MAX4624/MAX4625
1Ω, Low-Voltage, Single-Supply
SPDT Analog Switches
6 _______________________________________________________________________________________
Pin Description
Detailed Description
The MAX4624/MAX4625 are low-on-resistance (R
ON
),
low-voltage, single-pole/double-throw (SPDT) analog
switches that operate from a +1.8V to +5.5V supply.
The MAX4624 has break-before-make switching, and
the MAX4625 has make-before-break switching. These
devices also have fast switching speeds (t
ON
= 50ns
max, t
OFF
= 50ns max).
When powered from a +5V supply, their 1Ω max R
ON
allows high continuous currents to be switched in a
variety of applications. In an overcurrent condition,
these switches provide both current-limit and thermal-
shutdown protection.
Current-Limit Protection
The MAX4624/MAX4625 feature current-limit protection
circuitry. When the voltage drop across the on switch
reaches 0.6V typ, the internal circuitry activates. The
current limit is not instantaneous, but rather integrates
over time, so current limiting will not activate when the
switch output charges a small 0.1µF capacitor. For sus-
tained overload conditions, the switch turns off (opens).
The switch turns on after 5ms. If the overload persists,
the switch cycles off and on to produce a pulsed out-
put. A direct short circuit will be detected immediately,
and the switch will pulse on for 1µs, then remain off for
5ms.
Applications Information
Logic Inputs
The MAX4624/MAX4625 logic inputs can be driven up
to +5.5V regardless of the supply voltage. For example,
with a +3.3V supply, IN may be driven low to 0V and
high to 5.5V. Driving IN Rail-to-Rail
®
minimizes power
consumption.
Analog Signal Levels
Analog signals that range over the entire supply voltage
(V+ to GND) can be passed with very little change in
on-resistance (see Typical Operating Characteristics).
The switches are bidirectional, so the NO, NC, and
COM pins can be used as either inputs or outputs.
Power-Supply Sequencing and
Overvoltage Protection
Caution: Do not exceed the absolute maximum rat-
ings because stresses beyond the listed ratings
may cause permanent damage to the devices.
Proper power-supply sequencing is recommended for
all CMOS devices. Always apply V+ before applying
analog signals, especially if the analog signal is not
current limited. If this sequencing is not possible, and if
the analog inputs are not current limited to <20mA, add
Analog Switch—CommonCOM5
Analog Switch—Normally OpenNO6
Analog Switch—Normally ClosedNC4
GroundGND3
PIN
Positive Supply Voltage InputV+2
Digital Control InputIN
1
FUNCTIONNAME
