Analog Devices LT3686

Overview

Topology	Buck Converter
Input voltage	3.6-37 V
Switching frequency	300-2500 kHz
Output 1	1.2 A
IC revision	C

Description

The LT®3686 is a current mode PWM step-down DC/DC converter with an internal 1.2A power switch, packaged in 10-lead 3mm × 3mm DFN. The wide input range of 3.6V to 37V makes the LT3686 suitable for regulating power from a wide variety of sources, including 24V industrial supplies and automotive batteries. Its high maximum frequency allows the use of tiny inductors and capacitors, resulting in a very small solution. Operating frequency above the AM band avoids interfering with radio reception, making the LT3686 particularly suitable for automotive applications.

Cycle-by-cycle current limit and DA current sense provide protection against fault conditions. Soft-start and frequency foldback eliminate input current surge during start-up. An optional internal regulated active load at the output via the BD pin keeps the LT3686 at full switching frequency at light loads, resulting in low, predictable output ripple above the audio and AM bands. Internal compensation and an internal boost diode reduce external component count.

Features

Wide Input Range:Operation from 3.6V to 37VOvervoltage Lockout Protects Circuit Through 55V Transients
Low Minimum On-Time:Converts 16VIN to 3.3VOUT at 2MHz
1.2A Output Current
Adjustable Frequency: 300kHz to 2.5MHz
Constant Switching Frequency at Light Loads
Tracking and Soft-Start
Precision UVLO
Short-Circuit Robust
IQ in Shutdown <1μA
Internally Compensated
10-Lead 3mm × 3mm DFN Package

Remarks

Inductor Value Are Given in Page no-13

Typical applications

Battery-Powered Equipment
Distributed Supply Regulation
Automotive Systems
Wall Transformer Regulation

More information

Products

Order Code	Datasheet	Simulation	Downloads	Status	Product series	L(µH)	I_RP,40K(A)	R_{DC max.}(mΩ)	f_res(MHz)	Size	Version	SamplesAvailability & Sample
7447789001	SPECWE-PD SMT Power Inductor, 1 µH, 7.9 A	Simulation	Availability –	Downloads9 files EDA models: Components ZIP ALT WE-PD (rev25b).IntLib \| 2.3 MB CDS Cadence_WE-PD (rev25b).zip \| 13.4 MB EAG Eagle_WE-PD (rev25a).lbr \| 333.8 KB KIC KiCad_WE-PD (rev26b).zip \| 1.8 MB ZUK CadStar_WE-PD (rev20a).zip \| 36.5 KB CAD files ZIP IGS Download_WE-PD_7732R_IGS (rev1).igs \| 2.4 MB STP Download_WE-PD_7332R_STP (rev1).stp \| 1.4 MB Electric models ZIP PSP PSpice_WE-PD (rev25a).zip \| 59.6 KB SCS Spectre_WE-PD (rev25a).mod \| 78.4 KB Download all 9 files as zip archive ZIP	Status Activei\| Production is active. Expected lifetime: >10 years.	Product seriesWE-PD SMT Power Inductor	Inductance1 µH	Performance Rated Current7.9 A	DC Resistance12 mΩ	Self Resonant Frequency115 MHz	Size7332	VersionRobust	–Check availability
7447789002	SPECWE-PD SMT Power Inductor, 2.2 µH, 5.6 A	Simulation	Availability –	Downloads9 files EDA models: Components ZIP ALT WE-PD (rev25b).IntLib \| 2.3 MB CDS Cadence_WE-PD (rev25b).zip \| 13.4 MB EAG Eagle_WE-PD (rev25a).lbr \| 333.8 KB KIC KiCad_WE-PD (rev26b).zip \| 1.8 MB ZUK CadStar_WE-PD (rev20a).zip \| 36.5 KB CAD files ZIP IGS Download_WE-PD_7732R_IGS (rev1).igs \| 2.4 MB STP Download_WE-PD_7332R_STP (rev1).stp \| 1.4 MB Electric models ZIP PSP PSpice_WE-PD (rev25a).zip \| 59.6 KB SCS Spectre_WE-PD (rev25a).mod \| 78.4 KB Download all 9 files as zip archive ZIP	Status Activei\| Production is active. Expected lifetime: >10 years.	Product seriesWE-PD SMT Power Inductor	Inductance2.2 µH	Performance Rated Current5.6 A	DC Resistance23 mΩ	Self Resonant Frequency67 MHz	Size7332	VersionRobust	–Check availability
7447789003	SPECWE-PD SMT Power Inductor, 3.3 µH, 4.9 A	Simulation	Availability –	Downloads9 files EDA models: Components ZIP ALT WE-PD (rev25b).IntLib \| 2.3 MB CDS Cadence_WE-PD (rev25b).zip \| 13.4 MB EAG Eagle_WE-PD (rev25a).lbr \| 333.8 KB KIC KiCad_WE-PD (rev26b).zip \| 1.8 MB ZUK CadStar_WE-PD (rev20a).zip \| 36.5 KB CAD files ZIP IGS Download_WE-PD_7732R_IGS (rev1).igs \| 2.4 MB STP Download_WE-PD_7332R_STP (rev1).stp \| 1.4 MB Electric models ZIP PSP PSpice_WE-PD (rev25a).zip \| 59.6 KB SCS Spectre_WE-PD (rev25a).mod \| 78.4 KB Download all 9 files as zip archive ZIP	Status Activei\| Production is active. Expected lifetime: >10 years.	Product seriesWE-PD SMT Power Inductor	Inductance3.3 µH	Performance Rated Current4.9 A	DC Resistance30 mΩ	Self Resonant Frequency61 MHz	Size7332	VersionRobust	–Check availability
7447789004	SPECWE-PD SMT Power Inductor, 4.7 µH, 4.2 A	Simulation	Availability –	Downloads9 files EDA models: Components ZIP ALT WE-PD (rev25b).IntLib \| 2.3 MB CDS Cadence_WE-PD (rev25b).zip \| 13.4 MB EAG Eagle_WE-PD (rev25a).lbr \| 333.8 KB KIC KiCad_WE-PD (rev26b).zip \| 1.8 MB ZUK CadStar_WE-PD (rev20a).zip \| 36.5 KB CAD files ZIP IGS Download_WE-PD_7732R_IGS (rev1).igs \| 2.4 MB STP Download_WE-PD_7332R_STP (rev1).stp \| 1.4 MB Electric models ZIP PSP PSpice_WE-PD (rev25a).zip \| 59.6 KB SCS Spectre_WE-PD (rev25a).mod \| 78.4 KB Download all 9 files as zip archive ZIP	Status Activei\| Production is active. Expected lifetime: >10 years.	Product seriesWE-PD SMT Power Inductor	Inductance4.7 µH	Performance Rated Current4.2 A	DC Resistance35 mΩ	Self Resonant Frequency45 MHz	Size7332	VersionRobust	–Check availability
7447789006	SPECWE-PD SMT Power Inductor, 6.8 µH, 3.75 A	Simulation	Availability –	Downloads9 files EDA models: Components ZIP ALT WE-PD (rev25b).IntLib \| 2.3 MB CDS Cadence_WE-PD (rev25b).zip \| 13.4 MB EAG Eagle_WE-PD (rev25a).lbr \| 333.8 KB KIC KiCad_WE-PD (rev26b).zip \| 1.8 MB ZUK CadStar_WE-PD (rev20a).zip \| 36.5 KB CAD files ZIP IGS Download_WE-PD_7732R_IGS (rev1).igs \| 2.4 MB STP Download_WE-PD_7332R_STP (rev1).stp \| 1.4 MB Electric models ZIP PSP PSpice_WE-PD (rev25a).zip \| 59.6 KB SCS Spectre_WE-PD (rev25a).mod \| 78.4 KB Download all 9 files as zip archive ZIP	Status Activei\| Production is active. Expected lifetime: >10 years.	Product seriesWE-PD SMT Power Inductor	Inductance6.8 µH	Performance Rated Current3.75 A	DC Resistance44 mΩ	Self Resonant Frequency38 MHz	Size7332	VersionRobust	–Check availability
744778910	SPECWE-PD SMT Power Inductor, 10 µH, 2.9 A	Simulation	Availability –	Downloads9 files EDA models: Components ZIP ALT WE-PD (rev25b).IntLib \| 2.3 MB CDS Cadence_WE-PD (rev25b).zip \| 13.4 MB EAG Eagle_WE-PD (rev25a).lbr \| 333.8 KB KIC KiCad_WE-PD (rev26b).zip \| 1.8 MB ZUK CadStar_WE-PD (rev20a).zip \| 36.5 KB CAD files ZIP IGS Download_WE-PD_7732R_IGS (rev1).igs \| 2.4 MB STP Download_WE-PD_7332R_STP (rev1).stp \| 1.4 MB Electric models ZIP PSP PSpice_WE-PD (rev25a).zip \| 59.6 KB SCS Spectre_WE-PD (rev25a).mod \| 78.4 KB Download all 9 files as zip archive ZIP	Status Activei\| Production is active. Expected lifetime: >10 years.	Product seriesWE-PD SMT Power Inductor	Inductance10 µH	Performance Rated Current2.9 A	DC Resistance72 mΩ	Self Resonant Frequency32 MHz	Size7332	VersionRobust	–Check availability
7447789112	SPECWE-PD SMT Power Inductor, 12 µH, 2.65 A	Simulation	Availability –	Downloads9 files EDA models: Components ZIP ALT WE-PD (rev25b).IntLib \| 2.3 MB CDS Cadence_WE-PD (rev25b).zip \| 13.4 MB EAG Eagle_WE-PD (rev25a).lbr \| 333.8 KB KIC KiCad_WE-PD (rev26b).zip \| 1.8 MB ZUK CadStar_WE-PD (rev20a).zip \| 36.5 KB CAD files ZIP IGS Download_WE-PD_7732R_IGS (rev1).igs \| 2.4 MB STP Download_WE-PD_7332R_STP (rev1).stp \| 1.4 MB Electric models ZIP PSP PSpice_WE-PD (rev25a).zip \| 59.6 KB SCS Spectre_WE-PD (rev25a).mod \| 78.4 KB Download all 9 files as zip archive ZIP	Status Activei\| Production is active. Expected lifetime: >10 years.	Product seriesWE-PD SMT Power Inductor	Inductance12 µH	Performance Rated Current2.65 A	DC Resistance98 mΩ	Self Resonant Frequency27 MHz	Size7332	VersionRobust	–Check availability
7447789115	SPECWE-PD SMT Power Inductor, 15 µH, 2.25 A	Simulation	Availability –	Downloads9 files EDA models: Components ZIP ALT WE-PD (rev25b).IntLib \| 2.3 MB CDS Cadence_WE-PD (rev25b).zip \| 13.4 MB EAG Eagle_WE-PD (rev25a).lbr \| 333.8 KB KIC KiCad_WE-PD (rev26b).zip \| 1.8 MB ZUK CadStar_WE-PD (rev20a).zip \| 36.5 KB CAD files ZIP IGS Download_WE-PD_7732R_IGS (rev1).igs \| 2.4 MB STP Download_WE-PD_7332R_STP (rev1).stp \| 1.4 MB Electric models ZIP PSP PSpice_WE-PD (rev25a).zip \| 59.6 KB SCS Spectre_WE-PD (rev25a).mod \| 78.4 KB Download all 9 files as zip archive ZIP	Status Activei\| Production is active. Expected lifetime: >10 years.	Product seriesWE-PD SMT Power Inductor	Inductance15 µH	Performance Rated Current2.25 A	DC Resistance130 mΩ	Self Resonant Frequency26 MHz	Size7332	VersionRobust	–Check availability
7447789118	SPECWE-PD SMT Power Inductor, 18 µH, 2.1 A	Simulation	Availability –	Downloads9 files EDA models: Components ZIP ALT WE-PD (rev25b).IntLib \| 2.3 MB CDS Cadence_WE-PD (rev25b).zip \| 13.4 MB EAG Eagle_WE-PD (rev25a).lbr \| 333.8 KB KIC KiCad_WE-PD (rev26b).zip \| 1.8 MB ZUK CadStar_WE-PD (rev20a).zip \| 36.5 KB CAD files ZIP IGS Download_WE-PD_7732R_IGS (rev1).igs \| 2.4 MB STP Download_WE-PD_7332R_STP (rev1).stp \| 1.4 MB Electric models ZIP PSP PSpice_WE-PD (rev25a).zip \| 59.6 KB SCS Spectre_WE-PD (rev25a).mod \| 78.4 KB Download all 9 files as zip archive ZIP	Status Activei\| Production is active. Expected lifetime: >10 years.	Product seriesWE-PD SMT Power Inductor	Inductance18 µH	Performance Rated Current2.1 A	DC Resistance140 mΩ	Self Resonant Frequency24 MHz	Size7332	VersionRobust	–Check availability
7447789122	SPECWE-PD SMT Power Inductor, 22 µH, 2.1 A	Simulation	Availability –	Downloads9 files EDA models: Components ZIP ALT WE-PD (rev25b).IntLib \| 2.3 MB CDS Cadence_WE-PD (rev25b).zip \| 13.4 MB EAG Eagle_WE-PD (rev25a).lbr \| 333.8 KB KIC KiCad_WE-PD (rev26b).zip \| 1.8 MB ZUK CadStar_WE-PD (rev20a).zip \| 36.5 KB CAD files ZIP IGS Download_WE-PD_7732R_IGS (rev1).igs \| 2.4 MB STP Download_WE-PD_7332R_STP (rev1).stp \| 1.4 MB Electric models ZIP PSP PSpice_WE-PD (rev25a).zip \| 59.6 KB SCS Spectre_WE-PD (rev25a).mod \| 78.4 KB Download all 9 files as zip archive ZIP	Status Activei\| Production is active. Expected lifetime: >10 years.	Product seriesWE-PD SMT Power Inductor	Inductance22 µH	Performance Rated Current2.1 A	DC Resistance190 mΩ	Self Resonant Frequency20 MHz	Size7332	VersionRobust	–Check availability
7447789127	SPECWE-PD SMT Power Inductor, 27 µH, 2 A	Simulation	Availability –	Downloads9 files EDA models: Components ZIP ALT WE-PD (rev25b).IntLib \| 2.3 MB CDS Cadence_WE-PD (rev25b).zip \| 13.4 MB EAG Eagle_WE-PD (rev25a).lbr \| 333.8 KB KIC KiCad_WE-PD (rev26b).zip \| 1.8 MB ZUK CadStar_WE-PD (rev20a).zip \| 36.5 KB CAD files ZIP IGS Download_WE-PD_7732R_IGS (rev1).igs \| 2.4 MB STP Download_WE-PD_7332R_STP (rev1).stp \| 1.4 MB Electric models ZIP PSP PSpice_WE-PD (rev25a).zip \| 59.6 KB SCS Spectre_WE-PD (rev25a).mod \| 78.4 KB Download all 9 files as zip archive ZIP	Status Activei\| Production is active. Expected lifetime: >10 years.	Product seriesWE-PD SMT Power Inductor	Inductance27 µH	Performance Rated Current2 A	DC Resistance210 mΩ	Self Resonant Frequency18 MHz	Size7332	VersionRobust	–Check availability

IC manufacturers (103)

37V/1.2A Step-Down Regulator in 3mm × 3mm DFN