Datasheet

changes position, the second wiper has 126ms to change
or it changes automatically.
Power-On Reset
The power-on comparators monitor (V
DD
- V
SS
) and
(V
LOGIC
- 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 V
H
= V
L
to elimi-
nate clicks and pops during power-up. With DC inputs at
V
H
and V
L
, 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 resis-
tor string when V
H
= V
L
to eliminate clicks and pops during
shutdown. With DC inputs at V
H
and V
L
, 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 func-
tion returns the wipers to their previous settings. MUTE
is internally pulled high with a resistor to V
LOGIC
. 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 V
LOGIC
.
When the LED is on, the MAX5486 is in balance-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 balance
mode. The LED indicators are enabled by connecting a
1MΩ resistor between LEDIND4 and V
LOGIC
. Connect
the LEDIND_ outputs to the LEDs and to V
LOGIC
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).
Figures 3a and 3b. Balance-Control Operation
(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 WL
VOLUME LEVEL IS SET BY WR
PRESS BALL
ONCE
PRESS BALL
ONCE
PRESS BALL
ONCE
PRESS BALL
ONCE
MAX5486 Stereo Volume Control with Pushbutton
Interface
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