DG421/DG423/DG425
Improved Low-Power,
CMOS Analog Switches with Latches
_______________________________________________________________________________________ 5
___________________Pin Descriptions
1, 8 D1, D2 Drain Terminals
2
–
W
–—–
R
–
Write Select
3, 4, 5, 6 N.C. No Internal Connection
7
–
R
–—–
S
–
Reset Select
9, 16 S1, S2 Source Terminals
10, 15 IN1, IN2 Input Control
11 V+ Positive Supply
12 V
L
Logic Supply
13 GND Ground
14 V- Negative Supply
1, 8, 3, 6 2, 10, 4, 8 Drain Terminals
2 3 Write Select
–
W
–—–
R
–
16, 9, 4, 5 20, 12, 5, 7 Source TerminalsS1-S4
7 9 Resets Select
D1-D4
15, 10 19, 13 Input ControlIN1, IN2
11 14 Positive SupplyV+
–
R
–—–
S
–
12 15 Logic SupplyV
L
— 1, 6, 11, 16 No Internal ConnectionN.C.
14 18 Negative SupplyV-
13 17 GroundGND
PIN NAME FUNCTION
DIP PLCC FUNCTIONNAME
Figure 1. Overvoltage Protection Using External Blocking Diodes
__________Applications Information
Operation with Supply Voltages
Other Than ±15V
The DG421/DG423/DG425 switches operate with ±4.5V
to ±20V bipolar supplies or with a +10V to +30V single
supply. In either case, analog signals ranging from V+
to V- can be switched. The
Typical Operating
Characteristics
graphs illustrate typical analog-signal
and supply-voltage on-resistance variations. The usual
on-resistance temperature coefficient is 0.5%/°C (typ).
Logic Inputs
These devices operate with a single positive supply or
with bipolar supplies. They maintain TTL compatibility
with supplies anywhere in the ±4.5V to ±20V range as
long as V
L
= +5V. If V
L
is connected to V+ or another
supply at voltages other than +5V, the devices will
operate at CMOS-logic-level inputs.
Overvoltage Protection
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 may cause permanent damage to the devices.
Always sequence V+ on first, followed by V
L
, V-, and
logic inputs. If power-supply sequencing is not possi-
ble, add two small, external signal diodes in series with
supply pins for overvoltage protection (Figure 1).
Adding diodes reduces the analog signal range to 1V
below V+ and 1V above V-, without affecting low switch
resistance and low leakage characteristics. Device
operation is unchanged, and the difference between V+
and V- should not exceed +44V.
V+
D
V-
S
V
g
DG421
DG423/DG425
