DG421CJ Datasheet, PDF (5/12 Pages) Maxim Integrated Products – Improved Low-Power, CMOS Analog Switches with Latches

Improved Low-Power,
CMOS Analog Switches with Latches
___________________Pin Descriptions
DG421
PIN
NAME
FUNCTION
1, 8
D1, D2 Drain Terminals
2
W––—–R–
Write Select
3, 4, 5, 6
7
N.C.
–R–—–S–
No Internal Connection
Reset Select
9, 16
S1, S2 Source Terminals
10, 15 IN1, IN2 Input Control
11
V+
Positive Supply
12
VL
Logic Supply
13
GND
Ground
14
V-
Negative Supply
DG423/DG425
DIP
PLCC
NAME
FUNCTION
1, 8, 3, 6 2, 10, 4, 8
2
3
D1-D4
–W–—R––
Drain Terminals
Write Select
16, 9, 4, 5 20, 12, 5, 7
7
9
S1-S4
–R–—S––
Source Terminals
Resets Select
15, 10
19, 13
IN1, IN2 Input Control
11
14
V+
Positive Supply
12
15
VL
Logic Supply
—
1, 6, 11, 16 N.C.
No Internal Connection
14
18
V-
Negative Supply
13
17
GND Ground
__________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 VL = +5V. If VL 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 VL, 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+
S
D
Vg
V-
Figure 1. Overvoltage Protection Using External Blocking Diodes
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