Datasheet

Detailed Description
The MAX4635/MAX4636 are low-on-resistance (R
ON
),
low-voltage, dual SPDT analog switches that operate
from a +1.8V to +5.5V supply. The MAX4635/MAX4636
feature very fast switching speed (t
ON
= 14ns max,
t
OFF
= 6ns max) and guaranteed break-before-make
switching. The low maximum R
ON
allows high continu-
ous currents to be switched in a variety of applications.
Applications Information
Logic Inputs
The MAX4635/MAX4636 logic inputs (IN1, IN2) can be
driven up to +5.5V, regardless of the voltage on V+.
This allows interfacing to 5V logic signals while operat-
ing with a +3.3V supply voltage without external level
translation.
Analog Signal Levels
Analog signals ranging 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 may 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 can
cause permanent damage to the device. Proper
power-supply sequencing is recommended for all
CMOS devices. Always apply V+ before applying ana-
log 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 less than 30mA,
add a small-signal diode (D1) as shown in Figure 5. If
the analog signal can dip below GND, add D2. Adding
protection diodes reduces the analog range to a diode
drop (about 0.7V) below V+ (for D1), and a diode drop
above ground (for D2).
MAX4635/MAX4636
Fast, Low-Voltage, Dual 4Ω SPDT
CMOS Analog Switches
8 _______________________________________________________________________________________
CAPACITANCE
METER
NC_ OR
NO_
COM_
GND
IN_
V
INL
OR
V
INH
10nF
V+
f = 1MHz
V+
MAX4635
MAX4636
Figure 3. Channel Off/On-Capacitance
MEASUREMENTS ARE STANDARDIZED AGAINST SHORTS AT IC TERMINALS.
OFF-ISOLATION IS MEASURED BETWEEN COM_ AND "OFF" NO_ OR NC_ TERMINAL ON EACH SWITCH.
ON-LOSS IS MEASURED BETWEEN COM_ AND "ON" NO_ OR NC_ TERMINAL ON EACH SWITCH.
CROSSTALK IS MEASURED FROM ONE CHANNEL TO ALL OTHER CHANNELS.
SIGNAL DIRECTION THROUGH SWITCH IS REVERSED; WORST VALUES ARE RECORDED.
+5V
V
OUT
V+
IN_
NC_
COM_
NO_
V
IN
MAX4635
MAX4636
OFF-ISOLATION = 20log
V
OUT
V
IN
ON-LOSS = 20log
V
OUT
V
IN
CROSSTALK = 20log
V
OUT
V
IN
NETWORK
ANALYZER
50Ω
50Ω 50Ω
50Ω
MEAS REF
10nF
0 OR V+
50Ω
GND
Figure 4. On-Loss, Off-Isolation, and Crosstalk