New Content (1)
Features and Benefits
- High Efficiency Synchronous Operation
- > 90% Efficiency at 30mA, 12VIN to 3.3VOUT
- Ultralow Quiescent Current Burst Mode® Operation
- < 2.5µA IQ Regulating 48VIN to 3.3VOUT
- Output Ripple < 10mVP-P
- 3.4V to 60V Input Operation Range (65V Max)
- Fast Minimum Switch-On Time: 35ns
- Adjustable Switching Frequency: 200kHz to 2.2MHz
- Fixed 3.3V Output Voltage Version
- Allows Tiny Inductors
- Accurate 1V Enable Pin Threshold
- Internal Compensation
- Output Soft-Start and Tracking
- Small 10-Lead 3mm × 2mm DFN
- AEC-Q100 Qualification in Progress
The LT8618 is a compact, high speed synchronous monolithic step-down switching regulator that delivers up to 100mA with high efficiency at constant switching frequency, even up to 2.2MHz. It accepts a wide input voltage range up to 65V (transients only, 60V for continuous operation), and consumes only 2.5µA of quiescent current. Top and bottom power switches are included with all necessary circuitry to minimize the need for external components. Low ripple Burst Mode operation enables high efficiency down to very low output currents while keeping the output ripple below 10mVP-P. Additional features provide for flexible and robust operation. Internal compensation with peak current mode topology allows the use of small inductors and results in fast transient response and good loop stability. The EN/UV pin has an accurate 1V threshold and can be used to program VIN under voltage lockout or to shut down the LT8618 reducing the input supply current to 1µA. If there are no fault conditions, a PG flag signals when VOUT is within ±7.5% of the programmed output voltage. Thermal shutdown provides additional protection. The LT8618 is available in a small 10-Lead 3mm × 2mm DFN package with exposed pad for low thermal resistance.
- Industrial Sensors
- Industrial Internet of Things
- 4mA to 20mA Current Loops
- Flow Meters
- Automotive Housekeeping Supplies
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
Demonstration circuit 2822A features the LT8618, a high efficiency 65V, 100mA synchronous step-down regulator. The DC2822A demo board is designed for 100mA at 5V output from a 5.5V to 60V input with switching frequency of 2MHz. The wide input range allows a variety of input sources, such as automotive batteries and industrial supplies. The LT8618 is a high efficiency, and high frequency synchronous monolithic step-down switching regulator in a 3mm × 2mm DFN package with exposed pads for low thermal resistance. The regulator’s ultralow 2.5μA quiescent current with the output in full regulation enables applications requiring highest efficiency at very light load currents, such as automotive and battery powered portable instruments.
Peak current mode control with minimum on-time of as small as 35ns allows high step-down conversion even at high frequency. The LT8618 switching frequency can be programmed via an oscillator resistor over a 200kHz to 2.2MHz range. The default frequency of the DC2822A is 2MHz.
The DC2822A demo board has an EMI filter installed. The EMI performance of the board is shown on Figure 2. The red line in radiated EMI performance is CISPR25 Class 5 peak limit. The figure shows that the circuit passes the test with a wide margin.
The LT8618 data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this demo manual. The layout recommendations for best thermal performance are available in the data sheet Application Information section. Contact ADI applications engineer for technical support.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.
Models for the following parts are available in LTspice:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.