Datasheet LTC3894 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 150V Low IQ Step-Down DC/DC Controller with 100% Duty Cycle Capability |
| Pages / Page | 36 / 1 — FEATURES. DESCRIPTION. Wide Operating VIN Range: 4.5V to 150V. Wide VOUT … |
| Revision | A |
| File Format / Size | PDF / 2.9 Mb |
| Document Language | English |
FEATURES. DESCRIPTION. Wide Operating VIN Range: 4.5V to 150V. Wide VOUT Range: 0.8V to 60V
Model Line for this Datasheet
Text Version of Document
LTC3894 150V Low IQ Step-Down DC/DC Controller with 100% Duty Cycle Capability
FEATURES DESCRIPTION
n
Wide Operating VIN Range: 4.5V to 150V
The LTC®3894 is a high voltage step-down DC/DC switch- n
Wide VOUT Range: 0.8V to 60V
ing regulator controller. It drives a P-channel power n
9μA IQ when Regulating 48VIN to 3.3VOUT
MOSFET switch allowing 100% duty cycle operation. It n
16μA IQ when Regulating 12VIN to 3.3VOUT
enables a low part count, simple, and robust solution for n
Very Low Dropout Operation: 100% Duty Cycle
high reliability, high voltage applications. n
Adjustable Input Overvoltage Lockout
The LTC3894 operates over a wide input voltage range n
Programmable PGOOD Undervoltage Monitor
from 4.5V to 150V and can regulate output voltages n
RSENSE or Inductor DCR Current Sensing
from 0.8V to 60V. It offers excellent light load efficiency, n Selectable High Efficiency Burst Mode® Operation or drawing only 9μA quiescent current while regulating the Pulse-Skipping Mode at Light Loads output voltage with no load. Its peak current mode, con- n Programmable Fixed Frequency: 50kHz to 850kHz stant frequency architecture provides for good control of n Phase-Lockable Frequency: 75kHz to 800kHz switching frequency and output current limit. The switch- n Internal Fixed Soft-Start and External Programmable ing frequency can be programmed from 50kHz to 850kHz Soft-Start or Voltage Tracking with an external resistor and can be synchronized to an n Strong MOSFET Gate Driver with Selectable external clock from 75kHz to 800kHz. Undervoltage Lockout Thresholds n Optional External NMOS for Gate Driver Bias in High The LTC3894 offers programmable output voltage soft- Power Applications start or tracking. Safety features include overvoltage, overcurrent and overtemperature protection with a power good output monitor with adjustable threshold.
APPLICATIONS
The LTC3894 is available in a thermally enhanced 20-Pin n Automotive and Industrial Power Systems TSSOP package with leads removed to accommodate n Telecommunication Power Systems high voltage creepage and clearance requirements. n Distributed Power Systems All registered trademarks and trademarks are the property of their respective owners.
TYPICAL APPLICATION High Efficiency 150V to 5V Step-Down Regulator Efficiency and Power Loss vs Load Current
22µH 20mΩ V 100 10k IN VOUT 6V to 150V 5V, 3A Burst Mode OPERATION 90 12µF 1nF 330µF 10µF ×2 ×2 80 1k POWER LOSS (mW) 70 GATE SENSE+ SENSE– RUN 60 EFFICIENCY 100 VIN PGOOD 0.47µF 50 100k CAP 40 10 LTC3894 OVLO 422k EFFICIENCY (%) 30 POWER LOSS DRVUV/EXTG PGUV EXTS 20 1 VFB ITH VIN = 12V GND FREQ TRACK/SS PLLIN/MODE 10 3.3nF VIN = 24V 80.6k 0 0.1 47pF 5.76k 36.5k 0.1µF 0.0001 0.001 0.01 0.1 1 3 LOAD CURRENT (A) 3894 TA01b 3894 TA01a Rev. A Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
FEATURES DESCRIPTION
n
Wide Operating VIN Range: 4.5V to 150V
The LTC®3894 is a high voltage step-down DC/DC switch- n
Wide VOUT Range: 0.8V to 60V
ing regulator controller. It drives a P-channel power n
9μA IQ when Regulating 48VIN to 3.3VOUT
MOSFET switch allowing 100% duty cycle operation. It n
16μA IQ when Regulating 12VIN to 3.3VOUT
enables a low part count, simple, and robust solution for n
Very Low Dropout Operation: 100% Duty Cycle
high reliability, high voltage applications. n
Adjustable Input Overvoltage Lockout
The LTC3894 operates over a wide input voltage range n
Programmable PGOOD Undervoltage Monitor
from 4.5V to 150V and can regulate output voltages n
RSENSE or Inductor DCR Current Sensing
from 0.8V to 60V. It offers excellent light load efficiency, n Selectable High Efficiency Burst Mode® Operation or drawing only 9μA quiescent current while regulating the Pulse-Skipping Mode at Light Loads output voltage with no load. Its peak current mode, con- n Programmable Fixed Frequency: 50kHz to 850kHz stant frequency architecture provides for good control of n Phase-Lockable Frequency: 75kHz to 800kHz switching frequency and output current limit. The switch- n Internal Fixed Soft-Start and External Programmable ing frequency can be programmed from 50kHz to 850kHz Soft-Start or Voltage Tracking with an external resistor and can be synchronized to an n Strong MOSFET Gate Driver with Selectable external clock from 75kHz to 800kHz. Undervoltage Lockout Thresholds n Optional External NMOS for Gate Driver Bias in High The LTC3894 offers programmable output voltage soft- Power Applications start or tracking. Safety features include overvoltage, overcurrent and overtemperature protection with a power good output monitor with adjustable threshold.
APPLICATIONS
The LTC3894 is available in a thermally enhanced 20-Pin n Automotive and Industrial Power Systems TSSOP package with leads removed to accommodate n Telecommunication Power Systems high voltage creepage and clearance requirements. n Distributed Power Systems All registered trademarks and trademarks are the property of their respective owners.
TYPICAL APPLICATION High Efficiency 150V to 5V Step-Down Regulator Efficiency and Power Loss vs Load Current
22µH 20mΩ V 100 10k IN VOUT 6V to 150V 5V, 3A Burst Mode OPERATION 90 12µF 1nF 330µF 10µF ×2 ×2 80 1k POWER LOSS (mW) 70 GATE SENSE+ SENSE– RUN 60 EFFICIENCY 100 VIN PGOOD 0.47µF 50 100k CAP 40 10 LTC3894 OVLO 422k EFFICIENCY (%) 30 POWER LOSS DRVUV/EXTG PGUV EXTS 20 1 VFB ITH VIN = 12V GND FREQ TRACK/SS PLLIN/MODE 10 3.3nF VIN = 24V 80.6k 0 0.1 47pF 5.76k 36.5k 0.1µF 0.0001 0.001 0.01 0.1 1 3 LOAD CURRENT (A) 3894 TA01b 3894 TA01a Rev. A Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
