2MHz, High-Brightness LED Drivers with Integrated MOSFET and High-Side Current Sense

 

Part Number	Replacement	Explanation

Description

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The MAX16832A/MAX16832C step-down constant-current high-brightness LED (HB LED) drivers provide a cost-effective design solution for automotive interior/exterior lighting, architectural and ambient lighting, LED bulbs, and other LED illumination applications.

The MAX16832A/MAX16832C operate from a +6.5V to +65V input voltage range and can provide an output current up to 700mA, if operated up to a temperature of +125°C, or up to a 1A if operated up to a temperature of +105°C. A high-side current-sense resistor adjusts the output current, and a dedicated pulse-width modulation (PWM) input enables pulsed LED dimming over a wide range of brightness levels.

These devices are well suited for applications requiring a wide input voltage range. The high-side current sensing and an integrated current-setting circuitry minimize the number of external components while delivering an average output current with ±3% accuracy. A hysteretic control method ensures excellent input supply rejection and fast response during load transients and PWM dimming. The MAX16832A allows 10% current ripple, and the MAX16832C allows 30% current ripple. Both devices operate up to a 2MHz switching frequency, thus allowing the use of small-sized components.

The MAX16832A/MAX16832C offer an analog dimming feature that reduces the output current by applying an external DC voltage below the internal 2V threshold voltage from TEMP_I to GND. TEMP_I also sources 25µA to a negative temperature coefficient (NTC) thermistor connected between TEMP_I and GND, thus providing an analog thermal-foldback feature that reduces the LED current when the temperature of the LED string exceeds a specified temperature point. Additional features include thermal-shutdown protection.

The MAX16832A/MAX16832C operate over the -40°C to +125°C automotive temperature range and are available in a thermally enhanced 8-pin SO package.

MAX16832A, MAX16832C: Typical Application Circuit Enlarge+

Key Features

• Cost-Effective Solution for a Wide Range of LED Lighting Applications
  • 6.5V to 65V Input Voltage Range
  • Output Current Up to 1A
  • ±3% LED Current Accuracy
  • Selectable Dimming Options: Linear or PWM
• Minimal Component Count Saves Cost and Space
  • On-Board 65V, 0.45Ω Power MOSFET
  • Resistor-Programmable Constant LED Current
  • Integrated High-Side Current Sense with 200mV Current-Sense Reference
  • Hysteretic Control: Up to 2MHz Switching Frequency
• Protection Features and Wide Operating Temperature Range Improves Lighting Fixture Reliability
  • Thermal-Foldback Protection Dims LEDs to Minimize Overheating
  • Thermal-Shutdown Protection
  • Available in a Thermally Enhanced 8-Pin SO Package
  • Operation over -40°C to +125°C Temperature Range

Applications/Uses

• Architectural, Industrial, and Ambient Lighting
• Automotive RCL, DRL, and Fog Lights
• Heads-Up Displays
• Indicator and Emergency Lighting
• MR16 and MR111 LED Lights