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Diodes Incorporated AL1791AFE-13
- Part No.:
- AL1791AFE-13
- Manufacturer:
- Diodes Incorporated
- Category:
- LED Drivers
- Package:
- 14-UFDFN Exposed Pad
- Datasheet:
-
AL1791AFE-13.pdf
- Description:
- IC LED DRVR LINEAR PWM 1A 14UDFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,011
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Product details
Overview
AL1791AFE-13 from Diodes Incorporated is a single-channel, ratio-optimized constant-current LED driver for tunable-white smart lighting systems, supporting analog and PWM dimming with 0.1% deep dimming at 1kHz, 500mA max channel current, and integrated UVLO/OTP/LED open-short protection in U-DFN4030-14 package.
For engineers reviewing the AL1791AFE-13 datasheet, AL1791AFE-13 pinout, AL1791AFE-13 application, or AL1791AFE-13 equivalent, this device serves as the low-side current sink in AC-DC-powered smart bulbs requiring precise channel current matching, fault reporting via FAULTB/LEDPG, and thermal recovery at 100°C after shutdown at 160°C.
Technical Context
The AL1791AFE-13 implements a fixed-ratio, single-channel constant-current regulator with internal reference voltage of 1.5V ±30mV and adjustable output current up to 500mA via external RSET resistor (e.g., 12kΩ yields 500mA). It operates from 6.5V–30V input and features slew-rate-controlled soft-start over 100μs to limit LED current overshoot.
Dimming mode is auto-detected at startup: absence of ≥500Hz signal on PWM1 enables analog dimming (0.4V–1.5V linear control), while presence enables digital PWM dimming with minimum pulse width of 2.5μs. Fault reporting includes open-drain FAULTB (UVLO/OTP/LED short/open) and LEDPG (dropout headroom monitoring).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 6.5V to 30V - supports universal AC-DC offline supplies with ≥6.3V UVLO turn-on threshold and 300mV hysteresis. |
| Max Channel Current | 500mA - set by external RSET; enables high-brightness single-string white LED operation without external current amplification. |
| PWM Dimming Depth | 0.1% @ 1kHz - achieved with 2.5μs minimum ON time, enabling flicker-free dimming down to candlelight-level illumination. |
| Thermal Protection | Shuts down at 160°C junction temperature; auto-recovers when die cools to ≤100°C - ensures reliability in enclosed bulb housings. |
| Fault Reporting Pins | FAULTB (open-drain) and LEDPG (open-drain) - enable MCU-level system diagnostics and adaptive power supply adjustment to minimize VLED_REG overhead. |
| Reference Voltage | 1.47V to 1.53V - tight 2% tolerance enables accurate current setting across temperature (-40°C to +125°C ambient). |
| Quiescent Current | 2mA typical - reduces standby power in always-on smart lighting nodes where EN pin disables to 10μA shutdown state. |
Pinout & Package
U-DFN4030-14 package: 4.0mm × 3.0mm × 0.55mm body, exposed thermal pad (internally connected to GND), 0.5mm pitch, RoHS-compliant "Green" molding compound.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| EN (Pin 1) | Enable Control Input | Active-high logic; >2.5V enables IC, <0.4V disables; internal pulldown ensures safe default-off state. |
| PWM1 (Pin 5) | Dimming Signal Input | Dual-mode pin: interprets ≥500Hz signal as PWM dimming; DC voltage 0.4–1.5V as linear analog dimming. |
| LED1 (Pin 6) | Channel 1 Cathode Output | Low-side current sink - connects to LED cathode; supports common-anode topology for cost-effective multi-string designs. |
| GND (Pin 8) | Power & Signal Ground | Primary ground return; exposed pad must be externally connected to PCB ground plane for thermal management (θJA = 55°C/W). |
| REF (Pin 13) | Current Reference Terminal | Connects external RSET resistor to set channel current; IREF = 0.125mA with 12kΩ yields 500mA output. |
| VIN (Pin 14) | Power Input | Accepts 6.5–30V DC input; powers internal circuitry and supplies headroom for LED string regulation. |
| FAULTB (Pin 12) | Fault Reporting Output | Open-drain output asserted low for UVLO, OTP, LED short, or LED open - supports wired-OR fault bus with MCU interrupt. |
| LEDPG (Pin 11) | LED Power Good Output | Open-drain output pulled low when any enabled channel's VLEDx drops near dropout voltage (250mV), enabling dynamic supply optimization. |
Key Features
| Feature | Design Value |
|---|---|
| E-flicker free PWM dimming | Supports 0.1% @ 1kHz with 2.5μs minimum pulse width - eliminates perceptible flicker in human-centric lighting applications. |
| Ratio-optimized single-channel design | Fixed 1× current ratio (vs. AL1794's 4× ratio) - simplifies calibration and matching in monochromatic white LED systems. |
| Integrated LED open/short detection | 6-cycle deglitch for PWM mode and 2ms deglitch for analog mode - prevents false fault triggering during transient conditions. |
| Soft-start with current slew control | 100μs controlled ramp at LED1 output - suppresses inrush current and improves LED lifetime in thermally constrained bulb enclosures. |
| Wide ambient operating range | -40°C to +125°C - enables deployment in outdoor-rated fixtures and high-temperature indoor luminaires without derating. |
Applications
| 1-Channel Dimmable Smart Bulb | 2-Channel Tunable White Bulb |
|---|---|
|
Use Scenario: Retrofit A19 smart bulb with single-color temperature (2700K–6500K) and brightness control via BLE/Wi-Fi MCU. IC Role / Device Role / Timing Role: Single-channel constant-current sink driving warm-white LED string; PWM1 receives dimming commands from wireless MCU. Use Value: Enables smooth 0.1%–100% dimming without visible flicker while maintaining color consistency across intensity levels. |
Use Scenario: Dual-channel tunable-white bulb using separate warm-white (2700K) and cool-white (6500K) LED strings. IC Role / Device Role / Timing Role: AL1791AFE-13 drives warm-white string; second AL1792AFE-13 drives cool-white string - both synchronized via shared EN/PWM signals. Use Value: Delivers precise current matching (<±4% accuracy) between channels to ensure stable correlated color temperature (CCT) tuning. |
| Smart LED Tube Light | Panel Light with Adaptive Power Management |
|
Use Scenario: T8 LED tube with integrated AC-DC converter and Zigbee-enabled lighting controller. IC Role / Device Role / Timing Role: Low-side current regulator for primary LED string; FAULTB reports open-circuit faults during end-of-life detection. Use Value: Reduces BOM count by eliminating discrete current-sense resistors and discrete protection ICs - lowers total system cost. |
Use Scenario: Commercial ceiling panel light with dynamic power supply adjustment based on real-time LED headroom feedback. IC Role / Device Role / Timing Role: LEDPG pin provides real-time dropout margin status to MCU, which adjusts buck converter output voltage to minimize regulator dissipation. Use Value: Cuts thermal load by up to 30% in high-VF LED arrays - extends thermal design life and enables smaller heatsinks. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar single-channel LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AL1792AFE-13 | Dual-channel version with identical per-channel specs (500mA max/channel), shared REF, and independent PWM1/PWM2 inputs. | Supports two independent LED strings (e.g., warm+cool white) without needing two separate AL1791 ICs. | Select when dual-channel operation is required; same footprint but requires additional PWM routing and LED cathode connections. |
| AL8861Q-13 | Single-channel buck LED driver with integrated MOSFET, 30V input, 1.5A max output, and analog/PWM dimming - no FAULTB/LEDPG reporting pins. | Lacks fault reporting and power-good signaling; suited for cost-sensitive non-smart applications without MCU supervision. | Choose only if system lacks MCU-based diagnostics and thermal/fault monitoring is handled externally or omitted. |
Compared with AL1792AFE-13, AL1791AFE-13 saves board space and interconnect complexity in single-string designs; versus AL8861Q-13, it trades integrated switching capability for superior diagnostic integration and tighter current matching in smart-connected lighting.
Availability
AL1791AFE-13 is available at Aetrix Electronics and suitable for smart bulb manufacturing, tunable-white lighting modules, and commercial LED tube production requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for AL1791AFE-13 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
Diodes Incorporated is a global semiconductor company specializing in discrete, analog, and mixed-signal solutions for power management, signal integrity, and lighting applications.
The AL179x family was designed specifically for cost-effective, high-accuracy tunable-white and tunable-color smart lighting systems - emphasizing low standby power, deep dimming fidelity, and robust fault resilience in thermally constrained environments.
FAQ
What is the minimum recommended RSET value for AL1791AFE-13?
The datasheet specifies a minimum channel current of 0.2A for AL1791. With IREF = 0.125mA and nominal current ratio of 4000:1, RSET must not exceed 6.25kΩ to achieve 0.2A. However, standard practice uses 12kΩ for 500mA; lower values increase current but reduce accuracy and thermal margin. Always verify thermal performance at target current.
Can AL1791AFE-13 drive LEDs with forward voltage above 25V?
Yes - VIN supports up to 30V, and the device regulates current regardless of VF, provided sufficient headroom remains above the 250mV dropout voltage (VLED_REG). For a 28V LED string, VIN must exceed 28.25V. LEDPG will assert low if headroom falls below threshold, signaling need for higher supply voltage.
How does the FAULTB pin behave during UVLO condition?
FAULTB is actively pulled low during UVLO - confirmed in Electrical Characteristics table and Functional Block Diagram. This occurs only when EN is high and VIN drops below ~6.0V (after hysteresis). The pin remains low until VIN rises above 6.3V and EN stays asserted, ensuring reliable fault capture during brown-out events.
Is the exposed thermal pad electrically isolated?
No - the exposed pad is internally connected to GND, as stated in Pin Descriptions. It must be soldered to a PCB ground plane with thermal vias; using it as a floating thermal slug violates the absolute maximum rating and degrades θJA performance. Do not isolate or route signals under the pad.
AL1791AFE-13 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- 14-UFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Linear
- Topology:
- -
- Internal Switch(s):
- Yes
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- 6.5V
- Voltage - Supply (Max):
- 30V
- Voltage - Output:
- 30V
- Current - Output / Channel:
- 1A
- Frequency:
- -
- Dimming:
- Analog, PWM
- Applications:
- Lighting
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- U-DFN4030-14
AL1791AFE-13 FAQ
1.How can I place an order for AL1791AFE-13 through Aetrix?
Please submit a Request for Quotation (RFQ) for AL1791AFE-13 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 AL1791AFE-13 reliable?
The price and inventory of AL1791AFE-13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AL1791AFE-13 is usually 5 days.
3.What payment methods are accepted for AL1791AFE-13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AL1791AFE-13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AL1791AFE-13?
AL1791AFE-13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AL1791AFE-13 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 AL1791AFE-13?
For technical support, including AL1791AFE-13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AL1791AFE-13 requirements.
6.How does Aetrix verify that AL1791AFE-13 is sourced from the original manufacturer or authorized distributors?
All AL1791AFE-13 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 AL1791AFE-13 meets industry standards.
7.What is the process for return or replacement of AL1791AFE-13?
All AL1791AFE-13 units undergo pre-shipment inspection (PSI). If there is an issue with AL1791AFE-13, 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 AL1791AFE-13 part is unused and in its original packaging.
Return procedure for AL1791AFE-13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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