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LINEAR LT1680 High-Power DC-DC Step-Up Controller Data Sheet User Manual

Summary

The LT1680 is a powerful, current-mode switching DC/DC step-up controller designed specifically for robust boost converter topologies. Featuring high voltage support up to 60V and programmable average current limiting, this IC offers advanced protection and synchronization capabilities (up to 200kHz), making it ideal for demanding applications. This technical manual provides comprehensive specifications, electrical characteristics, and detailed application guidance for integrating the LT1680 into industrial control systems, automotive equipment, and battery back-up solutions requiring stable, high-power power regulation.

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Page 1 Text Content

查询LT1680供应商

LT1680

High Power DC/DC Step-Up Controller

FEATURES DESCRIPTION High Voltage: Operation Up to 60V Max The LT®1680 is a high power, current mode switching High Current: N-Channel Drive Handles Up to power supply controller optimized for boost topologies. 10,000p F Gate Capacitance The IC drives N-channel MOSFET switches for DC/DC Programmable Average Current Limiting converters in applications up to 60V input. A high current 5V Reference Output with 10m A External gate drive output handles up to 10,000p F gate capaci- tance, enabling the construction of high power DC/DC

Loading Capability

converters. Current sense common mode range up to 60V

Fixed Frequency Current Mode Operation

allows current sensing to be referenced to the input

Oscillator Synchronizable Up to 200k Hz

supply, eliminating the need for sense blanking circuits.

Undervoltage Lockout with Hysteresis Programmable Start Inhibit for Power Supply The LT1680 incorporates programmable average current Sequencing and Protection limiting allowing accurate limiting of DC current in the User Adjustable Slope Compensation magnetics, independent of ripple current . User adjustable

slope compensation provides stable operation at duty cycles up to 90%.

APPLICATIONS

The LT1680 operating frequency is programmable and

High Power Single Board Systems can be synchronized up to 200k Hz. Minimum off-time Distributed Power Converters operation provides switch protection. The IC also incorpo-

EF FI CI EN CY

Industrial Control Systems rates a soft start feature that is gated by both shutdown

Lead-Acid Battery Back-Up Systems and undervoltage lockout conditions. Automotive and Heavy Equipment , LTC and LT are registered trademarks of Linear Technology Corporation.

TYPICAL APPLICATION

12V to 48V, 250W Boost

12VIN 10V TO 15V

RSENSE Efficiency vs Output Power

C2 24A (DC)

CIN VOUT = 48V

RCT LT1680 680µF L1 CCT 15k 25V 25µH 1n F SL/ADJ 5VREF ×4

CT SYNC

IAVG 12VIN 1µF

C4 0.22µF M1 SS GATE IRFZ44 1N914 ×3

CVC 4.7n F VC PGND

R9 RVC 4.7k SGND RUN/SHDN 100k

MBR0520

VFB SENSE–

VREF SENSE+ D1

R7 R6 MBR20100CT

C6 0.1µF 2k 75k VOUT

OUTPUT POWER (W)

COUT 5.2A 680µF 1680 TA02

L1: Kool Mµ®, 18T #14 ON 77314-A7 63V

Kool Mµ IS A REGISTERED TRADEMARK OF MAGNETICS, INC. ×3 1680 TA01

Page Summary Contents For LINEAR LT1680 High-Power DC-DC Step-Up Controller Data Sheet User Manual

Page 1 查询LT1680供应商 LT1680 High Power DC/DC Step-Up Controller FEATURES DESCRIPTION High Voltage: Operation Up to 60V Max The LT®1680 is a high power, current mode switching High Current: N-Channel Drive Hand...
Page 2 LT1680 ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION (Note 1) TOP VIEW ORDER PART Power Supply Voltage (12VIN) –0.3V to 20V NUMBER1 SL/ADJ 5VREF Sense Amplifier Input Common Mode –0.3V to 60V CT ...
Page 3 LT1680 ELECTRICAL CHARACTERISTICS 12VIN = 12V, VVC = 2V, VFB = VREF = 1.25V, CGATE = 3000p F, TA = 25°C unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Error Amplifier VSENSE Pea...
Page 4 5V VO LT AG (V 5V RE SH OR T- CI RC UI CU RR EN (m A) 2V IN UP PL CU RR EN (m A) LT1680 TYPICAL PERFORMANCE CHARACTERISTICS I12VIN Supply Current I12VIN Supply Current vs Temperature vs 12VIN Supply V...
Page 5 (S OU RC E) µA RU N/ SH DN HR ES HO LD YS TE RE SI (m V) ER RO AM PL IF IE SO UR CE UR RE NT (µ A) LT1680 TYPICAL PERFORMANCE CHARACTERISTICS Error Amplifier Source Current SS Output Current RUN/SHDN ...
Page 6 RU N/ SH DN IN PU CU RR EN (µ A) LT1680 TYPICAL PERFORMANCE CHARACTERISTICS RUN/SHDN Input Current Operating Frequency vs Pin Voltage (Normalized) vs Temperature Maximum Duty Cycle vs RCT FULL OPERATI...
Page 7 LT1680 PIN FUNCTIONS RUN/SHDN (Pin 11): Precision Referenced Shutdown. GATE (Pin 13): Driver Output. Connect to gate of external Can be used as logic level input for shutdown control or as power FET s...
Page 8 LT1680 OPERATION Basic Control Loop supply will current limit and the output voltage will fall out of regulation. The average current limit circuit monitors The LT1680 uses a constant frequency, curre...
Page 9 LT1680 OPERATION Slope Compensation tions. However, if additional slope compensation is de- sired, it is available through the SL/ADJ pin. Excessive For duty cycles greater than 50%, slope compensatio...
Page 10 LT1680 OS CI LL AT OR RE QU EN CY (k Hz APPLICATIONS INFORMATION and a soft start timing capacitor CSS, the start-up delay CCT = 0.68n F time to full available average current will be: CCT = 1n F CCT ...
Page 11 LT1680 IN IM UM HU TD OW CO NT RO LI IT (m V) APPLICATIONS INFORMATION additional current can be minimized by making the con- DIGITAL RUN/SHDN nection through an external resistor (100k is typically u...
Page 12 LT1680 APPLICATIONS INFORMATION ments. Generally, the selection of inductor value can be at I1, the beginning of each oscillator switch cycle. reduced to desired maximum ripple current in the inductor...
Page 13 LT1680 AX IM UM EA RI PP LE UR RE NT (I PK /I VG APPLICATIONS INFORMATION This feature is implemented by referencing this pin via a 0.084 resistor divider from the 5VREF pin to ground. The addi- Amp/s...
Page 14 LT1680 APPLICATIONS INFORMATION Setting the resistor divider reference voltage to 2V assures In a typical LT1680 boost converter, the switch current is that the additional compensation waveform will b...
Page 15 LT1680 APPLICATIONS INFORMATION The input bypass capacitors generally have less ripple Gate Drive Buffer current than the output bypass capacitors as the input The LT1680 is designed to drive relative...
Page 16 LT1680 TYPICAL APPLICATION 48V to 5V 30W Forward Converter INPUT COM 35V 35V 1µF MBR2045CT 20µH 35V 35V OUT MBR2045CT INPUT 50Ω *SANYO CV-GX 330µF** 1W **SANYO OS-CON 6.3V ALL RESISTORS 1.4W, 1% UNLES...

Manual Details

Brand Linear
Pages 16
File Size 307.92 KB
Published June 03, 2026
52 views

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Frequently Asked Questions

What voltage range is the LT1680 optimized for?

It is a high power controller optimized for boost topologies, capable of operating up to 60V input.

How can I synchronize or control the switching frequency?

The oscillator is synchronizable up to 200kHz, and the frequency itself is programmable.

What protection mechanisms are provided by the chip?

It includes Undervoltage Lockout with Hysteresis, a soft start feature, and programmable average current limiting.