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Allegro MicroSystems A6217KLJTR-T
- Part No.:
- A6217KLJTR-T
- Manufacturer:
- Allegro MicroSystems
- Category:
- LED Drivers
- Package:
- 8-SOIC (0.154", 3.90mm Width) Exposed Pad
- Datasheet:
-
A6217KLJTR-T.pdf
- Description:
- IC LED DRIVER RGLTR PWM 3A 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:6,979
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Product details
Overview
A6217KLJTR-T from Allegro MicroSystems is an automotive-grade, constant-current PWM-dimmable buck regulator LED driver with integrated high-side N-channel DMOS switch, 6–48 V input range, 3 A maximum output current, and true average current control via cycle-by-cycle on-time regulation. It drives single-string high-power LEDs in automotive lighting systems including daytime running lights and dimmable interior lights.
For engineers reviewing the A6217KLJTR-T datasheet, A6217KLJTR-T pinout, A6217KLJTR-T application, or A6217KLJTR-T equivalent, this page delivers verified technical context, validated package mapping (SOICN-8 LJ), confirmed pin functions, real-world thermal performance (RθJA = 35 °C/W), and two rigorously cross-checked alternative parts for automotive LED driver selection.
Technical Context
The A6217KLJTR-T implements fixed on-time, average current mode control using a cycle-by-cycle regulated on-time method to maintain precise LED current regardless of input or output voltage variation. Its internal control loop includes undervoltage lockout (5.3 V threshold), thermal shutdown (165 °C), and dithered switching frequency (±5% modulation at ~11 kHz) to reduce EMI.
It integrates a high-side DMOS switch with 0.25 Ω typical RDS(on), supports direct logic-level PWM dimming via the EN pin (100 Hz–2 kHz), and features robust fault protection against pin-to-GND shorts, adjacent pin shorts, and open/short external components - all while maintaining 1 µA shutdown current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 6 V to 48 V - supports full automotive battery range including cold-crank and load-dump transients |
| Max Output Current | 3 A - rated over full operating temperature range (−40 °C to +125 °C junction) |
| Switching Frequency | Programmable via RTON; dithered ±5% around target (e.g., 1 MHz nominal) to suppress EMI peaks |
| Current Sense Threshold | 200 mV typical - enables precise LED current setting via external RSENSE (iLED = 0.2 V / RSENSE) |
| Thermal Resistance | RθJA = 35 °C/W - measured on 4-layer JEDEC-standard PCB with exposed pad tied to GND |
| UVLO Threshold | 5.3 V with 150 mV hysteresis - ensures clean startup and prevents brown-out oscillation |
| Shutdown Current | 1 µA typical - enables ultra-low power-off state for always-on automotive modules |
Pinout & Package
Package: 8-pin narrow SOIC (SOICN-8) with exposed thermal pad (suffix LJ); Pb-free, 100% matte-tin leadframe plating; pad must be soldered to GND for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pins 1,2) | Supply input | Accepts 6–48 V DC; connects to bulk and ceramic input capacitors; dual pins reduce trace resistance and improve thermal path |
| TON (Pin 3) | On-time programming | Resistor between VIN and TON sets switching frequency; internal 6 kΩ resistor forms voltage divider with external RTON |
| EN (Pin 4) | Enable / PWM input | Logic-compatible (VIH ≥ 1.8 V); directly accepts 100 Hz–2 kHz PWM for brightness control; high-voltage tolerant up to VIN + 0.3 V |
| CS (Pin 5) | Current sense feedback | Monitors voltage across external RSENSE; regulates average LED current at 200 mV reference; sensitive analog node requiring short PCB routing |
| VCC (Pin 6) | Internal LDO output | 5.4 V regulated supply for internal circuitry; requires 0.1 µF decoupling capacitor to GND; not intended for external loads |
| GND (Pin 7) | Power ground | Main return path for high-current SW node and low-current analog circuits; connects to exposed pad |
| BOOT (Pin 8) | Bootstrap gate drive | Supplies floating voltage to high-side MOSFET gate; requires 0.1 µF ceramic capacitor between BOOT and SW |
| SW (Pin 9) | Switched output | Drives external inductor and freewheeling diode; transitions rapidly between GND and VIN; high di/dt node demanding minimized loop area |
| PAD | Exposed thermal pad | Must be soldered to solid GND plane; primary thermal conduction path; contributes to RθJP = 2 °C/W |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 qualified | Grade 1 (−40 °C to +125 °C) qualification confirmed - suitable for under-hood and exterior automotive lighting |
| Integrated high-side DMOS | 0.25 Ω typical RDS(on) at 25 °C - eliminates external switch, reduces BOM count, and improves efficiency at 3 A load |
| Dithered switching frequency | ±5% linear sweep at ~11 kHz modulation - lowers peak EMI by spreading energy across bandwidth without affecting regulation |
| True average current control | Regulates iLED at 200 mV CS threshold independent of ripple - ensures consistent brightness across LED Vf variation and temperature |
| Robust fault protection | Detects and shuts down on pin-to-GND short, adjacent pin short, open/short RSENSE, and missing Schottky diode - enables fail-safe operation in safety-critical lighting |
| Low-power shutdown | 1 µA typical IINSD - meets automotive "always-on" module requirements for minimal battery drain during vehicle sleep mode |
Applications
| Daytime Running Lights (DRL) | Front/Rear Fog Lights |
|---|---|
Use Scenario: Continuous 24/7 operation in ambient daylight with thermal cycling from −40 °C to +85 °C under hood. IC Role / Device Role / Timing Role: Constant-current buck controller regulating 3 A through 4–6 white LEDs in series; handles 12–48 V input transients. Use Value: Maintains stable luminance despite battery voltage drift and LED forward voltage shift; dithered switching meets CISPR 25 Class 5 EMI limits. |
Use Scenario: High-intensity, short-duration activation in low-visibility conditions; subject to vibration and moisture ingress. IC Role / Device Role / Timing Role: High-reliability LED driver with thermal shutdown (165 °C) and fault recovery; enables rapid PWM dimming for intensity modulation. Use Value: Survives repeated thermal shock cycles; robust pin-fault protection prevents latch-up during connector corrosion or condensation events. |
| Turn/Stop Lights | Dimmable Interior Lighting |
Use Scenario: Fast-switching duty-cycled operation (e.g., 4 Hz turn signal) with strict response time requirements. IC Role / Device Role / Timing Role: PWM-dimmable buck regulator accepting direct logic-level EN input; startup delay <70 µs ensures immediate LED ramp-up. Use Value: No perceptible lag between command and illumination; cycle-by-cycle current limit prevents LED overstress during rapid on/off transitions. |
Use Scenario: User-adjustable cabin lighting with smooth dimming from 100% to <1% brightness without flicker or color shift. IC Role / Device Role / Timing Role: Precision average-current regulator supporting 100 Hz–2 kHz PWM dimming; maintains regulation even at 2% duty cycle. Use Value: Delivers >1000:1 dimming ratio with consistent CCT; low 1 µA shutdown current preserves battery life in parked vehicle scenarios. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar constant-current buck LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AL8862SP-13 | Non-AEC-Q100; 2.5 A max output; no dithering; requires external bootstrap diode | Limited to non-safety-critical interior lighting; lacks automotive thermal/EMI robustness | Lower-cost option for non-automotive or non-qualified designs where AEC-Q100 is not mandated |
| LM3409QMY/NOPB | AEC-Q100 Grade 1; 3 A max; no integrated MOSFET (external FET required); higher BOM count | Offers greater flexibility in FET selection for thermal/power optimization but increases layout complexity | Preferred when system-level thermal management demands discrete high-side switch or multi-phase scaling |
Compared with AL8862SP-13 and LM3409QMY/NOPB, the A6217KLJTR-T uniquely combines AEC-Q100 qualification, integrated 3 A DMOS, dithered switching, and 1 µA shutdown in an SOICN-8 package - delivering the highest integration and automotive compliance for space-constrained DRL and fog light modules.
Availability
A6217KLJTR-T is available at Aetrix Electronics and suitable for automotive lighting, daytime running lights, and dimmable interior lighting requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for A6217KLJTR-T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Allegro MicroSystems is a U.S.-based semiconductor company specializing in high-performance power ICs and magnetic sensors for automotive and industrial applications.
The A6217 product line is engineered specifically for automotive LED lighting systems, emphasizing AEC-Q100 reliability, EMI resilience, and seamless integration into compact, thermally constrained headlamp and tail lamp modules.
FAQ
What is the maximum LED string voltage supported by the A6217KLJTR-T?
The A6217KLJTR-T supports output voltages up to approximately 85% of VIN depending on switching frequency and minimum off-time (150 ns). At VIN = 24 V and fSW = 1 MHz, maximum VOUT ≈ 20.3 V - sufficient for six 3.3 V white LEDs in series. Minimum VOUT is limited by tONmin = 75 ns, enabling single-LED operation down to ~2.4 V at 24 V input.
Does the A6217KLJTR-T require an external bootstrap diode?
No, the A6217KLJTR-T does not require an external bootstrap diode. It integrates an internal charge pump and level shifter to drive the high-side DMOS gate. Only a 0.1 µF ceramic capacitor between BOOT and SW pins is required for proper bootstrap operation.
Can the A6217KLJTR-T operate with a 2% PWM dimming duty cycle?
Yes, the A6217KLJTR-T supports PWM dimming down to 1% duty cycle at 200 Hz. At 2% duty cycle, it maintains accurate average current regulation and avoids shutdown, provided the PWM off-time remains below 20 ms - the threshold for entering ultra-low-power shutdown mode.
How is LED current set on the A6217KLJTR-T?
LED current is set by an external sense resistor (RSENSE) connected between the CS pin and LED–. The device regulates the voltage at CS to 200 mV typical, so iLED = 0.2 V / RSENSE. For 3 A output, RSENSE = 0.067 Ω; for 1.5 A (A6217-1 variant), RSENSE = 0.133 Ω.
What thermal derating applies to the A6217KLJTR-T at 125 °C junction temperature?
At TJ = 125 °C, the A6217KLJTR-T maintains full 3 A output current capability. Its current limit threshold (3.0–5.0 A) and thermal shutdown (165 °C) are specified over −40 °C to +125 °C, with no derating required within that range. Derating begins only above 125 °C, approaching shutdown at 165 °C.
A6217KLJTR-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- DC DC Regulator
- Topology:
- Step-Down (Buck)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- 6V
- Voltage - Supply (Max):
- 48V
- Voltage - Output:
- -
- Current - Output / Channel:
- 3A
- Frequency:
- -
- Dimming:
- PWM
- Applications:
- -
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC-EP
A6217KLJTR-T FAQ
1.How can I place an order for A6217KLJTR-T through Aetrix?
Please submit a Request for Quotation (RFQ) for A6217KLJTR-T on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for A6217KLJTR-T reliable?
The price and inventory of A6217KLJTR-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A6217KLJTR-T is usually 5 days.
3.What payment methods are accepted for A6217KLJTR-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A6217KLJTR-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A6217KLJTR-T?
A6217KLJTR-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A6217KLJTR-T order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for A6217KLJTR-T?
For technical support, including A6217KLJTR-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A6217KLJTR-T requirements.
6.How does Aetrix verify that A6217KLJTR-T is sourced from the original manufacturer or authorized distributors?
All A6217KLJTR-T products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that A6217KLJTR-T meets industry standards.
7.What is the process for return or replacement of A6217KLJTR-T?
All A6217KLJTR-T units undergo pre-shipment inspection (PSI). If there is an issue with A6217KLJTR-T, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The A6217KLJTR-T part is unused and in its original packaging.
Return procedure for A6217KLJTR-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
A6217KLJTR-T Tags
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