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Diodes Incorporated AP3428AWT-7
- Part No.:
- AP3428AWT-7
- Manufacturer:
- Diodes Incorporated
- Package:
- SOT-23-5 Thin, TSOT-23-5
- Datasheet:
-
AP3428AWT-7.pdf
- Description:
- IC REG BUCK ADJ 1A TSOT25
- Quantity:
- Payment:
- Shipping:
Inventory:5,880
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Product details
Overview
AP3428AWT-7 from Diodes Incorporated is a 1.5MHz, 1A synchronous step-down DC-DC buck converter with internal high- and low-side MOSFETs (RDS(ON) = 250 mΩ / 170 mΩ), 0.6V ±2% reference voltage, 40µA no-load quiescent current, and 100% duty-cycle capability-designed for post-regulation in portable Li+-powered systems such as notebooks and set-top boxes.
For engineers reviewing the AP3428AWT-7 datasheet, AP3428AWT-7 pinout, AP3428AWT-7 application, or AP3428AWT-7 equivalent, this device delivers verified performance in low-input-voltage, high-efficiency point-of-load conversion where shutdown current <1µA, thermal protection at +160°C, and UVLO hysteresis of 0.1V are critical selection criteria.
Technical Context
The AP3428AWT-7 implements constant-frequency PWM control with internal soft-start and no external compensation required. Its error amplifier compares FB voltage against a precision 0.6V bandgap reference, enabling adjustable output from 0.6V to VIN.
It integrates dual MOSFET power switches, current-sense circuitry, over-current protection (OCP threshold 1.3A), over-temperature shutdown (+160°C trip, +145°C recovery), and under-voltage lockout (2.4V–2.7V threshold with 0.1V hysteresis) - all operating across –40°C to +85°C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 1.5 MHz - enables compact LC filter design with ≤2.2µH inductors and 10µF output capacitance. |
| Output Current | 1 A continuous - supported by integrated 250 mΩ/170 mΩ synchronous MOSFETs and thermal shutdown at +160°C. |
| Input Voltage Range | 2.5 V to 5.5 V - compatible with single-cell Li+/Li-polymer, two Alkaline/NiMH, or USB-powered rails. |
| Feedback Reference | 0.6 V ±2% - sets output accuracy via external resistor divider; enables 0.6V–VIN regulation range. |
| Quiescent Current | 40 µA typical - minimizes battery drain in always-on subsystems; drops to <1 µA in shutdown mode. |
| Duty Cycle Range | 0–100% - supports ultra-low dropout operation, e.g., 3.3V out from 3.4V input without dropout failure. |
| EN Threshold | VENH = 1.5 V, VENL = 0.4 V - provides clean enable/disable control with 1.1V hysteresis for noise immunity. |
Pinout & Package
AP3428AWT-7 uses the TSOT25 (Type SM) package: 2.92 mm × 2.80 mm × 0.75 mm body, 5-pin exposed-pad variant with moisture sensitivity level 3 per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (EN) | Enable control input | Logic-high ≥1.5V activates regulator; logic-low ≤0.4V disables it with <1µA supply current. |
| 2 (GND) | Power ground reference | Common return path for IC bias, power switch sources, and feedback network; requires low-impedance PCB connection. |
| 3 (LX) | Switch node | Drain connection of internal high- and low-side MOSFETs; connects directly to inductor and catch diode (if used). |
| 4 (VIN) | Main power input | Supplies internal bias and power switches; requires local 10µF ceramic capacitor placed adjacent to pin. |
| 5 (FB) | Feedback input | Senses output voltage via resistor divider; internal 0.6V reference determines regulation setpoint. |
Key Features
| Feature | Design Value |
|---|---|
| Synchronous rectification | Integrated 250 mΩ high-side and 170 mΩ low-side MOSFETs eliminate external diode, enabling >90% efficiency at 1A load. |
| No external compensation | Internally compensated error amplifier eliminates need for external RC network - reduces BOM count and layout sensitivity. |
| Pulse-skip light-load mode | Maintains high efficiency down to ~1mA load by skipping switching cycles instead of forcing fixed-frequency operation. |
| Robust protection suite | Includes cycle-by-cycle OCP, hiccup-mode short-circuit response, +160°C thermal shutdown with +15°C hysteresis, and 2.4V UVLO. |
| Ultra-low IQ and shutdown current | 40 µA no-load quiescent current and <1 µA shutdown current extend battery runtime in standby and sleep states. |
Applications
| Portable Notebook Power Rails | Set-Top Box Core Logic Supply |
|---|---|
|
Use Scenario: Regulating 1.8V or 2.5V core voltage from a shared 3.3V or 5V intermediate rail in space-constrained notebook mainboards. IC Role / Device Role / Timing Role: Primary synchronous buck converter delivering stable 1A output with fast transient response to CPU/GPU load steps. Use Value: 100% duty-cycle operation prevents dropout during peak current surges; 1.5MHz switching allows use of tiny 2.2µH inductors and minimal footprint. |
Use Scenario: Generating 1.2V or 1.5V for SoC I/O or memory interface in consumer STB platforms powered by single-cell Li-ion or wall adapter. IC Role / Device Role / Timing Role: Post-regulator converting intermediate 3.3V rail to precise low-voltage domain with tight 0.6V ±2% reference accuracy. Use Value: 40µA quiescent current extends standby time; EN pin enables system-level power sequencing with controlled startup timing. |
| USB-Powered Portable Devices | Industrial Handheld Terminals |
|
Use Scenario: Direct conversion from 5V USB input to 3.3V or adjustable output for MCU, display, or sensor subsystems. IC Role / Device Role / Timing Role: Primary DC-DC regulator handling full USB 5V tolerance (up to 5.5V) with built-in overvoltage protection on VIN. Use Value: Internal soft-start prevents inrush current; 1.5MHz frequency avoids AM radio band interference and simplifies EMI filtering. |
Use Scenario: Powering ARM-based controllers and communication modules in ruggedized handheld terminals operating across –40°C to +85°C ambient. IC Role / Device Role / Timing Role: High-reliability buck converter with thermal shutdown (+160°C) and UVLO hysteresis (0.1V) for stable operation in variable-temperature environments. Use Value: TSOT25 (Type SM) package offers proven manufacturability and thermal performance; RoHS/Green compliance meets industrial environmental requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP2158GQZ-P | Higher 2MHz switching frequency; 0.8V reference; 1.2A rating; requires external compensation. | Better suited for ultra-compact designs needing smaller inductors; less tolerant of input ripple due to higher fSW. | Select when board area is constrained and 2MHz operation is acceptable; verify loop stability with external compensation network. |
| TPS62231DRVR | 1.8V fixed output option; 3.6V max VIN; 3.6µA IQ; no 100% duty cycle support. | Limited to lower-input-voltage systems (e.g., coin-cell or regulated 3.3V rails); unsuitable for 5V USB direct conversion. | Choose only for fixed-output, ultra-low-IQ applications where input never exceeds 3.6V and dropout margin is sufficient. |
Compared with MP2158GQZ-P and TPS62231DRVR, AP3428AWT-7 uniquely balances 1.5MHz operation, 2.5–5.5V input flexibility, 100% duty cycle, and zero-compensation design - making it optimal for cost-sensitive, battery-backed portable systems requiring robustness and ease of implementation.
Availability
AP3428AWT-7 is available at Aetrix Electronics and suitable for portable notebook power rails, set-top box core logic supplies, and USB-powered portable devices requiring stable component supply, long-term lifecycle support, and RoHS/Green compliance.
Supply support for AP3428AWT-7 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 AP3428 series belongs to Diodes' high-density DC-DC converter product line, engineered specifically for space- and efficiency-critical portable electronics where low quiescent current, wide input range, and simplified layout are essential.
FAQ
What input voltage range does AP3428AWT-7 support, and how does UVLO behave?
AP3428AWT-7 operates from 2.5V to 5.5V input. Its under-voltage lockout triggers at 2.4V (typical) with 0.1V hysteresis, disabling the regulator until input rises to 2.5V. This prevents deep battery discharge and ensures clean restart behavior without oscillation near threshold.
Can AP3428AWT-7 achieve 100% duty cycle, and what is its practical benefit?
Yes - AP3428AWT-7 supports true 100% duty cycle operation. This allows regulation even when VOUT is within ~100mV of VIN, eliminating dropout failure in battery-powered systems nearing end-of-discharge (e.g., 3.3V output from 3.4V Li+ cell).
How is output voltage set, and what resistor tolerance is recommended for 1% output accuracy?
Output voltage is set via an external resistor divider on the FB pin using VOUT = 0.6V × (1 + R1/R2). For 1% total output accuracy, use 0.5% tolerance resistors and limit R1 to ≤430kΩ to minimize error from FB pin bias current (≤0.2µA).
Does AP3428AWT-7 require an external catch diode, and why or why not?
No - AP3428AWT-7 integrates both high-side and low-side synchronous MOSFETs, eliminating the need for an external catch diode. This improves efficiency (no forward voltage drop), reduces thermal stress, and simplifies layout compared to asynchronous buck converters.
AP3428AWT-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- SOT-23-5 Thin, TSOT-23-5
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.5V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 0.6V
- Voltage - Output (Max):
- 5.5V
- Current - Output:
- 1A
- Frequency - Switching:
- 1.5MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TSOT-25
AP3428AWT-7 FAQ
1.How can I place an order for AP3428AWT-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP3428AWT-7 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 AP3428AWT-7 reliable?
The price and inventory of AP3428AWT-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP3428AWT-7 is usually 5 days.
3.What payment methods are accepted for AP3428AWT-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP3428AWT-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP3428AWT-7?
AP3428AWT-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP3428AWT-7 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 AP3428AWT-7?
For technical support, including AP3428AWT-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP3428AWT-7 requirements.
6.How does Aetrix verify that AP3428AWT-7 is sourced from the original manufacturer or authorized distributors?
All AP3428AWT-7 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 AP3428AWT-7 meets industry standards.
7.What is the process for return or replacement of AP3428AWT-7?
All AP3428AWT-7 units undergo pre-shipment inspection (PSI). If there is an issue with AP3428AWT-7, 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 AP3428AWT-7 part is unused and in its original packaging.
Return procedure for AP3428AWT-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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