LINEAR TECHNOLOGY LT1683 User Guide
Summary
This switching regulator controller is engineered for power supplies requiring ultralow noise and stringent EMI compliance. The manual details its advanced features, including dual MOSFET drivers and independent control over current/voltage slew rates, allowing designers to drastically minimize conducted and radiated electromagnetic interference. Ideal for mission-critical, noise-sensitive applications such as medical instruments, precision data acquisition systems, and industrial automation where stable positive and negative voltage regulation is essential.
Page 1 Text Content
LT1683
Slew Rate Controlled
Ultralow Noise Push-Pull DC/DC Controller
FEATURES DESCRIPTIO Greatly Reduced Conducted and Radiated EMI The LT®1683 is a switching regulator controller designed Low Switching Harmonic Content to lower conducted and radiated electromagnetic interfer- Independent Control of Output Switch Voltage and ence (EMI). Ultralow noise and EMI are achieved by Current Slew Rates controlling the voltage and current slew rates of external Greatly Reduced Need for External Filters N-channel MOSFET switches. Current and voltage slew Dual N-Channel MOSFET Drivers rates can be independently set to optimize harmonic 20k Hz to 250k Hz Oscillator Frequency content of the switching waveforms vs efficiency. The Easily Synchronized to External Clock LT1683 can reduce high frequency harmonic power by as Regulates Positive and Negative Voltages much as 40d B with only minor losses in efficiency. Easier Layout Than with Conventional Switchers
The LT1683 utilizes a dual output (push-pull) current mode architecture optimized for low noise topologies. The
APPLICATIO S
IC includes gate drivers and all necessary oscillator, control and protection circuitry. Unique error amp cir-
Power Supplies for Noise Sensitive Communication
cuitry can regulate both positive and negative voltages.
Equipment
The oscillator may be synchronized to an external clock for
EMI Compliant Offline Power Supplies
more accurate placement of switching harmonics.
Precision Instrumentation Systems Isolated Supplies for Industrial Automation Protection features include gate drive lockout for low VIN, Medical Instruments opposite gate lockout, soft-start, output current limit, Data Acquisition Systems short-circuit current limiting, gate drive overvoltage clamp , LTC and LT are registered trademarks of Linear Technology Corporation.
and input supply undervoltage lockout.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
Ultralow Noise 48V to 5V DC/DC Converter
FZT853 MIDCOM 31244
1N4148 MBR0530 OPTIONAL
2N3904 22µH 22µH ABMBRS340 5V/2A
5V Output Noise
68µF OS-CON POSCAP
11V (Bandwidth = 100MHz)
VIN GCL
SHDN CAP A
976Ω V5 MBRS340
GATE A
SYNC 5p F 10p F
1.2n F 200µVP-P
200V 200µV/DIV
CT CAP B 16.9k LT1683 30p F RT GATE B
25k 3.3k Si9422Si9422
20m V/DIV
RVSL CS
FB 5µs/DIV 1683 TA01a
SS GND NFB 30p F22n F0.22µF
1683 TA01
1683fb
Page Summary Contents For LINEAR TECHNOLOGY LT1683 User Guide
Manual Details
| Brand | Linear |
|---|---|
| Pages | 24 |
| File Size | 267.18 KB |
| Published | June 05, 2026 |
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Frequently Asked Questions
Does the LT1683 require external filtering for low noise?
No, it greatly reduces the need for external filters due to its current and voltage slew rate control capabilities.
What unique power applications can the LT1683 support?
It is suitable for noise-sensitive electronics like medical instruments, data acquisition systems, and isolated industrial automation.
How is EMI controlled by this device?
It offers greatly reduced conducted and radiated EMI through independent control of output switch voltage and current slew rates.
Can the controller operate with varying voltages?
Yes, it can regulate both positive and negative voltages separately (push-pull architecture).