MAXIM MAX5486 User Manual

General Description

The MAX5486 dual 40kΩ 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
((V

DD

+ 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 V

LOGIC

.

The MAX5486 advances the wiper setting once per but­ton 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 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 40kΩ per potentiometer. The MAX5486 is
available in a 24-pin TSSOP package and is specified
for operation over the -40°C to +85°C extended temper­ature 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
♦ 40kΩ End-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 + VSS

) / 2

(V

DD + VSS

) / 2

V

LOGIC

V

PEAK

HR

L

R

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 + VSS

) / 2

V

PEAK

Typical Operating Circuit

SmartWiper is a trademark of Maxim Integrated Products, Inc.

+

Denotes lead-free package.

PART TEMP RANGE

MAX5486EUG+ -40°C to +85°C 24 TSSOP U24-1

PIN­PACKAGE

PKG

CODE

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, C

BIASCAP

= 1µF, BIAS = 3kΩ to GND, V

LOGIC

= +2.7V to VDD,

VH_ = V

DD

- 0.15V, VL_= (VDD- VSS) / 2, SHDN = MUTE = V

LOGIC

, all LED outputs open, pushbutton interface inactive, VH= V

BIAS

+ 1V

RMS

, V

BIAS

= (VDD- VSS) / 2, TA= T

MIN

to T

MAX

, 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 (V

LOGIC

+ 0.3V and +6V)

H_, L_, W_, BIASCAP,

BIAS to GND .........-0.3V to the lower of (V

DD

+ 0.3V and +6V)

LEDIND_, MODEIND to GND...................................-0.3V to +6V

V

LOGIC

to GND.........................................................-0.3V to +6V

V

DD

to GND..............................................................-0.3V to +6V

V

DD

to V

LOGIC

.............................................................-6V to +6V

GND to V

SS

...............................................................-0.3V to +6V

V

DD

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 (T

A

= +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

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

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

VDD = 5V, VSS = 0, VH = (V

= V

V

L

V

L

/ 2, 1kHz, tap at top, RL = 10kΩ to

DD

= V

/ 2, 20Hz to 20kHz

DD

DD

/ 2) + 1V

RMS

,

0.003

Total Harmonic Distortion Plus
Noise

THD+N

VDD = 5V, VSS = 0, VH = (V
V

= V

L

V

L

V

DD

1.5V
R

L

/ 2, 1kHz, tap at top, RL = ∞Ω to

DD

= V

/ 2, 20Hz to 20kHz

DD

= 5V, VSS = 0, VH = (V

, VL = V

RMS

= 10kΩ to VL = V

/ 2, 1kHz, tap at top,

DD

DD

Channel Isolation VDD = +2.7V, VSS = -2.7V, V

/ 2) + 1V

DD

DD

/ 2) +

RMS

/ 2, 20Hz to 20kHz

= GND 100 dB

BIAS

,

0.001

0.012

Interchannel Matching ±0.5 dB
Mute Attenuation SHDN = V

DD

Power-Supply Rejection Ratio PSRR Input referred, 217Hz, 100mV

H Terminal Capacitance C

L Terminal Capacitance C

H

L

End-to-End Resistance
Temperature Coefficient

Ratiometric Resistance
Temperature Coefficient

Bandwidth, -3dB f

CUTOFFCW

= 50pF 100 kHz

P-P

on V

DD

90 dB

72 dB

5pF

7pF

35 ppm/°C

5 ppm/°C

%

MAX5486

Stereo Volume Control with Pushbutton

Interface

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VDD= +2.7V to +5.5V, VSS= GND = 0, 2.7V ≤ (VDD- VSS) ≤ 5.5V, C

BIASCAP

= 1µF, BIAS = 3kΩ to GND, V

LOGIC

= +2.7V to VDD,

VH_ = V

DD

- 0.15V, VL_= (VDD- VSS) / 2, SHDN = MUTE = V

LOGIC

, all LED outputs open, pushbutton interface inactive, VH= V

BIAS

+ 1V

RMS

, V

BIAS

= (VDD- VSS) / 2, TA= T

MIN

to T

MAX

, unless otherwise specified. Typical values are at TA= +25°C.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Output Noise e

20Hz to 20kHz, VH = VL = V

N

ground, tap = -6dB

DD

/ 2 = AC

2.2 µV

RMS

WIPER BUFFER

Output Voltage Swing V

O

RL = 3kΩ to V

BIAS

VDD -

0.3V

V

Output Current 3mA

Output Resistance R

DC Offset V

OWB

OS

110Ω

±2 ±14 mV

INTEGRATED BIAS GENERATOR

Output Voltage RL > 100kΩ

Power-Supply Rejection Ratio At 1kHz, 100mV

P-P

on V

DD

(V

DD

V

) / 2

SS

- 20mV

+

+

(V

DD

V

) / 2

SS

60 dB

+

(V

DD

V

) / 2

SS

+ 20mV

V

Minimum Load Resistance 3kΩ

Maximum Load Capacitance 100 pF

Output Resistance R

OBR

Noise Voltage 20Hz to 20kHz 2.2 µV

6 Ω

RMS

Minimum Output Current 2mA

CONTACT INPUTS (MUTE, MODE, UP/BALL, DN/BALR)

Internal Pullup Resistor R

Single-Pulse Input Low Time t

Repetitive Input Pulse Separation
Time

Timeout Period t

CPW

t

IPWS

WS

PU

Time required for a single pulse to cause an
increment/decrement

16 ms

1ms

Click-and-pop suppression inactive 126 ms

42 kΩ

Debounce Corner Frequency Internal analog filter 10 kHz

DIGITAL INPUTS (V

Input High Voltage V

Input Low Voltage V

Input Leakage Current

LOGIC

> 4.5V)

V

> 4.5V 2.4

LOGIC

IH

V

< 4.5V

LOGIC

V

> 4.5V 0.8

LOGIC

IL

V

< 4.5V

LOGIC

To GND for inputs with internal pullup
resistors

0.7 x

V

LOGIC

0.3 x

V

LOGIC

±1 µA

V

V

Input Capacitance 5pF

Digital Clock Feedthrough f

= 1Hz to 40Hz, tap = -6dB -90 dB

CLK

MAX5486

Stereo Volume Control with Pushbutton
Interface

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(VDD= +2.7V to +5.5V, VSS= GND = 0, 2.7V ≤ (VDD- VSS) ≤ 5.5V, C

BIASCAP

= 1µF, BIAS = 3kΩ to GND, V

LOGIC

= +2.7V to VDD,

VH_ = V

DD

- 0.15V, VL_= (VDD- VSS) / 2, SHDN = MUTE = V

LOGIC

, all LED outputs open, pushbutton interface inactive, VH= V

BIAS

+ 1V

RMS

, V

BIAS

= (VDD- VSS) / 2, TA= T

MIN

to T

MAX

, 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.

POWER SUPPLIES

Positive Power Supply V

Negative Power Supply V

Supply-Voltage Difference VDD - V

Analog Supply Current I

Power-Up Time t

Logic Supply Voltage V

Logic Active Supply Current I

Logic Standby Supply Current
(Note 3)

Shutdown Current I

Shutdown Time/Return from
Shutdown

LED INDICATORS (LEDIND0–LEDIND4, MODEIND)

Output Low Voltage V

Maximum Output Leakage
Current

Output Capacitance 3pF

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DD

SS

DD

PU

LOGICVSS

LOGIC

I

LOGICSTBY

SHDN

t

SHDN

OL

VSS = 0 2.7 5.5 V

VDD = +2.7V -2.7 0 V

(Note 3) 1.4 mA

V

LOGIC

VDD = +5V, VSS = 0 1

VDD = +2.7V, VSS = -2.7V 1
SHDN = 0, total of all supplies 1 µA

After 1st zero crossing 1 ms

V

LOGIC

V

LOGIC

SS

= 0 2.7 V

= VDD (Note 4) 200 µA

= 2.7V, I

= 5V, I

= 10mA 0.4

SINK

= 10mA 0.2

SINK

5.5 V

126 ms

DD

10 µA

V

µA

V

MAX5486

Stereo Volume Control with Pushbutton

Interface

_______________________________________________________________________________________

5

Typical Operating Characteristics

(VDD= +5.0V, VSS= GND = 0, V

LOGIC

= +5.0, VH_= VDD- 0.15V, VL_= VDD/ 2, C

BIASCAP

= 1µF)

ATTENUATION vs. TAP POSITION

0

-10

-20

-30

-40

ATTENUATION (dB)

-50

-60

-70
08124 1620242832

WIPER SWITCHING TRANSIENT

5V/div

200mV/div

MAX5486 toc01

TAP POSITION

MAX5486 toc03

DN

WIPER TRANSITION
FROM -2dB TO -4dB

40ms/div

0.15

0.10

0.05

-0.05

-0.10

-0.15

END-TO-END RESISTANCE CHANGE (%)

-0.20

-0.25

)

HL

NOMINAL END-TO-END VOLTAGE (%V

END-TO-END RESISTANCE % CHANGE

vs. TEMPERATURE

VDD = V
V

0

-40 -15 10 35 60 85

= GND = 0

SS

= 5V

LOGIC

TEMPERATURE (°C)

WIPER-TO-END TERMINAL VOLTAGE

vs. TAP POSITION

100

90

80

70

60

50

40

30

20

10

0

08124 1620242832

TAP POSITION

V

HW

V

WL

MAX5486 toc02

MAX5486 toc04

FREQUENCY RESPONSE

5

0

-5

-10

RESPONSE (dB)

-15

-20

0.01 10.1 10 100 1000

VH1 = 2.5V ±1V

W_ SET TO 0dB

W_ SET TO -6dB

W_ SET TO -12dB

W_ SET TO -18dB

FREQUENCY (kHz)

, VL1 = 2.5V

RMS

MAX5486 toc05

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

100

VDD = 5V

= GND

V

SS

10

= 2.5V

V

L_

W_ SET TO 0dB

1

0.1

THD+N (%)

VH_ = 2.5V ±1.5V

0.01

VH_ = 2.5V ±1V

0.001

0.0001

0.01 100
FREQUENCY (kHz)

10kΩ OR NO LOAD

RMS

RMS

10kΩ OR NO LOAD

POWER-SUPPLY REJECTION RATIO

-30
VDD = 5V ±100mV

-35

= 5V, VL_ = 2.5V

V

H_

MAX5486 toc06

1010.1

-40
W_ SET TO -6dB

-45

-50

-55

-60

-65

-70

RESPONSE (dB)

-75

-80

-85

-90

-95

-100

0.01 100

, V

= GND

P-P

SS

FREQUENCY (kHz)

MAX5486 toc07

1010.1