General Description
The MAX5486 dual 40kΩlogarithmic taper volume con-
trol 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 potentiome-
ters. An integrated bias generator provides the required
((VDD + VSS) / 2) bias voltage, eliminating the need for
costly external op-amp circuits in unipolar audio applica-
tions. A mode-indicator LED output indicates volume or
balance control. Five integrated LED drivers indicate vol-
ume level or balance settings, depending on the status of
the mode indicator.
Use the MAX5486 digital inputs with momentary con-
tact single-pole/single-throw (SPST) pushbutton switch-
es. Each input includes internal debounced circuitry
and a pullup resistor to VLOGIC.
The MAX5486 advances the wiper setting once per but-
ton push. Maxim’s proprietary SmartWiper™ 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 hold-
ing 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 set-
ting. The mode input toggles between volume and bal-
ance control. The click-and-pop suppression feature
minimizes the audible noise generated by wiper transi-
tions. The typical total harmonic distortion plus noise
(THD+N) for the device is 0.003%. The MAX5486 pro-
vides a nominal temperature coefficient of 35ppm/°C
end-to-end and 5ppm/°C ratiometrically and a nominal
resistance of 40kΩper potentiometer. The MAX5486 is
available in a 24-pin TSSOP package and is specified
for operation over the -40°C to +85°C extended temper-
ature range.
Applications
Home-Theater Speakers
Desktop Speakers
Portable Media Players
Docking Stations
Automotive Rear-Seat Multimedia
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 1µA Shutdown Supply Current
♦40kΩEnd-to-End Fixed Resistance Value
♦Small, 24-Pin TSSOP Package
MAX5486
Stereo Volume Control with Pushbutton
Interface
________________________________________________________________
Maxim Integrated Products
1
19-0672; Rev 0; 11/06
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.
Ordering Information
V
DD
V
SS
(V
DD +
V
SS
) / 2
(V
DD +
V
SS
) / 2
V
LOGIC
V
PEAK
HR
LR
WR
SHDN
LEFT INPUT
RIGHT INPUT
MODEIND
MAX9761
LL
HL
WL
V
LOGIC
LEDIND4
LEDIND3
LEDIND0
GND MUTE
LEDIND1
LEDIND2
BIAS
BIASCAP
MAX5486
UP/BALL DN/BALR MODE
1MΩ
(V
DD +
V
SS
) / 2
V
PEAK
Typical Operating Circuit
PART TEMP RANGE PIN-
PACKAGE
PKG
CODE
MAX5486EUG+ -40°C to +85°C 24 TSSOP U24-1
SmartWiper is a trademark of Maxim Integrated Products, Inc.
+
Denotes lead-free package.
MAX5486
Stereo Volume Control with Pushbutton
Interface
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VDD = +2.7V to +5.5V, VSS = GND = 0, 2.7V ≤(VDD - VSS) ≤5.5V, CBIASCAP = 1µF, BIAS = 3kΩto 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= +25°C.) (Note 1)
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.
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= +70°C)
24-Pin TSSOP (derate 8.3mW/°C above +70°C) ..........657mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-60°C to +150°C
Maximum Junction Temperature .....................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
RESISTOR LADDER
End-to-End Resistance R 40 kΩ
Absolute Tolerance ±0.25 dB
Tap-to-Tap Tolerance (Note 2) ±0.1 dB
VOLUME CONTROL
VDD = 5V, VSS = 0, VH = (VDD / 2) + 1VRMS,
VL = VDD / 2, 1kHz, tap at top, RL = 10kΩ to
VL = VDD / 2, 20Hz to 20kHz
0.003
VDD = 5V, VSS = 0, VH = (VDD / 2) + 1VRMS,
VL = VDD / 2, 1kHz, tap at top, RL = ∞Ω to
VL = VDD / 2, 20Hz to 20kHz
0.001
Total Harmonic Distortion Plus
Noise THD+N
VDD = 5V, VSS = 0, VH = (VDD / 2) +
1.5VRMS, VL = VDD / 2, 1kHz, tap at top,
RL = 10kΩ to VL = VDD / 2, 20Hz to 20kHz
0.012
%
Channel Isolation VDD = +2.7V, VSS = -2.7V, VBIAS = GND 100 dB
Interchannel Matching ±0.5 dB
Mute Attenuation SHDN = VDD 90 dB
Power-Supply Rejection Ratio PSRR Input referred, 217Hz, 100mVP-P on VDD 72 dB
H Terminal Capacitance CH5pF
L Terminal Capacitance CL7pF
End-to-End Resistance
Temperature Coefficient 35 ppm/°C
Ratiometric Resistance
Temperature Coefficient 5 ppm/°C
Bandwidth, -3dB fCUTOFF CW = 50pF 100 kHz
MAX5486
Stereo Volume Control with Pushbutton
Interface
_______________________________________________________________________________________ 3
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Output Noise eN20Hz to 20kHz, VH = VL = VDD / 2 = AC
ground, tap = -6dB 2.2 µVRMS
WIPER BUFFER
Output Voltage Swing VORL = 3kΩ to VBIAS VDD -
0.3V V
Output Current 3mA
Output Resistance ROWB 110Ω
DC Offset VOS ±2 ±14 mV
INTEGRATED BIAS GENERATOR
Output Voltage RL > 100kΩ
(VDD +
VSS) / 2
- 20mV
(VDD +
VSS) / 2
(VDD +
VSS) / 2
+ 20mV
V
Power-Supply Rejection Ratio At 1kHz, 100mVP-P on VDD 60 dB
Minimum Load Resistance 3kΩ
Maximum Load Capacitance 100 pF
Output Resistance ROBR 6Ω
Noise Voltage 20Hz to 20kHz 2.2 µVRMS
Minimum Output Current 2mA
CONTACT INPUTS (MUTE, MODE, UP/BALL, DN/BALR)
Internal Pullup Resistor RPU 42 kΩ
Single-Pulse Input Low Time tCPW Time required for a single pulse to cause an
increment/decrement 16 ms
Repetitive Input Pulse Separation
Time tIPWS 1ms
Timeout Period tWS Click-and-pop suppression inactive 126 ms
Debounce Corner Frequency Internal analog filter 10 kHz
DIGITAL INPUTS (VLOGIC > 4.5V)
VLOGIC > 4.5V 2.4
Input High Voltage VIH VLOGIC < 4.5V 0.7 x
VLOGIC
V
VLOGIC > 4.5V 0.8
Input Low Voltage VIL VLOGIC < 4.5V 0.3 x
VLOGIC
V
Input Leakage Current To GND for inputs with internal pullup
resistors ±1 µA
Input Capacitance 5pF
Digital Clock Feedthrough fCLK = 1Hz to 40Hz, tap = -6dB -90 dB
ELECTRICAL CHARACTERISTICS (continued)
(VDD = +2.7V to +5.5V, VSS = GND = 0, 2.7V ≤(VDD - VSS) ≤5.5V, CBIASCAP = 1µF, BIAS = 3kΩto 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= +25°C.) (Note 1)
MAX5486
Stereo Volume Control with Pushbutton
Interface
4 _______________________________________________________________________________________
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
POWER SUPPLIES
Positive Power Supply VDD VSS = 0 2.7 5.5 V
Negative Power Supply VSS VDD = +2.7V -2.7 0 V
Supply-Voltage Difference VDD - VSS 5.5 V
Analog Supply Current IDD (Note 3) 1.4 mA
Power-Up Time tPU 126 ms
Logic Supply Voltage VLOGIC VSS = 0 2.7 VDD V
Logic Active Supply Current ILOGIC VLOGIC = VDD (Note 4) 200 µA
VDD = +5V, VSS = 0 1
Logic Standby Supply Current
(Note 3) ILOGICSTBY VDD = +2.7V, VSS = -2.7V 1 µA
Shutdown Current ISHDN SHDN = 0, total of all supplies 1 µA
Shutdown Time/Return from
Shutdown tSHDN After 1st zero crossing 1 ms
LED INDICATORS (LEDIND0–LEDIND4, MODEIND)
VLOGIC = 2.7V, ISINK = 10mA 0.4
Output Low Voltage VOL VLOGIC = 5V, ISINK = 10mA 0.2 V
Maximum Output Leakage
Current 10 µA
Output Capacitance 3pF
ELECTRICAL CHARACTERISTICS (continued)
(VDD = +2.7V to +5.5V, VSS = GND = 0, 2.7V ≤(VDD - VSS) ≤5.5V, CBIASCAP = 1µF, BIAS = 3kΩto 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= +25°C.) (Note 1)
Note 1: Parameters are 100% production tested at +85°C and limits through the temperature range are guaranteed by design.
Note 2: Tap-to-tap tolerance is the error in voltage change between successive tap positions.
Note 3: Supply current measured while wiper position is fixed.
Note 4: One button pressed.
MAX5486
Stereo Volume Control with Pushbutton
Interface
_______________________________________________________________________________________
5
-70
-60
-40
-50
-20
-10
-30
0
08124 1620242832
ATTENUATION vs. TAP POSITION
MAX5486 toc01
TAP POSITION
ATTENUATION (dB)
-0.25
-0.20
-0.15
-0.10
-0.05
0
0.05
0.10
0.15
-40 -15 10 35 60 85
END-TO-END RESISTANCE % CHANGE
vs. TEMPERATURE
MAX5486 toc02
TEMPERATURE (°C)
END-TO-END RESISTANCE CHANGE (%)
VDD = VLOGIC = 5V
VSS = GND = 0
40ms/div
WIPER SWITCHING TRANSIENT
5V/div DN
MAX5486 toc03
200mV/div
WIPER TRANSITION
FROM -2dB TO -4dB
0
20
10
40
30
60
50
70
90
80
100
08124 1620242832
WIPER-TO-END TERMINAL VOLTAGE
vs. TAP POSITION
MAX5486 toc04
TAP POSITION
NOMINAL END-TO-END VOLTAGE (%VHL)
VHW
VWL
-20
-15
-5
-10
0
5
0.01 10.1 10 100 1000
FREQUENCY RESPONSE
MAX5486 toc05
FREQUENCY (kHz)
RESPONSE (dB)
VH1 = 2.5V ±1VRMS, VL1 = 2.5V
W_ SET TO 0dB
W_ SET TO -6dB
W_ SET TO -12dB
W_ SET TO -18dB
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
MAX5486 toc06
FREQUENCY (kHz)
THD+N (%)
1010.1
0.001
0.01
0.1
1
10
100
0.0001
0.01 100
VDD = 5V
VSS = GND
VL_ = 2.5V
W_ SET TO 0dB
VH_ = 2.5V ±1.5VRMS
VH_ = 2.5V ±1VRMS
10kΩ OR NO LOAD
10kΩ OR NO LOAD
POWER-SUPPLY REJECTION RATIO
MAX5486 toc07
FREQUENCY (kHz)
RESPONSE (dB)
1010.1
-95
-90
-85
-80
-75
-70
-65
-60
-55
-50
-45
-40
-35
-30
-100
0.01 100
VDD = 5V ±100mVP-P, VSS = GND
VH_ = 5V, VL_ = 2.5V
W_ SET TO -6dB
Typical Operating Characteristics
(VDD = +5.0V, VSS = GND = 0, VLOGIC = +5.0, VH_ = VDD - 0.15V, VL_ = VDD / 2, CBIASCAP = 1µF)
MAX5486
Stereo Volume Control with Pushbutton
Interface
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VDD = +5.0V, VSS = GND = 0, VLOGIC = +5.0, VH_ = VDD - 0.15V, VL_ = VDD / 2, CBIASCAP = 1µF)
140
142
146
144
148
150
-40 10-15 35 60 85
ACTIVE LOGIC SUPPLY CURRENT
vs. TEMPERATURE
MAX5486 toc10
TEMPERATURE (°C)
ACTIVE ILOGIC (μA)
VDD = VLOGIC = 5.5V
2.0
1.5
1.0
0.5
0
0312 456
ACTIVE SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX5486 toc11
SUPPLY VOLTAGE (V)
ACTIVE SUPPLY CURRENT (mA)
UP = 0
VLOGIC = 5.5V
ACTIVE SUPPLY CURRENT
vs. TEMPERATURE
MAX5486 toc12
TEMPERATURE (°C)
ACTIVE SUPPLY CURRENT (mA)
603510-15
0.5
1.0
1.5
2.0
0
-40 85
VDD = VLOGIC = 5.5V
UP = 0
SPECTRAL NOISE DENSITY
MAX5486 toc13
FREQUENCY (kHz)
1010.1
50
100
150
200
250
300
0
0.01 100
NOISE (nV/√Hz)
CROSSTALK vs. FREQUENCY
MAX5486 toc14
FREQUENCY (Hz)
CROSSTALK (dB)
1010.1
-140
-120
-100
-80
-60
-40
-20
0
-160
0.01 100
VDD = 2.7V, VSS = -2.7V, VLOGIC = 5V
W_SET TO 0dB, VHR = 1VRMS
VLR = VLL = VHL = 0V
500ns/div
DIGITAL FEEDTHROUGH
50μV/div WIPER
OUTPUT
MAX5486 toc15
2V/div
PUSHBUTTON
INPUT
LOGIC SUPPLY CURRENT
vs. LOGIC INPUT VOLTAGE
MAX5486 toc09
LOGIC INPUT VOLTAGE (V)
LOGIC SUPPLY CUURENT (μA)
4.54.03.53.02.52.01.51.00.5
100
1000
10
05.0
MAX5486
Stereo Volume Control with Pushbutton
Interface
_______________________________________________________________________________________ 7
_______________________________________________________________________________________
7
Pin Description
PIN NAME FUNCTION
1V
LOGIC Digital Logic Power Supply. Bypass VLOGIC to ground with a 0.1µF capacitor as close as possible to
the device.
2DN/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.
3UP/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.
4MUTE 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.
5MODE
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.
6SHDN
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 Midbias Voltage Output. VBIAS = (VDD + VSS) / 2; connect a 100pF capacitor from BIAS to VSS.
12 BIASCAP Bias Generator Bypass. Connect a 1µF filter capacitor from BIASCAP to VSS.
13 VDD Analog Power Supply. Bypass VDD to ground with a 0.1µF capacitor as close as possible to the
device.
14 VSS Negative Power Supply. Bypass VSS to ground with a 0.1µF 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
18–22 LEDIND0–
LEDIND4
LED Indicator Open-Drain Output 0–LED Indicator Open-Drain Output 4. Connect a 1MΩ 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 Ground
MAX5486
Stereo Volume Control with Pushbutton
Interface
8 _______________________________________________________________________________________8 _______________________________________________________________________________________
Detailed Description
The MAX5486 dual 40kΩlogarithmic taper digital vol-
ume 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.
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
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 microcom-
puter to increase the wiper transition rate.
The MAX5486 MODE input toggles the part between vol-
ume 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.
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 main-
tained 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).
GND
MOMENTARY
CONTACT
SPST
PUSHBUTTONS
DN
VLOGIC
UP
MAX5486
Figure 1. Pushbutton Interface
POSITION ATTENUATION (dB)
00
12
24
36
48
MM
30 60
31 62
32 (mute) > 90
Table 1. Wiper Position and Attenuation
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.
Table 2. Wiper Action vs. Pushbutton
Contact Duration
MAX5486
Stereo Volume Control with Pushbutton
Interface
_______________________________________________________________________________________ 9
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 bal-
ance between the right and left channels while main-
taining 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 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 allow-
ing 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 time-
out 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 chan-
nels separately. In volume-control mode, when the first
_______________________________________________________________________________________ 9
WR
H_
H_
H_
H_
L_
L_
WL WR WRWL WL
PRESS UP
TWICE
PRESS DN
ONCE
NO CHANGE
WR WL WR WRWL WL
PRESS UP
ONCE PRESS UP
ONCE
WR WL WR WRWL WL
PRESS DN
ONCE PRESS DN
ONCE
WR WL WR WRWL WL
PRESS UP
ONCE
PRESS UP
ONCE
BALANCE SEPARATION
MAINTAINED
ORIGINAL BALANCE SEPARATION
MAINTAINED
TO 2d
FROM 2c
L_
L_
(2a)
(2b)
(2c)
(2d)
Figures 2a–2d. Volume-Control Operation
MAX5486
wiper 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= VLto eliminate clicks and pops during power-up.
With DC inputs at VHand VL, the wipers move after
exceeding the timeout period. A power-on reset places
the MAX5486 in volume-control 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= VLto eliminate clicks and
pops during shutdown. With DC inputs at VHand 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-
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 vol-
ume 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 bal-
ance-control mode. When the LED is off, the MAX5486
is in volume-control 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 dis-
play the current wiper settings in either volume or bal-
ance mode. The LED indicators are enabled by
connecting a 1MΩresistor 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).
Stereo Volume Control with Pushbutton
Interface
10 ______________________________________________________________________________________
(3a)
WR
H_
L_
H_
L_
WL WR WRWL WL
WR WL WR WRWL WL
(3b)
VOLUME LEVEL IS SET
VOLUME LEVEL MAINTAINED
BALANCE SHIFTS TO WL
VOLUME LEVEL MAINTAINED
BALANCE SHIFTS TO WLVOLUME LEVEL IS SET BY WR
PRESS BALL
ONCE
PRESS BALL
ONCE
PRESS BALL
ONCE
PRESS BALL
ONCE
Figures 3a and 3b. Balance-Control Operation
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.
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.
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 sin-
gle-supply configuration. The internally generated BIAS
voltage eliminates the need for external op amps, and
the wipers have internal low-power buffers for low dis-
tortion. 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 attenu-
ate the input signals. Use the MODE input to switch
between volume-control and balance-control modes.
MAX5486
Stereo Volume Control with Pushbutton
Interface
______________________________________________________________________________________ 11
VOLUME LED OUTPUTS ( 1 = LED IS ON)
VOLUME POSITION LED0 LED1 LED2 LED3 LED4
0dB to -8dB 11111
-10dB to -18dB 11110
-20dB to -28dB 11100
-30dB to -38dB 11000
-40dB to -52dB 10000
-54dB to mute (-90dB) 00000
Table 3. LED Settings in Volume Mode
MAX5486
Stereo Volume Control with Pushbutton
Interface
12 ______________________________________________________________________________________
DN OR UP
1
0
USER PRESSES PUSHBUTTON
SWITCH
CONTACT
IS BOUNCING
SWITCH
CONTACT
IS STABLE
SWITCH
CONTACT
IS BOUNCING
READY TO ACCEPT
ANOTHER KEYPRESS
INPUT ACCEPTED
tIPW tWS
tHPW
DEBOUNCE BY
WAITING FOR
STABLE LOW, tIPW
WAIT FOR
FIRST ZERO
CROSSING, tWS
DEBOUNCE BY
WAITING FOR
STABLE HIGH, tHPW
VH
VL
WIPER MOTION
WIPER MOVES HERE
2dB
STEPS
Figure 4a. Wiper Transition Timing Diagram—Suppression Circuitry Active
MAX5486
Stereo Volume Control with Pushbutton
Interface
______________________________________________________________________________________ 13
1
0
SWITCH
CONTACT
IS BOUNCING
SWITCH
CONTACT
IS STABLE
SWITCH
CONTACT
IS BOUNCING
READY TO ACCEPT
ANOTHER KEYPRESS
INPUT ACCEPTED
tIPW tWS
tHPW
DEBOUNCE BY
WAITING FOR
STABLE LOW,
tIPW
WAIT FOR
FIRST ZERO
CROSSING OR
TIMEOUT, tWS
DEBOUNCE BY
WAITING FOR
STABLE HIGH, tHPW
VH
VL
WIPER MOVES HERE
2dB
STEPS
(tIPW + tWS)
Figure 4b. Wiper Transition Timing Diagram—Timeout
FULL L L + 12 L + 6 R + 6 R + 12 FULL R
CENTERED PB PRESS (CHANNEL R) PB PRESS (CHANNEL L)
LED0 ON LED1 ON LED2 ON LED3 ON LED4 ON
Figure 5. LED Settings in Balance Mode
MAX5486
Stereo Volume Control with Pushbutton
Interface
14 ______________________________________________________________________________________
SWITCH CONTROL, CLICK-AND-POP SUPPRESSION
DEBOUNCE, TIMEOUT, ACCELERATION
MODEIND
LEDIND4
LEDIND3
LEDIND2
LEDIND1
LEDIND0
WR
BIAS
BIASCAP
BIAS GENERATOR
VDD
VSS
VDD
LED DRIVERS
WL
VSS
GND
SHDNMUTE
MODE
UP/BALL DN/BALR
LL
HR
LR
HL
MAX5486
VLOGIC
Functional Diagram
MAX5486
Stereo Volume Control with Pushbutton
Interface
______________________________________________________________________________________ 15
24
23
22
21
20
19
18
17
1
2
3
4
5
6
7
8
GND
MODEIND
LEDIND4
LEDIND3MUTE
UP/BALL
DN/BALR
VLOGIC
TOP VIEW
LEDIND2
LEDIND1
LEDIND0
HLHR
N.C.
SHDN
MODE
16
15
14
13
9
10
11
12
LL
WL
VSS
VDD
BIASCAP
BIAS
WR
LR
TSSOP
MAX5486
+
Pin Configuration Chip Information
PROCESS: BiCMOS
MAX5486
Stereo Volume Control with Pushbutton
Interface
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.
16
____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2006 Maxim Integrated Products is a registered trademark of Maxim Integrated Products. Inc.
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.)
TSSOP4.40mm.EPS
PACKAGE OUTLINE, TSSOP 4.40mm BODY
21-0066 1
1
G