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Diodes Incorporated AP1681MTR-G1
- Part No.:
- AP1681MTR-G1
- Manufacturer:
- Diodes Incorporated
- Category:
- LED Drivers
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
AP1681MTR-G1.pdf
- Description:
- IC LED DRIVER OFFL 300MA 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,355
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Product details
Overview
AP1681MTR-G1 from BCD Semiconductor is an off-line primary-side regulation (PSR) controller IC for dimmable AC/DC LED drivers, implementing pulse frequency modulation (PFM) to regulate output current based on wall-dimmer conduction angle. It supports leading-edge, trailing-edge, R, R-C, and R-L dimmers; achieves 100%–1% dimming range with no visible flicker; and integrates over-voltage, short-circuit, over-current, and over-temperature protection. Typical application: 120VAC/60Hz, 18W, 8-LED string with 26VLOAD and 5.0–550mA adjustable output.
For engineers reviewing the AP1681MTR-G1 datasheet, AP1681MTR-G1 pinout, AP1681MTR-G1 application, or AP1681MTR-G1 equivalent, this page delivers verified technical context, SOIC-8 package mapping, functional pin roles, dimming curve adjustability, CV open-load regulation, and real-world compatibility with analog/digital/hybrid dimming modes - all critical for LED driver design validation and BOM selection.
Technical Context
The AP1681 operates in primary-side control mode, eliminating optocouplers and secondary-side CV/CC circuitry by sensing demagnetization timing and auxiliary winding voltage for accurate output current regulation. Its PFM architecture dynamically adjusts switching frequency per dimmer phase-cut angle, enabling smooth 100:1 dimming without flicker.
Internal blocks include a dedicated dimming control logic that processes DIM input voltage to scale RI and RD reference levels, a 0.5V current-sense threshold with 600ns leading-edge blanking, and dual-stage protection: latch-type OTP (140°C shutdown, 20°C hysteresis) and FB-OVP at 6.5–9.5V. The 16.5µs maximum on-time prevents transformer saturation under low-line conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Operating Range | 10.8–21.5 V: Ensures stable operation across universal AC input after bulk capacitor ripple. |
| Current Sense Threshold | 450–560 mV: Sets primary peak current limit; directly determines max LED output current. |
| FB CV Threshold | 3.0–5.0 V: Controls constant-voltage regulation point during open-load or reload detection. |
| Dimming Input Gain | −1.2 to −1.0 V/V: Linear scaling of DIM voltage to RI reference enables precise human-eye-matched dimming curves. |
| Start-up Current | 1.7–10 µA: Enables ultra-low-power start-up from high-impedance bias networks. |
| Max Switch On-time | 16.5 µs: Prevents core saturation in flyback transformers under low-input-voltage, high-duty-cycle conditions. |
| Thermal Shutdown | 140°C with 20°C hysteresis: Latch-off behavior protects MOSFET and transformer during sustained overload. |
Pinout & Package
AP1681MTR-G1 is housed in an industry-standard SOIC-8 (M) package with exposed pad not present; thermal resistance θJA = 150°C/W at TA = 50°C. Pin functions are validated per Figure 2 and Table 1 of the preliminary datasheet (Rev. 1.2, Jul. 2011).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - DIM | Dimming control analog input | Accepts 0–7V signal to set dimming level; internally scaled to adjust RI reference for human-eye-sensitive dimming curve. |
| 2 - RD | Full brightness reference setting | 1.3–1.75V pin voltage sets upper current limit; defines 100% brightness point in dimming range. |
| 3 - RI | Full dimming reference setting | Adjusts lower current limit; combined with DIM gain, enables 1% minimum output current without cutoff. |
| 4 - FB | Auxiliary winding feedback input | Senses reflected voltage for PSR-based output current estimation; includes 1.75V acceleration-start threshold and 6.5–9.5V OVP. |
| 5 - CS | Primary current sense input | Monitors MOSFET source current via shunt resistor; 450–560mV threshold triggers cycle-by-cycle OCP. |
| 6 - GND | Power and signal ground return | Common reference for gate driver, bias, and protection circuits; must be low-inductance connection to power ground plane. |
| 7 - OUT | High-current gate driver output | ±300mA capable, 120–320ns rise/fall times; drives external N-channel MOSFET (e.g., 3N60, 4N60) directly. |
| 8 - VCC | IC supply input | 10.8–21.5V operating range; UVLO start-up at 16.5–21.5V; internal clamp limits to 30V absolute max. |
Key Features
| Feature | Design Value |
|---|---|
| Primary-side current regulation | Eliminates optocoupler and secondary-side feedback components, reducing BOM cost and improving reliability in isolated LED drivers. |
| Adjustable dimming curve | Configurable via DIM-to-RI gain and RD/RI voltage settings to match logarithmic human eye response, avoiding perceptible steps. |
| CV open-load regulation | Maintains stable VCC and prevents runaway during LED string open-circuit, enabling safe hot-plug and fault recovery. |
| Built-in acceleration start | Uses FB voltage >1.75V to trigger fast initial charging of VCC capacitor, reducing start-up time below 100ms. |
| Maximum switch on-time limit | Hardware-enforced 16.5µs cap prevents transformer saturation during deep dimming or low-line brownout conditions. |
Applications
| Residential Wall-Dimmer LED Lighting | Commercial Office Dimmable Fixtures |
|---|---|
|
Use Scenario: 120VAC/60Hz retrofit LED lamp replacing incandescent bulbs in homes with standard TRIAC dimmers. IC Role / Device Role / Timing Role: Primary-side controller executing PFM-based current regulation synchronized to dimmer conduction angle; senses ZCD and demag timing for PSR. Use Value: Delivers flicker-free 100:1 dimming without requiring dimmer-specific firmware or secondary feedback, lowering system cost and certification effort. |
Use Scenario: 277VAC LED troffer in office ceiling with 0–10V or DALI-compatible hybrid dimming interface. IC Role / Device Role / Timing Role: PSR controller accepting analog dimming voltage on DIM pin while maintaining tight current regulation across wide input voltage range. Use Value: Enables single-driver platform supporting multiple dimming standards (analog/digital/hybrid), reducing SKU count and inventory complexity. |
| Industrial High-Bay LED Drivers | Outdoor Streetlight Dimming Systems |
|
Use Scenario: 347VAC high-bay fixture in warehouse with temperature-hardened operation from −40°C to +105°C ambient. IC Role / Device Role / Timing Role: Robust PSR controller with 140°C thermal shutdown and 20°C hysteresis, ensuring reliable restart after transient overloads. Use Value: Sustains full 18W output with no derating up to 105°C ambient, eliminating need for heatsink oversizing in enclosed fixtures. |
Use Scenario: Smart streetlight using dusk-to-dawn dimming profiles with adaptive current reduction during off-peak hours. IC Role / Device Role / Timing Role: Dimming controller with reload detection and CV regulation, enabling seamless transition between full load and open-circuit (sensor-disconnected) states. Use Value: Maintains stable VCC and prevents false OCP triggering when photocell or motion sensor disconnects, improving field reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar primary-side dimmable LED driver controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BP3319D | Integrated 650V MOSFET; fixed 100:1 dimming range; no adjustable dimming curve. | Targeted for cost-sensitive, non-adjustable LED bulbs; lacks RD/RI pins for fine-tuning. | Select BP3319D only if integrated FET and simplified layout outweigh need for dimming curve customization. |
| LNK306DG | Secondary-side feedback required; uses optocoupler; no native dimming interface. | Requires external dimming circuitry (e.g., PWM-to-analog converter); higher component count and isolation complexity. | Choose LNK306DG only when legacy secondary-feedback architecture or specific safety certifications mandate optocoupler use. |
Compared with BP3319D and LNK306DG, AP1681MTR-G1 uniquely combines SOIC-8 footprint, fully adjustable dimming curve, and true primary-side regulation - enabling compact, flicker-free, and field-configurable LED drivers without compromising thermal robustness or protection coverage.
Availability
AP1681MTR-G1 is available at Aetrix Electronics and suitable for residential lighting retrofits, commercial office fixtures, and industrial high-bay LED drivers requiring stable component supply, RoHS-compliant green packaging, and tape-and-reel delivery for automated assembly.
Supply support for AP1681MTR-G1 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
BCD Semiconductor Manufacturing Limited is a Shanghai-based analog and power IC designer specializing in high-voltage, high-efficiency power management solutions for lighting, industrial, and consumer applications.
The AP1681 belongs to BCD's PSR LED driver controller product line, engineered specifically for flicker-free, dimmer-compatible AC/DC conversion in cost-sensitive, space-constrained LED lighting systems - prioritizing integration, thermal resilience, and universal dimmer interoperability.
FAQ
What dimmer types does AP1681MTR-G1 support?
AP1681MTR-G1 supports leading-edge (TRIAC), trailing-edge (electronic low-voltage), R-type, R-C-type, and R-L-type wall dimmers per datasheet Section 1 and Figure 17. It achieves flicker-free dimming across all types by synchronizing PFM frequency to dimmer conduction angle and using acceleration start to maintain stability during phase-cut transitions.
How is output current regulated without an optocoupler?
AP1681MTR-G1 uses primary-side regulation (PSR) by sampling auxiliary winding voltage at transformer demagnetization zero-crossing to estimate output voltage and current. Combined with precise current-sense threshold (450–560mV) and FB feedback timing, it achieves ±5% output current accuracy without secondary-side components.
What protection features are integrated?
AP1681MTR-G1 integrates over-voltage protection (FB-OVP at 6.5–9.5V), short-circuit protection (via CS pin latching), over-current protection (cycle-by-cycle at CS threshold), over-temperature protection (140°C shutdown with 20°C hysteresis), and maximum switch on-time limiting (16.5µs) - all hardware-based with no external components required.
Can AP1681MTR-G1 operate with 277VAC input?
Yes - AP1681MTR-G1 itself operates from VCC = 10.8–21.5V, but the associated flyback circuit (e.g., Figure 17) can be designed for 277VAC input using appropriate bulk capacitor rating, MOSFET voltage grade (≥650V), and transformer turns ratio. Datasheet Section 11 confirms operation up to 18W with proper front-end rectification and clamping.
AP1681MTR-G1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- AC DC Offline Switcher
- Topology:
- -
- Internal Switch(s):
- No
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- 10.8V
- Voltage - Supply (Max):
- 21.5V
- Voltage - Output:
- -
- Current - Output / Channel:
- -
- Frequency:
- -
- Dimming:
- -
- Applications:
- -
- Operating Temperature:
- -40°C ~ 105°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
AP1681MTR-G1 FAQ
1.How can I place an order for AP1681MTR-G1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP1681MTR-G1 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 AP1681MTR-G1 reliable?
The price and inventory of AP1681MTR-G1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP1681MTR-G1 is usually 5 days.
3.What payment methods are accepted for AP1681MTR-G1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP1681MTR-G1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP1681MTR-G1?
AP1681MTR-G1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP1681MTR-G1 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 AP1681MTR-G1?
For technical support, including AP1681MTR-G1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP1681MTR-G1 requirements.
6.How does Aetrix verify that AP1681MTR-G1 is sourced from the original manufacturer or authorized distributors?
All AP1681MTR-G1 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 AP1681MTR-G1 meets industry standards.
7.What is the process for return or replacement of AP1681MTR-G1?
All AP1681MTR-G1 units undergo pre-shipment inspection (PSI). If there is an issue with AP1681MTR-G1, 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 AP1681MTR-G1 part is unused and in its original packaging.
Return procedure for AP1681MTR-G1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AP1681MTR-G1 Tags
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BCR402RE6327HTSA1
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BCR430UXTSA2
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BCR420UE6433HTMA1
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HV9910CLG-G
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CL2N8-G
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BCR420UW6-7
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BCR420UFD-7
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BCR421UFD-7
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