Datasheet LTC3850, LTC3850-1 (Analog Devices) - 10
| Manufacturer | Analog Devices |
| Description | Dual, 2-Phase Synchronous Step-Down Switching Controller |
| Pages / Page | 38 / 10 — PIN FUNCTIONS MODE/PLLIN (Pin 27/Pin 24/Pin 25):. FREQ/PLLFLTR (Pin … |
| Revision | D |
| File Format / Size | PDF / 1.2 Mb |
| Document Language | English |
PIN FUNCTIONS MODE/PLLIN (Pin 27/Pin 24/Pin 25):. FREQ/PLLFLTR (Pin 28/Pin 25/Pin 26):
Model Line for this Datasheet
- LTC3850EGN#PBF LTC3850EGN#TRPBF LTC3850EGN#WPBF LTC3850EGN#WTRPBF LTC3850EGN-1#PBF LTC3850EGN-1#TRPBF LTC3850EGN-1#WPBF LTC3850EGN-1#WTRPBF LTC3850EUF#PBF LTC3850EUF#TRPBF LTC3850EUFD#PBF LTC3850EUFD#TRPBF LTC3850IGN#PBF LTC3850IGN#TRPBF LTC3850IGN#WPBF LTC3850IGN#WTRPBF LTC3850IGN-1#PBF LTC3850IGN-1#TRPBF LTC3850IGN-1#WPBF LTC3850IGN-1#WTRPBF LTC3850IUF#PBF LTC3850IUF#TRPBF LTC3850IUFD#PBF LTC3850IUFD#TRPBF
Text Version of Document
LTC3850/LTC3850-1
PIN FUNCTIONS MODE/PLLIN (Pin 27/Pin 24/Pin 25):
Force Continuous
FREQ/PLLFLTR (Pin 28/Pin 25/Pin 26):
The Phase-Locked Mode, Burst Mode, or Pulse-Skipping Mode Selection Loop’s Low-Pass Filter is Tied to This Pin. Alternatively, Pin and External Synchronization Input to Phase Detector this pin can be driven with a DC voltage to vary the fre- Pin. Connect this pin to SGND to force both channels into quency of the internal oscillator. the continuous mode of operation. Connect to INTVCC
Exposed Pad (Pin 29, UF/UFD Packages Only):
Signal to enable pulse-skipping mode of operation. Leaving the Ground. Must be soldered to PCB, providing a local pin floating will enable Burst Mode operation. A clock on ground for the control components of the IC, and be tied the pin will force the controller into continuous mode of to the PGND pin under the IC. operation and synchronize the internal oscillator.
FUNCTIONAL DIAGRAM
FREQ/PLLFLTR MODE/PLLIN EXTVCC VIN VIN 4.7V + CIN – + F 0.8V MODE/SYNC 5V DETECT REG PLL-SYNC INTV – + CC INTVCC F BOOST OSC S BURSTEN TG CB R Q FCNT M1 SW L1 ON 3k SWITCH VOUT + – LOGIC AND SENSE+ DB ANTI- ICMP IREV SHOOT – + THROUGH SENSE– + RUN COUT BG OV M2 CVCC SLOPE COMPENSATION ILIM PGND PGOOD INTVCC UVLO + 0.74V 1 SLOPE RECOVERY R2 UV V 51k ACTIVE CLAMP FB I – THB + VIN SLEEP R1 OV – 0.86V – SS 0.8V + – RUN + SGND REF 1.3µA EA – + + + – 0.64V 1.2V 0.5µA 0.55V 38501 FD I CC1 CSS TH RC RUN TK/SS Rev. D 10 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
PIN FUNCTIONS MODE/PLLIN (Pin 27/Pin 24/Pin 25):
Force Continuous
FREQ/PLLFLTR (Pin 28/Pin 25/Pin 26):
The Phase-Locked Mode, Burst Mode, or Pulse-Skipping Mode Selection Loop’s Low-Pass Filter is Tied to This Pin. Alternatively, Pin and External Synchronization Input to Phase Detector this pin can be driven with a DC voltage to vary the fre- Pin. Connect this pin to SGND to force both channels into quency of the internal oscillator. the continuous mode of operation. Connect to INTVCC
Exposed Pad (Pin 29, UF/UFD Packages Only):
Signal to enable pulse-skipping mode of operation. Leaving the Ground. Must be soldered to PCB, providing a local pin floating will enable Burst Mode operation. A clock on ground for the control components of the IC, and be tied the pin will force the controller into continuous mode of to the PGND pin under the IC. operation and synchronize the internal oscillator.
FUNCTIONAL DIAGRAM
FREQ/PLLFLTR MODE/PLLIN EXTVCC VIN VIN 4.7V + CIN – + F 0.8V MODE/SYNC 5V DETECT REG PLL-SYNC INTV – + CC INTVCC F BOOST OSC S BURSTEN TG CB R Q FCNT M1 SW L1 ON 3k SWITCH VOUT + – LOGIC AND SENSE+ DB ANTI- ICMP IREV SHOOT – + THROUGH SENSE– + RUN COUT BG OV M2 CVCC SLOPE COMPENSATION ILIM PGND PGOOD INTVCC UVLO + 0.74V 1 SLOPE RECOVERY R2 UV V 51k ACTIVE CLAMP FB I – THB + VIN SLEEP R1 OV – 0.86V – SS 0.8V + – RUN + SGND REF 1.3µA EA – + + + – 0.64V 1.2V 0.5µA 0.55V 38501 FD I CC1 CSS TH RC RUN TK/SS Rev. D 10 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
