MAX5440_V01 [MAXIM]
Stereo Volume Control with Rotary Encoder Interface;
| 型号： | MAX5440_V01 |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Stereo Volume Control with Rotary Encoder Interface |
| 文件： | 总16页 (文件大小：1579K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
General Description
Features
The MAX5440 dual, 40kΩ logarithmic taper volume con-
trol 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
● 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
the required ((V
+ V )/2) bias voltage, eliminating
DD
SS
● Low 0.5μA Shutdown Supply Current
● Integrated Bias Voltage Generator
● Five-Segment LED Volume/Balance Indicator
● Clickless Switching
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.
● 40kΩ End-to-End Fixed Resistance Value
● Mute Function Toggles to -90dB (typ)
● Power-On Reset to -12dBFS Wiper Position
The MAX5440 includes debounced pushbutton inputs for
mute and mode. The mute input allows a single pushbut-
ton 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 transi-
tions. The MAX5440 provides a nominal temperature
coefficient of 35ppm/°C end-toend and 5ppm/°C, ratio-
metrically. 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.
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX5440EAG+
-40°C to +85°C
24 SSOP
+Denotes a lead(Pb)-free/RoHS-compliant package.
Note: For leaded version, contact factory.
Typical Operating Circuit
Applications
● Stereo Volume Control
V
DD
V
LOGIC
● Desktop Speakers
● Multimedia Docking Stations
● Set-Top Boxes
V
LOGIC
SHDN
MODEIND
V
PEAK
(V
DD
V
SS
) / 2
+
MAX5440
Pin Configuration
H1
W1
L1
TOP VIEW
V
1
2
3
4
24
23
22
21
20
19
LOGIC
GND
RIGHT INPUT
MODEIND
LEDIND4
LEDIND3
RENCODEB
RENCODEA
MUTE
HEADPHONE
DRIVER
MIDBIAS
(V
DD
V ) / 2
SS
+
MAX5440
LEDIND0
LEDIND1
LEFT INPUT
L0
LEDIND2
LEDIND1
MODE
SHDN
GND
H0
5
6
W0
LEDIND2
LEDIND3
18 LEDIND0
17 H1
7
8
H0
LEDIND4
BIAS
V
SS
16 L1
L0
9
15 W1
10
11
12
W0
14
13
V
MIDBIAS
BIAS
SS
DD
V
ROTARY
ENCODER
SSOP
19-0542; Rev 3; 4/14
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
Absolute Maximum Ratings
SHDN, MUTE, RENCODEA, RENCODEB,
V
to GND.............................................................-3V to +0.3V
SS
and MODE to GND..........................-0.3V to (V
+ 0.3V)
+ 0.3V)
+ 0.3V)
+ 0.3V)
+ 0.3V)
Input and Output Latchup Immunity...............................±200mA
Continuous Power Dissipation (T = +70°C)
LOGIC
H_, L_, and W_ to V ............................ -0.3V to (V
SS
DD
LOGIC
A
LEDIND_, MODEIND to GND.............-0.3V to (V
24-Pin SSOP (derate 12.3mW/°C above +70°C) .....987.7mW
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
MIDBIAS, BIAS to V ..................(V - 0.3V) to (V
SS
SS
DD
V
V
V
to GND........................................ -0.3V to (V
to GND ............................................................-0.3V to +6V
LOGIC
DD
DD
to V ..............................................................-0.3V to +6V
DD
SS
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
(V
= +2.7V to +5.5V, V
= V
= 0, 2.7V ≤ (V
- V ) ≤ 5.5V, V
= +2.7V to V , V
= V , V = V /2,
H_ DD L_ DD
DD
SS
GND
DD
SS
LOGIC
DD
T
= T
to T
, unless otherwise specified. Typical values are at T = +25°C.) (Note 1)
MAX A
A
MIN
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
40
MAX
UNITS
kΩ
End-to-End Resistance
Absolute Tolerance
R
36
52
±0.25
±0.1
dB
Tap-to-Tap Tolerance
dB
V
= (V
/ 2) + 1V
, 1kHz tap at top,
H_
DD
RMS
0.004
0.006
R = J to V = V
/ 2, 20Hz to 20kHz
L
L_
DD
V
= (V
/ 2) + 1.5VRMS, 1kHz tap at top,
H_
DD
R = J to V = V
/ 2, 20Hz to 20kHz
L
L_
DD
Total Harmonic Distortion Plus
Noise
V
V
= 5V,V = 0V, V = 1.5V,
SS L_
DD
THD+N
%
= (V
/ 2) + 1V
, 1kHz tap at top,
0.004
0.006
H_
DD
RMS
R = 10kΩ to V
, 20Hz to 20kHz
L
MIDBIAS
V
V
= 5V,V = 0V, V = 5V,
SS L_
DD
= (V
/ 2) + 1.5V
, 1kHz tap at top,
H_
DD
RMS
R = 10kΩ to V
L
, 20Hz to 20kHz
MIDBIAS
Channel Isolation
100
±0.5
90
-60
5
dB
dB
Interchannel Matching
Mute Attenuation
SHDN = V
dB
DD
Power-Supply Rejection Ratio
H Terminal Capacitance
L Terminal Capacitance
End-to-End Resistance
Ratiometric Resistance
Bandwidth, -3dB
PSRR
Input referred, 217Hz, 100mV
on V
dB
P-P
DD
C
pF
H
C
7
pF
L
35
5
ppm/°C
ppm/°C
kHz
f
C
= 33pF
100
3.2
CUTOFF
W
Output Noise
e
20Hz to 20kHz
µV
n
RMS
WIPER BUFFER
Output Voltage Swing
Output Current
V
R = 10kΩ to V
V
- 0.2
V
O
L
MIDBIAS
DD
3
mA
Ω
Output Resistance
R
1
10
OWB
DC Offset
-14
±2
+14
mV
INTEGRATED BIAS GENERATOR
(V
+
(V
+
(V
+
DD
DD
DD
Output Voltage
I
= 1mA
V
) / 2
V
)
V ) / 2
V
LOAD
SS
SS
SS
- 30mV
/ 2
+ 30mV
Maxim Integrated
│ 2
www.maximintegrated.com
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
Electrical Characteristics (continued)
(V
= +2.7V to +5.5V, V
= V
= 0, 2.7V ≤ (V
- V ) ≤ 5.5V, V
= +2.7V to V , V
= V , V = V /2,
H_ DD L_ DD
DD
SS
GND
DD
SS
LOGIC
DD
T
= T
to T
, unless otherwise specified. Typical values are at T = +25°C.) (Note 1)
MAX A
A
MIN
PARAMETER
SYMBOL
PSRR
CONDITIONS
1kHz, 100mV on V , 1µF on BIAS
MIN
TYP
MAX
UNITS
dB
Power-Supply Rejection Ratio
Maximum Load
60
BR
DD
To V
or GND
3
kΩ
DD
Output Resistance
R
6
Ω
OBR
CONTACT INPUTS (MUTE, MODE, RENCODEA, RENCODEB)
Internal Pullup Resistor
Single Pulse Input Low Time
Repetitive Input Pulse Separation
Timeout Period
R
45
kΩ
ms
ms
ms
PULLUP
t
22
66
CPW
t
IPWS
t
Click/pop suppression inactive
32
WS
DIGITAL INPUTS (MUTE, MODE, RENCODEA, RENCODEB, SHDN)
3.6V < V
2.7V ≤ V
3.6V < V
2.7V ≤ V
≤ 5.5V
≤ 3.6V
≤ 5.5V
≤ 3.6V
2.4
2.0
LOGIC
LOGIC
LOGIC
LOGIC
Input High Voltage (Note 2)
V
V
V
IH
0.8
0.6
+1
Input Low Voltage (Note 2)
V
IL
Input Leakage Current
Input Capacitance
Inputs unconnected
-1
µA
5
pF
POWER SUPPLIES
Supply Voltage
V
V
V
V
= 0
2.7
5.5
0
V
V
DD
SS
DD
DD
Negative Power Supply
Supply Voltage Difference
Active Supply Current
V
= +2.7V
-2.7
SS
- V
5.5
1.4
1.3
1.3
1
V
SS
I
mA
DD
V
V
= +5V, V = 0
SS
Standby Supply Current
(Notes 3, 4)
DD
I
mA
STBY
= +2.7V, V = -2.7V
DD
SS
Shutdown Supply Current
Power-Up Time
I
(Note 3)
µA
ms
V
SHDN
t
Click/pop suppression inactive
50
PU
Logic Supply Voltage
V
V
V
= 0
2.7
V
DD
LOGIC
SS
Logic Active Supply Current
Logic Standby Supply Current
Logic Shutdown Current
I
= V
= 0V
320
µA
µA
µA
L
RENCODEA
RENCODEB
I
(Note 4)
1
1
LSTBY
I
LSHDN
LED INDICATORS (LEDIND0–LEDIND4, MODEIND)
V
= 2.7V, I
= 5.5V, I
= 10mA
= 10mA
0.4
0.2
10
LOGIC
SINK
Output Low Voltage
V
V
OL
V
LOGIC
SINK
Output Leakage Current
Output Capacitance
0.1
3
µA
pF
Maximum Sink Current
150
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
(V - 0.5V) and (GND + 0.5V). See Digital Supply Current vs. Digital Input Voltage in the Typical Operating Characteristics.
DD
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.
Maxim Integrated
│ 3
www.maximintegrated.com
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
Typical Operating Characteristics
(T = +25°C, unless otherwise noted.)
A
END-TO-END RESISTANCE % CHANGE
vs. TEMPERATURE
TOTAL SUPPLY CURRENT
vs. TEMPERATURE
ATTENUATION vs. TAP POSITION
1.48
1.47
1.46
1.45
1.44
1.43
1.42
1.41
1.40
1.39
1.38
0
-10
-20
-30
-40
-50
-60
-70
0.10
0.05
0
V
= V = 5.5V
DD
LOGIC
-0.05
-0.10
-0.15
-0.20
-0.25
0
4
8
12 16 20 24 28 32
TAP POSITION
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
WIPER-TO-END TERMINAL VOLTAGE
vs. TAP POSITION
WIPER SWITCHING TRANSIENT
FREQUENCY RESPONSE
MAX5440 toc04
100
90
80
70
60
50
40
30
20
10
0
V
H_
= 2.5 1V
, V = 2.5V, C = 33pF
RMS L_ L_
0.8
0.4
0
RENCODEA
RENCODEB
V
HW
W_ SET TO 0dB
-0.4
-0.8
-1.2
51ms
-1.6
-2.0
-2.4
WIPER
TRANSITION
FROM -2dB
TO -4dB
V
WL
-2.8
20ms/div
0
4
8
12 16 20 24 28 32
TAP POSITION
0.01
0.1
1
10
100
1000
FREQUENCY (kHz)
FREQUENCY RESPONSE
THD+N vs. FREQUENCY
THD+N vs. FREQUENCY
0.1
0.1
V
H_
= 2.5 1V
, V = 2.5V, C = 33pF
RMS L_ L_
-5.2
-5.6
-6.0
-6.4
-6.8
-7.2
-7.6
-8.0
-8.4
-8.8
V
V
= 2.5V
= -2.5V
DD
V
= 5.0V
= GND
DD
SS
V
SS
L_ = V
H_ = V
MIDBIAS
L_ = V
H_ = V
MIDBIAS
+ 1V
RMS
MIDBIAS
+ 1V
MIDBIAS RMS
W_ SET AT -6dB
W_ SET TO -6dB
0.01
0.01
W_ SET AT -6dB
W_ SET AT -2dB
W_ SET AT -2dB
W_ SET AT 0dB
W_ SET AT 0dB
0.001
0.001
0.01
0.1
1
10
100
1000
0.001
0.01
0.1
1
10
100
0.001
0.01
0.1
1
10
100
FREQUENCY (kHz)
FREQUENCY (kHz)
FREQUENCY (kHz)
Maxim Integrated
│ 4
www.maximintegrated.com
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
Typical Operating Characteristics (continued)
(T = +25°C, unless otherwise noted.)
A
POWER-SUPPLY REJECTION RATIO
LOGIC SUPPLY CURRENT
ACTIVE LOGIC SUPPLY CURRENT
vs. FREQUENCY
vs. LOGIC SUPPLY VOLTAGE
vs. TEMPERATURE
350
-25
300
250
200
150
100
50
V
V
= 5V 100mV , V = 5V
P-P H
= 2.5V, W_ SET TO -6dB
DD_
V
DD
= V
= 5.5V,
LOGIC
-30
L_
300
250
200
150
100
50
RENCODEA = RENCODEB = 0
-35
-40
ACTIVE CURRENT
-45
-50
-55
-60
-65
-70
-75
STANDBY CURRENT
SHUTDOWN
0
0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
0.01
0.1
1
10
100
-40
-15
10
35
60
85
FREQUENCY (kHz)
LOGIC SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
DIGITAL SUPPLY CURRENT
vs. DIGITAL INPUT VOLTAGE
ACTIVE SUPPLY CURRENT
vs. TEMPERATURE
1.1770
1.1768
1.1766
1.1764
1.1762
1.1760
1.1758
1.1756
1.1754
1.1752
1000
100
10
V
= V
= 5.5V,
LOGIC
DD
RENCODEA = RENCODEB = 0
-40
-15
10
35
60
85
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
DIGITAL INPUT VOLTAGE (V)
TEMPERATURE (°C)
SUPPLY CURRENT
SPECTRAL NOISE DENSITY
vs. INPUT VOLTAGE SWEEP
8
7
6
5
4
3
2
1
0
1200
1000
800
V
= V
= 5V, W_ AT 0dB
LOGIC
DD
R = 10kΩ TO V
L
MIDBIAS
600
400
200
0
2.5
3.0
3.5
4.0
4.5
5.0
0.01
0.1
1
10
100
INPUT VOLTAGE SWEEP (V
)
H_
FREQUENCY (kHz)
Maxim Integrated
│
5
www.maximintegrated.com
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
Pin Description
PIN
NAME
FUNCTION
to ground with a 0.1µF capacitor as close to the device as
Digital Logic Power Supply. Bypass V
possible.
LOGIC
1
V
LOGIC
Rotary Encoder Input B. With RENCODEA, this input provides the rotary encoder control for the
2
3
4
RENCODEB
potentiometer (see Figure 1). RENCODEB is internally pulled up to V
with a 45kΩ resistor.
LOGIC
Rotary Encoder Input A. With RENCODEB, this input provides the rotary encoder control for the
RENCODEA
MUTE
potentiometer (see Figure 1). RENCODEA is internally pulled up to V
with a 45kΩ resistor.
LOGIC
Mute Input. Pull MUTE low to toggle the wiper between the mute setting (see Table 1) and the current
setting. MUTE is pulled up to V with an internal 45kΩ resistor.
LOGIC
Volume/Balance Control Input. Each high-to-low transition on MODE toggles between the volume
5
MODE
SHDN
and balance modes. MODE is pulled high internally with a 45kΩ resistor to V
. On power-up, the
LOGIC
MAX5440 is in volume-control mode.
Active-Low Shutdown Input. Drive SHDN low to place the device in shutdown mode. In shutdown mode,
the MAX5440 stores the last wipers settings. The wipers move to the L_ end of the resistor string.
Terminating shutdown mode restores the wipers to their previous settings.
6
7, 24
8
GND
H0
Ground. Connect pins 7 and 24 together.
Potentiometer 0 High Terminal. H0 and L0 terminals can be reversed.
Potentiometer 0 Low Terminal. L0 and H0 terminals can be reversed.
Potentiometer 0 Wiper Buffered Output
9
L0
10
11
12
13
W0
MIDBIAS
BIAS
Midbias Voltage Output. V
= (V
+ V ) / 2.
MIDBIAS
DD SS
Bias Generator Input. Bypass with a 1µF capacitor to system ground.
Analog Power Supply. Bypass V to ground with a 0.1µF capacitor as close to the device as possible.
V
DD
DD
Negative Power Supply. Bypass V to ground with a 0.1µF capacitor as close to the device as possible.
Connect to GND for single-supply operation.
SS
14
V
SS
15
16
17
W1
L1
Potentiometer 1 Wiper Buffered Output
Potentiometer 1 Low Terminal. L1 and H1 terminals can be reversed.
Potentiometer 1 High Terminal. H1 and L1 terminals can be reversed.
H1
LED Indicator Open-Drain Output 0 through LED Indicator Open-Drain Output 4. LEDIND0–LEDIND4 form
a bar graph indication of the current volume or balance. In volume mode, all LEDs off indicates mute and
all LEDs on indicates maximum volume. In balanced mode, LED2 on indicates centered or balanced.
LEDIND0–
LEDIND4
18–22
23
Volume-Control/Balance-Control Mode Indicator Open-Drain Output. Connect to an LED through a resistor
MODEIND to V
. When the LED is on, the MAX5440 is in balance-control mode. When the LED is off, the
LOGIC
MAX5440 is in volume-control mode.
Maxim Integrated
│ 6
www.maximintegrated.com
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
Rotary Encoder Interface
Detailed Description
The MAX5440 interfaces with rotary encoder switches.
The rotary encoder is a contact closure type switch with
two outputs that connect to RENCODEA and RENCODEB
on the device. As the shaft is rotated, RENCODEA and
RENCODEB produce a gray code count. Figure 1 shows
a typical rotary encoder interface.
The MAX5440 dual, 40kΩ logarithmic taper digital poten-
tiometer features a debounced up/down interface for use
with a simple rotary encoder without using a microcon-
troller. Each potentiometer has 32 log-spaced tap points
with a buffered wiper output and replaces mechanical
potentiometers.
State changes trigger a wiper movement and the direction
of the count dictates the direction of wiper movement. An
increasing gray code count moves the wiper up to a lower
attenuation setting in volume mode and towards a full
right channel (CH1) in balance mode. A decreasing gray
code count moves the wiper down to a higher attenuation
in volume mode and towards a full left channel (CH0) in
balance mode. Both switch inputs are internally pulled up
Mode Control (MODE)
The MAX5440 MODE input toggles between volume
and balance modes. Force MODE low to toggle between
volume and balance modes. For example, driving MODE
low once while in volume-control mode switches the
MAX5440 to balance mode. Driving MODE low again
switches the MAX5440 back to volume mode. MODE
is internally pulled high with a 45kΩ resistor to V
The MAX5440 powers up in volume-control mode. Leave
unconnected or connect to V
required.
.
LOGIC
to V
by internal 45kΩ resistors.
LOGIC
During rapid rotation, the inputs must be stable for at least
20ms and have separation between state changes by at
least 40ms for the debounce circuitry to accurately detect
the input states.
if balance mode is not
LOGIC
V
LOGIC
1/4 CYCLE PER DETENT
CW
CHANNEL A
45kΩ
45kΩ
OPEN CIRCUIT
RENCODEA
RENCODEB
A
CLOSED CIRCUIT
OPEN CIRCUIT
B
CLOSED CIRCUIT
MAX5440
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
ROTARY
ENCODER
GND
CHANNEL B
CLOCKWISE ROTATION
INCREASING GRAY CODE (AB)
11, 10, 00, 01, 11, 10, ETC.
COUNTERCLOCKWISE ROTATION
DECREASING GRAY CODE (AB)
11, 01, 00, 10, 11, 01, ETC.
Figure 1. Rotary Encoder Interface
Maxim Integrated
│ 7
www.maximintegrated.com
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
the volume adjust the other wiper until it also reaches the
minimum tap position (Figure 2c).
Volume Control
In volume-control mode, the MAX5440’s wipers move
simultaneously, maintaining the balance separation
between each wiper (Figure 2a).
Increasing the volume from this minimum position restores
the original balance separation of the wipers (Figure 2d).
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 both wipers are in the tap 31 position (-62dB
attenuation), further decreasing rotations place the wipers
in the mute position (see Table 1). Rotating the encoder to
a lower attenuation or a pulse to MUTE returns the wipers
to tap 31.
When either wiper reaches the minimum tap position
(position closest to L_), further commands to decrease
BALANCE SEPARATION
MAINTAINED
H_
W0
W1
W0
W1
W0
W1
ROTATE CW
TWICE
ROTATE CCW
ONCE
L_
a
NO CHANGE
W0
W1
W0
W1
W0
W1
H_
ROTATE CW
ONCE
ROTATE CW
L_
b
H_
W0
W1
W0
W1
W0
W1
ROTATE CCW
ONCE
ROTATE CCW
TO D
L_
c
ORIGINAL BALANCE SEPARATION
MAINTAINED
H_
W0
W1
W0
W1
W0
W1
ROTATE CW
ONCE
ROTATE CW
ONCE
FROM C
L_
d
Figure 2. Volume-Control Operation
Maxim Integrated
│ 8
www.maximintegrated.com
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
Balance Control
Table 1. Wiper Position and Attenuation
In balance-control mode, the MAX5440 adjusts the bal-
ance 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 3a). 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 chan-
nel 0 before it was attenuated (Figure 3b).
POSITION
ATTENUATION (dB)
0
0
-2
1
2
-4
…
6 (POR)
…
…
-12
…
30
-60
-62
≥ 90
Click-and-Pop Suppression
31
The click-and-pop suppression feature reduces the audi-
ble noise (clicks and pops) that results from wiper transi-
tions. The MAX5440 minimizes this noise by allowing
32 (MUTE)
the wiper to change position only when V = V . Each
H
L
wiper has its own suppression and timeout circuitry. The
MAX5440 changes wiper position when V = V , or after
H
L
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
changes position, the second wiper has 32ms to change
or it will be forced to change.
VOLUME LEVEL IS SET
VOLUME LEVEL MAINTAINED
BALANCE SHIFTS TO W1
H_
W0
W1
W0
W1
W0
W1
ROTATE CW
ONCE
ROTATE CW
ONCE
L_
VOLUME LEVEL MAINTAINED
BALANCE SHIFTS TO W1
VOLUME LEVEL IS SET BY W0
W0 W1
H_
W0
W1
W0
W1
ROTATE CW
ONCE
ROTATE CW
ONCE
L_
Figure 3. Balance-Control Operation
Maxim Integrated
│ 9
www.maximintegrated.com
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
USER ROTATES ENCODER
SWITCH
CONTACT
IS BOUNCING
SWITCH
CONTACT
IS STABLE
SWITCH CONTACT
IS BOUNCING
01
INPUT ACCEPTED
00
t
WS
t
HPW
WAIT FOR FIRST
ZERO CROSSING, t
DEBOUNCE BY WAITING
FOR STABLE HIGH, t
WS
HPW
t
LPW
DEBOUNCE BY WAITING
FOR STABLE LOW, t
LPW
V
H_
V
L_
WIPER MOVES HERE
2dB STEPS
WIPER MOTION
Figure 4a. Wiper Transition Timing Diagram—Suppression Circuitry Active
Maxim Integrated
│ 10
www.maximintegrated.com
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
SWITCH
CONTACT
IS STABLE
SWITCH CONTACT
IS BOUNCING
SWITCH CONTACT
IS BOUNCING
01
READY TO ACCEPT
ANOTHER ENCODER
INPUT SIGNAL
INPUT ACCEPTED
00
t
WS
t
HPW
WAIT FOR FIRST
ZERO CROSSING OR
TIMEOUT, t
WS
t
LPW
DEBOUNCE BY WAITING
FOR STABLE HIGH, t
HPW
DEBOUNCE BY WAITING
FOR STABLE LOW, t
LPW
V
H
V
L
WIPER MOVES HERE
(t
+ t
LPW WS)
2dB STEPS
Figure 4b. Wiper Transition Timing Diagram—Timed Out
Maxim Integrated
│ 11
www.maximintegrated.com
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
Power-On Reset
The power-on comparators monitor (V
Mode Indicator (MODEIND)
- V ) and
The open-drain MODEIND indicates volume-control
DD
SS
(V
- GND). A power-on reset is initiated when either
mode or balance-control mode for the MAX5440. Connect
LOGIC
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)
MODEIND to an LED with a series resistor to V
.
LOGIC
When the LED is on, the MAX5440 is in balancecontrol
mode. When the LED is off, the MAX5440 is in volume-
control mode. See the Mode Control (MODE) section for
more detail on switching between modes.
and move to the -12dB position when V = V to elimi-
H
L
nate clicks and pops during power-up. With DC inputs at
V
and V , the wipers move after exceeding the timeout
H
L
Level Indicator LEDs
period. A power-on reset places the MAX5440 in volume-
The MAX5440 includes five indicator LED drivers to dis-
play the current wiper settings in either volume or balance
mode. Connect the LEDIND_ outputs to the LEDs and to
control mode.
Shutdown (SHDN)
Upon entering shutdown, the MAX5440 stores the last
wiper settings. The wipers move to the L_ end of the
resistor string. The wipers move to the L_ end of the
V
through a series resistor as shown in the typical
LOGIC
application circuits.
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). Table 2 shows
the LED display as the wipers transition through various
attenuation levels.
resistor string when V = V to eliminate clicks and pops
during shutdown. With DC inputs at V and V , the wipers
move after exceeding the timeout period. Exiting shut-
down restores the wipers to their previous settings.
H
L
H
L
Mute Function (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. Turning the encoder
clockwise (an increasing gray code count) turns LED3
on to represent a balance shift towards channel 1. When
LED4 turns on, the balance shifts completely toward
channel 1 and channel 0 is fully attenuated. From a bal-
anced position, turning the encoder counterclockwise (a
decreasing gray code count) turns on LED1, and then
LED0 to indicate a balance shift towards channel 0.
The MAX5440 features a mute function input, MUTE.
Successive low pulses on MUTE toggle its setting.Activating
the mute function forces both wipers to maximum attenua-
tion (-90dB typ). Deactivating the mute function returns
the wipers to their previous settings. Rotating the encoder
clockwise (increasing gray code count) also deactivates
mute, setting the wipers to their previous positions. MUTE
is internally pulled high with a 45kΩ resistor to V
.
LOGIC
When both wipers are in the tap 31 position (-62dB attenu-
ation) further commands to lower the volume (decreasing
gray code count) place the wipers in the mute position (see
Table 1). Rotating the encoder to a lower attenuation or a
pulse to MUTE returns the wipers to tap 31.
Table 2. LED Settings in Volume Mode
VOLUME LED OUTPUTS (1 = LED IS ON)
VOLUME POSITION (dB)
LED0
LED1
LED2
LED3
LED4
0 to -8
-10 to -18
1
1
1
1
1
0
1
1
1
1
0
0
1
1
1
0
0
0
1
1
0
0
0
0
1
0
0
0
0
0
-20 to -28
-30 to -38
-40 to -52
-54 to mute (-90)
Maxim Integrated
│ 12
www.maximintegrated.com
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
FULL L
L + 12
L + 6
R + 6
R + 12
FULL R
CCW ROTATION (CH0)
CW ROTATION (CH1)
CENTERED
LED2 ON
LED0 ON
LED1 ON
LED3 ON
LED4 ON
Figure 5. LED Setting in Balance Mode
V
DD
V
LOGIC
V
LOGIC
SHDN
MODEIND
V
PEAK
0V
MAX5440
H1
W1
RIGHT INPUT
L1
HEADPHONE
DRIVER
MIDBIAS
(V V ) / 2
DD + SS
LEDIND0
LEDIND1
LEFT INPUT
L0
W0
LEDIND2
LEDIND3
H0
LEDIND4
BIAS
V
SS
= -V
DD
ROTARY
ENCODER
Figure 6. Dual-Supply Volume/Balance Control
Maxim Integrated
│ 13
www.maximintegrated.com
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
Multiple Button Pushes (MODE, MUTE)
Chip Information
PROCESS: BiCMOS
The MAX5440 does 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 but-
ton push configures the device.
Applications Information
Typical Application Circuit
The Typical Operating Circuit shows the MAX5440 in a
typical volume/balance application using a single-supply
configuration. Figure 6 shows a typical volume/balance
application circuit using the MAX5440 in a dual-supply
configuration. The MAX5440 does not require external
op amps because the bias is generated internally, and
the wipers have internal low-power buffers for low distor-
tion. Connect the W_ outputs of the MAX5440 to the left
and right inputs of a stereo audio amplifier, such as the
MAX9761. The rotary encoder controls the potentiometer
attenuation levels without using a microcontroller. Use
the MODE input to switch between volume-control and
balance-control modes.
Maxim Integrated
│ 14
www.maximintegrated.com
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
Revision History
V
LOGIC
V
DD
V
SS
SHDN
MODEIND
BIAS
MIDBIAS
LEDIND0 LEDIND1 LEDIND2 LEDIND3 LEDIND4
BIAS GENERATOR
MAX5440
H1
H0
CLICK-AND-POP
SUPPRESSION
CIRCUITRY
CLICK-AND-POP
SUPPRESSION
CIRCUITRY
0
0
1
1
2
3
4
2
3
4
POSITION COUNTER
POSITION COUNTER
W0
W1
UP/DOWN
UP/DOWN
28
28
29
30
31
TIMING AND CONTROL
29
30
31
DEBOUNCE
DEBOUNCE
DEBOUNCE
DEBOUNCE
DEBOUNCE
LOGIC
V
45kΩ
45kΩ
45kΩ
45kΩ
MUTE
MUTE
L0
L1
GND
RENCODEA
RENCODEB
MODE
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 DOCUMENT NO.
A24-1 21-0056
24 SSOP
Maxim Integrated
│
15
www.maximintegrated.com
MAX5440
Stereo Volume Control
with Rotary Encoder Interface
Revision History
REVISION
NUMBER
REVISION
DATE
PAGES
CHANGED
DESCRIPTION
2
3
11/08
4/14
Fixed pin names and thermal data. Updated two specifications in EC table
1, 2, 3, 6, 13
1
Updated Applications
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.
2014 Maxim Integrated Products, Inc.
│ 16
相关型号：
MAX5441ACUA+T
D/A Converter, 1 Func, Serial Input Loading, 1us Settling Time, PDSO8, 3 X 5 MM, MICRO MAX PACKAGE-8
MAXIM
MAX5441ACUA-T
D/A Converter, 1 Func, Serial Input Loading, 1us Settling Time, PDSO8, 3 X 5 MM, MICRO MAX PACKAGE-8
MAXIM
MAX5441AEUA+T
D/A Converter, 1 Func, Serial Input Loading, 1us Settling Time, PDSO8, 3 X 5 MM, MICRO MAX PACKAGE-8
MAXIM
MAX5441BCUA+T
D/A Converter, 1 Func, Serial Input Loading, 1us Settling Time, PDSO8, 3 X 5 MM, MICRO MAX PACKAGE-8
MAXIM
©2020 ICPDF网 联系我们和版权申明