LTC1701 View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'LTC1701' PDF : 12 Pages View PDF
LTC1701/LTC1701B
PI FU CTIO S
SW (Pin 1): The Switch Node Connection to the Inductor.
This pin swings from VIN to a Schottky diode (external)
voltage drop below ground. The cathode of the Schottky
diode must be closely connected to this pin.
GND (Pin 2): Ground Pin. Connect to the (–) terminal of
COUT, the Schottky diode and (–) terminal of CIN.
VFB (Pin 3): Receives the feedback voltage from the
external resistive divider across the output. Nominal volt-
age for this pin is 1.25V.
ITH/RUN (Pin 4): Combination of Error Amplifier Compen-
sation Point and Run Control Input. The current compara-
tor threshold increases with this control voltage. Nominal
voltage range for this pin is 1.25V to 2.25V. Forcing this
pin below 0.8V causes the device to be shut down. In
shutdown all functions are disabled.
VIN (Pin 5): Main Supply Pin and the (+) Input to the
Current Comparator. Must be closely decoupled to ground.
Pin Limit Table
PIN
NAME
1
SW
2
GND
3
VFB
4
ITH/RUN
5
VIN
DESCRIPTION
Switch Node
Ground Pin
Output Feedback Pin
Error Amplifier Compensation and RUN Pin
Main Power Supply
NOMINAL (V)
MIN TYP MAX
– 0.3
VIN
0
0
1.25 1.35
0
2.25
2.5
5.5
ABSOLUTE MAX (V)
MIN
MAX
VIN – 8.5
VIN + 0.3
– 0.3
3
– 0.3
3
– 0.3
6
BLOCK DIAGRA
VREF
ITH/RUN
VREF
VFB
+
ITH/REF
CLAMP
–
+
ERROR
AMP
–
VIN
50µA
VIN
1.25V
BANDGAP
REFERENCE
VREF
(1.25V)
1.5V
SHDN
(1.25V TO 2.25V)
+
ITH
COMP
–
(LTC1701 only)
+
OVER
VOLTAGE
1.4V
– COMP
PULSE
STRETCHER
VFB < 0.6V
VIN
+
CURRENT
COMP
–
VREF
+
CURRENT
SENSE
AMP –
OFF-TIMER
AND GATE
CONTROL LOGIC
GATE
DRIVER
GND
SW
1701 BD
4
Share Link: 
