A6261
Automotive-grade linear LED driver with 60V input, 350mA output, and comprehensive fault protection for exterior ligh...
Product Overview
Description
The A6261 is a single-channel linear LED driver designed for automotive exterior lighting applications. The device drives high-brightness LEDs with constant current up to 350mA from input voltages up to 60V, making it suitable for 12V and 24V automotive systems.
The linear architecture provides low EMI and eliminates the need for inductors, simplifying design and reducing BOM cost. The device includes comprehensive protection features including LED open/short detection, overcurrent protection, and thermal shutdown. Fault conditions are reported via a dedicated status pin.
PWM dimming capability allows brightness control with consistent color temperature. The device maintains constant LED current during the on-time, ensuring uniform light output. The AEC-Q100 qualification and wide operating temperature range (-40°C to 150°C) ensure reliable operation in harsh automotive environments.
Product Series
A
Primary Application
Daytime running lights
Key Features
- Wide 6V to 60V input voltage range
- Up to 350mA constant current output
- Low EMI linear architecture
- PWM dimming up to 1kHz
- LED open and short detection
- Comprehensive fault protection
- AEC-Q100 Grade 0 qualified
- Compact SOIC-8 package
Specifications
| Input Voltage | 6V to 60V |
|---|---|
| Output Current | Up to 350mA |
| Number of Channels | 1 |
| Topology | Linear |
| Dimming | PWM up to 1kHz |
| Fault Detection | LED open/short, overcurrent, overtemperature |
| Protection | UVLO, overvoltage, thermal shutdown |
| Package | SOIC-8, MSOP-8 |
| Temperature Range | -40°C to +150°C |
Applications
Daytime running lights
Electronic system design
Turn signals
Sensor signal conditioning
Brake lights
Electronic system design
Side marker lights
Electronic system design
Interior lighting
Electronic system design
Dashboard backlighting
Electronic system design
FAE Expert Insights
"The A6261 is my preferred solution for automotive LED lighting up to 350mA. The linear architecture eliminates EMI concerns and the need for inductors, making it ideal for cost-sensitive exterior lighting applications. The 60V input range handles automotive load dump conditions without additional protection. I've successfully used it in taillight and turn signal applications where the simple design and robust protection are key advantages. Key design considerations: Calculate power dissipation at maximum input voltage; ensure adequate PCB copper area for heat sinking; implement proper PWM dimming frequency to avoid flicker. The fault detection features are comprehensive - open LED, short LED, and overtemperature are all detected and reported. For higher current requirements, consider the A6265 switching driver. The AEC-Q100 Grade 0 qualification provides confidence for harsh automotive environments."
Low EMI linear design; 60V input handles load dump; comprehensive fault detection; AEC-Q100 qualified
— Jennifer Liu, BeiLuo
Frequently Asked Questions
How do I set the LED current on A6261?
A6261 LED current setting procedure: Current set resistor - I_led = 1.2V / R_set; Where R_set is the external resistor value; 1.2V is the internal reference voltage. Resistor calculation: For 350mA: R_set = 1.2V / 0.35A = 3.43Ω; For 200mA: R_set = 1.2V / 0.2A = 6Ω; For 100mA: R_set = 1.2V / 0.1A = 12Ω. Resistor selection: Use 1% tolerance resistor for accurate current; Power rating: P = I² × R (e.g., 0.35² × 3.43 = 0.42W, use 1W resistor); Consider temperature coefficient for stability. Current accuracy: ±5% with 1% resistor; Includes variations in reference voltage and internal circuitry. Multiple LEDs: Connect LEDs in series for higher voltage; Total V_led must be < V_in - 2V (headroom for regulation); Parallel strings require separate drivers. PWM dimming: Current remains constant during on-time; Brightness controlled by duty cycle; No color shift with dimming.
Calculate R_set = 1.2V / I_led; use 1% resistor with adequate power rating; ensure V_in > V_led + 2V.
What input voltage range can A6261 handle?
A6261 input voltage capabilities: Operating range - 6V to 60V continuous operation; Supports 12V and 24V automotive systems; Handles load dump transients up to 60V. Automotive considerations: Nominal 12V: 9V to 16V typical operating; Load dump: Up to 60V for 400ms (ISO 16750-2); Jump start: 24V for 60 seconds; Cold crank: Down to 6V during engine start. LED voltage requirements: Minimum headroom: V_in must be > V_led + 2V; Typical LED forward voltage: 2.8-3.5V per LED; Example: 3 LEDs in series: V_led = 9.6V, V_in_min = 11.6V. Power dissipation: P = (V_in - V_led) × I_led; Higher V_in increases dissipation; Calculate worst-case at max V_in. Protection features: UVLO shuts down below 6V; Overvoltage protection above 60V; Thermal shutdown protects from overheating. The wide 6-60V range makes A6261 suitable for various automotive and industrial applications.
Handles 6V to 60V; suitable for 12V/24V automotive; ensure V_in > V_led + 2V for regulation.
How do I calculate the LED current set resistor?
Current calculation formula: I_led = V_ref / R_set, where V_ref is typically 1.2V. For 350mA: R_set = 1.2V / 0.35A = 3.43Ω. For 200mA: R_set = 1.2V / 0.2A = 6Ω. Use 1% tolerance resistor for accuracy. Power rating: P = I² × R (use 2× safety margin). Consider temperature coefficient for stability. Multiple LEDs in series reduce current requirements.
Calculate R = 1.2V / I; use 1% resistor with adequate power rating.
What is the maximum input voltage for automotive applications?
The driver handles 6V to 60V continuous operation. For automotive 12V systems: Normal operation 9-16V; Load dump transients up to 60V for 400ms; Jump start 24V for 60 seconds; Cold crank down to 6V. The wide range eliminates need for external protection. UVLO shuts down below 6V. Overvoltage protection above 60V.
60V max handles all automotive transients; no external protection needed.
How does the fault detection work?
Fault detection features: LED open detection identifies disconnected LED strings. LED short detection finds shorted LEDs. Overcurrent protection limits output current. Overtemperature protection reduces current or shuts down. Faults reported via status pin and SPI interface. Automatic retry for transient faults. Diagnostic information helps identify fault location.
All faults automatically detected and reported; use SPI for detailed diagnostics.