Features and Benefits
- Wide Input Operating Range: 2.7V to 36V
- Dual 1A Switches with Programmable Current Limit
- Programmable Switching Frequency: 50kHz to 1MHz
- Frequency Synchronization Up to 1MHz
- ΔVIN Compensation Using Duty Cycle Control
- Low Noise Topology
- Programmable Input Over and Undervoltage Lockout
- Cross Conduction Prevention Circuitry
- Programmable Soft-Start
- Low Shutdown Current: <1μA
- 10-Lead MSOP and DFN Packages
The LT3999 is a monolithic, high voltage, high frequency DC/DC transformer driver providing isolated power in a small solution footprint.
The LT3999 has two 1A current limited power switches that switch out of phase. The duty cycle is programmable to adjust the output voltage. The switching frequency is programmed up to 1MHz and can be synchronized to an external clock for more accurate placement of switcher harmonics. The input operating range is programmed with the precision undervoltage and overvoltage lockouts. The supply current is reduced to less than 1μA during shutdown. A user-defined RC time constant provides an adjustable soft-start capability by limiting the inrush current at start-up.
The LT3999 is available in a 10-lead MSOP and 3mm × 3mm DFN package with exposed pad.
- Low Noise Isolated Supplies
- Medical Instrument and Safety
- Distributed Power
- Multiple Output Supplies
- Positive-to-Negative Supplies
- Noise Immunity in Data Acquisition, RS232 and RS485
Markets and Technologies
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (3)
The ADSKPMB10-EV-FMCZ signal chain kit is a two-board solution, which consists of a Precision Medium Bandwidth Data Acquisition Solution on a PMOD form factor and a Fully Isolated PMOD-to-FMC interposer board.
The Precision Medium Bandwidth Data Acquisition Solution features a discrete programmable gain instrumentation amplifier (PGIA) that was built using a 30V, High Speed, Low Noise, Low Bias Current, JFET Operational Amplifier, the ADA4627-1, a Precision Quad Matched Resistor Network, the LT5400, a Low Capacitance, 4-Channel, ±15 V/+12 V iCMOS™ Multiplexer, the ADG1209 and the internal Fully Differential Amplifier (FDA) ADC driver of the ADAQ4003. The PGIA in thru front-end offers high input impedance that allows direct interface with a variety of sensors. A programmable gain is often needed to adapt the circuit to different input signal amplitudes—unipolar or bipolar and single-ended or differential with varying common-mode voltages. The PGIA works with the ADAQ4003, an 18-Bit, 2 MSPS, µModule® Data Acquisition Solution.
The Fully Isolated PMOD-to-FMC interposer board was designed using a Low Noise, 1A, 1MHz Push-Pull DC/DC Driver with Duty Cycle Control, the LT3999, a Robust 3.0kVrms Digital Isolators w/ Fail-Safe for the SPI lines and PGIA gain control pins, the ADuM152N and the ADuM120N, and a Low noise and ultra-low noise LDO regulators the ADP7105 and the ADP150N respectively.
- Data acquisition and system monitoring
- Automated test equipment
- Medical equipment
Features & Benefits
- Fully Isolated PMOD-to-FMC interposer board
- Software programmable bipolar input ranges (±1.1 V to ±11.0 V)
- Allows single-ended and differential signals
- GΩ input impedance allows direct interface with sensors
- On-board 5 V reference and buffer
- Complete power management solution
- SPI-/QSPI-/MICROWIRE-/DSP-compatible serial interface
- PC software for control and data analysis of time and frequency domain
High power evaluation board, up to 1200V & 50A @ 200kHz switching frequency featuring the combo ADI ADuM4135 isolated gate driver + LT3999 isolated power supply controller + Microsemi SiC power module in half bridge configuration.
For more information, email RenwBoards@analog.com.
Features & Benefits
- Half Bridge Topology
- 1200V, 50A, 200kHz
- >100kV/us CMTI
- 4 layers PCB
- 12V VIN supply
- Independent High Side and Low Side PWM inputs (Single control with 70ns deadtime for testing)
- 1 LT3999 + 1 ADuM4135 for both High Side and Low Side
- Full tested ‘Desat protection’
- Low inductive and high current terminals for V+, V- and AC phase connection
The DC2049A demonstrates how a power supply regulates two output voltage by using the LT3999 and low dropout (LDO) regulators.
The LT3999 is a monolithic push-pull DC/DC driver which features a wide input range and small external passive components.
The LT3999 has duty circle control for ΔVIN compensation, which allows for a wide input voltage range and low LDO losses.
Documentation & Resources
R530 Reliability Data3/26/2018
DC2049A - Demo Manual11/24/2014
Designing Optimized Power Solutions for Precision Signal Chains (2023)10/30/2023
Signal Chain Power: New Integrated Hardware and Software Tool for Power Design, Development and Evaluation9/6/2023
Why Power Choices Matter in Precision Signal Chains4/12/2022
Energy Storage Systems Boost Electric Vehicles’ Fast Charger Infrastructure3/18/2021
Isolation for SAR ADCs5/3/2021
Energy Storage Systems Boost Electric Vehicles’ Fast Charger Infrastructure2/1/2020 Thought Leadership
How to Design an Isolated, High Frequency, Push-Pull DC/DC Converter4/1/2015 LT Journal
Tools & Simulations
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Sample & Buy
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.