Figure 2. Switching Time
Applications Information
General Operation
• Switches are open when power is off.
• IN, D, and S should not exceed V+ or V-, even with
the power off.
• Switch leakage is from each analog switch terminal
to V+ or V-, not to other switch terminals.
Operation with Supply Voltages
Other than ±15V
Using supply voltages other than ±15V will reduce the
analog signal range. The DG444/DG445 switches oper-
ate with ±4.5V to ±20V bipolar supplies or with a +10V
to +30V single supply; connect V- to 0V when operating
with a single supply. Also, all device types can operate
with unbalanced supplies such as +24V and -5V. V
L
must be connected to +5V to be TTL compatible, or to
V+ for CMOS-logic level inputs. The Typical Operating
Characteristics graphs show typical on-resistance with
±20V, ±15V, ±10V, and ±5V supplies. (Switching times
increase by a factor of two or more for operation at ±5V.)
Overvoltage Protection
Proper power-supply sequencing is recommended
for all CMOS devices. Do not exceed the absolute
maximum ratings because stresses beyond the list-
ed ratings may cause permanent damage to the
devices. Always sequence V+ on first, followed by
V
L
, V-, and logic inputs. If power-supply sequenc-
ing is not possible, 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-, but low switch resistance and low leakage char-
acteristics are unaffected. Device operation is
unchanged, and the difference between V+ and V-
should not exceed +44V.