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Allegro MicroSystems A8511KLPTR-T
- Part No.:
- A8511KLPTR-T
- Manufacturer:
- Allegro MicroSystems
- Category:
- LED Drivers
- Package:
- 28-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
A8511KLPTR-T.pdf
- Description:
- IC LED DRVR RGLTR PWM 28TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,512
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Product details
Overview
A8511KLPTR-T from Allegro MicroSystems is a discontinued 4-channel WLED/RGB backlight driver IC with integrated 40 V/3.6 A boost DMOS switch, four 150 mA current sinks, 2 MHz constant-frequency current-mode boost converter, and output disconnect protection. It operates from 6.8–21 V input, supports 4000:1 dimming, and targets automotive LCD backlighting in infotainment and cluster displays.
For engineers reviewing the A8511KLPTR-T datasheet, A8511KLPTR-T pinout, A8511KLPTR-T application, or A8511KLPTR-T equivalent, this page delivers verified technical context, validated pin functions, confirmed thermal and protection behavior, and two documented alternative parts for legacy design continuity and repair sourcing.
Technical Context
The A8511KLPTR-T implements a current-mode boost converter with externally adjustable switching frequency (600 kHz–2.2 MHz via RFSET), integrated 40 V DMOS switch with pulse-by-pulse current limiting (3.6 A typ), and OVP–load-dump protection. Its four matched LED current sinks provide 0.7% accuracy and 0.8% matching across –40°C to +125°C.
It features true output disconnect via an integrated switch (RODS(on) = 2 Ω typ at 125°C), open/short LED fault detection with latched shutdown, external thermistor-based thermal derating via VTI, and triple dimming modes: EN-pin PWM (100–300 Hz optimal), DIM-pin analog (4:1), and VTI-pin analog control.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| LED Sink Current | 150 mA per channel (600 mA total when paralleled); enables uniform brightness across 4 LED strings |
| Boost Switch Rating | 40 V / 3.6 A DMOS; withstands load-dump transients up to 40 V and supports high-efficiency medium-power backlighting |
| Switching Frequency | 2 MHz (set by 24.3 kΩ RFSET); avoids AM radio band interference and allows compact external magnetics |
| Dimming Range | 4000:1 total (1000:1 via EN-PWM + 4:1 via DIM pin); meets automotive display contrast and ambient light adaptation requirements |
| Thermal Range | –40°C to +125°C (K-grade); qualified for under-hood and instrument cluster environments |
| OVP Threshold | Default 19.5 V, adjustable up to 38 V via ROVP resistor; protects against overvoltage during open-LED faults or Schottky failure |
| Shutdown Current | 3.5 µA max at –40°C to +125°C; minimizes battery drain in always-on automotive systems |
Pinout & Package
Supplied in a 28-pin TSSOP package (suffix LP) with exposed thermal pad for enhanced heat dissipation; Pb-free, 100% matte-tin leadframe plating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| LED1–LED4 | Current sink outputs | Each sinks up to 150 mA; internally matched for ≤0.8% current mismatch across temperature |
| SW (pins 4–6) | Boost switch drain node | Three pins tied together on PCB; connect to boost inductor; rated 40 V/3.6 A |
| OUT (pin 18) | Output disconnect switch source | Connects to common cathode of LED strings; opens during overcurrent or fault to isolate load |
| CAP (pin 8) | Disconnect switch gate control | Input to internal disconnect FET; connects to OVP resistor network for overvoltage sensing |
| ISET (pin 10) | LED current reference input | Set 100% current via RISET resistor (e.g., 7.87 kΩ → 156 µA → 150 mA per string) |
| DIM (pin 3) | Analog dimming select | VIL = 100% current gain (960×), VIH = 25% gain (240×); enables 4:1 analog dimming without PWM |
| EN (pin 28) | Enable & PWM input | Logic-level PWM control (100–300 Hz optimal); low >65 ms triggers shutdown and fault reset |
| FSET (pin 19) | Frequency set input | RFSET to AGND sets fSW = 51 / RFSET (MHz); 24.3 kΩ → 2.1 MHz typical |
| VTI (pin 11) | Thermal derating input | Accepts external NTC voltage; reduces LED current linearly as panel temperature rises |
| VTO (pin 12) | 2.46 V reference output | Stable reference for NTC biasing or logic-level signaling; drives SEL/DIM inputs directly |
Key Features
| Feature | Design Value |
|---|---|
| Integrated output disconnect switch | RODS(on) = 2 Ω typ at 125°C; isolates LED strings during short-circuit or overcurrent faults to prevent damage |
| Active current sharing | 0.8% matching and 0.7% accuracy across all 4 channels; ensures consistent luminance in multi-string displays |
| Triple dimming architecture | PWM (EN), analog (DIM), and analog thermal (VTI) - enables simultaneous brightness + temperature compensation |
| Comprehensive fault protection | Open/short LED detect, OVP (adjustable), OTP (172°C typ), UVLO/OVLO, SW overcurrent, and open-Schottky detection |
| Single-supply operation | Internal 6 V BIAS supply (pin 1); eliminates need for external LDO; supports VIN = 6.8–21 V range |
Applications
| Automotive Instrument Cluster Backlighting | Infotainment Display Backlighting |
|---|---|
Use Scenario: Driving 4 parallel LED strings behind TFT LCD in vehicle dashboard with wide ambient temperature variation (–40°C to +125°C). IC Role / Device Role / Timing Role: WLED driver with integrated boost, current regulation, and output disconnect; provides stable current despite battery voltage fluctuations and load transients. Use Value: Eliminates need for external MOSFETs and discrete protection circuitry; 4000:1 dimming meets daylight-to-nighttime readability requirements. |
Use Scenario: Backlighting for 7–10 inch center-stack LCD in automotive infotainment system with PWM-controlled brightness and thermal derating. IC Role / Device Role / Timing Role: RGB/WLED driver with VTI-based analog thermal control and EN-pin PWM dimming synchronized to display frame rate. Use Value: Prevents LED thermal runaway at high ambient temperatures; 2 MHz switching enables compact layout and EMI compliance. |
| Backup Camera Display Module | Industrial LCD Panel Backlight |
Use Scenario: Compact rear-view camera display in vehicles requiring fast startup, robust fault handling, and reverse-polarity tolerance. IC Role / Device Role / Timing Role: Fault-resilient LED driver with open/short LED detection, latched shutdown, and soft-start to avoid inrush current. Use Value: Ensures display remains functional after single-LED failure; output disconnect prevents damage during connector shorts. |
Use Scenario: Backlight for industrial HMI panels operating continuously in factory environments with elevated ambient temperature. IC Role / Device Role / Timing Role: High-accuracy current sink driver with 0.7% LED current accuracy and thermal derating via external NTC. Use Value: Maintains consistent brightness over time and temperature; extended lifetime due to reduced thermal stress on LEDs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar WLED/RGB backlight driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AL8863Q-7 | 4-channel, 120 mA/channel, 2.5 MHz fixed-frequency boost; no integrated output disconnect switch; requires external OVP | Lacks true output disconnect and open-LED lockout; suitable only where fault isolation is handled externally | Use if board space permits external protection and thermal range requirement is ≤105°C (Q-grade) |
| MAX20057ATG/V+T | 4-channel, 150 mA/channel, 2.2 MHz boost; includes output disconnect and OVP; but rated only to +105°C (T-grade) | Same functional scope but narrower temperature range; no VTI-based thermal derating capability | Select for new designs needing active lifecycle support; not suitable for 125°C cluster applications |
Compared with A8511KLPTR-T, AL8863Q-7 lacks integrated fault isolation and thermal derating, while MAX20057ATG/V+T offers full feature parity except for extended temperature rating and VTI flexibility - making it viable only in non-cluster automotive roles.
Availability
A8511KLPTR-T is available at Aetrix Electronics and suitable for automotive instrument cluster backlighting, infotainment display modules, and industrial LCD panels requiring stable component supply for repair, legacy production, and obsolescence mitigation.
Supply support for A8511KLPTR-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 designer of high-performance power ICs and magnetic sensors, specializing in automotive-grade analog and mixed-signal solutions.
The A8511 product line was engineered specifically for high-brightness LED backlighting in automotive displays, integrating boost conversion, precision current regulation, and comprehensive fault protection into a single surface-mount package.
FAQ
What is the operating temperature range for the A8511KLPTR-T?
The A8511KLPTR-T is rated for –40°C to +125°C ambient operation (K-grade), validated across full electrical specifications. This makes it suitable for under-hood and instrument cluster applications where junction temperatures may reach 150°C. The thermal shutdown threshold is 172°C typical, with 20°C hysteresis.
Does the A8511KLPTR-T support true output disconnect, and how does it work?
Yes, the A8511KLPTR-T integrates a dedicated output disconnect switch between CAP and OUT pins. When overcurrent (>1.35 A) or overvoltage is detected, the switch opens to physically isolate the LED strings from the boost output, preventing damage during shorts or open-circuit faults. RODS(on) is 2 Ω typical at 125°C.
How is LED current set and trimmed on the A8511KLPTR-T?
LED current is set via RISET resistor on the ISET pin: IISET = 1.235 V / RISET (mA/kΩ). With DIM = VIL, gain = 960× → ILED = IISET × 960. For 150 mA per string, use RISET = 7.87 kΩ. Accuracy is 0.7% and matching is 0.8% across all four channels over temperature.
Can the A8511KLPTR-T be used in new designs, and what is its status?
No - the A8511KLPTR-T is officially discontinued by Allegro MicroSystems as of July 1, 2024. It is not recommended for new designs. Samples are no longer available. Aetrix Electronics supplies remaining inventory for legacy repair, maintenance, and obsolescence management under controlled allocation.
What dimming methods does the A8511KLPTR-T support, and what are their ranges?
The A8511KLPTR-T supports three independent dimming methods: (1) EN-pin PWM (100–300 Hz optimal, 1000:1 range), (2) DIM-pin analog (4:1 range via gain switching), and (3) VTI-pin analog (continuous 0–100% via external voltage). Combined, they deliver up to 4000:1 total dimming ratio.
A8511KLPTR-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Allegro MicroSystems
- Series:
- -
- Package/Case:
- 28-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- DC DC Regulator
- Topology:
- Step-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 4
- Voltage - Supply (Min):
- 8V
- Voltage - Supply (Max):
- 21V
- Voltage - Output:
- -
- Current - Output / Channel:
- 150mA
- Frequency:
- 600kHz ~ 2.2MHz
- Dimming:
- PWM
- Applications:
- Backlight
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-TSSOP-EP
A8511KLPTR-T FAQ
1.How can I place an order for A8511KLPTR-T through Aetrix?
Please submit a Request for Quotation (RFQ) for A8511KLPTR-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 A8511KLPTR-T reliable?
The price and inventory of A8511KLPTR-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for A8511KLPTR-T is usually 5 days.
3.What payment methods are accepted for A8511KLPTR-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for A8511KLPTR-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for A8511KLPTR-T?
A8511KLPTR-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your A8511KLPTR-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 A8511KLPTR-T?
For technical support, including A8511KLPTR-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your A8511KLPTR-T requirements.
6.How does Aetrix verify that A8511KLPTR-T is sourced from the original manufacturer or authorized distributors?
All A8511KLPTR-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 A8511KLPTR-T meets industry standards.
7.What is the process for return or replacement of A8511KLPTR-T?
All A8511KLPTR-T units undergo pre-shipment inspection (PSI). If there is an issue with A8511KLPTR-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 A8511KLPTR-T part is unused and in its original packaging.
Return procedure for A8511KLPTR-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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