DG417AK/883 TEMIC [TEMIC Semiconductors], DG417AK/883 Datasheet - Page 10

• Manufacturer Part Number: DG417AK/883
• Description: Precision CMOS Analog Switches
• Manufacturer: TEMIC [TEMIC Semiconductors]

Applications (Cont’d)
Micropower UPS Transfer Switch
When V
closing SW
Figure 11. D
the rest of the circuit. Current consumption by the CMOS
analog switch is around 100 pA; this ensures that most of the
power available is applied to the memory, where it is really
needed. In the stand-by mode, hundreds of A are sufficient
to retain memory data.
When the 5-V supply comes back up, the resistor divider
senses the presence of at least 3.5 V, and causes a new
DG417/418/419
10
V
IN
Figure 12. Programmable Gain Amplifier
CC
1
drops to 3.3 V, the DG417 changes states,
and connecting the backup cell, as shown in
1
IN
prevents current from leaking back towards
(5 V)
V
CC
D
DG419
–
+
R
453 k
R
383 k
S
S
1
2
1
2
D
1
V
R
R
SENSE
1
2
Figure 11. Micropower UPS Circuit
Memory
V
OUT
5 V
change of state in the analog switch, restoring normal
operation.
Programmable Gain Amplifier
The DG419, as shown in Figure 12, allows accurate gain
selection in a small package. Switching into virtual ground
reduces distortion caused by r
of analog signal amplitude.
GaAs FET Driver
The DG419, as shown in Figure 13 may be used as a GaAs
FET driver. It translates a TTL control signal into –8-V, 0-V
level outputs to drive the gate.
D
IN
GND
V+
DG417
SW
Figure 13. GaAs FET Driver
1
V
V–
S
S
GND
L
1
2
V
S
L
S-52880—Rev. D, 28-Apr-97
DG419
+5 V
–8 V
V+
V–
DS(on)
D
variation as a function
+
–
V
3 V Li Cell
OUT
GaAs FET
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