April 1990
DS3686 Dual Positive Voltage Relay Driver
General Description
The DS3686 is a high voltage/current positive voltage relay
driver having many features not available in present relay
drivers.
levelsÐbase drive for the output transistor is obtained from
the load in proportion to the required loading conditions.
Typical V
power with both outputs ‘‘ON’’ is 90 mW.
CC
The circuit also features output transistor protection if the
supply is lost by forcing the output into the high imped-
PNP inputs provide both TTL/LS compatibility and high in-
put impedance for low input loading.
V
CC
ance ‘‘OFF’’ state with the same breakdown levels as when
was applied.
Output leakage is specified over temperature at an output
voltage of 54V. Minimum output breakdown (ac/latch break-
down) is specified over temperature at 5 mA. This clearly
defines the actual breakdown of the device since the circuit
has incorporated in it an internal reference which does not
allow output breakdown latching found in existing relay driv-
ers. Additionally, this internal reference circuit feature will
eliminate the need in most cases of an external clamping
(inductive transient voltage protection) diode. When the out-
put is turned ‘‘OFF’’ by input logic conditions the resulting
inductive voltage transient seen at the output is detected by
an internal zener reference. The reference then momentari-
ly activates the output transistor long enough so that the
relay energy is discharged. This feature eliminates the need
of external circuit protection components and insures output
transistor protection.
V
CC
Features
Y
TTL/LS/CMOS compatible inputs
Y
High impedance inputs (PNP’s)
Y
High output voltage breakdown (65V typ)
Y
High output current capability (300 mA max)
Y
Internal protection circuit eliminates need for output
protection diode
Y
Output breakdown protection if V
supply is lost
CC
power dissipation (90 mW (typ) both outputs
Y
Low V
‘‘ON’’)
CC
Y
Voltage and current levels compatible for use in tele-
phone relay applications
The outputs are Darlington connected transistors, which al-
V
low high current operation at low internal
current
CC
Connection Diagrams
Metal Can Package
Dual-In-Line Package
TL/F/5822–1
Top View
Pin 4 is in electrical contact with the case
TL/F/5822–2
Order Number DS3686H
See NS Package Number H08C
Top View
Order Number DS3686J-8 or DS3686N
See NS Package Number J08A or N08E
Truth Table
e
Positive logic: AB
X
A
B
Output X
0
1
0
1
0
0
1
1
1
1
1
0
Logic ‘‘0’’ output ‘‘ON’’
Logic ‘‘1’’ output ‘‘OFF’’
C
1995 National Semiconductor Corporation
TL/F/5822
RRD-B30M105/Printed in U. S. A.