Datasheet

12
LTC3704
3704fb
APPLICATIO S I FOR ATIO
WUUU
–
+
RUN
COMPARATOR
V
IN
RUN
R2
R1
INPUT
SUPPLY
OPTIONAL
FILTER
CAPACITOR
+
–
GND
3704 F08a
BIAS AND
START-UP
CONTROL
1.248V
μPOWER
REFERENCE
6V
Figure 8b. On/Off Control Using External Logic
Figure 8c. External Pull-Up Resistor On
RUN Pin for “Always On” Operation
Figure 8a. Programming the Turn-On and Turn-Off Thresholds Using the RUN Pin
–
+
RUN
COMPARATOR
1.248V
3704 F08b
RUN
6V
EXTERNAL
LOGIC CONTROL
–
+
RUN
COMPARATOR
V
IN
RUN
R2
1M
INPUT
SUPPLY
+
–
GND
1.248V
3704 F08c
6V
The resistor R1 is typically chosen to be less than 1M.
For applications where the RUN pin is only to be used as
a logic input, the user should be aware of the 7V
Absolute Maximum Rating for this pin! The RUN pin can
be connected to the input voltage through an external 1M
resistor, as shown in Figure 8c, for “always on” operation.