max5407ekat Maxim Integrated Products, Inc., max5407ekat Datasheet - Page 6

• Manufacturer Part Number: max5407ekat
• Description: Max5407 32-tap Audio Logarithmic Taper Digital Potentiometer
• Manufacturer: Maxim Integrated Products, Inc.

The power-on reset feature sets the wiper to the maxi-
mum attenuation (tap position 31, -31dB) at power-up.
If CS is initially high, the MAX5407 is in the increment
mode by default.
When the ZCEN input is low, the zero-crossing detect
feature is enabled. This feature reduces the audible
noise (“clicks and pops”) that result from wiper transi-
tions. When zero-crossing detection is enabled, the
wiper changes position only when the voltage at L is
the same as the voltage at H. If no zero crossing is
detected after 50ms, the device will timeout and
change the wiper position.
The MAX5407 can interface to +3V logic as well as +5V
logic, while using a +3V to +5V power supply. In order
to minimize the supply current, set all digital inputs low
while the part is inactive.
32-Tap Audio Logarithmic Taper
Digital Potentiometer
Figure 3. Volume Control Circuit
Figure 4. Signal Attenuator Circuit
6
_______________________________________________________________________________________
MAX5407
MAX5407
+5V
U/D
U/D
CS
CS
ZCEN
ZCEN
SIGNAL INPUT
H
H
AUDIO INPUT
L
L
V
CM
W
W
Zero-Crossing Detection
+5V
+5V
V
V
DD
DD
Digital Logic Inputs
MAX4336
MAX4336
V
V
Power-On Reset
DD
DD
V
V
OUT
OUT
The MAX5407 is intended for circuits requiring digitally
controlled adjustable voltage or adjustable gain, such
as applications involving volume control.
The zero-crossing feature of the MAX5407 makes it
ideal for applications involving volume control. Figure 3
shows a typical application circuit, where the MAX5407
is followed by an op amp for output buffering and gain.
V
audio signal swings.
Figure 4 shows a typical signal attenuator. Use an op
amp to provide buffering and gain to the output of the
MAX5407. Connect the MAX5407 to the positive input
of a noninverting op amp to select the level of attenua-
tion of the input signal, by digitally controlling the wiper
terminal.
Figure 5 shows how to use the MAX5407 to digitally
adjust the gain of a noninverting op amp configuration.
The MAX5407 has a low 5ppm/°C ratiometric tempco
that allows for a very stable adjustable gain configura-
tion over temperature.
TRANSISTOR COUNT: 1942
Figure 5. Adjustable Gain Circuit
CM
represents the common voltage around which the
MAX5407
Applications Information
V
IN
L
W
MAX5407
H
Chip Information
MAX4336
Signal Attenuator
V
DD
Adjustable Gain
Volume Control
V
OUT