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Diodes Incorporated AP1533SG-13
- Part No.:
- AP1533SG-13
- Manufacturer:
- Diodes Incorporated
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
AP1533SG-13.pdf
- Description:
- IC REG BUCK ADJ 1.8A 8SOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,722
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Product details
Overview
AP1533SG-13 from Diodes Incorporated is a PWM-controlled 1.8A step-down DC/DC converter with integrated P-channel MOSFET, 300kHz fixed switching frequency, 4V–23V input range, and adjustable 0.8V–VCC output voltage. It delivers low-ripple power with soft-start, over-current protection (OCP), short-circuit protection (SCP), thermal shutdown, and enable control-ideal for microprocessor core supplies in PC motherboards and graphic cards.
For engineers reviewing the AP1533SG-13 datasheet, AP1533SG-13 pinout, AP1533SG-13 application, or AP1533SG-13 equivalent, key selection criteria include internal PMOS RDS(ON) (80–150 mΩ), OCSET-based current limit programming, SOP-8L thermal resistance (θJA = 134°C/W), and 50kHz foldback frequency during fault conditions.
Technical Context
The AP1533SG-13 implements a fixed-frequency PWM control architecture with linear duty-cycle adjustment (0–99%) and internal error amplifier feedback referenced to 0.8V ±2%. Its oscillator operates at 300kHz typ., dropping to 50kHz under OCP/SCP to reduce stress and heat.
It integrates an internal high-side P-channel MOSFET, soft-start circuitry, under-voltage lockout (UVLO: 3.3V off / 3.5V on), and thermal shutdown at +150°C with +55°C hysteresis-enabling robust, self-protected operation without external current-sense amplifiers or timing components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4V to 23V - supports AC adapter inputs and wide industrial rail voltages without pre-regulation. |
| Output Current | 1.8A continuous, 2A peak - sufficient for CPU/GPU core rails in embedded and peripheral equipment. |
| Feedback Voltage | 0.8V ±2% - sets precise output regulation threshold; enables 0.8V–VCC programmability via resistor divider. |
| Switching Frequency | 300kHz typ. (240–400kHz) - balances EMI, inductor size, and efficiency; folds back to 50kHz during faults. |
| RDS(ON) | 80–150 mΩ (VIN=12V) - defines conduction loss and thermal rise; dictates minimum heatsinking requirements. |
| Efficiency | 91% @ 12VIN/5VOUT/1.8A - reduces power dissipation and improves system thermal margin. |
| Thermal Shutdown | +150°C with +55°C hysteresis - prevents permanent damage and enables automatic recovery after cooling. |
Pinout & Package
SOP-8L (Small Outline Package, 8-pin, exposed pad-compatible layout) with dual SW pins (5&6) and dual VSS pins (7&8) internally bonded to die pad for enhanced thermal performance and EMI reduction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| FB (Pin 1) | Feedback input | Monitors output voltage via resistor divider; regulates output to 0.8V reference; sensitive to noise-requires short, shielded routing. |
| EN (Pin 2) | Enable control | Active-high logic: >2.0V enables regulation; <0.8V disables all circuits and reduces quiescent current to 10µA. |
| OCSET (Pin 3) | Over-current threshold set | External resistor (ROCSET) programs current limit; 90µA sink current determines trip point per datasheet equation. |
| VCC (Pin 4) | Bias supply | Powers internal circuitry; must be decoupled with ≥0.1µF ceramic capacitor close to pin; UVLO active below 3.3V. |
| Output (Pins 5&6) | Switch node | High-side P-MOS drain connection; drives external inductor/diode; minimize trace area to reduce EMI and switching losses. |
| VSS (Pins 7&8) | Ground reference | Power ground return for IC and switch; dual pins reduce impedance; connect directly to large copper pour for thermal relief. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated P-channel MOSFET | Eliminates need for external high-side switch; reduces BOM count and layout complexity while maintaining 1.8A capability. |
| Programmable over-current protection | ROCSET resistor allows precise current limit tuning across input/output combinations-supports 4V–23V designs without redesign. |
| Soft-start circuit | Prevents output overshoot and inrush current at startup; eliminates need for external timing capacitor or sequencing control. |
| Internal compensation network | Reduces external component count to only inductor, input/output capacitors, diode, and feedback resistors-simplifies design validation. |
| Green SOP-8L package | Lead-free, halogen-free, antimony-free construction compliant with RoHS 3 (2015/863/EU); suitable for automotive and consumer applications. |
Applications
| PC Motherboard VRM | LCD Monitor Power Supply |
|---|---|
|
Use Scenario: Regulating 1.05V/1.2V core voltage for Intel/AMD chipset I/O or memory controller. IC Role / Device Role / Timing Role: Primary buck regulator delivering stable, low-noise power with fast transient response to dynamic load changes. Use Value: Integrated soft-start and 0.8V reference enable precise core voltage tracking; 91% efficiency minimizes thermal load on densely packed PCBs. |
Use Scenario: Generating 3.3V or 5V bias rails for LCD panel timing controllers and backlight drivers. IC Role / Device Role / Timing Role: Secondary DC/DC converter supplying regulated power to display subsystems with variable load profiles. Use Value: 300kHz switching allows compact 22–33µH inductors; built-in OCP protects against backlight short-circuit failures. |
| Graphic Card GPU Core Supply | ADSL Modem Power Management |
|
Use Scenario: Delivering up to 1.8A at 0.8–1.3V to GPU cores under burst-load conditions. IC Role / Device Role / Timing Role: High-current step-down regulator with thermal shutdown and foldback frequency for reliability during thermal throttling. Use Value: Dual SW and VSS pins improve thermal dissipation in space-constrained modules; 150°C shutdown prevents silicon damage during sustained overload. |
Use Scenario: Providing isolated 3.3V/5V rails for DSL PHY, microcontroller, and line driver ICs from 12V adapter input. IC Role / Device Role / Timing Role: Main power converter enabling single-rail adapter operation with enable control for power cycling. Use Value: EN pin allows firmware-controlled power gating; 4–23V input range accommodates aging adapters and brownout conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP1471GJ-Z (Monolithic Power) | 4.5–28V input, 2A, 500kHz, external MOSFETs; no integrated high-side FET. | Requires external high-side/low-side MOSFETs and gate drivers; higher BOM cost but greater flexibility in current rating and thermal layout. | Select when >1.8A peak or >23V input is required; avoid if minimizing component count is critical. |
| TPS54331DR (Texas Instruments) | 3.5–28V input, 3A, 570kHz, integrated N-MOSFET; requires external bootstrap capacitor and diode. | Higher current and frequency support smaller magnetics but adds complexity in bootstrap design and EMI filtering. | Choose for higher efficiency at light loads or tighter output ripple specs; not drop-in due to different pinout and biasing. |
Compared with MP1471GJ-Z and TPS54331DR, the AP1533SG-13 offers lowest component count and simplest layout for ≤1.8A applications, trading off maximum current and frequency for integration, thermal robustness in SOP-8L, and seamless enable/fault management.
Availability
AP1533SG-13 is available at Aetrix Electronics and suitable for PC motherboard VRMs, LCD monitor power supplies, and ADSL modem power management requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant green packaging.
Supply support for AP1533SG-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 manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and protection solutions for industrial, computing, and communications markets.
The AP1533 belongs to Diodes' PWM step-down converter product line, designed specifically for cost-sensitive, space-constrained applications requiring integrated high-side MOSFETs, minimal external components, and robust fault protection without sacrificing efficiency.
FAQ
What is the recommended ROCSET resistor value for 12V input and 5V output?
The datasheet specifies a 3.3kΩ resistor for 12VIN/5VOUT configurations. This value sets the over-current threshold to match the 1.8A continuous rating while accounting for RDS(ON) variation and inductor ripple. Using 3.3kΩ ensures reliable current limiting without premature tripping under transient loads.
Can AP1533SG-13 operate with input voltage below 4V?
No. The absolute minimum input voltage is 4V per the Recommended Operating Conditions table. Below this, the under-voltage lockout prevents operation, and the internal reference and oscillator may not stabilize. Operation at 3.5V (UVLO turn-on threshold) is insufficient for functional regulation.
How does the 50kHz foldback frequency improve reliability during short-circuit events?
Folding back from 300kHz to 50kHz reduces switching losses and peak current stress on the internal MOSFET and external inductor during sustained overloads. This lowers junction temperature rise, extends time-to-thermal-shutdown, and prevents catastrophic failure during intermittent shorts or start-up faults.
Is the SOP-8L package thermally adequate for 1.8A continuous operation at 85°C ambient?
Yes, when implemented per the datasheet's PCB layout guidelines: using dual VSS pins connected to ≥2"×2" 2oz copper pour, minimizing SW pin trace area, and adding thermal vias under the exposed pad. θJA = 134°C/W yields ~120°C junction at 1.8A/12VIN, staying within the 125°C max operating limit with margin.
AP1533SG-13 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
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 23V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 23V
- Current - Output:
- 1.8A
- Frequency - Switching:
- 300kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -25°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOP
AP1533SG-13 FAQ
1.How can I place an order for AP1533SG-13 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP1533SG-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 AP1533SG-13 reliable?
The price and inventory of AP1533SG-13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP1533SG-13 is usually 5 days.
3.What payment methods are accepted for AP1533SG-13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP1533SG-13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP1533SG-13?
AP1533SG-13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP1533SG-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 AP1533SG-13?
For technical support, including AP1533SG-13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP1533SG-13 requirements.
6.How does Aetrix verify that AP1533SG-13 is sourced from the original manufacturer or authorized distributors?
All AP1533SG-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 AP1533SG-13 meets industry standards.
7.What is the process for return or replacement of AP1533SG-13?
All AP1533SG-13 units undergo pre-shipment inspection (PSI). If there is an issue with AP1533SG-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 AP1533SG-13 part is unused and in its original packaging.
Return procedure for AP1533SG-13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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