LED headlamp — key device selection
Engineering problem
A headlamp module drives multiple LED strings from a noisy vehicle supply: current regulation must stay stable across temperature and input variation, thermal foldback must protect the LEDs, and the whole driver fits in a sealed lamp housing.
System block diagram
Block list (text version)
- Input protection TVS / ESD protection
- Control Automotive MCU
- Power conversion Buck / boost LED driver, LDO
- Power stage MOSFET
- LED LED string (load)
Input protection
Why this device： Lamp connectors are the most exposed points on the vehicle harness.
How to choose： Stand-off above jump-start voltage, clamping below the driver IC maximum, and pulse energy matched to ISO 7637-2.
| Part number | Brand | Category | Package | Qualification | Operating temperature | Key parameters | Docs | Actions |
|---|---|---|---|---|---|---|---|---|
| 1SMB30CAT3G In stock | onsemi | TVS Diodes | SMB | AEC-Q101 qualified | -55 °C ~ +150 °C | vrwm: 30 V · ppp: 600 W · direction: Uni-directional | Datasheet ↗ | |
| 1.5KE24CA-TP | MCC | Transient Voltage Suppressor | — | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| 1.5KE250A-TP In stock | MCC | TVS Diodes | DO-201AE | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| 1.5KE480A | WAYON | Transient Voltage Suppressor | — | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| 1.5SMC33CA | LITTLEFUSE | Transient Voltage Suppressor | — | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| 1.5SMC6.8CA In stock | Littelfuse | TVS Diodes | SMC | Qualification to be verified | To be confirmed | To be confirmed | To be confirmed |
Control
Why this device： Handles dimming curves, thermal foldback, diagnostics and LIN/CAN communication with the body module.
How to choose： PWM channel count and resolution, ADC inputs for NTC sensing, and the temperature grade for lamp-housing mounting.
| Part number | Brand | Category | Package | Qualification | Operating temperature | Key parameters | Docs | Actions |
|---|---|---|---|---|---|---|---|---|
| MKE04Z8VWJ4 In stock | NXP | Microcontrollers (MCU) | SOIC-20 | AEC-Q100 Grade 1 qualified | -40 °C ~ +125 °C | core: Arm Cortex-M0+ · freq: 48 MHz · flash: 8 KB | Datasheet ↗ | |
| ATMEGA32A-AU In stock | Microchip | Microcontrollers (MCU) | TQFP-44 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| ATSAM4S2AA-MU In stock | Microchip | Microcontrollers (MCU) | QFN-48 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| BS83A01C In stock | Holtek | Microcontrollers (MCU) | SOT-23-6 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| HT66F002/MSOP10 In stock | Holtek | Microcontrollers (MCU) | MSOP-10 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| MM32F0010A1N In stock | MindMotion | MCU (Value Line) | QFN-20 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ |
Power conversion
Why this device： Converts battery voltage to the LED string voltage with regulated current.
How to choose： Match topology to the string voltage vs. battery window, then check dimming range, EMI behaviour and spread-spectrum options.
| Part number | Brand | Category | Package | Qualification | Operating temperature | Key parameters | Docs | Actions |
|---|---|---|---|---|---|---|---|---|
| ADP1755ACPZ-R7 In stock | ADI | LDO Linear Regulators | LFCSP-16 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| AMS1117-3.3 In stock | ams | LDO Linear Regulators | SOT-223 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| AMS1117-ADJ In stock | ams | LDO Linear Regulators | TO-263 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| AP2962B In stock | Chipown | DC-DC Converters (Synchronous Buck) | SOP-8 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| APS2406-ADJ In stock | Chipown | DC-DC Converters (Synchronous Buck) | SOT23 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| APS2420 In stock | Chipown | DC-DC Converters (Synchronous Buck) | SOP8 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ |
Power stage
Why this device： Switching element of the LED driver and of matrix-beam channel selection.
How to choose： Voltage rating plus RDS(on) at temperature; low gate charge helps keep the driver efficient at high dimming frequency.
| Part number | Brand | Category | Package | Qualification | Operating temperature | Key parameters | Docs | Actions |
|---|---|---|---|---|---|---|---|---|
| BSC026N02KSGAUMA1 In stock | Infineon | OptiMOS Low-Voltage MOSFETs | SC026 | AEC-Q101 qualified | -55 °C ~ +150 °C | channel: N · vds: 25 V · id: 100 A | Datasheet ↗ | |
| 2N7002-TP In stock | MCC | Small-Signal MOSFETs | SOT-23 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| 2N7002DW-TP In stock | MCC | Small-Signal MOSFETs | SOT-363 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| 2N7002E-7-F In stock | Diodes | Small-Signal N-Channel MOSFETs | SOT-23 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| 2N7002K-TP In stock | MCC | Small-Signal MOSFETs | SOT-23 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| 2N7002KDQ-TP In stock | MCC | Small-Signal MOSFETs | SOT-23 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ |
Data storage
Why this device： Stores calibration, binning data and accumulated operating hours.
How to choose： Small density is usually enough; verify endurance at the lamp's operating temperature.
| Part number | Brand | Category | Package | Qualification | Operating temperature | Key parameters | Docs | Actions |
|---|---|---|---|---|---|---|---|---|
| AT24C64D-SSHM-T In stock | Microchip | Memory (EEPROM/Flash) | SOIC-8 | AEC-Q100 Grade 1 qualified | -40 °C ~ +125 °C | density: 64 Kbit · iface: I²C · vcc: 1.7 ~ 5.5 V | Datasheet ↗ | |
| 24LC256-I/SM In stock | Microchip | Memory (EEPROM/Flash) | DFN | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| AT24C02C-SSHM-T In stock | Microchip | Memory (EEPROM/Flash) | SOT23 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| AT24CM01-SSHD-T In stock | Microchip | Memory (EEPROM/Flash) | SOIC-8 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| AT93C46DN-SH-T In stock | Microchip | Memory (EEPROM/Flash) | SOIC-8 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ | |
| DS1624S+ In stock | ADI | Digital Temperature Sensors (with EEPROM) | SOIC-8 | Qualification to be verified | To be confirmed | To be confirmed | Datasheet ↗ |
Key selection parameters
| Input voltage | 12 V (9–16 V, jump start up to 26 V) |
| String voltage / current | Set by LED binning and channel count |
| Dimming method | PWM / analogue, 100:1 or wider |
| Housing temperature | Sealed lamp housing, high ambient |
FAQ
Why does thermal foldback matter?
LED junction temperature drives lumen maintenance and colour shift. Foldback trades a little brightness for a much longer service life.
Project inquiry
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We normally reply within one business day; urgent requests are escalated the same day.
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