Datasheet LT3686 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 37V/1.2A Step-Down Regulator in 3mm × 3mm DFN |
| Pages / Page | 28 / 1 — FeAtures. Description. Wide Input Range:. Operation from 3.6V to 37V. … |
| File Format / Size | PDF / 527 Kb |
| Document Language | English |
FeAtures. Description. Wide Input Range:. Operation from 3.6V to 37V. Overvoltage Lockout Protects Circuit Through
Model Line for this Datasheet
Text Version of Document
LT3686 37V/1.2A Step-Down Regulator in 3mm × 3mm DFN
FeAtures Description
n
Wide Input Range:
The LT®3686 is a current mode PWM step-down DC/DC
Operation from 3.6V to 37V
converter with an internal 1.2A power switch, packaged in
Overvoltage Lockout Protects Circuit Through
10-lead 3mm × 3mm DFN. The wide input range of 3.6V to
55V Transients
37V makes the LT3686 suitable for regulating power from n
Low Minimum On-Time:
a wide variety of sources, including 24V industrial supplies
Converts 16VIN to 3.3VOUT at 2MHz
and automotive batteries. Its high maximum frequency al- n
1.2A Output Current
lows the use of tiny inductors and capacitors, resulting in n
Adjustable Frequency: 300kHz to 2.5MHz
a very small solution. Operating frequency above the AM n
Constant Switching Frequency at Light Loads
band avoids interfering with radio reception, making the n Tracking and Soft-Start LT3686 particularly suitable for automotive applications. n Precision UVLO Cycle-by-cycle current limit and DA current sense provide n Short-Circuit Robust protection against fault conditions. Soft-start and frequency n IQ in Shutdown <1µA foldback eliminate input current surge during start-up. An n Internally Compensated optional internal regulated active load at the output via n 10-Lead 3mm × 3mm DFN Package the BD pin keeps the LT3686 at full switching frequency
ApplicAtions
at light loads, resulting in low, predictable output ripple above the audio and AM bands. Internal compensation and n an internal boost diode reduce external component count. Automotive Systems L n , LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks Battery-Powered Equipment of Linear Technology Corporation. All other trademarks are the property of their respective n owners. Wall Transformer Regulation n Distributed Supply Regulation
typicAl ApplicAtion 3.3V Step-Down Converter 12VIN Efficiency (2.1MHz)
90 VIN V 6V TO 37V IN BD 80 2.2µF 3.3V EN/UVLO BOOST OUT 0.22µF 70 LT3686 5V 6.8µH OUT 60 MODE SW VOUT 3.3V 50 MBRM140 SS 1.2A DA 40 10nF RT 31.6k FB EFFICIENCY (%) 30 GND 20 15.4k 10k 22µF 10 3686 TA01a 0 (V 0 200 400 600 800 1000 1200 IN 6V TO 16V AT 2.1MHz) LOAD CURRENT (mA) 3686 TA01b 3686fc 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Related Parts
FeAtures Description
n
Wide Input Range:
The LT®3686 is a current mode PWM step-down DC/DC
Operation from 3.6V to 37V
converter with an internal 1.2A power switch, packaged in
Overvoltage Lockout Protects Circuit Through
10-lead 3mm × 3mm DFN. The wide input range of 3.6V to
55V Transients
37V makes the LT3686 suitable for regulating power from n
Low Minimum On-Time:
a wide variety of sources, including 24V industrial supplies
Converts 16VIN to 3.3VOUT at 2MHz
and automotive batteries. Its high maximum frequency al- n
1.2A Output Current
lows the use of tiny inductors and capacitors, resulting in n
Adjustable Frequency: 300kHz to 2.5MHz
a very small solution. Operating frequency above the AM n
Constant Switching Frequency at Light Loads
band avoids interfering with radio reception, making the n Tracking and Soft-Start LT3686 particularly suitable for automotive applications. n Precision UVLO Cycle-by-cycle current limit and DA current sense provide n Short-Circuit Robust protection against fault conditions. Soft-start and frequency n IQ in Shutdown <1µA foldback eliminate input current surge during start-up. An n Internally Compensated optional internal regulated active load at the output via n 10-Lead 3mm × 3mm DFN Package the BD pin keeps the LT3686 at full switching frequency
ApplicAtions
at light loads, resulting in low, predictable output ripple above the audio and AM bands. Internal compensation and n an internal boost diode reduce external component count. Automotive Systems L n , LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks Battery-Powered Equipment of Linear Technology Corporation. All other trademarks are the property of their respective n owners. Wall Transformer Regulation n Distributed Supply Regulation
typicAl ApplicAtion 3.3V Step-Down Converter 12VIN Efficiency (2.1MHz)
90 VIN V 6V TO 37V IN BD 80 2.2µF 3.3V EN/UVLO BOOST OUT 0.22µF 70 LT3686 5V 6.8µH OUT 60 MODE SW VOUT 3.3V 50 MBRM140 SS 1.2A DA 40 10nF RT 31.6k FB EFFICIENCY (%) 30 GND 20 15.4k 10k 22µF 10 3686 TA01a 0 (V 0 200 400 600 800 1000 1200 IN 6V TO 16V AT 2.1MHz) LOAD CURRENT (mA) 3686 TA01b 3686fc 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Related Parts
