MAX14535E Datasheet, PDF (2/8 Pages) Maxim Integrated Products – Low-Resistance DPDT Switches with Negative Rail

Low-Resistance DPDT Switches
with Negative Rail
Detailed Description
The MAX14535E–MAX14539E are low on-resistance
and high ESD-protected single DPDT switches that
operate from a +2.4V to +5.5V supply and are
designed to multiplex AC-coupled analog signals.
These switches combine the low on-capacitance (C_ON)
and low on-resistance (R_ON) necessary for high-perfor-
mance switching applications. The negative signal
capability of the analog channel allows signals below
ground to pass through without distortion.
Analog Signal Levels
The MAX14535E−MAX14539E are bidirectional, allow-
ing NO_, NC_, and COM_ to be configured as either
inputs or outputs. Note that NC_ and NO_ are only pro-
tected against ESD up to ±2kV (Human Body Model)
and may require additional ESD protection if used as
outputs. These devices feature a charge pump that
generates a negative supply to allow analog signals as
low as -1.5V to pass through NO_, NC_, or COM_. This
allows AC-coupled signals that drop below ground to
pass even when operating from a 3.0V to 5.5V supply.
For the MAX14537E/MAX14538E, the negative charge
pump is controlled by the enable input and is active
when EN is high. When EN is driven low, the negative
charge pump is disabled, which puts the devices in the
lowest possible current consumption, and the signal
range is 0 to V_CC. The negative charge pump is always
active for the MAX14535E/MAX14536E/MAX14539E,
therefore, a negative signal (at most -1.5V) can be
applied through NC_, NO_, or COM_, even when EN is
driven low. A negative rail signal (signal voltage < 0)
must not be applied to the switch unless the negative
charge pump is active.
Digital Control Input
The MAX14535E−MAX14539E provide a single-bit con-
trol logic input, CB. CB controls the switch position as
shown in the Functional Diagrams. Drive CB rail-to-rail
to minimize power consumption.
Enable Input
The MAX14535E−MAX14539E feature a shutdown
mode that reduces the supply current (less than 1µA
for MAX14537E/MAX14538E) and places the switches
in high impedance. Drive EN low to place the device in
shutdown mode. Drive EN high for normal operation.
Shunt Resistors
(MAX14535E/MAX14537E/MAX14539E)
When EN is high, the shunt resistors are controlled by
CB. When CB is low, NC_ is connected to COM_ and
NO_ is connected to shunt resistors. When CB is high,
NO_ is connected to COM_ and NC_ is connected to
shunt resistors (MAX14539E). When EN is low, all the
switches are open and all the shunt resistors are active.
Click-and-Pop Suppression
The 500Ω shunt resistors on the MAX14535E/
MAX14537E/MAX14539E automatically discharge any
capacitance at the NO_ terminals (or NC_ terminals,
MAX14539E) when they are unconnected from COM_.
This reduces audio click-and-pop sounds that may
occur when switching between capacitively coupled
audio sources.
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