LINEAR TECHNOLOGY LT3800 High-Voltage Synchronous Current Mode Step-Down Controller User Manual
Summary
Optimize your power systems with this high-voltage synchronous step-down controller. Capable of operating across a wide 4V to 60V input range, it is engineered for efficiency and reliability in demanding environments like automotive, industrial, and telecom applications. The accompanying manual provides comprehensive technical documentation, covering detailed electrical specifications, operational features such as Burst Mode and reverse current inhibit, and multiple DC/DC converter design examples (e.g., 12V to 48V).
Page 1 Text Content
POW ER LOSS (W
LT3800
High-Voltage Synchronous Current Mode Step-Down
Controller
FEATURES DESCRIPTIO Wide 4V to 60V Input Voltage Range The LT®3800 is a 200k Hz fixed frequency high voltage Output Voltages up to 36V synchronous current mode step-down switching regula-
Adaptive Nonoverlap Circuitry Prevents Switch tor controller. The IC drives standard gate N-channel power Shoot-Through MOSFETs and can operate with input voltages from 4V to Reverse Inductor Current Inhibit for Discontinuous 60V. An onboard regulator provides IC power directly from Operation Improves Efficiency with Light Loads VIN and provides for output-derived power to minimize VIN
Output Slew Rate Controlled Soft-Start with quiescent current. MOSFET drivers employ an internal Auto-Reset dynamic bootstrap feature, maximizing gate-source “ON”
100µA No Load Quiescent Current voltages during normal operation for improved operating Low 10µA Current Shutdown efficiencies. The LT3800 incorporates Burst Mode® opera-
1% Regulation Accuracy tion, which reduces no load quiescent current to under 200k Hz Operating Frequency 100µA. Light load efficiencies are also improved through Standard Gate N-Channel Power MOSFETs a reverse inductor current inhibit, allowing the controller Current Limit Unaffected by Duty Cycle to support discontinuous operation. Both Burst Mode Reverse Overcurrent Protection operation and the reverse-current inhibit features can be 16-Lead Thermally Enhanced TSSOP Package disabled if desired. The LT3800 incorporates a program-
mable soft-start that directly controls the voltage slew rate
APPLICATIO S of the converter output for reduced startup surge currents
EF FI CI EN CY and overshoot errors. The LT3800 is available in a 16-lead
12V and 42V Automotive and Heavy Equipment
thermally enhanced TSSOP package.
48V Telecom Power Supplies
, LTC and LT are registered trademarks of Linear Technology Corporation.
Avionics and Industrial Control Systems Burst Mode is a registered trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Distributed Power Converters
Protected by U.S. Patents, including 5481178, 6611131, 6304066, 6498466, 6580258.
TYPICAL APPLICATIO 12V 75W DC/DC Converter with Reverse Current Inhibit and Input UVLO VIN 20V TO 55V
56µF 1µF Efficiency and Power Loss ×2 ×3
VIN BOOST
Si7850DP VIN = 24V
1M TG
82.5k LT3800 VIN = 36V
SHDN SW
1.5n F VIN = 60V
200k BAS19
15µH VIN = 48V
BURST_EN VCC
VFB BG Si7370DP B160
LOSS (48V)
VC PGND
SENSE– SENSE+ SGND
VOUT ILOAD (A) 12V AT 75W 3800 TA01b
3800 TA01a
Page Summary Contents For LINEAR TECHNOLOGY LT3800 High-Voltage Synchronous Current Mode Step-Down Controller User Manual
Manual Details
| Brand | Current |
|---|---|
| Pages | 24 |
| File Size | 245.17 KB |
| Published | May 18, 2026 |
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