capacitor to Ground — 8 10 G1 Gain-Selectable Input. Connect an external resistor between G1 and G2 to set the gain for the differential amplifier. Detailed Description The MAX4060/MAX4061/MAX4062 are differential microphone preamplifiers providing high-quality audio, optimized for use in computer and mobile applications. These devices feature rail-to-rail outputs, very high power-supply rejection, and common-mode rejection, making them ideal for low-noise applications. The MAX4060/MAX4061/MAX4062 are particularly effective when layout constraints force the microphone amplifier to be physically remote from the ECM microphone and/or the rest of the audio circuitry. The MAX4060/MAX4062 are capable of switching their output between the differential input and an inverting single-ended input. INT/AUX selects either the differential input or single-ended auxiliary input. In addition, the MAX4060/MAX4061 have an internal bias generator to bias the microphone in either differential or singleended modes. The MAX4061 includes a complete 8 0.3µA shutdown mode for ultimate power savings. The differential gain of the MAX4061/MAX4062 is set with a single resistor connected between the G1 and G2 pins. The MAX4060 has a fixed gain of 10V/V. Differential Input The main microphone input is a low-noise, differential input structure. This is an almost essential element when faced with amplification of low-amplitude analog signals in digitally intense environments such as notebook PCs or PDAs. Used correctly, the advantages over a single-ended solution are: • Better power-supply noise rejection. • Less degradation from noise in PC board ground planes. • The microphone and preamplifier can be placed physically further apart, easing PC board layout restrictions. _______________________________________________________________________________________ Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown 2.4V TO 5.5V BIAS 4 VCC MAX4060 8 AUX_IN x10 INT/AUX 1 BIAS OUT 2 5 IN+ x10 6 IN- BIAS BIAS 3 VBIAS GND 7 Fixed Differential Gain (MAX4060) The MAX4060 has an internal fixed gain of 10V/V for its differential input. This feature simplifies design, reduces pin count, footprint, and eliminates external gain-setting resistors. Adjustable Differential-Gain Setting The MAX4061/MAX4062 allow the user to alter the gain to optimize the signal-to-noise ratio (SNR) of their system. The gain is set by a single external resistor (RG) connected between the G1 and G2 pins, where: RG = 100kΩ / (AV - 1) where AV is the required voltage gain. Hence, an 11.11kΩ resistor yields a gain of 10V/V, or 20dB. Leaving the pins unconnected results in a gain of 1V/V. Gain for the MAX4061/MAX4062 is defined as: AV = VOUT / (VIN+ - VIN-) The resistor can be either fixed or variable, allowing the use of a digitally controlled potentiometer to alter the gain under software control. Input Capacitors The two differential microphone inputs and the singleended auxiliary input of the MAX4060/MAX4061/ MAX4062 have on-chip bias components, allowing the user to AC-couple any signals onto the input. The input resistance is 100kΩ (typ), so the capacitor size may be chosen accordingly to define the LF rolloff desired. This can be calculated as: CIN = 1 / (2πfCUTRIN) This assumes a low source impedance driving the inputs. A further consideration for the differential input is the effect of these series input capacitors on low-frequency, common-mode rejection. Any mismatch in the values of these two capacitors degrades the CMRR at frequencies where the impedance of the capacitor is significant compared to the input resistance of the amplifier—this is usually most noticeable at low frequencies. One way to avoid the need for matched or tight tolerance capacitors is to deliberately oversize the values on the differ- _______________________________________________________________________________________ 9 MAX4060/MAX4061/MAX4062 Functional Diagram MAX4060/MAX4061/MAX4062 Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown 2.4V TO 5.5V 5 100kΩ VCC RBIAS 4 BIAS VBIAS CBIAS MAX4062 9 AUX_IN x10 INT/AUX 2 OUT 3 6 IN+ 7 IN- G1 10 G2 1 GND 8 Figure 1. MAX4062 with Auxiliary Input Configuration ential inputs and to set the lower 3dB point (fCUT) of the amplifier by sizing the output capacitor appropriately. The input impedance matching on the differential input is typically 1%, allowing input capacitor matching to be effective at improving low-frequency PSRR. Common-Mode Rejection Ratio The common-mode rejection ratio (CMRR) refers to the amount of rejection that the amplifier is capable of providing to any signal applied equally to the IN+ and INinputs. In the case of amplifying low-level microphone signals in noisy digital environments, it is a key figure of merit. In audio circuits, this is generally measured for VIN as an AC signal: CMRR(dB) = ADM / ACM where ADM is the differential gain, ACM is the commonmode gain. Input voltages are sufficiently small such that the output is not clipped in either differential or common-mode application. The topology used in the MAX4061/ MAX4062 means that the CMRR actually improves at higher differential gains—another advantage of using differential sensing. 10 Auxiliary Input The auxiliary input is a single-ended input intended to be used with a jack-socket-type microphone input (Figure 1). Internal DC-bias components (as on the main inputs) allow the input signal to be AC-coupled. Mechanically switched jack sockets can be used in conjunction with the INT/AUX select pin, allowing the auxiliary microphone input to be automatically selected when a jack socket is inserted. Microphone Bias Voltage MAX4060 The MAX4060 has a microphone bias voltage designed to comply with the Microsoft/Intel PC99/2001 audio standard. It features source impedance of greater than 2kΩ, and delivers more than 2V of bias when loaded with a current of 800µA. This limits operation of this part to supplies between 4.5V to 5.5V (see Figure 2). ______________________________________________________________________________________ Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown MAX4060/MAX4061/MAX4062 4.5V TO 5.5V 4 VCC MICROPHONE INPUT MAX4060 8 AUX_IN x10 3 BIAS INT/AUX 1 OUT 2 VBIAS RBIAS 5 IN+ x10 6 INGND 7 Figure 2. MAX4060 Used for Biasing a Microphone MAX4061/MAX4062 The MAX4061/MAX4062 have a lower bias voltage and low-impedance outputs (optimum electret bias resistor can then be set externally). This gives a low-noise, flexible solution that can run from 2.4V to 5.5V, suitable for hand-held devices such as PDAs that typically have audio power supplies in the 3V region (see Figure 3). In applications where the differential microphone is placed some distance from the MAX4060/MAX4061/ MAX4062, using a remote differential bias scheme as shown in Figure 4 can provide improved noise rejection. Output MAX4060/MAX4061 DC Bias The output voltage has a DC-bias voltage independent of the power supplies, resulting in superior PSRR performance. The MAX4061 output is high impedance when the part is in shutdown mode. AC-coupling the output into the next audio stage (e.g., CODEC) is recommended. Applications Information Shutdown Mode The MAX4061 features a low-power, complete shutdown mode. When SHDN goes low, the supply current drops to 0.3µA, the output enters a high-impedance state, and the bias current to the microphone is switched off. Driving SHDN high enables the amplifier. SHDN should not be left floating. Power Supplies and Layout The MAX4060 operates from a 4.5V to 5.5V single supply and the MAX4061/MAX4062 operate from a 2.4V to 5.5V single supply. Bypass the power supply with a 0.1µF capacitor to ground. In systems where analog and digital grounds are available, the MAX4060/ MAX4061 should be connected to the analog ground. ______________________________________________________________________________________ 11 MAX4060/MAX4061/MAX4062 Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown 2.4V TO 5.5V 5 VCC 4 BIAS VBIAS MAX4062 0.1µF 9 AUX_IN x10 0.1µF INT/AUX 2 2.2kΩ 10 G1 RG 11kΩ OUT 3 1 G2 2.2kΩ 0.1µF 6 IN+ 7 IN0.1µF GND 8 Figure 3. MAX4062 Used to Bias a Microphone Connected to the Auxiliary Input and the Differential Input 12 ______________________________________________________________________________________ Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown MAX4060/MAX4061/MAX4062 2.4V TO 5.5V 5 VCC 4 BIAS VBIAS MAX4062 0.1µF 9 AUX_IN 2.2kΩ x10 0.1µF INT/AUX 2 VDD 10 G1 1kΩ RG 11kΩ OUT 3 1 G2 1kΩ 2.2µF 0.1µF 6 IN+ 7 IN1kΩ 0.1µF GND 8 1kΩ 2.2µF Figure 4. Remote Differential Microphone Bias Network Optimizes Noise Rejection in Long-Run, PC Board Traces Pin Configurations TOP VIEW INT/AUX 1 8 AUX_IN OUT 2 7 GND BIAS 3 VCC 4 MAX4060 G2 1 8 G1 SHDN 2 7 GND 6 IN- OUT 3 5 IN+ VCC 4 µMAX/THIN QFN MAX4061 6 IN- 5 IN+ µMAX/THIN QFN G2 1 INT/AUX 10 G1 2 MAX4062 9 AUX_IN OUT 3 8 GND BIAS 4 7 IN- VCC 5 6 IN+ µMAX ______________________________________________________________________________________ 13 Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown MAX4060/MAX4061/MAX4062 Block Diagrams 4.5V TO 5.5V 2.4V TO 5.5V 4 5 VCC 4 VCC MAX4060 8 VCC 2.4V TO 5.5V AUX_IN MAX4062 8 AUX_IN x10 x10 INT/AUX 3 BIAS 1 MAX4061 2 SHDN INT/AUX 2 4 BIAS VBIAS VBIAS 5 IN+ OUT 5 IN+ 6 IN- 2 OUT OUT 3 3 6 IN+ 6 INx10 GND G1 G2 8 1 GND 7 7 IN- 7 G1 G2 10 1 GND 8 Selector Guide AUXILIARY INPUT DIFF INPUT GAIN SINGLE-ENDED INPUT GAIN (dB) MAX4060 ✔ 20dB MAX4061 — ADJ MAX4062 ✔ ADJ PRODUCT* MICROPHONE BIAS SHUTDOWN MODE SUPPLY VOLTAGE (V) 20 ✔ — 4.5 to 5.5 — — ✔ 2.4 to 5.5 20 ✔ — 2.4 to 5.5 *See Block Diagrams. Chip Information TRANSISTOR COUNT: 264 PROCESS: BiCMOS 14 ______________________________________________________________________________________ Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown 6, 8, &10L, QFN THIN.EPS PACKAGE OUTLINE, 6, 8 & 10L, QFN THIN (DUAL), EXPOSED PAD, 3x3x0.80 mm 21-0137 C COMMON DIMENSIONS SYMBOL A MIN. 0.70 0.80 D 2.90 MAX. 3.10 E 2.90 3.10 A1 0.00 0.05 L k 0.20 0.40 0.25 MIN A2 0.20 REF. PACKAGE VARIATIONS PKG. CODE N D2 E2 e JEDEC SPEC b T633-1 6 1.50±0.10 2.30±0.10 0.95 BSC MO229 / WEEA 0.40±0.05 1.90 REF T833-1 8 1.50±0.10 2.30±0.10 0.65 BSC MO229 / WEEC 0.30±0.05 1.95 REF T1033-1 10 1.50±0.10 2.30±0.10 0.50 BSC MO229 / WEED-3 0.25±0.05 2.00 REF [(N/2)-1] x e PACKAGE OUTLINE, 6, 8 & 10L, QFN THIN (DUAL), EXPOSED PAD, 3x3x0.80 mm 21-0137 C ______________________________________________________________________________________ 15 MAX4060/MAX4061/MAX4062 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) 4X S 8 8 INCHES DIM A A1 A2 b E ÿ 0.50±0.1 H c D e E H 0.6±0.1 L 1 1 α 0.6±0.1 S BOTTOM VIEW D MIN 0.002 0.030 MAX 0.043 0.006 0.037 0.010 0.014 0.005 0.007 0.116 0.120 0.0256 BSC 0.116 0.120 0.188 0.198 0.016 0.026 6∞ 0∞ 0.0207 BSC 8LUMAXD.EPS MAX4060/MAX4061/MAX4062 Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown MILLIMETERS MAX MIN 0.05 0.75 1.10 0.15 0.95 0.25 0.36 0.13 0.18 2.95 3.05 0.65 BSC 2.95 3.05 5.03 4.78 0.41 0.66 0∞ 6∞ 0.5250 BSC TOP VIEW A1 A2 A α c e FRONT VIEW b L SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, 8L uMAX/uSOP APPROVAL DOCUMENT CONTROL NO. 21-0036 16 ______________________________________________________________________________________ REV. J 1 1 Differential Microphone Preamplifiers with Internal Bias and Complete Shutdown 10LUMAX.EPS e 4X S 10 10 INCHES H ÿ 0.50±0.1 0.6±0.1 1 1 0.6±0.1 BOTTOM VIEW TOP VIEW D2 MILLIMETERS MAX DIM MIN 0.043 A 0.006 A1 0.002 A2 0.030 0.037 D1 0.116 0.120 D2 0.114 0.118 E1 0.116 0.120 E2 0.114 0.118 H 0.187 0.199 L 0.0157 0.0275 L1 0.037 REF b 0.007 0.0106 e 0.0197 BSC c 0.0035 0.0078 0.0196 REF S α 0∞ 6∞ MAX MIN 1.10 0.05 0.15 0.75 0.95 2.95 3.05 2.89 3.00 2.95 3.05 2.89 3.00 4.75 5.05 0.40 0.70 0.940 REF 0.177 0.270 0.500 BSC 0.090 0.200 0.498 REF 0∞ 6∞ E2 GAGE PLANE A2 c A b A1 α E1 D1 L L1 FRONT VIEW SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, 10L uMAX/uSOP APPROVAL DOCUMENT CONTROL NO. 21-0061 REV. I 1 1 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 17 © 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX4060/MAX4061/MAX4062 Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.)