MAX4762–MAX4764/MAX4764A/MAX4765
Detailed Description
The MAX4762–MAX4764/MAX4764A/MAX4765 are low
on-resistance, low-voltage, dual SPDT analog switches
that operate from a +1.8V to +5.5V supply and are fully
specified for nominal 3.0V applications. The devices
feature a negative signal capability that allows signals
below ground to pass through without distortion and
have break-before-make switching.
The MAX4763/MAX4765 feature a comparator that can be
used for headphone or mute detection. The comparator
threshold is internally generated to be approximately 1/3
of V
CC
. The MAX4764/MAX4764A/MAX4765 feature an
internal shunt switch to discharge any capacitance at the
NO and NC connection points. This reduces the click-
and-pop sounds that occur when switching audio signals.
Applications Information
Digital Control Inputs
The MAX4762–MAX4764/MAX4764A/MAX4765 logic
inputs accept up to +5.5V, regardless of supply voltage.
For example, with a +3.3V supply, IN_ can be driven low
to GND and high to +5.5V allowing for mixing of logic
levels in a system. Driving IN_ rail-to-rail minimizes
power consumption. For a +1.8V supply voltage, the
logic thresholds are 0.5V (low) and 1.4V (high); for a
+5V supply voltage, the logic thresholds are 0.8V (low)
and 2.0V (high).
Analog Signal Levels
The on-resistance of the MAX4762–MAX4764/
MAX4764A/MAX4765 changes very little for analog input
signals across the entire supply voltage range (see the
Typical Operating Characteristics). The switches are bidi-
rectional, so the NO_, NC_, and COM_ pins can be either
inputs or outputs.
The MAX4762–MAX4764/MAX4764A/MAX4765 pass
signals as low as V
CC
- 5.5V, including signals below
ground with minimal distortion.
Comparator (MAX4763/MAX4765)
The MAX4763/MAX4765 include a comparator that can
be used for mute and headphone detection functions.
The positive terminal of the comparator is internally set to
V
CC
/ 3. When the negative terminal (CMP-) is below the
threshold, the comparator output (CMPO) is a logic high.
When CMP- rises above V
CC
/ 3, CMPO is a logic low.
The comparator threshold of V
CC
/ 3 allows for detection
of headphones because headphone audio signals are
typically biased to V
CC
/ 2.
Shunt Switch
(MAX4764/MAX4764A/MAX4765)
The 100Ω shunt switches on the MAX4764/MAX4764A/
MAX4765 automatically discharge any capacitance at
the NC_ or NO_ terminals when they are unconnected
to COM_. This reduces audible click-and-pop sounds
that occur when switching between audio sources.
Audible clicks and pops are caused when a step DC
voltage is switched into the speaker. By automatically
discharging the side that is not connected, any residual
DC voltage is removed, thereby reducing the clicks
and pops.
Power-Supply Sequencing and
Overvoltage Protection
Caution: Do not exceed the absolute maximum ratings
since stresses beyond the listed ratings may cause
permanent damage to the device.
Proper power-supply sequencing is recommended for
all CMOS devices. Always apply V
CC
before applying
analog signals, especially if the analog signal is not
current-limited.
UCSP Applications Information
For the latest application details on UCSP construction,
dimensions, tape carrier information, printed circuit board
techniques, bump-pad layout, and recommended reflow
temperature profile, as well as the latest information on
reliability testing results, go to the Maxim’s website at
www.maxim-ic.com/ucsp and search for the Application
Note, “UCSP—A Wafer-Level Chip-Scale Package.”
Low-Voltage, Dual SPDT, Audio Clickless
Switches with Negative Rail Capability
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