Summary of LT8390 – 60V Synchronous 4-Switch Buck-Boost Controller with Spread Spectrum
The LT8390 is a synchronous 4-switch buck-boost DC/DC controller supporting input voltages above, below, or equal to the output. It offers up to 98% efficiency, wide voltage ranges (4V–60V), and ±1.5% output accuracy. Features include current monitoring, fault protection, spread spectrum modulation for low EMI, and adjustable frequency operation from 150kHz to 650kHz. Ideal for automotive, industrial, and battery-powered systems requiring seamless transitions between buck, boost, and pass-through modes.
Parts used in the LT8390 Project:
- Synchronous 4-Switch Buck-Boost Controller
- High Side PMOS Load Switch Driver
- Integrated Bootstrap Diodes
- Input Voltage Monitor
- Output Current Monitor
- Power Good Flag
- Spread Spectrum Frequency Modulation Circuit
- Fault Protection Logic
Features
- 4-Switch Single Inductor Architecture Allows VIN Above, Below or Equal to VOUT
- Synchronous Switching: Up to 98% Efficiency
- Proprietary Peak-Buck Peak-Boost Current Mode
- Wide VIN Range: 4V to 60V
- ±1.5% Output Voltage Accuracy: 1V ≤ VOUT ≤ 60V
- ±3% Input or Output Current Accuracy with Monitor
- Spread Spectrum Frequency Modulation for Low EMI
- High Side PMOS Load Switch Driver
- Integrated Bootstrap Diodes
- No Top MOSFET Refresh Noise in Buck or Boost
- Adjustable and Synchronizable: 150kHz to 650kHz
- VOUT Disconnected from VIN During Shutdown
- Available in 28-Lead TSSOP with Exposed Pad and 28-Lead QFN (4mm × 5mm)
Typical Application
Description
The LT®8390 is a synchronous 4-switch buck-boost DC/DC controller that regulates output voltage, input or output current from an input voltage above, below, or equal to the output voltage. The proprietary peak-buck/peak-boost current mode control scheme allows adjustable and synchronizable 150kHz to 650kHz fixed frequency operation, or internal ±15% triangle spread spectrum frequency modulation for low EMI. With a 4V to 60V input voltage range, 0V to 60V output voltage capability, and seamless low-noise transitions between operation regions, the LT8390 is ideal for voltage regulator, battery and supercapacitor charger applications in automotive, industrial, telecom, and even battery-powered systems.
The LT8390 provides input or output current monitor and power good flag. Fault protection is also provided to detect output short-circuit condition, during which the LT8390 retries, latches off, or keeps running.
For more detail: LT8390 – 60V Synchronous 4-Switch Buck-Boost Controller with Spread Spectrum
- What is the primary function of the LT8390?
The LT8390 is a synchronous 4-switch buck-boost DC/DC controller that regulates output voltage and input or output current. - Can the LT8390 handle input voltages both above and below the output voltage?
Yes, it allows VIN to be above, below, or equal to VOUT. - How efficient is the LT8390 during operation?
It achieves up to 98% efficiency through synchronous switching. - What is the input voltage range supported by the LT8390?
The device supports a wide VIN range from 4V to 60V. - Does the LT8390 support low EMI operations?
Yes, it uses spread spectrum frequency modulation to reduce electromagnetic interference. - Is the operating frequency adjustable on the LT8390?
Yes, the frequency is adjustable and synchronizable from 150kHz to 650kHz. - What fault protections are included in the LT8390?
It includes fault protection to detect output short-circuit conditions with retry, latch-off, or continuous run options. - Can the LT8390 monitor input or output current?
Yes, it provides input or output current monitoring with ±3% accuracy. - What happens to the output voltage during shutdown?
VOUT disconnects from VIN during shutdown. - In which applications is the LT8390 ideally suited?
It is ideal for voltage regulator, battery, and supercapacitor charger applications in automotive, industrial, and telecom sectors.
