MAX4645 Maxim, MAX4645 Datasheet - Page 6

• Manufacturer Part Number: MAX4645
• Description: The MAX4645/MAX4646 single-pole, single-throw (SPST) analog switches feature a 2
• Manufacturer: Maxim

The MAX4645/MAX4646 are low 2.5Ω max on-resis-
tance (at V+ = 5V), low-voltage analog switches that
operate from a +1.8V to +5.5V single supply. CMOS
switch construction allows processing analog signals
that are within the supply voltage range (GND to V+).
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 the logic
inputs, NO, or COM. If power-supply sequencing is not
possible, add two small signal diodes (D1, D2) in series
with the supply pins for overvoltage protection (Figure
1). Adding these diodes reduces the analog signal by
one diode drop below V+ and one diode drop above
GND, but does not affect the low switch resistance and
low leakage characteristics of the device. Device oper-
ation is unchanged, and the difference between V+ and
GND should not exceed 6V.
Although it is not required, power-supply bypassing
improves noise margin and prevents switching noise
from propagating from the V+ supply to other compo-
nents. A 0.1µF capacitor, connected from V+ to GND,
is adequate for most applications.
Fast, Low-Voltage, 2.5Ω, SPST,
CMOS Analog Switches
6
SOT23-5
_______________________________________________________________________________________
—
—
1
2
3
4
5
MAX4645
SOT23-6
—
1
2
3
4
5
6
Applications Information
µMAX
2, 3, 5
Detailed Description
—
1
8
7
6
4
PIN
SOT23-5
—
—
1
2
3
4
5
MAX4646
SOT23-6
—
1
2
3
4
5
6
2, 3, 5
µMAX
—
1
8
7
6
4
Figure 1. Overvoltage Protection Using Two External Blocking
Diodes
NAME
COM
GND
N.C.
NO
NC
V+
IN
V g
Analog Switch Common Terminal
Analog Switch Normally Open Terminal
Analog Switch Normally Closed Terminal
Ground
Logic Control Input
No Connection. Not internally connected.
Positive Supply Voltage
COM
POSITIVE SUPPLY
V+
GND
FUNCTION
D2
D1
Pin Description
NO
MAX4645
MAX4646