EVALUATION KIT AVAILABLE MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface General Description The MAX5456/MAX5457 dual, logarithmic taper digital potentiometers feature a simple pushbutton interface that controls volume and balance in audio applications. Each potentiometer has 32 tap points and replaces mechanical potentiometers. Refer to the MAX5408- MAX5411 data sheet for SPI versions of the MAX5456/ MAX5457. Use the MAX5456/MAX5457 digital inputs with momentary contact single-pole/single-throw (SPST) pushbutton switches. Each input includes internal debounce circuitry and a 50k pullup resistor. The MAX5456/MAX5457 advance the wiper setting once per button push. Maxim's proprietary SmartWiperTM control eliminates the need for a microcomputer to increase the wiper transition rate. Holding the control input low for more than 1s advances the wiper at a rate of 4Hz for 4s and 16Hz per second thereafter. The MAX5456/MAX5457 provide temperature coefficients of 50ppm/C end-to-end and 5ppm/C ratiometric and a nominal resistance of 10k per potentiometer. An integrated click/pop suppression feature minimizes the audible noise generated by wiper transitions. The typical total harmonic distortion plus noise (THD+N) for these devices is 0.01%. The MAX5457 features a 3-button interface with a MODE input that toggles between volume- and balancecontrol modes. An LED output indicates volume or balance mode. The MAX5456 features a 4-button interface with separate inputs for up and down volume controls and left and right balance controls. Features o SmartWiper Control Provides Accelerated Wiper Motion o Debounced Pushbutton Interface with Internal Pullup Resistors o Logarithmic Taper with 2dB Steps Between Taps o Single +2.7V to +5.5V or Dual 2.7V Supply Operation o Low 0.5A Standby Supply Current o Clickless Switching o 10k End-to-End Fixed Resistance Value o Mute Function to -90dB (typ) o Power-On Reset to -12dB Wiper Position o 32 Tap Positions for Each Wiper o Small 16-Pin QSOP Package Ordering Information TEMP RANGE PIN-PACKAGE MAX5456EEE+ PART -40oC to +85oC 16 QSOP MAX5457EEE+ -40oC to +85oC 16 QSOP +Denotes a lead(Pb)-free/RoHS-compliant package. Note: For leaded version, contact factory. The MAX5456/MAX5457 is available in a 16-pin QSOP packages and specified over the extended (-40C to +85C) temperature range. Pin Configurations TOP VIEW Applications Stereo Volume Control DN/BAL0 1 Fading and Balancing Stereo Signals UP/BAL1 2 Stereo Blending and Mixing SmartWiper is a trademark of Maxim Integrated Products, Inc. 16 VDD 15 VLOGIC 14 GND MODE 3 MODE_IND 4 Typical Application Circuits and Selector Guide appear at end of data sheet. + MAX5457 13 VSS H0 5 12 H1 L0 6 11 L1 W0 7 10 W1 9 SHDN 8 MUTE QSOP Pin Configurations are continued at end of data sheet. For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated's website at www.maximintegrated.com. 19-3490; Rev 2; 8/12 MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface ABSOLUTE MAXIMUM RATINGS (MAX5456) SHDN, MUTE, VOLUP, VOLDN, BAL_ to GND.....................................-0.3V to (VLOGIC + 0.3V) (MAX5457) SHDN, MUTE, UP/BAL1, DN/BAL0, MODE, MODE_IND to GND...........................-0.3V to (VLOGIC + 0.3V) H_, L_, and W_ to VSS ..............................-0.3V to (VDD + 0.3 V) VDD to GND ..............................................................-0.3V to +6V VDD to VSS ................................................................-0.3V to +6V VLOGIC to GND.........................................................-0.3V to +6V VLOGIC to VSS ...........................................................-0.3V to +6V VSS to GND............................................................-3.0V to +0.3V Peak Current into H_, L_, and W_.......................................1mA Average Current into H_, L_, and W_ ..............................500A Input and Output Latchup Immunity...............................200mA Continuous Power Dissipation (TA = +70C) 16-Pin QSOP (derate 8.3mW/C above +70C)........666.7mW Operating Temperature Range ...........................-40C to +85C Junction Temperature ......................................................+150C Storage Temperature Range .............................-60C to +150C Lead Temperature (soldering, 10s) .................................+300C Soldering Temperature (reflow) .......................................+260C 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 (VDD = VLOGIC = +2.7V to +5.5V, VSS = 0V, GND = 0V, VH_ = VDD, VL_ = VSS, TA = TMIN to TMAX. Typical values are at TA = +25C, unless otherwise specified.) (Note 1) PARAMETER End-to-End Resistance Maximum Bandwidth SYMBOL R fCUTOFF Absolute Ratio Tolerance CONDITIONS Figures 1, 2 MIN TYP MAX UNITS 7 10 13 k From H_ to W_, CLOAD = 10pF No load at the output of the wiper, W_ = -6dB Tap-to-Tap Tolerance Total Harmonic Distortion Plus Noise THD+N kHz dB 0.1 dB VDD = 5V, VH_ = (VDD / 2) + 1VRMS, f = 1kHz, tap = -6dB, VL_ = VDD / 2, RL = 0.01 VDD = 3V, VSS = 0V, VL_ = 1.5V, VH_ = 1.5V + 1VRMS, f = 1kHz, RL = 10k to (VDD / 2), CL = 5pF, tap = -6dB 0.23 f = 20Hz to 20kHz, tap = -6dB 0.5 dB -90 dB % Channel-to-Channel Isolation -100 Interchannel Matching Mute Attenuation Power-Supply Rejection Ratio 100 0.25 dB PSRR -80 Wiper Resistance RW 1000 Wiper Capacitance CW 10 pF H Terminal Capacitance CH 5 pF L Terminal Capacitance CL 7 pF End-to-End Resistance Temperature Coefficient 50 ppm/C Ratiometric Resistance Temperature Coefficient 5 ppm/C 0.95 VRMS Output Noise en 20Hz to 20kHz dB 1700 PUSHBUTTON CONTACT INPUTS (UP/BAL1, DN/BAL0, MUTE, VOLUP, VOLDN, BAL0, BAL1, MODE) Internal Pullup Resistor RPULLUP 32 Single Pulse-Width Input tlPW Figure 5 22.5 Repetitive Input Pulse High Time tHPW Figure 5 40 Timeout Period 2 tWS Click/pop suppression inactive 50 65 k ms ms 32 ms Maxim Integrated MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface ELECTRICAL CHARACTERISTICS (continued) (VDD = VLOGIC = +2.7V to +5.5V, VSS = 0V, GND = 0V, VH_ = VDD, VL_ = VSS, TA = TMIN to TMAX. Typical values are at TA = +25C, unless otherwise specified.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS First Autoincrement Point 1 s First Autoincrement Rate 4 Hz Second Autoincrement Point 4 s Second Autoincrement Rate 16 Hz DIGITAL INPUTS (VLOGIC > 4.5V) Input High Voltage VIH Input Low Voltage VIL Input Leakage Current 2.4 V 0.8 Inputs floating 1 Input Capacitance 5 V A pF DIGITAL INPUTS (VLOGIC < 4.5V) Input High Voltage VIH Input Low Voltage VIL Input Leakage Current 0.7 x VLOGIC V 0.3 x VLOGIC V 1 A Inputs floating Input Capacitance 5 pF POWER SUPPLIES Supply Voltage VDD Negative Power Supply VSS Supply-Voltage Difference Active Supply Current IDD Standby Supply Current ISTBY Shutdown Supply Current ISHDN Power-Up Time 2.7 -2.7 5.5 V 0 V VDD - VSS 5.5 V (Note 2) 100 A VDD = +5.5V, VSS = 0V, VLOGIC = 2.7V (Note 3) 2 10 VLOGIC = VDD = +2.7V, VSS = -2.7V (Note 3) 0.5 1 (Note 4) 1 tPU 10 Logic Standby Voltage VLOGIC 2.7 Logic Active Supply Current ILOGIC (Note 2) Logic Standby Supply Current ILOGICSTBY (Note 3) Logic Shutdown Current ILOGICSHDN (Note 4) 0.5 A A ms VDD V 160 A 1 A 1 A DIGITAL OUTPUT, MODE_IND Output Low Voltage Output Leakage Current Output Capacitance Maximum Sink Current VOL VLOGIC = 2.7V, ISINK = 10mA 0.4 VLOGIC = 5.5V, ISINK = 10mA 0.2 0.1 10 V A 3 pF 150 mA Note 1: Parameters are 100% production tested at +85C and limits through temperature are guaranteed by design. Note 2: Supply current measured with the supply on and a button pushed. Note 3: Supply current measured with the power on, no button pushed, and the wiper position fixed. Note 4: This is the measured current with SHDN low and MODE_IND unconnected. Maxim Integrated 3 MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface Typical Operating Characteristics (VDD = VLOGIC = +2.7V to +5.5V, VSS = 0V, GND = 0V, VH_ = VDD, VL_ = VSS, TA = TMIN to TMAX. Typical values are at TA = +25C, unless otherwise specified.) -10 1000 950 900 850 800 750 700 650 END-TO-END RESISTANCE CHANGE (%) 1050 0.5 MAX5456/7 toc02 0 MAX5456/7 toc01 VDD = VLOGIC = 5V ATTENUATION (dB) WIPER RESISTANCE () 1200 1150 1100 END-TO-END RESISTANCE % CHANGE vs. TEMPERATURE ATTENUATION vs. TAP POSITION -20 -30 -40 -50 -60 600 4 0 WIPER VOLTAGE (V) 8 12 16 20 24 28 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 -0.4 -15 -40 32 10 35 60 85 TEMPERATURE (C) TAP POSITION WIPER SWITCHING TRANSIENT (TIMING OUT) ACTIVE SUPPLY CURRENT vs. TEMPERATURE MAX5456/7 toc05a MAX5456/7 toc04 220 VDD = VLOGIC = 5.5V, ILOGIC + IVDD 215 ACTIVE SUPPLY CURRENT (A) 0.4 -0.5 -70 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 MAX5456/7 tpc03 WIPER RESISTANCE vs. WIPER VOLTAGE 210 5V/div VOLUP VH_ = VDD VL_ = 0 205 200 1V/div 195 WIPER TRANSITION FROM -2dB to 0dB 190 185 180 -40 -15 10 35 60 10ms/div 85 TEMPERATURE (C) WIPER SWITCHING TRANSIENT (SUPPRESSION CIRCUIT ACTIVE) LOGIC SUPPLY CURRENT vs. LOGIC SUPPLY VOLTAGE MAX5456/7 toc05b MAX5456/7 toc06a 200 VOLUP VH_ = SQUARE WAVE FROM VDD TO VSS, VL_ = VDD / 2 2V/div WIPER TRANSITION FROM -2dB to 0dB LOGIC SUPPLY CURRENT (A) 180 5V/div 160 ACTIVE LOGIC SUPPLY CURRENT 140 120 100 80 60 40 20 0 4ms/div 2.7 3.2 3.7 4.2 4.7 5.2 5.5 LOGIC SUPPLY VOLTAGE (V) 4 Maxim Integrated MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface Typical Operating Characteristics (continued) (VDD = VLOGIC = +2.7V to +5.5V, VSS = 0V, GND = 0V, VH_ = VDD, VL_ = VSS, TA = TMIN to TMAX. Typical values are at TA = +25C, unless otherwise specified.) WIPER-TO-END TERMINAL RESISTANCE vs. TAP POSITION STANDBY LOGIC SUPPLY CURRENT 0.15 0.10 0.05 RWH 75 3.2 3.7 4.2 4.7 W_ SET TO 0dB -2 -4 25 W_ SET TO -6dB -6 RWL 0 -8 8 0 5.2 5.5 16 24 32 0.01 0.1 1 10 100 TAP POSITION FREQUENCY (kHz) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY DIGITAL SUPPLY CURRENT vs. DIGITAL INPUT VOLTAGE POWER-SUPPLY REJECTION RATIO vs. FREQUENCY 1 LOAD = 10k 0.1 0.01 NO LOAD 0.001 800 -30 600 500 400 1000 10,000 -70 100 -80 100,000 -90 0 1 2 3 4 147 1000 ACTIVE LOGIC SUPPLY CURRENT 144 143 MAX5456 toc13 9 8 NOISE (nVRMS/Hz) LOGIC SUPPLY CURRENT (mA) VLOGIC = 5.5V 148 100 FREQUENCY (kHz) SPECTRAL NOISE DENSITY 7 6 5 4 3 142 2 141 1 140 0 -40 -15 10 35 TEMPERATURE (C) Maxim Integrated 10 1 10 MAX5456/7 toc12 150 145 5 DIGITAL INPUT VOLTAGE (V) LOGIC SUPPLY CURRENT vs. TEMPERATURE 146 -50 200 FREQUENCY (Hz) 149 -40 -60 300 0 100 VDD = 5V 1VP-P, VH_ = 5V, VL_ = 2.5V, W_ SET TO -6dB -20 700 0.0001 10 0 -10 1000 MAX5456/7 toc11 900 PSRR (dB) 10 1000 MAX5456/7 toc10 VH_ = 2.5V 1VP-P, VL_ = 2.5V, W_ SET TO -6dB, 20Hz TO 20kHz BANDPASS DIGITAL SUPPLY CURRENT (A) MAX5456/7 toc09 LOGIC SUPPLY VOLTAGE (V) 100 THD+N (%) 0 50 0 2.7 VH_ = 2.5V 1VP-P, VL_ = 2.5V, CL_ = 10pF 2 RESPONSE (dB) 0.20 FREQUENCY RESPONSE MAX5456/7 toc07 0.25 100 NOMINAL END-TO-END RESISTANCE (%RHL) MAX5456/7 toc06b LOGIC SUPPLY CURRENT (A) 0.30 MAX5456/7 toc08 LOGIC SUPPLY CURRENT vs. LOGIC SUPPLY VOLTAGE 60 85 0.01 0.1 1 10 100 FREQUENCY (kHz) 5 MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface Pin Description PIN MAX5457 MAX5456 3 -- FUNCTION MODE Volume/Balance Control. Each transition from high to low toggles between volume and balance modes. MODE is pulled high internally with a 50k resistor to VLOGIC. On power-up, the MAX5457 is in volume-control mode. Volume-Control/Balance-Control Mode Indicator Open-Drain Output. Connect to an LED through a resistor to VLOGIC. When the LED is on, the MAX5457 is in balancecontrol mode. When the LED is off, the MAX5457 is in volume-control mode. See the Mode Indicator, MODE_IND section for more detail. 4 -- MODE_IND 5 5 H0 Potentiometer 0 High Terminal. H0 and L0 terminals can be reversed. 6 6 L0 Potentiometer 0 Low Terminal. L0 and H0 terminals can be reversed. 7 7 W0 Potentiometer 0 Wiper Terminal 8 8 SHDN Active-Low Shutdown Input. In shutdown mode, the MAX5456/MAX5457 store the last wiper settings. The wipers move to the L end of the resistor string, and the H end of the resistor string disconnects from the signal input. Terminating shutdown mode restores the wipers to their previous settings. 9 9 MUTE Mute Input. When MUTE is low, the wiper goes to the highest attenuation setting (see Table 1). MUTE is internally pulled up with 50k to VLOGIC. 10 10 W1 Potentiometer 1 Wiper Terminal 11 11 L1 Potentiometer 1 Low Terminal. L1 and H1 terminals can be reversed. 12 12 H1 Potentiometer 1 High Terminal. H1 and L1 terminals can be reversed. 13 13 VSS Negative Power Supply. Bypass with 0.1F to ground. 14 14 GND 15 15 VLOGIC 16 16 VDD 1 6 NAME -- Ground Digital Logic Power Supply. Bypass with 0.1F to ground. Analog Power Supply. Bypass with 0.1F to ground. DN/BAL0 Downward Volume/Channel 0 Balance-Control Input. In volume mode, pressing DN/BAL0 moves both wipers towards the L terminals. In balance mode, pressing DN/BAL0 moves the balance towards channel 0. DN/BAL0 is internally pulled up with 50k to VLOGIC. 2 -- UP/BAL1 Upward Volume/Channel 1 Balance-Control Input. In volume mode, pressing UP/BAL1 moves both wipers towards the H terminals. In balance mode, pressing UP/BAL1 moves the balance towards channel 1. UP/BAL1 is internally pulled up with 50k to VLOGIC. -- 3 BAL1 Channel 1 Balance-Control Input. Pressing BAL1 moves the balance towards channel 1. BAL1 is internally pulled up with 50k to VLOGIC. -- 4 BAL0 Channel 0 Balance-Control Input. Pressing BAL0 moves the balance towards channel 0. BAL0 is internally pulled up with 50k to VLOGIC. -- 1 VOLDN Downward Volume-Control Input. Pressing VOLDN moves both wipers towards the L terminals. VOLDN is internally pulled up with 50k to VLOGIC. -- 2 VOLUP Upward Volume-Control Input. Pressing VOLUP moves both wipers towards the H terminals. VOLUP is internally pulled up with 50k to VLOGIC. Maxim Integrated MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface Detailed Description The MAX5456/MAX5457 dual, logarithmic taper digital potentiometers feature a simple pushbutton interface that controls volume and balance in audio applications. Each potentiometer has 32 tap points and replaces mechanical potentiometers (see the Functional Diagrams). Up and Down Interface The MAX5456/MAX5457 interface with momentary contact SPST switches. All switch inputs are internally debounced and pulled up to V LOGIC through 50k resistors. The wiper setting advances once per button press up to 1s. Maxim's SmartWiper control circuitry allows the wiper to advance at a rate of 4Hz when an input is held low from 1s up to 4s, and at a rate of 16Hz if the contact is maintained for greater than 4s (see Table 2). The SmartWiper control eliminates the need for a microcomputer to increase the wiper transition rate. The MAX5456 features independent control inputs for volume and balance control while the MAX5457 MODE input toggles between volume and balance control. Each transition of MODE from high to low toggles the MAX5457 between volume-control and balance-control modes. MODE is internally pulled high with a 50k resistor to VLOGIC. Volume Control In volume-control mode, the MAX5456/MAX5457s' wipers move simultaneously, maintaining the balance separation between each wiper (Figure 3a). When either wiper reaches the maximum tap position (position closest to H_), further commands to increase the volume are ignored. Balance separation is maintained in the maximum volume configuration (Figure 3b). When either wiper reaches the minimum tap position (position closest to L_), further commands to decrease the volume adjust the other wiper until it also reaches the minimum tap position (Figure 3c). Increasing the volume from this minimum position restores the original balance separation of the wipers (Figure 3d). When both wipers are in the 31st tap position (-62dB attenuation), further commands to VOLDN place the wipers in the mute position (see Table 1). VOLUP or MUTE pulses return wipers to position 31. Maxim Integrated MAX5456 MAX5457 H_ CH RW R W_ CW L_ CL Figure 1. Potentiometer Model (Active) MAX5456 MAX5457 H_ CH R RW W_ L_ CW CL Figure 2. Potentiometer Model (Shutdown) 7 MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface BALANCE SEPARATION MAINTAINED H_ W0 W1 W0 W1 PRESS VOLUP TWICE W0 W1 W0 W1 PRESS VOLDN ONCE W0 W1 (a) L_ NO CHANGE PRESS VOLUP ONCE H_ W0 W1 W0 W1 PRESS VOLUP (b) L_ H_ W0 W1 PRESS VOLDN ONCE W0 W1 PRESS VOLDN TO 3d (c) L_ ORIGINAL BALANCE SEPARATION MAINTAINED H_ W0 W1 PRESS VOLUP ONCE FROM 3c W0 W1 PRESS VOLUP ONCE W0 W1 (d) L_ Figure 3. Volume-Control Operation Table 1. Wiper Position and Attenuation ATTENUATION (dB) 0 0 1 2 2 4 ... ... 6 (POR) 12 ... ... 8 POSITION 30 60 31 62 32 (mute) >90 Maxim Integrated MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface Balance Control In balance-control mode, the MAX5456/MAX5457 adjust the balance between channel 0 and channel 1 while maintaining the set volume. For example, if the volume of channel 0 equals the volume of channel 1, forcing the balance towards channel 1 increases the attenuation of channel 0 (Figure 4a). If channel 1 is at a higher attenuation than channel 0, adjusting the balance to channel 1 moves channel 1's wiper up to the same wiper position as channel 0 before attenuating channel 0 (Figure 4b). To control the wiper quickly with a logic signal, maintain pulses at least 22.5ms wide and separated by at least 40ms. Table 2. Wiper Action vs. Pushbutton Contact Duration CONTACT DURATION t < 22.5ms No motion (debouncing). 22.5ms < t 1s W0 W1 Wiper changes position once. 1s < t 4s Wiper changes position at a rate of 4Hz. t > 4s Wiper changes position at a rate of 16Hz. VOLUME LEVEL MAINTAINED BALANCE SHIFTS TO W1 VOLUME LEVEL IS SET H_ WIPER ACTION PRESS BAL1 ONCE W0 W1 PRESS BAL1 ONCE W0 W1 (a) L_ H_ VOLUME LEVEL MAINTAINED BALANCE SHIFTS TO W1 VOLUME LEVEL IS SET BY W0 W0 W1 PRESS BAL1 ONCE W0 W1 PRESS BAL1 ONCE W0 W1 (b) L_ Figure 4. Balance-Control Operation Maxim Integrated 9 MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface Click/Pop Suppression The click/pop suppression feature reduces the audible noise (clicks and pops) that result from wiper transitions. The MAX5456/MAX5457 minimize this noise by allowing the wiper position changes only when VH_ = VL_. Thus, the wiper changes position only when the voltage at L_ is the same as the voltage at the corresponding H_. Each wiper has its own suppression and timeout circuitry (see Figure 5a). The MAX5456/MAX5457 change wiper position after 32ms or when VH_ = VL, whichever occurs first (see Figure 5b). The suppression circuitry monitors left and right channels separately. In volume-control mode, when the first wiper changes position, the second wiper has 32ms to change or it will be forced to change. Power-On Reset The power-on comparators monitor V DD - V SS and VLOGIC - GND. A power-on reset is initiated when either of the supplies is brought back to normal operating voltage. The power-on-reset feature sets both wipers to -12dB. Power-on reset places the MAX5457 in volumecontrol mode. SWITCH SWITCH CONTACT CONTACT IS BOUNCING IS STABLE USER PRESSES PUSHBUTTON SWITCH CONTACT IS BOUNCING READY TO ACCEPT ANOTHER KEYPRESS 1 DN OR UP INPUT ACCEPTED 0 tHPW tIPW tWS DEBOUNCE BY WAITING FOR STABLE HIGH, tHPW WAIT FOR DEBOUNCE BY FIRST ZERO WAITING FOR CROSSING, tWS STABLE LOW, tIPW VH VL WIPER MOVES HERE WIPER MOTION 2dB STEPS Figure 5a. Wiper Transition Timing Diagram 10 Maxim Integrated MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface Shutdown, SHDN Upon entering shutdown mode, the MAX5456/MAX5457 store the last wiper settings. The wipers move to the L_ end of the resistor string, and the H_ end of the resistor string disconnects from the signal input. Terminating shutdown mode restores the wipers to their previous settings (see Figure 2). Shutdown does not affect the state of MODE_IND. Mute Function, MUTE function forces both wipers to maximum attenuation (90dB typ). Deactivating the mute function returns the wipers to their previous settings. Pressing VOLUP also deactivates mute, setting the wipers to their previous positions. MUTE is internally pulled high with a 50k resistor to VLOGIC. When both wipers are in the 31st tap position (-62dB attenuation), further commands to VOLDN place the wipers in the mute position (see Table 1). VOLUP or MUTE pulses return the wipers to position 31. The MAX5456/MAX5457 feature a mute function. Successive pulses on MUTE toggle its setting. Activating the mute SWITCH SWITCH CONTACT CONTACT IS BOUNCING IS STABLE SWITCH CONTACT IS BOUNCING READY TO ACCEPT ANOTHER KEYPRESS 1 INPUT ACCEPTED 0 tHPW tWS tIPW WAIT FOR DEBOUNCE BY FIRST ZERO WAITING FOR CROSSING OR STABLE LOW, TIMEOUT, tWS tIPW DEBOUNCE BY WAITING FOR STABLE HIGH, tHPW VH VL WIPER MOVES HERE (tIPW + tWS) 2dB STEPS Figure 5b. Wiper Transition Timing Diagram Maxim Integrated 11 MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface Mode Control, MODE Multiple Button Pushes The MAX5457 MODE input toggles between volumeand balance-control modes. Force MODE low to toggle between volume-control and balance-control modes. For example, driving MODE low once while in volumecontrol mode, switches the MAX5457 to balance-control mode. Driving mode low once again, switches the MAX5457 back to volume-control mode. MODE is internally pulled high with a 50k resistor to VLOGIC. The MAX5457 powers up in volume-control mode. The MAX5456/MAX5457 do not respond to simultaneous button pushes. Pushing more than one button at the same time stops the wipers in their present states. Only a single button push configures the device. Additionally, a 40ms blocking period affects all other inputs when releasing any input forced low. The MAX5456/MAX5457 do not respond to any logic input until the blocking period ends. If multiple wiper-control buttons are pressed, all wiper-control connections must be released before the part will respond to further commands. Mode Indicator, MODE_IND MODE_IND is the volume-control and balance-control mode indicator with an open-drain output. Connect MODE_IND to an LED through a pullup resistor to VLOGIC. When the LED is on, the MAX5457 is in balancecontrol mode. When the LED is off, the MAX5457 is in volume-control mode. See the Mode Control, MODE section for more detail on switching between modes. Shutdown does not affect the state of MODE_IND. 12 Applications Information Stereo Volume/Balance Control Figure 6 shows a volume/balance application using the MAX5457. The op amp is connected in a follower (noninverting gain) configuration to isolate the potentiometer's wiper impedance from the load and provide drive capability. Connect the W_ of the MAX5457 to the positive input of a noninverting gain amp. The pushbutton potentiometers attenuate the input signals. Use the MODE input to switch between volume-control and balance-control modes. Maxim Integrated MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface VDD VLOGIC VDD LEFT CHANNEL IN SHDN VLOGIC MODE_IND H1 H0 L0 RIGHT CHANNEL IN L1 MAX5457 VDD / 2 VDD / 2 W1 W0 GND VSS MUTE UP/BAL1 DN/BAL0 MODE VDD VDD LEFT AUDIO INPUT RIGHT AUDIO INPUT INL- INL+ SHDN INR+ MAX4494 INR- MAX4494 VDD SVDD PGND MAX9722 OUTL OUTR STEREO HEADPHONE Figure 6. Volume/Balance Control Maxim Integrated 13 MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface Typical Application Circuit (Single Supply) VDD VPEAK VDD / 2 RLOAD = VPEAK VDD / 2 H_ RH VDD W_ VPEAK VDD / 2 RL MAX5456/MAX5457 L_ VDD VDD Typical Application Circuit (Dual Supplies) VDD VPEAK 0V RLOAD = VPEAK 0V H_ RH VDD W_ VPEAK 0V RL MAX5456/MAX5457 VSS L_ VSS = -VDD 14 Maxim Integrated MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface Functional Diagrams VDD VLOGIC SHDN MAX5456 H0 SHUTDOWN SHUTDOWN CLICK/POP SUPPRESSION CIRCUITRY 0 CLICK/POP SUPPRESSION CIRCUITRY 1 1 2 2 3 3 4 H1 0 4 POSITION COUNTER POSITION COUNTER W1 W0 UP/DN UP/DN 28 28 TIMING AND CONTROL T F-F 29 DEBOUNCE DEBOUNCE DEBOUNCE DEBOUNCE 29 DEBOUNCE VLOGIC 30 30 31 31 32 32 MUTE MUTE L1 L0 VSS Maxim Integrated GND VOLUP VOLDN BAL0 BAL1 MUTE 15 MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface Functional Diagrams (continued) VDD H0 VLOGIC MODE_IND SHDN MAX5457 SHUTDOWN SHUTDOWN CLICK/POP SUPPRESSION CIRCUITRY 0 CLICK/POP SUPPRESSION CIRCUITRY 0 1 1 2 2 3 3 4 H1 4 POSITION COUNTER POSITION COUNTER W1 W0 UP/DN UP/DN 28 28 TIMING AND CONTROL 29 DEBOUNCE DEBOUNCE T F-F T F-F DEBOUNCE DEBOUNCE VLOGIC 30 30 31 31 32 MUTE 32 MUTE L1 L0 VSS 16 29 GND DN/BAL0 UP/BAL1 MODE MUTE Maxim Integrated MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface Pin Configurations (continued) Chip Information PROCESS: CMOS TOP VIEW VOLDN 1 + 16 VDD 15 VLOGIC VOLUP 2 14 GND BAL1 3 BAL0 4 MAX5456 13 VSS H0 5 12 H1 L0 6 11 L1 W0 7 10 W1 9 SHDN 8 MUTE Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a "+", "#", or "-" in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 16 QSOP E16+1 21-0055 90-0167 QSOP Maxim Integrated 17 MAX5456/MAX5457 Stereo Audio Taper Potentiometers with Pushbutton Interface Revision History REVISION REVISION NUMBER DATE 0 11/04 2 8/12 DESCRIPTION Initial release Update Ordering Information, Absolute Maximum Ratings, Pin Description, Pin Configuration. Removed Selector Guide and added Package Information table and Revision History. PAGES CHANGED -- 1, 2, 6, 14, 18-20 Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. 18 (c) 2012 Maxim Integrated Products, Inc. Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Maxim Integrated: MAX5456EEE+ MAX5456EEE+T MAX5456ETE+ MAX5456ETE+T MAX5457EEE+ MAX5457EEE+T MAX5457ETE+ MAX5457ETE+T