Detailed Description
The MAX4741/MAX4742/MAX4743 are low 0.8Ωmax
(at V+ = +3V) on-resistance, low-voltage, dual analog
switches that operate from a +1.6V to +3.6V single sup-
ply. CMOS switch construction allows switching analog
signals that are within the supply voltage range (GND
to V+).
When powered from a +3V supply, the 0.8Ωmax RON
allows high continuous currents to be switched in a
variety of applications.
Applications Information
Proper power-supply sequencing is recommended for
all CMOS devices. Do not exceed the absolute maxi-
mum ratings, because stresses beyond the listed rat-
ings can cause permanent damage to the devices.
Always sequence V+ on first, followed by NO_, NC_, or
COM_.
Although it is not required, power-supply bypassing
improves noise margin and prevents switching noise
propagation from the V+ supply to other components.
A 0.1µF capacitor, connected from V+ to GND, is ade-
quate for most applications.
Logic Inputs
The MAX4741/MAX4742/MAX4743 logic inputs can be
driven up to +3.6V regardless of the supply voltage.
For example, with a +1.8V supply, IN_ may be driven
low to GND and high to +3.6V. 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.
Layout
High-speed switches require proper layout and design
procedures for optimum performance. Reduce stray
inductance and capacitance by keeping traces short
and wide. Ensure that bypass capacitors are as close
to the device as possible. Use large ground planes
where possible.
MAX4741/MAX4742/MAX4743
0.8
Ω
, Low-Voltage, Single-Supply Dual SPST
Analog Switches
_______________________________________________________________________________________ 7
Pin Description
NAME FUNCTION
18—— 18NO1 Analog Switch 1 Normally Open
——18——NC1 Analog Switch 1 Normally Closed
272727COM1 Analog Switch 1 Common
363636IN2 Logic Control Input Switch 2
454545GND Ground
53————NO2 Analog Switch 2 Normally Open
——5353NC2 Analog Switch 2 Normally Closed
646464COM2 Analog Switch 2 Common
717171IN1 Logic Control Input Switch 1
828282V+Positive Supply Voltage