DG417/418/419
Test Circuits (Cont’d)
+5 V
+15 V
+15 V
NC
C
C
C
V
L
V+
S
S
2
S
1
V+
DG417/418
DG419
Meter
Meter
V, 2.4 V
0 V, 2.4 V
IN
HP4192A
Impedance
Analyzer
HP4192A
Impedance
Analyzer
IN
or Equivalent
or Equivalent
D
D
D
1
2
GND
V–
GND
V–
f = 1 MHz
f = 1 MHz
C
C
–15 V
–15 V
Figure 9. Source/Drain Capacitances
Applications
A positive input pulse turns on the clamping diode D and
Switched Signal Powers Analog Switch
1
charges C . The charge stored on C is used to power the
1
1
The analog switch in Figure 10 derives power from its input
signal, provided the input signal amplitude exceeds 4 V and
its frequency exceeds 1 kHz.
chip; operation is satisfactory because the switch requires
less than 1 mA of stand-by supply current. Loading of the
signal source is imperceptible. The DG419’s on-resistance
is a low 100 W for a 5-V input signal.
This circuit is useful when signals have to be routed to either
of two remote loads. Only three conductors are required:
one for the signal to be switched, one for the control signal
and a common return.
D
1
C
1
0.01 mF
V
L
V+
S
S
1
D
V
OUT
Input
2
R
10 kW
L2
IN
Control
R
10 kW
L1
DG419
GND
V–
Figure 10. Switched Signal Powers Remote
SPDT Analog Switch
Siliconix
9
S-52880—Rev. D, 28-Apr-97