Features and Benefits
- Wide VIN Range: 5.5V to 60V
- Configurable for Dual Phase Single/Dual Output Operation
- Peak Current Mode Control with Smooth Quadratic Slope Compensation and Dynamic Slope Recovery
- Adjustable Max Duty Cycle
- Adjustable Min On-Time
- Hiccup Mode for Overcurrent Protection
- Adjustable Current Sense Limit
- Output Overvoltage Protection
- Programmable and Phase-Lockable Operating Frequency (from 50kHz to 425kHz)
- Adjustable Soft-Start Current Ramping
- ±1% Internal Voltage Reference
- Internal 10V LDO Regulator for Gate Driver
- Two RUN Pins and Dual Power Good Monitors
- Flexible Topology for Boost, SEPIC and Flyback
The LTC®7840 is a dual phase dual output, constant frequency current mode, nonsynchronous boost controller that drives N-channel power MOSFETs. The nonsynchronous topology makes the output voltage dependent on the choice of external components.
A wide 5.5V to 60V input supply range can accommodate high input voltage surges. The LTC7840 can be configured as a dual phase single output or dual output controller. It can be also configured for the SEPIC and flyback topologies. The switching frequency is programmed by the voltage on the FREQ pin or synchronized to an external clock. The LTC7840 features a precise 1.2V internal reference. It has two RUN pins and two power good output indicators.
The LTC7840 has an internal 10V LDO with undervoltage lockout protection for its on-chip gate driver. The maximum duty cycle and blanking time can be programmed by the voltage on DMAX and BLANK pins, respectively. The hiccup mode protects the system in the event of faults.
The LTC7840 is available in a 28-lead thermally enhanced TSSOP package (FE28) or a 28-lead QFN package (UFD28).
- Automotive System, Telecom System and Industrial Power Supplies
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 (1)
Demonstration circuit DC2744 is a two stage DC/DC boost converter featuring the LTC7840, a constant frequency current mode boost controller. The DC2744A operates over a 9V to 36V input voltage range. The first stage boost generates VOUT1 at 48V. The second stage boost takes this 48V input and provides a 240V output with 0.7A of load current. The 150kHz constant frequency operation results in a small and efficient circuit. The converter provides high output voltage accuracy (typically ±3%) over a wide load range with no minimum load requirement. The demonstration circuit can be easily modified to generate different output voltages.
The DC2744 has small circuit footprint. It is a high performance cost effective solution for applications that require high step-up voltage ratios and high output power.
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.
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.