Datasheet LTC3543 (Analog Devices) - 7
| Manufacturer | Analog Devices |
| Description | 600mA Synchronous Step Down Buck Regulator with PLL, Soft-Start and Spread Spectrum |
| Pages / Page | 20 / 7 — PIN FUNCTIONS. SW (Pin 1):. VFB (Pin 4):. RUN (Pin 5):. CAP (Pin 2):. … |
| File Format / Size | PDF / 342 Kb |
| Document Language | English |
PIN FUNCTIONS. SW (Pin 1):. VFB (Pin 4):. RUN (Pin 5):. CAP (Pin 2):. MODE (Pin 3):. VIN (Pin 6):. Exposed Pad (Pin 7):
Model Line for this Datasheet
Text Version of Document
LTC3543
PIN FUNCTIONS SW (Pin 1):
Switch Node Connector to Inductor. This pin
VFB (Pin 4):
Feedback sensing pin for the external feedback connects to the drains of the internal main and synchronous resistors. power MOSFET switches.
RUN (Pin 5):
Run Control Input. Forcing pin above 1.5V
CAP (Pin 2):
Capacitor used for smoothing out spread enables the part. Forcing the pin below 0.3V shuts down spectrum or for PLL response. Connect to a capacitor the device. In shutdown, all functions are disabled, whose other plate is connected to GND, or allow the pin drawing <1μA of supply current. Do not leave the RUN to fl oat. Value = 1nF – 10nF. pin fl oating.
MODE (Pin 3):
Mode Selection Pin. Connect as follows
VIN (Pin 6):
Main Supply Pin. to invoke desired operation: MODE = GND → Burst Mode
Exposed Pad (Pin 7):
Exposed Pad connected to operation, MODE = VFB → Pulse skip with spread spec- ground. trum, MODE = VIN → Pulse skip, MODE = External clock → PLL mode.
FUNCTIONAL DIAGRAM
VOUT VIN R2 6 VIN VFB 4 C PEAK CURRENT LEVEL REF IN EA 0.6V RS R1 ICOMP S Q BP OSC MAIN L SW R QB L LOGIC 1 VOUT CAP L COUT 2 SYNCHRONOUS C1 SPREAD PLL SPECTRUM MODE 3 MODE SELECT BURST IRCMP RUN 5 7 3543 FD GND 3543fa 7
PIN FUNCTIONS SW (Pin 1):
Switch Node Connector to Inductor. This pin
VFB (Pin 4):
Feedback sensing pin for the external feedback connects to the drains of the internal main and synchronous resistors. power MOSFET switches.
RUN (Pin 5):
Run Control Input. Forcing pin above 1.5V
CAP (Pin 2):
Capacitor used for smoothing out spread enables the part. Forcing the pin below 0.3V shuts down spectrum or for PLL response. Connect to a capacitor the device. In shutdown, all functions are disabled, whose other plate is connected to GND, or allow the pin drawing <1μA of supply current. Do not leave the RUN to fl oat. Value = 1nF – 10nF. pin fl oating.
MODE (Pin 3):
Mode Selection Pin. Connect as follows
VIN (Pin 6):
Main Supply Pin. to invoke desired operation: MODE = GND → Burst Mode
Exposed Pad (Pin 7):
Exposed Pad connected to operation, MODE = VFB → Pulse skip with spread spec- ground. trum, MODE = VIN → Pulse skip, MODE = External clock → PLL mode.
FUNCTIONAL DIAGRAM
VOUT VIN R2 6 VIN VFB 4 C PEAK CURRENT LEVEL REF IN EA 0.6V RS R1 ICOMP S Q BP OSC MAIN L SW R QB L LOGIC 1 VOUT CAP L COUT 2 SYNCHRONOUS C1 SPREAD PLL SPECTRUM MODE 3 MODE SELECT BURST IRCMP RUN 5 7 3543 FD GND 3543fa 7
