Datasheet LTC1772 (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | Constant Frequency Current Mode Step-Down DC/DC Controller in SOT-23 |
| Pages / Page | 12 / 4 — PIN FUNCTIONS. ITH/RUN (Pin 1):. VFB (Pin 3):. SENSE– (Pin 4):. VIN (Pin … |
| File Format / Size | PDF / 172 Kb |
| Document Language | English |
PIN FUNCTIONS. ITH/RUN (Pin 1):. VFB (Pin 3):. SENSE– (Pin 4):. VIN (Pin 5):. GND (Pin 2):. PGATE (Pin 6):. FUNCTIONAL DIAGRA
Model Line for this Datasheet
- LTC1772CS6#PBF LTC1772CS6#TRMPBF LTC1772CS6#TRMPBF LTC1772CS6#TRPBF LTC1772CS6#TRPBF LTC1772ES6#PBF LTC1772ES6#TRMPBF LTC1772ES6#TRMPBF LTC1772ES6#TRPBF LTC1772ES6#TRPBF LTC1772HS6#PBF LTC1772HS6#TRMPBF LTC1772HS6#TRMPBF LTC1772HS6#TRPBF LTC1772HS6#TRPBF LTC1772IS6#PBF LTC1772IS6#TRMPBF LTC1772IS6#TRMPBF LTC1772IS6#TRPBF LTC1772IS6#TRPBF
Text Version of Document
LTC1772
U U U PIN FUNCTIONS ITH/RUN (Pin 1):
This pin performs two functions. It
VFB (Pin 3):
Receives the feedback voltage from an exter- serves as the error amplifier compensation point as well as nal resistive divider across the output. the run control input. The current comparator threshold
SENSE– (Pin 4):
The Negative Input to the Current Com- increases with this control voltage. Nominal voltage range parator. for this pin is 0.7V to 1.9V. Forcing this pin below 0.35V causes the device to be shut down. In shutdown all
VIN (Pin 5):
Supply Pin. Must be closely decoupled to GND functions are disabled and the PGATE pin is held high. Pin 2.
GND (Pin 2):
Ground Pin.
PGATE (Pin 6):
Gate Drive for the External P-Channel MOSFET. This pin swings from 0V to VIN.
U U W FUNCTIONAL DIAGRA
SENSE– VIN 5 4 + ICMP – VIN RS1 SLOPE SWITCHING PGATE R COMP LOGIC AND OSC Q 6 BLANKING S CIRCUIT – FREQ OVP FOLDBACK + BURST + 0.3V + CMP SHORT-CIRCUIT V DETECT REF 0.15V – + SLEEP 60mV – VIN EAMP VREF + 0.8V 0.5µA VFB + 1 ITH/RUN – 3 V V IN IN 0.3V – 0.35V + SHDN VOLTAGE VREF SHDN REFERENCE 0.8V CMP – UV GND 2 UNDERVOLTAGE LOCKOUT 1.2V 1772 FD 1772fb 4
U U U PIN FUNCTIONS ITH/RUN (Pin 1):
This pin performs two functions. It
VFB (Pin 3):
Receives the feedback voltage from an exter- serves as the error amplifier compensation point as well as nal resistive divider across the output. the run control input. The current comparator threshold
SENSE– (Pin 4):
The Negative Input to the Current Com- increases with this control voltage. Nominal voltage range parator. for this pin is 0.7V to 1.9V. Forcing this pin below 0.35V causes the device to be shut down. In shutdown all
VIN (Pin 5):
Supply Pin. Must be closely decoupled to GND functions are disabled and the PGATE pin is held high. Pin 2.
GND (Pin 2):
Ground Pin.
PGATE (Pin 6):
Gate Drive for the External P-Channel MOSFET. This pin swings from 0V to VIN.
U U W FUNCTIONAL DIAGRA
SENSE– VIN 5 4 + ICMP – VIN RS1 SLOPE SWITCHING PGATE R COMP LOGIC AND OSC Q 6 BLANKING S CIRCUIT – FREQ OVP FOLDBACK + BURST + 0.3V + CMP SHORT-CIRCUIT V DETECT REF 0.15V – + SLEEP 60mV – VIN EAMP VREF + 0.8V 0.5µA VFB + 1 ITH/RUN – 3 V V IN IN 0.3V – 0.35V + SHDN VOLTAGE VREF SHDN REFERENCE 0.8V CMP – UV GND 2 UNDERVOLTAGE LOCKOUT 1.2V 1772 FD 1772fb 4
