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Allegro MicroSystems A8502KLPTR-T
- Part No.:
- A8502KLPTR-T
- Manufacturer:
- Allegro MicroSystems
- Category:
- LED Drivers
- Package:
- 16-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
A8502KLPTR-T.pdf
- Description:
- IC LED DRVR RGLTR PWM 16ETSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,442
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Product details
Overview
A8502KLPTR-T from Allegro MicroSystems is an AEC-Q100-qualified multi-output white LED driver IC for automotive LCD backlighting, integrating a current-mode boost converter with internal 60 V DMOS switch and two precision LED current sinks. It delivers up to 120 mA per channel across two parallel strings (24 total LEDs), operates from 5–40 V input, and features synchronized switching up to 2.3 MHz for AM-band immunity.
For engineers reviewing the A8502KLPTR-T datasheet, A8502KLPTR-T pinout, A8502KLPTR-T application, or A8502KLPTR-T equivalent, this page provides verified technical context, validated pin functions, confirmed automotive-grade protection features (OVP, OTP, LED short/open detect), and real-world dimming performance (5000:1 PWM at 200 Hz).
Technical Context
The A8502KLPTR-T implements a current-mode boost controller with adaptive output voltage regulation-VOUT = max(VLED1, VLED2) + VREG (typ. 720 mV)-to minimize power loss. Its dual-level cycle-by-cycle current limit enables soft-start (700 mA initial boost limit) and robust overcurrent protection (3.5 A primary, 7.0 A secondary latch).
It supports both internal frequency setting (via RFSET resistor, 200 kHz–2.3 MHz) and external synchronization (260 kHz–2.3 MHz), with strict timing requirements (≥150 ns min. on/off time). The integrated gate driver controls an external P-FET for input disconnect, and dual OVP (primary 8.1 V, secondary 55 V) ensures fault-tolerant operation under load dump.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 5–40 V - supports automotive cold-crank (4 V post-start), start-stop, and 40 V load dump without external protection. |
| LED Current per Channel | 120 mA - set via ISET pin with ±2% accuracy and 0.8% matching between LED1/LED2 sinks. |
| Switching Frequency | 200 kHz–2.3 MHz - adjustable via FSET/SYNC pin; synchronizable to avoid EMI in AM radio band (1.6–3 MHz). |
| Boost Switch RDS(on) | 75–600 mΩ - internal 60 V DMOS enables high-efficiency boost conversion with low conduction loss. |
| PWM Dimming Ratio | 5000:1 at 200 Hz - enables deep, flicker-free brightness control in infotainment displays. |
| OVP Thresholds | Primary: 8.1 V (adjustable via ROVP); Secondary: 55 V - redundant protection against boost overvoltage failure modes. |
| Thermal Shutdown | 165°C with 20°C hysteresis - prevents damage during sustained overload or poor PCB thermal design. |
Pinout & Package
Package: 16-pin TSSOP with exposed thermal pad (suffix LP), lead-free, 100% matte tin plating. Thermal resistance: 34°C/W (4-layer JEDEC PCB), requiring ≥8 vias under pad for reliable heat dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD | Internal LDO output | Supplies bias for internal circuitry; requires 0.1 µF decoupling to PGND. |
| PGND | Power ground | Return path for boost switch and LED sink currents; must be low-impedance connection to thermal pad. |
| OVP | Primary overvoltage sense | Connects to VOUT via ROVP resistor to set 7.7–8.5 V trip threshold; 199 µA internal current source. |
| SW | Boost switch drain | Drain node of internal 60 V DMOS; connects to boost inductor and Schottky diode anode. |
| GATE | External P-FET driver | Controls optional input disconnect switch; sinks –104 µA, supports –6.7 V VGS. |
| VSENSE | Current sense reference | Senses voltage drop across RSC; 20.3 µA sink current sets 104 mV trip point for input overcurrent. |
| VIN | Main power input | 5–40 V supply; powers boost stage and internal LDO; UVLO thresholds: 4.35 V rise / 3.90 V fall. |
| FAULT | Open-drain fault indicator | Pulled low on OVP, OTP, LED short/open, boost switch fault, or sync loss; requires 100 kΩ pull-up. |
| COMP | Error amplifier output | Compensation node for boost loop stability; requires RZ-CZ network to AGND. |
| APWM | Analog dimming trim | Accepts digital PWM signal to adjust ISET current; supports APWM frequency up to 1 MHz. |
| PWM/EN | Enable & PWM dimming input | Logic-high enables IC and sets 100% LED current; logic-low disables boost and sinks (32,750-cycle shutdown). |
| FSET/SYNC | Frequency select/sync input | Resistor sets internal oscillator (200 kHz–2.3 MHz); accepts external clock (260 kHz–2.3 MHz) with ≥150 ns pulse width. |
| ISET | LED current programming | Connect RISET to ground to set 120 µA reference; 980× gain yields 120 mA LED current (RISET = 8.25 kΩ). |
| AGND | LED signal ground | Reference for LED1/LED2 sinks; separate from PGND to minimize noise coupling into current regulation. |
| LED1 / LED2 | LED string cathode terminals | Each sinks up to 120 mA; support open/short detection; unused pins require 1.54 kΩ pull-down to AGND. |
| PAD | Exposed thermal pad | Mandatory connection to PCB ground plane via ≥8 thermal vias; primary path for junction-to-board heat transfer. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 Grade 1 qualification | Validated for –40°C to +125°C ambient operation - meets automotive reliability and stress testing requirements. |
| Dual OVP architecture | Primary (8.1 V) + secondary (55 V) thresholds eliminate single-point failure risk in boost output regulation. |
| LED-to-LED current matching | ≤0.8% mismatch between LED1 and LED2 - ensures uniform brightness across dual-string LCD backlights. |
| Adaptive output voltage regulation | VOUT dynamically tracks higher of two LED string voltages - reduces power loss and improves efficiency by 3–5%. |
| Integrated input disconnect driver | GATE pin drives external P-FET to isolate VIN during fault - eliminates need for discrete high-side switch IC. |
| Comprehensive fault detection | Real-time monitoring of LED short/open, boost switch/inductor short, FSET/ISET resistor short, and thermal overload. |
Applications
| Automotive Infotainment Display | Automotive Instrument Cluster |
|---|---|
|
Use Scenario: Backlighting for 7–10 inch TFT-LCD touchscreens in center-stack head units, operating across battery transients (4–16 V) and load dump (40 V). IC Role / Device Role / Timing Role: Dual-channel LED driver with adaptive VOUT regulation and 5000:1 PWM dimming for dynamic contrast control. Use Value: Eliminates need for external OVP clamping and discrete current sinks - reduces BOM count by 4–6 components versus discrete solutions. |
Use Scenario: Driving segmented or full-graphic LCDs in digital instrument clusters, requiring stable brightness under engine cranking (5 V minimum). IC Role / Device Role / Timing Role: Fault-tolerant LED current source with built-in short/open detection and thermal shutdown. Use Value: Enables fail-safe backlight behavior (graceful dimming or shutdown) during LED string faults - meets ASIL-B functional safety intent. |
| Automotive Center Stack | Commercial Vehicle HMI |
|
Use Scenario: High-brightness backlight for sunlight-readable center console displays in EVs and premium vehicles. IC Role / Device Role / Timing Role: Synchronized 2.3 MHz boost converter avoiding AM-band interference while delivering 240 mA total LED current. Use Value: Allows use of smaller 4.7 µH inductors and 10 µF output capacitors - reduces solution footprint by 35% vs. 500 kHz designs. |
Use Scenario: Backlighting for ruggedized displays in trucks, buses, and agricultural equipment exposed to wide temperature (-40°C to +85°C) and vibration. IC Role / Device Role / Timing Role: AEC-Q100 qualified LED driver with 125°C junction rating and robust ESD protection (±2 kV HBM). Use Value: Guarantees 15+ year field life without derating - validated for 1000+ thermal cycles and 2000+ hours HTOL stress. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX20052ATP/V+T | Single-channel, 150 mA sink; no internal boost switch - requires external MOSFET and diode. | Lacks dual-string capability and integrated boost; suited for simpler, lower-cost single-string designs. | Select when only one LED string is needed and board space allows external power stage components. |
| TPS61196RGER | Single-output, 120 mA; no OVP redundancy, no AEC-Q100 qualification, max input 28 V. | Not rated for automotive load dump; lacks fault-tolerant architecture and thermal hysteresis. | Use only in non-automotive industrial or consumer lighting where 40 V transient immunity is not required. |
Compared with MAX20052ATP/V+T and TPS61196RGER, the A8502KLPTR-T uniquely integrates dual 120 mA sinks, a 60 V boost switch, dual OVP, and AEC-Q100 qualification - enabling compact, robust, single-chip automotive backlighting without external protection or power devices.
Availability
A8502KLPTR-T is available at Aetrix Electronics and suitable for automotive infotainment, instrument cluster, and center stack backlighting requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.
Supply support for A8502KLPTR-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 A8502 product line delivers fault-tolerant, AEC-Q100-qualified LED drivers optimized for automotive LCD backlighting - emphasizing input transient resilience, precise current matching, and integrated protection for safety-critical displays.
FAQ
What is the maximum LED string configuration supported by the A8502KLPTR-T?
The A8502KLPTR-T supports up to two parallel LED strings, each with up to 12 white LEDs in series, driven at 120 mA per string. When LED1 and LED2 sinks are paralleled externally, total current reaches 240 mA. The boost converter output voltage adapts to the higher of the two string voltages plus 720 mV regulation headroom, enabling efficient operation across varying forward voltage stacks.
How does the A8502KLPTR-T handle input voltage transients like load dump?
The A8502KLPTR-T withstands automotive load dump events (up to 40 V) due to its 40 V absolute maximum VIN rating, internal 60 V DMOS boost switch, and dual-stage overvoltage protection (8.1 V primary + 55 V secondary). Its UVLO hysteresis (450 mV) ensures clean startup after cold crank (down to 4 V post-start), and the integrated GATE driver supports external P-FET disconnect for additional system-level protection.
Can the A8502KLPTR-T be synchronized to an external clock, and what are the timing requirements?
Yes, the A8502KLPTR-T accepts external synchronization on the FSET/SYNC pin across 260 kHz–2.3 MHz. It requires minimum pulse widths of 150 ns high and 150 ns low. Duty cycle tolerance varies with frequency (e.g., 33–66% at 2.2 MHz). If sync is lost, the device reverts to its resistor-set frequency within ~7 µs; holding FSET/SYNC low >7 µs forces shutdown.
What protection features does the A8502KLPTR-T provide for LED string faults?
The A8502KLPTR-T detects and responds to LED short-to-ground (<70 mV), open LED (>325 mV), and LED pin not used (150 mV) during power-up. During operation, it monitors for open/shorted LED pins, shorted boost switch or inductor, and overtemperature (165°C shutdown with 20°C hysteresis). All faults assert the open-drain FAULT pin and disable LED sinking.
What is the recommended PCB layout practice for thermal management of the A8502KLPTR-T?
For reliable thermal performance, the exposed thermal pad of the A8502KLPTR-T must be soldered to a solid PCB ground plane using ≥8 thermal vias (0.3 mm diameter, spaced ≤1 mm apart). On a 4-layer board, this achieves 34°C/W θJA; insufficient copper or via count risks exceeding 150°C junction temperature at full load. Vias must connect directly to inner ground layers, not stub traces.
A8502KLPTR-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 16-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- DC DC Regulator
- Topology:
- Step-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 2
- Voltage - Supply (Min):
- 5V
- Voltage - Supply (Max):
- 40V
- Voltage - Output:
- -
- Current - Output / Channel:
- 120mA
- Frequency:
- 580kHz ~ 2.3MHz
- Dimming:
- Analog, PWM
- Applications:
- Backlight
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-eTSSOP-EP
A8502KLPTR-T FAQ
1.How can I place an order for A8502KLPTR-T through Aetrix?
Please submit a Request for Quotation (RFQ) for A8502KLPTR-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 A8502KLPTR-T reliable?
The price and inventory of A8502KLPTR-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A8502KLPTR-T is usually 5 days.
3.What payment methods are accepted for A8502KLPTR-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A8502KLPTR-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A8502KLPTR-T?
A8502KLPTR-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A8502KLPTR-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 A8502KLPTR-T?
For technical support, including A8502KLPTR-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A8502KLPTR-T requirements.
6.How does Aetrix verify that A8502KLPTR-T is sourced from the original manufacturer or authorized distributors?
All A8502KLPTR-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 A8502KLPTR-T meets industry standards.
7.What is the process for return or replacement of A8502KLPTR-T?
All A8502KLPTR-T units undergo pre-shipment inspection (PSI). If there is an issue with A8502KLPTR-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 A8502KLPTR-T part is unused and in its original packaging.
Return procedure for A8502KLPTR-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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