Vishay Siliconix
DG221B
Document Number: 71616
S-80263-Rev. B, 11-Feb-08
www.vishay.com
1
Quad SPST CMOS Analog Switch with Latches
FEATURES
• Accepts 150 ns write pulse width
• 5 V on-chip regulator
• Latches are transparent with WR low
• Low on-resistance: 60 W
BENEFITS
• Compatible with most µP buses
• Allows wide power supply tolerance without affecting TTL
compatibility
• Reduced power consumption
• Allows flexibility of design
APPLICATIONS
• µP based systems
• Automatic test equipment
• Communication systems
• Data acquisition systems
• Medical instrumentation
• Factory automation
DESCRIPTION
The DG221B is a monolithic quad single-pole, single-throw
analog switch designed for precision switching applications
in communication, instrumentation and process control
systems.
Featuring independent onboard latches and a common WR
pin, each DG221B can be memory mapped, and addressed
as a single data byte for simultaneous switching.
The DG221B combines low power and low on-resistance
(60 typical) while handling continuous currents up to 20 mA.
An epitaxial layer prevents latchup.
The device features true bidirectional performance in the on
condition.
FUNCTIONAL BLOCK DIAGRAM AND PIN CONFIGURATION
Four latchable SPST switches per package
Logic "0" ≤ 0.8 V
Logic "1" ≥ 2.4 V
* Pb containing terminations are not RoHS compliant, exemptions may apply.
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2
3
4
5
6
7
8
16
15
14
13
12
11
10
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Top View
IN
1
IN
2
D
1
D
2
S
1
S
2
V- V+
GND WR
S
4
S
3
D
4
D
3
IN
4
IN
3
Dual-In-Line and SOIC
Input Latch
TRUTH TABLE
IN
X
WR Switch
0 0 ON
10 OFF
X
Control data latched-in, switches on
or off as selected by last IN
X
X 1 Maintains previous state
Available
Pb-free
RoHS*
COMPLIANT
