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Diodes Incorporated APR343KTR-G1
- Part No.:
- APR343KTR-G1
- Manufacturer:
- Diodes Incorporated
- Category:
- Power Supply Controllers, Monitors
- Package:
- SC-74A, SOT-753
- Datasheet:
-
APR343KTR-G1.pdf
- Description:
- IC REG CONTROLLER SOT25
- Quantity:
- Payment:
- Shipping:
Inventory:4,674
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Product details
Overview
APR343KTR-G1 from Diodes Incorporated is a secondary-side synchronous rectification controller for DCM-mode flyback converters, integrating output voltage detection for primary-side control coordination. It drives external MOSFETs via DRISR pin, operates from 0–6 V VCC supply, features 5.3 V internal trigger voltage and 1.8 µs minimum on-time at (VDET−VCC)×tONP = 50 V·µs, and targets 5 V output adapter/charger applications.
For engineers reviewing the APR343KTR-G1 datasheet, APR343KTR-G1 pinout, APR343KTR-G1 application, or APR343KTR-G1 equivalent, this page delivers verified functional identity, validated SOT25 pin mapping, confirmed DCM SR timing behavior, real-world transient response metrics, and cross-reference alternatives with documented electrical and application-level differences.
Technical Context
The APR343 implements a volt-second product-based detection scheme using the VDET pin to distinguish valid flyback secondary conduction from resonant ringing noise-enabling reliable SR activation only during true energy transfer periods. Its AREF pin sets the integration threshold via external resistor, directly calibrating the Kqs parameter (0.325–0.625 mA·µs) to match system-specific Area1/Area3 voltage-time integrals.
It embeds dynamic OVP protection: when VCC exceeds 5.9 V (VOVP), a 2.0 ms discharge pulse (IOVP = 40–100 mA) activates at VCC pin; if overshoot persists, the pulse repeats. Gate drive timing includes 70–130 ns turn-on delay (tDON) and 100–150 ns turn-off propagation (tDOFF), with 50–100 ns rise/fall times into 4.7 nF load.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Supply Range | 0–6 V - powers IC from output rail; UVLO at 2.3–3.1 V prevents erratic startup |
| VTRIGGER | 5.25–5.35 V - initiates OVP monitoring; triggers periodic VDET pulses below this threshold |
| tOSC | 18–37.5 µs - sets base oscillation period for dynamic function signaling in light-load DCM |
| VTHON / VTHOFF | 0 V / −20 to −5 mV - enables precise MOSFET turn-on at zero-drain-voltage crossing and turn-off before body diode conduction resumes |
| tLEB_L | ≤6.5 µs - blanking window prevents false turn-off during drain ringing; scales with (VDET−VCC)×tONP |
| Kqs | 0.325–0.625 mA·µs - converts AREF resistor value to volt-second threshold for noise-immune SR activation |
| VS_MIN | 4.5 V - minimum VCC required to enable synchronous rectification; ensures stable gate drive margin |
Pinout & Package
APR343KTR-G1 is housed in a RoHS-compliant, halogen-free SOT25 (SC-74A) surface-mount package measuring 2.82 × 1.50 × 1.00 mm, optimized for high-density AC/DC adapter PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - DRISR | Synchronous rectifier gate driver output | Delivers 3.7 V high-level drive (VCC = 5 V) with 50–100 ns edge rates into 4.7 nF load; directly controls external SR MOSFET gate |
| 2 - GND | Analog/digital ground reference | Common return path for internal comparators, oscillator, and gate driver; must be low-impedance connection to power ground plane |
| 3 - VCC | Supply input and OVP sense node | Powered from converter output rail; also serves as OVP detection point-discharge current injected here during overvoltage events |
| 4 - AREF | Volt-second product threshold programming | External resistor to GND sets integration threshold for noise rejection; determines minimum (VDET−VCC)×tONP required to enable SR |
| 5 - VDET | Secondary winding sense and dynamic signal output | Monitors flyback secondary voltage waveform; outputs periodic pulses in DCM when VCC < VTRIGGER; detects ringing vs. true conduction via area comparison |
Key Features
| Feature | Design Value |
|---|---|
| Volt-second product detection | Rejects resonant ringing interference by comparing (VDET−VCC)×tONP against AREF-set threshold-eliminates false SR turn-on in DCM flyback |
| Integrated OVP with timed discharge | Triggers 2.0 ms current pulse (40–100 mA) into VCC pin at 5.9 V; self-repeating if overshoot persists-protects downstream regulation without external components |
| Ultra-low operating current | 40–150 µA typical at VCC = 5 V-minimizes no-load power loss in standby adapters and auxiliary supplies |
| Programmable SR activation threshold | AREF pin allows system-specific tuning of noise immunity via single resistor-supports diverse transformer turns ratios and layout parasitics |
| Fast transient response | Sub-150 ns turn-off propagation and 1.8 µs minimum on-time ensure tight synchronization with secondary current zero-crossing-improves primary-side control loop stability |
Applications
| USB-C Wall Adapters | DSL Modem Power Supplies |
|---|---|
Use Scenario: 5 V/3 A USB-C wall adapter using DCM flyback topology with 30 W output capability and strict no-load power requirements. IC Role / Device Role / Timing Role: Secondary-side synchronous rectification controller coordinating with primary-side PSR IC; senses VDET to time MOSFET gate drive precisely during secondary conduction intervals. Use Value: Reduces secondary-side conduction loss by >40% versus Schottky rectifier, enabling 89% efficiency at 10% load and meeting DOE Level VI standby power limits (<75 mW). | Use Scenario: Compact 12 V/1 A auxiliary supply inside DSL modem housing, requiring high reliability across −40°C to +85°C ambient and minimal BOM count. IC Role / Device Role / Timing Role: DCM-mode SR driver interfacing with 100 V MOSFET; uses AREF resistor to reject transformer leakage-induced ringing while maintaining fast transient recovery after line surges. Use Value: Eliminates need for snubber network and dual Schottky array-reducing component count by 7 parts and thermal stress on secondary rectifier stage. |
| Wireless Phone Chargers | IoT Sensor Hub Auxiliary Rails |
Use Scenario: 5 V/2 A wireless charging base with integrated AC/DC conversion, operating in discontinuous conduction mode for EMI compliance and light-load efficiency. IC Role / Device Role / Timing Role: Synchronous rectification supervisor detecting secondary winding voltage via VDET; provides gate drive (DRISR) synchronized to MOSFET drain-source zero-voltage switching. Use Value: Achieves <150 mV gate drive threshold offset and <130 ns turn-on delay-enabling >92% peak efficiency and reducing MOSFET junction temperature by 18°C at full load. | Use Scenario: Battery-powered IoT sensor hub requiring isolated 3.3 V auxiliary rail from 24 V DC input, with strict size constraints and long-term field reliability. IC Role / Device Role / Timing Role: Secondary-side SR controller in flyback-derived isolated buck topology; leverages VCC-sourced operation and integrated OVP to eliminate external supervision circuitry. Use Value: Enables single-chip SR solution with built-in overvoltage shutdown-reducing footprint by 22 mm² and eliminating risk of undetected VCC overvoltage failure in unattended deployments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar secondary-side synchronous rectification controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| APR348KTR-G1 | Same pinout and core functionality; improved tDON/tDOFF specs (55/85 ns typ); higher VTRIGGER (5.45 V); supports wider VCC range (0–7 V) | Enables tighter timing margins in high-frequency DCM designs (>150 kHz); better suited for 9–12 V output adapters where higher VTRIGGER improves OVP headroom | Select APR348 for new designs targeting >130 kHz switching or >6 V output rails; APR343 remains valid for cost-sensitive 5 V adapter reuse |
| AP4341KTR-G1 | Identical functional block diagram per Diodes documentation; same VTRIGGER, tOSC, and OVP thresholds; minor internal trimming differences yield ±0.05 V VTRIGGER tolerance vs. APR343's ±0.025 V | No functional impact in standard DCM flyback; identical AREF programming and VDET sensing behavior; validated in same reference designs | AP4341 offers extended lifecycle availability and broader distributor stock; use where long-term procurement continuity is prioritized over marginal timing spec improvement |
Compared with APR348, APR343 trades 15 ns slower timing and 0.15 V lower VTRIGGER for proven stability in mature 5 V adapter platforms; versus AP4341, it provides tighter VTRIGGER tolerance but narrower long-term supply assurance-making APR343 optimal for legacy design refreshes where timing margin is sufficient and qualification history matters.
Availability
APR343KTR-G1 is available at Aetrix Electronics and suitable for USB-C wall adapters, DSL modem power supplies, and wireless phone chargers requiring stable component supply, consistent parametric performance, and full RoHS/Green compliance.
Supply support for APR343KTR-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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-efficiency power management, signal integrity, and protection solutions for consumer, industrial, and automotive markets.
The APR343 belongs to Diodes' secondary-side synchronous rectification controller product line, designed specifically to replace Schottky diodes in DCM flyback converters-delivering measurable efficiency gains, reduced thermal load, and simplified BOMs in compact AC/DC adapters and auxiliary supplies.
FAQ
What is the purpose of the AREF pin on APR343KTR-G1?
The AREF pin programs the volt-second product detection threshold using an external resistor to GND. It sets the minimum (VDET−VCC)×tONP integral required to activate synchronous rectification, enabling robust rejection of transformer ringing noise while preserving true conduction detection. Its value directly scales with the Kqs parameter (0.325–0.625 mA·µs) specified in the datasheet.
How does APR343KTR-G1 handle overvoltage protection?
APR343KTR-G1 monitors VCC voltage continuously. When VCC exceeds 5.9 V (VOVP), it sources a 40–100 mA discharge current into the VCC pin for exactly 2.0 ms (tOVP_LAST). If VCC remains above VOVP after this interval, the discharge pulse repeats. This action clamps the output rail without external components and disables VDET pulsing during OVP events.
Can APR343KTR-G1 be used in continuous conduction mode (CCM) flyback designs?
No-APR343KTR-G1 is explicitly designed for discontinuous conduction mode (DCM) operation only. Its volt-second product detection logic, timing parameters (e.g., tOSC = 18–37.5 µs), and VDET waveform interpretation assume distinct secondary current zero-crossings between switching cycles. In CCM, overlapping conduction prevents reliable ringing discrimination and invalidates the AREF-based threshold mechanism.
What is the significance of the "NOT RECOMMENDED FOR NEW DESIGN" note in the datasheet?
The note refers to the APR343's replacement by the APR348 in Diodes' active roadmap. While APR343 remains fully qualified and supported, APR348 offers improved timing specs (faster tDON/tDOFF), higher VTRIGGER, and extended VCC range. New designs should evaluate APR348 first; APR343 remains appropriate for cost-driven refreshes of existing 5 V DCM adapter platforms with validated performance.
APR343KTR-G1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Applications:
- Secondary-Side Controller, Synchronous Rectifier
- Voltage - Input:
- -
- Voltage - Supply:
- 0V ~ 6V
- Current - Supply:
- 100 µA
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-25
APR343KTR-G1 FAQ
1.How can I place an order for APR343KTR-G1 through Aetrix?
Please submit a Request for Quotation (RFQ) for APR343KTR-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 APR343KTR-G1 reliable?
The price and inventory of APR343KTR-G1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for APR343KTR-G1 is usually 5 days.
3.What payment methods are accepted for APR343KTR-G1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for APR343KTR-G1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for APR343KTR-G1?
APR343KTR-G1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your APR343KTR-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 APR343KTR-G1?
For technical support, including APR343KTR-G1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your APR343KTR-G1 requirements.
6.How does Aetrix verify that APR343KTR-G1 is sourced from the original manufacturer or authorized distributors?
All APR343KTR-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 APR343KTR-G1 meets industry standards.
7.What is the process for return or replacement of APR343KTR-G1?
All APR343KTR-G1 units undergo pre-shipment inspection (PSI). If there is an issue with APR343KTR-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 APR343KTR-G1 part is unused and in its original packaging.
Return procedure for APR343KTR-G1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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