MAX5486 Stereo Volume Control with Pushbutton Interface General Description The MAX5486 dual 40k logarithmic taper volume control features a debounced pushbutton up/down interface that controls volume and balance in audio applications. Each potentiometer has 32 log-spaced tap points with a buffered wiper output to replace mechanical potentiometers. An integrated bias generator provides the required ((VDD + VSS)/2) bias voltage, eliminating the need for costly external op-amp circuits in unipolar audio applications. A mode-indicator LED output indicates volume or balance control. Five integrated LED drivers indicate volume level or balance settings, depending on the status of the mode indicator. Use the MAX5486 digital inputs with momentary contact single-pole/single-throw (SPST) pushbutton switches. Each input includes internal debounced circuitry and a pullup resistor to VLOGIC. The MAX5486 advances the wiper setting once per button push. Maxim's proprietary SmartWiperTM control eliminates the need for a microcomputer to increase the wiper transition rate. The accelerated auto-advance feature provides a wiper-changing rate at 4Hz for holding the control input low for more than 250ms and at 8Hz after 500ms and then at 11Hz after 1000ms (see Table 2). All of the MAX5486's pushbutton inputs are debounced. The mute input allows a single pushbutton to change between volume control and the -90dB (typ) mute setting. The mode input toggles between volume and balance control. The click-and-pop suppression feature minimizes the audible noise generated by wiper transitions. The typical total harmonic distortion plus noise (THD+N) for the device is 0.003%. The MAX5486 provides a nominal temperature coefficient of 35ppm/C end-to-end and 5ppm/C ratiometrically and a nominal resistance of 40k per potentiometer. The MAX5486 is available in a 24-pin TSSOP package and is specified for operation over the -40C to +85C extended temperature range. Features Debounced Pushbutton Interface SmartWiper Control Advances Wiper Rate Low-Power Wiper Buffers Provide 0.003% THD+N Bias Generator Eliminates External Op Amps Five-Segment LED Volume/Balance Indicator Clickless Switching Logarithmic Taper Volume Control with (31) 2dB Steps Single +2.7V to +5.5V or Dual 2.7V Supply Voltage Operation Power-On Reset to -12dBFS Wiper Position MUTE Function Toggles to 90dB (typ) Low 1A Shutdown Supply Current 40k End-to-End Fixed Resistance Value Small, 24-Pin TSSOP Package Ordering Information PART TEMP RANGE MAX5486EUG+ -40C to +125C Home-Theater Speakers Desktop Speakers Portable Media Players Docking Stations Typical Operating Circuit VLOGIC VDD VLOGIC SHDN 19-0672; Rev 1; 4/14 VPEAK MODEIND (VDD + VSS) / 2 MAX5486 HR WR 1M RIGHT INPUT LR MAX9761 BIAS (VDD + VSS) / 2 LEDIND0 LL LEFT INPUT LEDIND1 WL LEDIND2 LEDIND3 HL LEDIND4 GND VSS MUTE UP/BALL DN/BALR SmartWiper is a trademark of Maxim Integrated Products, Inc. 24 TSSOP +Denotes a lead(Pb)-free/RoHS-compliant package. Applications PIN-PACKAGE BIASCAP MODE VPEAK (VDD + VSS) / 2 MAX5486 Stereo Volume Control with Pushbutton Interface Absolute Maximum Ratings SHDN, MODE, MUTE, UP/BALL, and DN/BALR to GND............... -0.3V to the lower of (VLOGIC + 0.3V and +6V) H_, L_, W_, BIASCAP, BIAS to GND.......-0.3V to the lower of (VDD + 0.3V and +6V) LEDIND_, MODEIND to GND..................................-0.3V to +6V VLOGIC to GND........................................................-0.3V to +6V VDD to GND.............................................................-0.3V to +6V VDD to VLOGIC............................................................-6V to +6V GND to VSS..............................................................-0.3V to +6V VDD to VSS...............................................................-0.3V to +6V Average Current into H_, L_, and W_.................................1mA Maximum Continuous Current into H_, L_..........................4mA Input and Output Latchup Immunity................................200mA Continuous Power Dissipation (TA = +70C) 24-Pin TSSOP (derate 8.3mW/C above +70C).........657mW Operating Temperature Range............................ -40C to +85C Storage Temperature Range............................. -60C to +150C Maximum Junction Temperature......................................+150C Lead Temperature (soldering, 10s).................................. +300C 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 = +2.7V to +5.5V, VSS = GND = 0V, 2.7V (VDD - VSS) 5.5V, CBIASCAP = 1F, BIAS = 3k to GND, VLOGIC = +2.7V to VDD, VH_ = VDD - 0.15V, VL_ = (VDD - VSS)/2, SHDN = MUTE = VLOGIC, all LED outputs open, pushbutton interface inactive, VH = VBIAS + 1VRMS, VBIAS = (VDD - VSS)/2, TA = TMIN to TMAX, unless otherwise specified. Typical values are at TA = +25C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS RESISTOR LADDER End-to-End Resistance R 40 k 0.25 dB (Note 2) 0.1 dB VDD = 5V, VSS = 0V, VH = (VDD/2) + 1VRMS, VL = VDD/2, 1kHz, tap at top, RL = 10k to VL = VDD/2, 20Hz to 20kHz 0.003 VDD = 5V, VSS = 0V, VH = (VDD/2) + 1VRMS, VL = VDD/2, 1kHz, tap at top, RL = to VL = VDD/2, 20Hz to 20kHz 0.001 VDD = 5V, VSS = 0V, VH = (VDD/2) + 1.5VRMS, VL = VDD/2, 1kHz, tap at top, RL = 10k to VL = VDD/2, 20Hz to 20kHz 0.012 VDD = +2.7V, VSS = -2.7V, VBIAS = GND 100 dB 0.5 dB SHDN = VDD 90 dB Input referred, 217Hz, 100mVP-P on VDD 72 dB Absolute Tolerance Tap-to-Tap Tolerance VOLUME CONTROL Total Harmonic Distortion Plus Noise THD+N Channel Isolation Interchannel Matching Mute Attenuation Power-Supply Rejection Ratio PSRR % H Terminal Capacitance CH 5 pF L Terminal Capacitance CL 7 pF End-to-End Resistance Temperature Coefficient 35 ppm/C Ratiometric Resistance Temperature Coefficient 5 ppm/C 100 kHz Bandwidth, -3dB www.maximintegrated.com fCUTOFF CW = 50pF Maxim Integrated 2 MAX5486 Stereo Volume Control with Pushbutton Interface Electrical Characteristics (continued) (VDD = +2.7V to +5.5V, VSS = GND = 0V, 2.7V (VDD - VSS) 5.5V, CBIASCAP = 1F, BIAS = 3k to GND, VLOGIC = +2.7V to VDD, VH_ = VDD - 0.15V, VL_ = (VDD - VSS)/2, SHDN = MUTE = VLOGIC, all LED outputs open, pushbutton interface inactive, VH = VBIAS + 1VRMS, VBIAS = (VDD - VSS)/2, TA = TMIN to TMAX, unless otherwise specified. Typical values are at TA = +25C.) (Note 1) PARAMETER Output Noise SYMBOL CONDITIONS eN 20Hz to 20kHz, VH = VL = VDD/2 = AC ground, tap = -6dB VO RL = 3k to VBIAS MIN TYP MAX UNITS 2.2 VRMS VDD - 0.3V V WIPER BUFFER Output Voltage Swing Output Current Output Current DC Offset 3 mA ROWB 1 10 VOS 2 14 mV (VDD + VSS)/2 (VDD + VSS)/2 + 20mV V INTEGRATED BIAS GENERATOR Output Voltage RL > 100k Power-Supply Rejection Ratio At 1kHz, 100mVP-P on VDD (VDD + VSS)/2 - 20mV Minimum Load Resistance Maximum Load Capacitance Output Resistance ROBR Noise Voltage 20Hz to 20kHz Minimum Output Current 60 dB 3 k 100 pF 6 2.2 VRMS 2 mA 42 k CONTACT INPUTS (MUTE, MODE, UP/BALL, DN/BALR) Internal Pullup Resistor RPU Single-Pulse Input Low Time tCPW Repetitive Input Pulse Separation Time tIPWS Timeout Period tWS Debounce Corner Frequency Time required for a single pulse to cause an increment/decrement 16 ms 1 ms Click-and-pop suppression inactive 126 ms Internal analog filter 10 kHz DIGITAL INPUTS (VLOGIC > 4.5V) Input High Voltage VIH Input Low Voltage VIL Input Leakage Current VLOGIC > 4.5V VLOGIC < 4.5V www.maximintegrated.com V 0.7 x VLOGIC VLOGIC > 4.5V VLOGIC < 4.5V 0.8 0.3 x VLOGIC To GND for inputs with internal pullup resistors Input Capacitance Digital Clock Feedthrough 2.4 fCLK = 1Hz to 40Hz, tap = -6dB 1 V A 5 pF -90 dB Maxim Integrated 3 MAX5486 Stereo Volume Control with Pushbutton Interface Electrical Characteristics (continued) (VDD = +2.7V to +5.5V, VSS = GND = 0V, 2.7V (VDD - VSS) 5.5V, CBIASCAP = 1F, BIAS = 3k to GND, VLOGIC = +2.7V to VDD, VH_ = VDD - 0.15V, VL_ = (VDD - VSS)/2, SHDN = MUTE = VLOGIC, all LED outputs open, pushbutton interface inactive, VH = VBIAS + 1VRMS, VBIAS = (VDD - VSS)/2, TA = TMIN to TMAX, unless otherwise specified. Typical values are at TA = +25C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWER SUPPLIES Positive Power Supply VDD VSS = 0V 2.7 5.5 V Negative Power Supply VSS VDD = +2.7V -2.7 0 V VDD - VSS 5.5 V (Note 3) 1.4 mA Supply-Voltage Difference Analog Supply Current IDD Power-Up Time tPU 126 Logic Supply Voltage VLOGIC VSS = 0V Logic Active Supply Current ILOGIC VLOGIC = VDD (Note 4) Logic Standby Supply Current (Note 3) ILOGICSTBY 27 ms VDD V 200 A VDD = +5V, VSS = 0V 1 VDD = +2.7V, VSS = -2.7V 1 A Shutdown Current ISHDN VSHDN = 0V, total of all supplies 1 A Shutdown Time/Return from Shutdown tSHDN After 1st zero crossing 1 ms LED INDICATORS (LEDIND0-LEDIND4, MODEIND) Output Low Voltage VOL VLOGIC = 2.7V, ISINK = 10mA 0.4 VLOGIC = 5V, ISINK = 10mA 0.2 V Maximum Output Leakage Current 10 A Output Capacitance 3 pF Note Note Note Note 1: 2: 3: 4: Parameters are 100% production tested at +85C and limits through the temperature range are guaranteed by design. Tap-to-tap tolerance is the error in voltage change between successive tap positions. Supply current measured while wiper position is fixed. One button pressed. www.maximintegrated.com Maxim Integrated 4 MAX5486 Stereo Volume Control with Pushbutton Interface Typical Operating Characteristics (VDD = +5.0V, VSS = GND = 0V, VLOGIC = +5.0V, VH_ = VDD - 0.15V, VL_ = VDD/2, CBIASCAP = 1F.) END-TO-END RESISTANCE CHANGE (%) -10 -20 -30 -40 -50 -60 -70 0 4 8 12 16 20 24 28 VDD = VLOGIC = 5V VSS = VGND = 0V 0.10 0.05 0 -0.05 -0.10 -0.15 -0.20 -0.25 32 -40 -15 TAP POSITION 10 35 60 85 TEMPERATURE (C) WIPER SWITCHING TRANSIENT MAX5486 toc03 NOMINAL END-TO-END VOLTAGE (%VHL) 100 DN 5V/div WIPER-TO-END TERMINAL VOLTAGE vs. TAP POSITION 200mV/div WIPER TRANSITION FROM -2dB TO -4dB MAX5486 toc04 ATTENUATION (dB) 0.15 MAX5486 toc01 0 MAX5486 toc02 END-TO-END RESISTANCE % CHANGE vs. TEMPERATURE ATTENUATION vs. TAP POSITION VHW 90 80 70 60 50 40 30 20 10 VWL 0 40ms/div 0 4 8 12 16 20 24 28 32 TAP POSITION W_ SET TO 0dB -5 THD+N (%) RESPONSE (dB) W_ SET TO -6dB -10 -20 0.1 1 10 FREQUENCY (kHz) www.maximintegrated.com 10k OR NO LOAD 0.1 VH_ = 2.5V 1.5VRMS VH_ = 2.5V 1VRMS 0.001 W_ SET TO -18dB 0.01 1 0.01 W_ SET TO -12dB -15 VDD = 5V VSS = GND VL_ = 2.5V W_ SET TO 0dB 100 1000 0.0001 10k OR NO LOAD 0.01 0.1 1 FREQUENCY (kHz) 10 100 -30 -35 -40 -45 -50 -55 -60 -65 -70 -75 -80 -85 -90 -95 -100 POWER-SUPPLY REJECTION RATIO MAX5486 toc07 0 10 RESPONSE (dB) VH1 = 2.5V 1VRMS, VL1 = 2.5V 100 MAX5486 toc05 5 MAX5486 toc06 TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY FREQUENCY RESPONSE VDD = 5V 100mVP-P, VSS = GND VH_ = 5V, VL_ = 2.5V W_ SET TO -6dB 0.01 0.1 1 10 100 FREQUENCY (kHz) Maxim Integrated 5 MAX5486 Stereo Volume Control with Pushbutton Interface Typical Operating Characteristics (continued) (VDD = +5.0V, VSS = GND = 0V, VLOGIC = +5.0V, VH_ = VDD - 0.15V, VL_ = VDD/2, CBIASCAP = 1F.) 80 60 STANDBY CURRENT 2.0 3.0 3.5 4.0 4.5 5.0 ACTIVE SUPPLY CURRENT vs. SUPPLY VOLTAGE ACTIVE SUPPLY CURRENT vs. TEMPERATURE 1.0 0.5 0 1 2 3 4 5 2.0 VDD = VLOGIC = 5.5V VUP = 0V CROSSTALK (dB) -40 35 60 250 85 200 150 100 0.5 50 -40 -15 10 35 60 85 0 0.01 CROSSTALK vs. FREQUENCY 0.1 1 10 100 FREQUENCY (kHz) DIGITAL FEEDTHROUGH MAX5486 toc15 MAX5486 toc14 -20 10 SPECTRAL NOISE DENSITY 300 TEMPERATURE (C) VDD = 2.7V, VSS = -2.7V, VLOGIC = 5V W_SET TO 0dB, VHR = 1VRMS VLR = VLL = VHL = 0V -15 TEMPERATURE (C) 1.0 SUPPLY VOLTAGE (V) 0 -40 1.5 0 6 MAX5486 toc10 MAX5486 toc09 LOGIC INPUT VOLTAGE (V) VUP = 0V VLOGIC = 5.5V 144 140 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 0 LOGIC SUPPLY VOLTAGE (V) 1.5 0 10 5.5 146 142 NOISE (nV/Hz) 2.5 VDD = VLOGIC = 5.5V 148 MAX5486 toc12 0 100 ACTIVE SUPPLY CURRENT (mA) 40 150 ACTIVE ILOGIC (A) 100 1000 LOGIC SUPPLY CUURENT (A) ACTIVE CURRENT 120 20 ACTIVE SUPPLY CURRENT (mA) MAX5486 toc08 140 MAX5486 toc11 LOGIC SUPPLY CURRENT (A) 160 ACTIVE LOGIC SUPPLY CURRENT vs. TEMPERATURE LOGIC SUPPLY CURRENT vs. LOGIC INPUT VOLTAGE MAX5486 toc13 LOGIC SUPPLY CURRENT vs. LOGIC SUPPLY VOLTAGE WIPER OUTPUT 50V/div -60 PUSHBUTTON INPUT -80 -100 2V/div -120 -140 -160 0.01 0.1 1 10 100 500ns/div FREQUENCY (Hz) www.maximintegrated.com Maxim Integrated 6 MAX5486 Stereo Volume Control with Pushbutton Interface Pin Description PIN NAME FUNCTION 1 VLOGIC Digital Logic Power Supply. Bypass VLOGIC to ground with a 0.1F capacitor as close as possible to the device. 2 DN/BALR Active-Low Downward Volume/Balance Control. Press DN/BALR to decrease the volume in volume mode and move balance to the right in balance mode. DN/BALR is internally pulled high with a resistor to VLOGIC. 3 UP/BALL Active-Low Upward Volume/Balance Control. Press UP/BALL to increase the volume in volume mode and move balance to the left in balance mode. UP/BALL is internally pulled high with a resistor to VLOGIC. 4 MUTE Active-Low Mute Input. Pull MUTE low to toggle the wiper between the mute setting (see Table 1) and the current setting. MUTE is internally pulled up to VLOGIC with a resistor. 5 MODE Active-Low Volume/Balance Control Input. Each high-to-low transition on MODE toggles between the volume and balance modes. MODE is pulled high internally with a resistor to VLOGIC. On power-up, the MAX5486 is in volume control mode. 6 SHDN Active-Low Shutdown Input. Drive SHDN low to place the device in shutdown mode. In shutdown mode, the MAX5486 stores the last wiper settings. The wipers move to the L_ end of the resistor string. Terminating the shutdown mode restores the wipers to the previous settings. 7 N.C. Internally connected. Leave unconnected. 8 HR Potentiometer R High Terminal 9 LR Potentiometer R Low Terminal 10 WR Potentiometer R Wiper Buffered Output 11 BIAS 12 BIASCAP Midbias Voltage Output. VBIAS = (VDD + VSS)/2; connect a 100pF capacitor from BIAS to VSS. 13 VDD Analog Power Supply. Bypass VDD to ground with a 0.1F capacitor as close as possible to the device. 14 VSS Negative Power Supply. Bypass VSS to ground with a 0.1F capacitor as close as possible to the device. Connect to GND for single-supply operation. 15 WL Potentiometer L Wiper Buffered Output 16 LL Potentiometer L Low Terminal 17 HL Potentiometer L High Terminal Bias Generator Bypass. Connect a 1F filter capacitor from BIASCAP to VSS. 18-22 LEDIND0- LEDIND4 LED Indicator Open-Drain Output 0-LED Indicator Open-Drain Output 4. Connect a 1M resistor from LEDIND4 to VLOGIC to enable these LED inductor drivers. LEDIND0-LEDIND4 form a bar graph indication of the current volume or balance. In volume mode, all LEDs off indicate mute and all LEDs on indicate maximum volume. In balanced mode, LED2 on indicates centered or balanced. Connect LEDIND0-LEDIND4 to GND when LED indicator drivers are not used. 23 MODEIND Active-Low Volume-Control/Balance-Control Mode-Indicator Open-Drain Output. Connect to an LED through a resistor to VLOGIC. When the LED is on, the MAX5486 is in balance-control mode. When the LED is off, the MAX5486 is in volume-control mode. 24 GND www.maximintegrated.com Ground Maxim Integrated 7 MAX5486 Stereo Volume Control with Pushbutton Interface Detailed Description VLOGIC The MAX5486 dual 40k logarithmic taper digital volume control features a debounced pushbutton interface that controls volume and balance in audio applications. Each potentiometer has 32 log-spaced tap points with a buffered wiper output and replaces mechanical potentiometers. UP Mode Control (MODE) The MAX5486 MODE input toggles between volume and balance modes. Each time MODE is forced low, the device switches between volume and balance modes. For example, driving MODE low once while in volume-control mode switches the MAX5486 to balance mode. Driving MODE low again switches the MAX5486 back to volume mode. MODE is internally pulled high with a resistor to VLOGIC. The MAX5486 powers up in volume-control mode. Leave unconnected or connect to VLOGIC if balance mode is not required. Up-and-Down Interface DN MOMENTARY CONTACT SPST PUSHBUTTONS Volume Control In volume-control mode, the MAX5486's wipers move simultaneously, maintaining the balance separation between each wiper (Figure 2a). 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 2b). 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 2c). Increasing the volume from this minimum position restores the original balance separation of the wipers (Figure 2d). www.maximintegrated.com MAX5486 Figure 1. Pushbutton Interface Table 1. Wiper Position and Attenuation POSITION ATTENUATION (dB) 0 0 1 2 2 4 3 6 4 8 ... ... 30 60 The MAX5486 interfaces with momentary contact SPST switches. All switch inputs are internally debounced and pulled up to VLOGIC through resistors. The wiper setting advances once per button press up to 250ms. Maxim's SmartWiper control circuitry allows the wiper to advance at a 4Hz rate after holding the button for approximately 250ms. After 500ms, the wiper moves at an 8Hz rate. After 1s, the rate increases to 11Hz (see Table 2). The SmartWiper control eliminates the need for a microcomputer to increase the wiper transition rate. The MAX5486 MODE input toggles the part between volume and balance-control modes. The UP/BALL and DN/BALR inputs control the wiper according to the selected mode. MODE is internally pulled high with a resistor to VLOGIC. GND 31 62 32 (mute) > 90 Table 2. Wiper Action vs. Pushbutton Contact Duration CONTACT DURATION WIPER ACTION t 16ms No motion. 16ms < t 250ms Wiper changes position once. 250ms < t 500ms SmartWiper begins. Wiper changes position at a rate of 4Hz. 500ms < t 1000ms Wiper changes position at a rate of 8Hz. t > 1000 ms Wiper changes position at a rate of 11Hz. Maxim Integrated 8 MAX5486 Stereo Volume Control with Pushbutton Interface BALANCE SEPARATION MAINTAINED H_ WR WL WR WL PRESS UP TWICE WR WL WR WL WR WL PRESS DN ONCE WR WL (2a) L_ H_ PRESS UP ONCE WR NO CHANGE WL PRESS UP ONCE (2b) L_ H_ WR WL PRESS DN ONCE WR WL PRESS DN ONCE TO 2d (2c) L_ ORIGINAL BALANCE SEPARATION MAINTAINED H_ WR FROM 2c WL PRESS UP ONCE WR WL PRESS UP ONCE WR WL (2d) L_ Figures 2a-2d. Volume-Control Operation When both wipers are in the tap 31 position (-62dB attenuation), further commands to DN/BALR place the wipers in the mute position (see Table 1). UP/BALL or MUTE pulses return the wipers to tap 31. Balance Control In balance-control mode, the MAX5486 adjusts the balance between the right and left channels while maintaining the set volume. For example, if the volume of the right channel equals the volume of the left channel, forcing the balance towards the left channel increases the attenuation of the right channel (Figure 3a). If the left channel is at a higher attenuation than the right channel, adjusting the balance to the left channel moves the left channel's wiper www.maximintegrated.com up to the same wiper position as the right channel before it was attenuated (Figure 3b). Click-and-Pop Suppression The click-and-pop suppression feature reduces the audible noise (clicks and pops) that results from wiper transitions. The MAX5486 minimizes this noise by allowing the wiper to change position only when VH = VL (zero crossing) or after the zero crossing timeout (126ms). Each wiper has its own suppression and timeout circuitry. The MAX5486 changes wiper position when VH = VL, or after 32ms, whichever occurs first (see Figures 4a and 4b). The suppression circuitry monitors left and right channels separately. In volume-control mode, when the first wiper Maxim Integrated 9 MAX5486 Stereo Volume Control with Pushbutton Interface VOLUME LEVEL MAINTAINED BALANCE SHIFTS TO WL VOLUME LEVEL IS SET H_ WR WL PRESS BALL ONCE WR WL PRESS BALL ONCE WR WL (3a) L_ H_ VOLUME LEVEL MAINTAINED BALANCE SHIFTS TO WL VOLUME LEVEL IS SET BY WR WR WL PRESS BALL ONCE WR WL PRESS BALL ONCE WR WL (3b) L_ Figures 3a and 3b. Balance-Control Operation changes position, the second wiper has 126ms to change or it changes automatically. Power-On Reset The power-on comparators monitor (VDD - VSS) and (VLOGIC - GND). A power-on reset is initiated when either of the supplies is brought back to the normal operating voltage. The power-on reset feature sets both wipers to -12dB. The wipers initially wake up in mute mode (-90dB) and move to the -12dB position when VH = VL to eliminate clicks and pops during power-up. With DC inputs at VH and VL, the wipers move after exceeding the timeout period. A power-on reset places the MAX5486 in volumecontrol mode. Shutdown (SHDN) Upon entering shutdown, the MAX5486 stores the last wiper settings. The wipers move to the L_ end of the resistor string when VH = VL to eliminate clicks and pops during shutdown. With DC inputs at VH and VL, the wipers move after exceeding the timeout period. Exiting shutdown restores the wipers to their previous settings. Shutdown also turns off all the LED indicators to save power. Mute Function (MUTE) The MAX5486 features a mute function input, MUTE. Successive low pulses on MUTE toggle its setting. Activating the mute function forces both wipers to maxi- www.maximintegrated.com mum attenuation (-90dB typ). Deactivating the mute function returns the wipers to their previous settings. MUTE is internally pulled high with a resistor to VLOGIC. When both wipers are in the tap 31 position (-62dB attenuation) further commands to lower the volume place the wipers in the mute position (see Table 1). Mode Indicator (MODEIND) The open-drain MODEIND indicates volume-control mode or balance-control mode for the MAX5486. Connect MODEIND to an LED with a series resistor to VLOGIC. When the LED is on, the MAX5486 is in balance-control mode. When the LED is off, the MAX5486 is in volumecontrol mode. See the Mode Control (MODE) section for more detail on switching between modes. Level Indicator LEDs The MAX5486 includes five indicator LED drivers to display the current wiper settings in either volume or balance mode. The LED indicators are enabled by connecting a 1M resistor between LEDIND4 and VLOGIC. Connect the LEDIND_ outputs to the LEDs and to VLOGIC through a series resistor as shown in the Typical Operating Circuit. Connect LEDIND_ outputs to GND when LED indicator drivers are not used. In volume-control mode, all LEDs are off when the wipers reach the highest attenuation levels (mute). All LEDs are on at the lowest attenuation levels (0dB). Maxim Integrated 10 MAX5486 Stereo Volume Control with Pushbutton Interface Table 3. LED Settings in Volume Mode VOLUME POSITION WIPER ACTION LED0 LED1 LED2 LED3 LED4 0dB to -8dB 1 1 1 1 1 -10dB to -18dB 1 1 1 1 0 -20dB to -28dB 1 1 1 0 0 -30dB to -38dB 1 1 0 0 0 -40dB to -52dB 1 0 0 0 0 -54dB to mute (-90dB) 0 0 0 0 0 Table 3 shows the LED display as the wipers transition through various attenuation levels. A PWM circuit interpolates the high-resolution 32 steps between the five LEDs over the volume range from 0dB to -54dB. This feature provides visible indication for the attenuation levels from 0dB to -54dB. For example, LED4 brightness level decreases progressively with each -2dB step from 0dB to -8dB. PWM is disabled in the range -56dB to mute. In balance-control mode, only one LED is on at a time to indicate the current balance setting. Figure 5 shows the LEDs display for the current balance setting. When LED2 is on, the display indicates that the channels are centered or balanced at a set volume level. When LED4 turns on, the balance shifts completely toward the right channel and the left channel becomes fully attenuated. The MAX5486 does not respond to any logic input until the blocking period ends. If multiple-control buttons are pressed, all wiper-control connections must be released before the device responds to further commands. Applications Information The Typical Operating Circuit shows a typical volume/ balance application circuit using the MAX5486 in a single-supply configuration. The internally generated BIAS voltage eliminates the need for external op amps, and the wipers have internal low-power buffers for low distortion. Connect the W_ outputs of the MAX5486 to the left and right inputs of a stereo audio amplifier, such as the MAX9761. The pushbutton potentiometers attenuate the input signals. Use the MODE input to switch between volume-control and balance-control modes. Multiple Button Pushes The MAX5486 does not respond to simultaneous button pushes. Additionally, a 16ms blocking period affects all other inputs when releasing any input that was forced low. www.maximintegrated.com Maxim Integrated 11 MAX5486 Stereo Volume Control with Pushbutton Interface 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 4a. Wiper Transition Timing Diagram--Suppression Circuitry Active www.maximintegrated.com Maxim Integrated 12 MAX5486 Stereo Volume Control with Pushbutton Interface SWITCH SWITCH CONTACT CONTACT IS BOUNCING IS STABLE SWITCH CONTACT IS BOUNCING READY TO ACCEPT ANOTHER KEYPRESS 1 INPUT ACCEPTED 0 tHPW tIPW tWS DEBOUNCE BY WAITING FOR STABLE HIGH, tHPW WAIT FOR DEBOUNCE BY FIRST ZERO WAITING FOR CROSSING OR STABLE LOW, TIMEOUT, tWS tIPW VH VL WIPER MOVES HERE (tIPW + tWS) 2dB STEPS Figure 4a. Wiper Transition Timing Diagram--Suppression Circuitry Active FULL L L + 12 L+6 PB PRESS (CHANNEL L) LED0 ON LED1 ON R+6 CENTERED LED2 ON R + 12 FULL R PB PRESS (CHANNEL R) LED3 ON LED4 ON Figure 5. LED Settings in Balance Mode www.maximintegrated.com Maxim Integrated 13 MAX5486 Stereo Volume Control with Pushbutton Interface Functional Diagram VDD VDD HR BIAS BIAS GENERATOR MAX5486 BIASCAP VSS WR LR MODEIND LEDIND4 LEDIND3 LED DRIVERS HL LEDIND2 LEDIND1 LEDIND0 WL SWITCH CONTROL, CLICK-AND-POP SUPPRESSION LL UP/BALL www.maximintegrated.com VLOGIC DEBOUNCE, TIMEOUT, ACCELERATION DN/BALR MODE MUTE SHDN GND VSS Maxim Integrated 14 MAX5486 Stereo Volume Control with Pushbutton Interface Functional Diagram Chip Information TOP VIEW VLOGIC 1 PROCESS: BiCMOS + 24 GND DN/BALR 2 23 MODEIND UP/BALL 3 22 LEDIND4 MUTE 4 21 LEDIND3 MODE 5 MAX5486 20 LEDIND2 SHDN 6 19 LEDIND1 N.C. 7 18 LEDIND0 HR 8 17 HL LR 9 16 LL WR 10 15 WL BIAS 11 14 VSS BIASCAP 12 13 VDD 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 24 TSSOP PACKAGE CODE U24+1 OUTLINE NO. 21-0066 LAND PATTERN NO. 90-0118 TSSOP www.maximintegrated.com Maxim Integrated 15 MAX5486 Stereo Volume Control with Pushbutton Interface Revision History REVISION NUMBER REVISION DATE 0 11/06 Initial Release -- 1 4/14 Updated Applications 1 DESCRIPTION PAGES CHANGED 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. 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. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. (c) 2014 Maxim Integrated Products, Inc. 16 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Maxim Integrated: MAX5486EUG+ MAX5486EUG+T