Stereo Volume Control

www.DataSheet4U.com 19-0542; Rev 1; 5/06 Stereo Volume Control with Rotary Encoder Interface General Description The MAX5440 dual, 40kΩ logarithmic taper volume control features a debounced up/down interface for use with a simple rotary encoder without using a microcontroller (µC). Each potentiometer has 32 log-spaced tap points with a buffered wiper output and replaces 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 specifies volume or balance control. Five integrated LED drivers indicate volume level or balance settings, depending on the status of the mode indicator. The MAX5440 includes debounced pushbutton inputs for mute and mode. 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. A click-and-pop suppression feature minimizes the audible noise generated by wiper transitions. The MAX5440 provides a nominal temperature coefficient of 35ppm/°C end-toend and 5ppm/°C, ratiometrically. The MAX5440 is available in a 24-pin SSOP package and is specified for operation over the -40°C to +85°C extended temperature range. Features ♦ Logarithmic Taper Volume Control with (31) 2dB Steps ♦ Low-Power Wiper Buffers Provide 0.003% THD ♦ Single +2.7V to +5.5V or Dual ±2.7V Supply Voltage Operation ♦ Low 0.5µA Shutdown Supply Current ♦ Integrated Bias Voltage Generator ♦ Five-Segment LED Volume/Balance Indicator ♦ Clickless Switching ♦ 40kΩ End-to-End Fixed Resistance Value ♦ Mute Function Toggles to -90dB (typ) ♦ Power-On Reset to -12dBFS Wiper Position MAX5440 Ordering Information PART MAX5440EAG TEMP RANGE -40°C to +85°C PIN-PACKAGE 24 SSOP PKG CODE A24-1 Applications Stereo Volume Control Desktop Speakers Multimedia Docking Stations Set-Top Boxes Automotive Back-Seat Multimedia Typical Operating Circuit VDD VLOGIC VLOGIC Pin Configuration TOP VIEW VLOGIC RENCODEA RENCODEB MUTE MODE SHDN GND H0 L0 1 2 3 4 5 6 7 8 9 24 GND 23 MODEIND 22 LEDIND4 SHDN MODEIND VPEAK (VDD + VSS) / 2 MAX5440 H1 W1 RIGHT INPUT L1 MIDBIAS HEADPHONE DRIVER MAX5440 21 LEDIND3 20 LEDIND2 19 LEDIND1 18 LEDIND0 17 H1 VSS LEDIND0 LEDIND1 LEDIND2 LEDIND3 (VDD + VSS) / 2 L0 W0 LEFT INPUT H0 LEDIND4 BIAS 16 L1 GND MUTE MODE RENCODEA RENCODEA W0 10 MIDBIAS 11 BIAS 12 15 W1 14 VSS 13 VDD ROTARY ENCODER SSOP ________________________________________________________________ Maxim Integrated Products 1 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. Stereo Volume Control with Rotary Encoder Interface ABSOLUTE MAXIMUM RATINGS MAX5440 SHDN, MUTE, RENCODEA, RENCODEB, and MODE to GND............................-0.3V to (VLOGIC + 0.3V) H_, L_, and W_ to VSS ...............................-0.3V to (VDD + 0.3V) LEDIND_, MODEIND to GND................-0.3V to (VLOGIC + 0.3V) MIDBIAS, BIAS to VSS......................(VSS - 0.3V) to (VDD + 0.3V) VLOGIC to GND...........................................-0.3V to (VDD + 0.3V) VDD to GND ..............................................................-0.3V to +6V VDD to VSS ................................................................-0.3V to +6V VSS to GND...............................................................-3V to +0.3V Input and Output Latchup Immunity...............................±200mA Continuous Power Dissipation (TA = +70°C) 24-Pin SSOP (derate 8mW/°C above +70°C) ..............640mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-60°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 (VDD = +2.7V to +5.5V, VSS = GND = 0, 2.7V ≤ (VDD - VSS) ≤ 5.5V, VLOGIC = +2.7V to VDD, VH_ = VDD, VL_ = VDD / 2, TA = TMIN to TMAX, unless otherwise specified. Typical values are at TA = +25°C.) (Note 1) PARAMETER End-to-End Resistance Absolute Tolerance Tap-to-Tap Tolerance VH_= (VDD / 2) + 1VRMS, 1kHz tap at top, RL = ∞ to VL_ = VDD / 2, 20Hz to 20kHz VH_= (VDD / 2) + 1.5VRMS, 1kHz tap at top, RL = ∞ to VL_ = VDD / 2, 20Hz to 20kHz Total Harmonic Distortion Plus Noise THD+N VDD = 5V,VSS = 0V, VL_ = 1.5V, VH_ = (VDD / 2) + 1VRMS, 1kHz tap at top, RL = 10kΩ to VMIDBIAS, 20Hz to 20kHz VDD = 5V,VSS = 0V, VL_ = 5V, VH_= (VDD / 2) + 1.5VRMS, 1kHz tap at top, RL = 10kΩ to VMIDBIAS, 20Hz to 20kHz Channel Isolation Interchannel Matching Mute Attenuation Power-Supply Rejection Ratio H Terminal Capacitance L Terminal Capacitance End-to-End Resistance Ratiometric Resistance Bandwidth, -3dB Output Noise WIPER BUFFER Output Voltage Swing Output Current Output Resistance DC Offset INTEGRATED BIAS GENERATOR Output Voltage ILOAD = 1mA (VDD + VSS) / 2 - 10mV (VDD + VSS) /2 (VDD + VSS) / 2 + 10mV V ROWB -5 1 ±2 VO RL = 10kΩ to VMIDBIAS VDD - 0.2 3 10 +5 V mA Ω mV fCUTOFF en CW = 33pF 20Hz to 20kHz PSRR CH CL SHDN = VDD Input referred, 217Hz, 100mVP-P on VDD SYMBOL R CONDITIONS MIN 36 TYP 40 ±0.25 ±0.1 0.004 0.006 % 0.004 MAX 52 UNITS kΩ dB dB 0.006 100 ±0.5 90 -60 5 7 35 5 100 3.2 dB dB dB dB pF pF ppm/°C ppm/°C kHz µVRMS 2 _______________________________________________________________________________________ Stereo Volume Control with Rotary Encoder Interface ELECTRICAL CHARACTERISTICS (continued) (VDD = +2.7V to +5.5V, VSS = GND = 0, 2.7V ≤ (VDD - VSS) ≤ 5.5V, VLOGIC = +2.7V to VDD, VH_ = VDD, VL_ = VDD / 2, TA = TMIN to TMAX, unless otherwise specified. Typical values are at TA = +25°C.) (Note 1) PARAMETER Power-Supply Rejection Ratio Maximum Load Output Resistance Internal Pullup Resistor Single Pulse Input Low Time Repetitive Input Pulse Separation Timeout Period ROBR RPULLUP tCPW tIPWS tWS Click/pop suppression inactive 3.6V < VLOGIC ≤ 5.5V 2.7V ≤ VLOGIC ≤ 3.6V 3.6V < VLOGIC ≤ 5.5V 2.7V ≤ VLOGIC ≤ 3.6V Inputs unconnected -1 5 VDD VSS IDD ISTBY ISHDN tPU VLOGIC IL ILSTBY ILSHDN VLOGIC = 2.7V, ISINK = 10mA VLOGIC = 5.5V, ISINK = 10mA 0.1 3 150 VDD = +5V, VSS = 0 VDD = +2.7V, VSS = -2.7V (Note 3) Click/pop suppression inactive VSS = 0 VRENCODEA = VRENCODEB = 0V (Note 4) 2.7 50 VDD 320 1 1 0.4 0.2 10 VSS = 0 VDD = +2.7V VDD - VSS 2.7 -2.7 5.5 0 5.5 1.4 1.3 1.3 1 2.4 2.0 0.8 0.6 +1 22 50 32 SYMBOL PSRRBR CONDITIONS 1kHz, 100mV on VDD, 1µF on BIAS To VDD or GND 3 6 45 MIN TYP 60 MAX UNITS dB kΩ Ω kΩ ms ms ms MAX5440 CONTACT INPUTS (MUTE, MODE, RENCODEA, RENCODEB) DIGITAL INPUTS (MUTE, MODE, RENCODEA, RENCODEB, SHDN) Input High Voltage (Note 2) Input Low Voltage (Note 2) Input Leakage Current Input Capacitance POWER SUPPLIES Supply Voltage Negative Power Supply Supply Voltage Difference Active Supply Current Standby Supply Current (Notes 3, 4) Shutdown Supply Current Power-Up Time Logic Supply Voltage Logic Active Supply Current Logic Standby Supply Current Logic Shutdown Current V V V mA mA µA ms V µA µA µA VIH VIL V V µA pF LED INDICATORS (LEDIND0–LEDIND4, MODEIND) Output Low Voltage Output Leakage Current Output Capacitance Maximum Sink Current VOL V µA pF mA Note 1: Parameters are 100% production tested at +85°C and limits through temperature are guaranteed by design. Note 2: The device draws current in excess of the specified supply current when the digital inputs are driven with voltages between (VDD - 0.5V) and (GND + 0.5V). See Digital Supply Current vs. Digital Input Voltage in the Typical Operating Characteristics. Note 3: Shutdown refers to the SHDN input being asserted low. Standby refers to SHDN not being asserted and all I/O inactive. Note 4: Supply current measured with the wiper position fixed. _______________________________________________________________________________________ 3 Stereo Volume Control with Rotary Encoder Interface MAX5440 Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) END-TO-END RESISTANCE % CHANGE vs. TEMPERATURE MAX5440 toc02 MAX5440 toc01 ATTENUATION vs. TAP POSITION 0 -10 ATTENUATION (dB) -20 -30 -40 -50 -60 -70 0 4 8 12 16 20 24 28 32 TAP POSITION 0.10 END-TO-END RESISTANCE CHANGE (%) 0.05 0 -0.05 -0.10 -0.15 -0.20 -0.25 TOTAL SUPPLY CURRENT vs. TEMPERATURE 1.47 TOTAL SUPPLY CURRENT (mA) 1.46 1.45 1.44 1.43 1.42 1.41 1.40 1.39 1.38 VLOGIC = VDD = 5.5V MAX5440 toc03 1.48 -40 -15 10 35 60 85 -40 -15 10 35 60 85 TEMPERATURE (°C) TEMPERATURE (°C) WIPER SWITCHING TRANSIENT MAX5440 toc04 WIPER-TO-END TERMINAL VOLTAGE vs. TAP POSITION MAX5440 toc05 FREQUENCY RESPONSE 0.8 0.4 0 RESPONSE (dB) -0.4 -0.8 -1.2 -1.6 -2.0 W_ SET TO 0dB VH_ = 2.5 ±1VRMS, VL_ = 2.5V, CL_ = 33pF MAX5440 toc06 100 NOMINAL END-TO-END VOLTAGE (%VHL) RENCODEA RENCODEB 90 80 70 60 50 40 30 20 10 0 0 4 8 VWL VHW 51ms WIPER TRANSITION FROM -2dB TO -4dB -2.4 -2.8 20ms/div 12 16 20 24 28 32 0.01 0.1 1 10 100 1000 TAP POSITION FREQUENCY (kHz) FREQUENCY RESPONSE MAX5440 toc07 THD+N vs. FREQUENCY MAX5440 toc08 THD+N vs. FREQUENCY VDD = 5.0V VSS = GND L_ = VMIDBIAS H_ = VMIDBIAS + 1VRMS THD+N (%) MAX5440 toc09 -5.2 -5.6 -6.0 RESPONSE (dB) VH_ = 2.5 ±1VRMS, VL_ = 2.5V, CL_ = 33pF 0.1 VDD = 2.5V VSS = -2.5V L_ = VMIDBIAS H_ = VMIDBIAS + 1VRMS THD+N (%) 0.1 -6.4 -6.8 -7.2 -7.6 -8.0 -8.4 -8.8 0.01 W_ SET TO -6dB 0.01 W_ SET AT -