Features and Benefits
- Up to 30A Output Current
- True-Differential Remote Output Sensing
- Average Current-Mode Control
- 4.75V to 5.5V or 7V to 28V Input-Voltage Range
- 0.1V/0.03V LED Current-Sense Options Maximize Efficiency (MAX16821B/MAX16821C)
- Thermal Shutdown
- Nonlatching Output Overvoltage Protection
- Low-Side Buck Mode with or without Synchronous Rectification
- High-Side Buck and Low-Side Boost Mode with or without Synchronous Rectification
- 125kHz to 1.5MHz Programmable/Synchronizable Switching Frequency
- Integrated 4A Gate Drivers
- Clock Output for 180° Out-of-Phase Operation for Second Driver
- -40°C to +125°C Operating Temperature Range
The MAX16821A/MAX16821B/MAX16821C pulse-width-modulation (PWM) LED driver controllers provide high output-current capability in a compact package with a minimum number of external components. The MAX16821A/MAX16821B/MAX16821C are suitable for use in synchronous and nonsynchronous step-down (buck), boost, buck-boost, SEPIC, and Cuk LED drivers. A logic input (MODE) allows the devices to switch between synchronous buck and boost modes of operation. These devices are the first high-power drivers designed specifically to accommodate common-anode HB LEDs.
The ICs offer average current-mode control that enable the use of MOSFETs with optimal charge and on-resistance figure of merit, thus minimizing the need for external heatsinking even when delivering up to 30A of LED current.
The differential sensing scheme provides accurate control of the LED current. The ICs operate from a 4.75V to 5.5V supply range with the internal regulator disabled (VCC connected to IN). These devices operate from a 7V to 28V input supply voltage with the internal regulator enabled.
The MAX16821A/MAX16821B/MAX16821C feature a clock output with 180° phase delay to control a second out-of-phase LED driver to reduce input and output filter capacitor size and to minimize ripple currents. The wide switching frequency range (125kHz to 1.5MHz) allows the use of small inductors and capacitors.
Additional features include programmable overvoltage protection and an output enable function.
- Front Projectors/Rear Projection TVs
- LCD TVs and Display Backlight
- Portable and Pocket Projectors
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)
The MAX16821B evaluation kit (EV kit) is a fully assembled and tested surface-mount printed-circuit board (PCB) designed to evaluate the MAX16821B pulse-width-modulation (PWM) LED driver controller in a boost configuration.
The MAX16821B EV kit operates from a DC supply voltage of 7V to 24V. The EV kit's output is configured to deliver 660mA of current into series LED string with a maximum forward voltage of 28V. The LED brightness can be dimmed using a digital PWM signal.
The EV kit provides an option to configure the MAX16821B IC's overvoltage protection, switching frequency, and frequency compensation. The MAX16821B EV kit also features a clock output PCB pad to drive a second LED current regulator out-of-phase.
Features & Benefits
- 7V to 24V Input-Voltage Range
- 660mA Output Current
- Pulse-Width-Modulated LED Current Dimming
- Resistor-Adjustable Overvoltage Protection and Switching Frequency
- Clock Output
- Fully Assembled and Tested
Documentation & Resources
MAX16821B Companion Parts
Recommended Related Parts
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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.