Features and Benefits
- Three 100mA Buck Regulators, Each Drives Up to 10 LEDs with Fast NPN Current Sources
- Fast Current Sources for <1µs Pulse Widths (10,000:1 True Color PWM™ Dimming at 100Hz)
- LEDs Disconnected in Shutdown
- Adaptive VOUT for Increased Efficiency
- 6V to 60V Input Voltage Range
- ±2% LED Current Matching
- External Resistor Sets LED Current for Each Channel
- Internal Compensation and Soft-Start
- Programmable Switching Frequency (200kHz to 1MHz)
- Synchronizable to External Clock
- Open LED Detection and Reporting
- Shorted LED Pin Protection and Reporting
- Programmable LED Thermal Derating
- Programmable Temperature Protection
- 5mm × 8mm Thermally Enhanced QFN Package with a 0.6mm High Voltage Pin Spacing
The LT3597 is a 60V triple step-down LED driver capable of achieving 10,000:1 digital PWM dimming at 100Hz with fast NPN current sources driving up to 10 LEDs in each channel. LED dimming can also be achieved via analog control of the CTRL1-3 pin.
The step-down switching frequency is programmed between 200kHz and 1MHz. The frequency is also synchronizable to an external clock. The LT3597 provides maximum LED brightness while adhering to manufacturers’ specifications for thermal derating. The derate temperature is programmed by placing a negative temperature coefficient (NTC) resistor on the master control pin.
The LT3597 adaptively controls VOUT in order to achieve optimal efficiency. Other features include: 2% LED current matching between channels, open LED reporting, shorted LED protection, programmable LED current, and programmable temperature protection.
- LED Billboards and Signboards
- Mono, Multi, Full-Color LED Displays
- Large Screen Display LED Backlighting
- Automotive, Industrial, and Medical Displays
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 1497A is a 60V triple step-down LED driver featuring the LT3597. The demo board is optimized for driving nine white LEDs at 100mA output per regulator from a 48V input. The LT3597 features a 5V to 55V input voltage range; depending on the number of LEDs used, the minimum input voltage will change. When a different number or different color of LED is used for evaluation, attention should be given to the maximum output voltage setting and open LED detection fault reporting.
The connections between the board and LEDs strings should be as short as feasible. The circuit achieves 10,000:1 PWM dimming at 100Hz PWM frequency. LED dimming can also be by analog control of the CTRL1-3 pin.
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.