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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > DC DC Switching Controllers

Diodes Incorporated AP3581AMP-G1

Name: AP3581AMP-G1
Brand: Diodes Incorporated
SKU: AP3581AMP-G1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP3581AMP-G1

Manufacturer:: Diodes Incorporated

Category:: DC DC Switching Controllers

Package:: 8-SOIC (0.154", 3.90mm Width) Exposed Pad

Datasheet:: AP3581AMP-G1.pdf

Description:: IC REG CTRLR BUCK 8PSOP

Quantity:: RFQ Add To RFQ list

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Inventory:4,156

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Product details

Overview

AP3581AMP-G1 from BCD Semiconductor is a single-phase synchronous buck PWM controller designed for 5V/12V input DC-DC conversion, delivering regulated output down to 0.6V with ±1% reference accuracy, fixed 300kHz switching frequency (AP3581A variant), and integrated 12V bootstrap drivers supporting N-channel MOSFETs. It operates across –40°C to +85°C in PSOP-8 package and targets microprocessor core supplies requiring fast transient response.

For engineers reviewing the AP3581AMP-G1 datasheet, AP3581AMP-G1 pinout, AP3581AMP-G1 application, or AP3581AMP-G1 equivalent, key selection criteria include its voltage-mode control architecture, lossless R_DS(ON)-based overcurrent protection, built-in boot diode, 10MHz error amplifier bandwidth, and compatibility with pre-biased start-up in high-density power systems.

Technical Context

The AP3581AMP-G1 implements voltage-mode PWM control with a single feedback loop referenced to an internal 0.6V precision bandgap. Its error amplifier delivers 10MHz gain-bandwidth and 6V/µs slew rate to support high-loop bandwidth for sub-10µs load transient recovery in DDR memory and DSP core supplies.

Adaptive shoot-through protection monitors UGATE, LGATE, and PHASE pins to prevent cross-conduction; the integrated bootstrap diode eliminates external components while enabling 12V gate drive for high-side N-MOSFETs. Soft-start, UVLO (4.2V threshold), thermal shutdown (160°C), and programmable overcurrent via OPS resistor complete the protection suite.

Key Specifications

Parameter	Value and Actual Design Meaning
Control Mode	Voltage-mode PWM with single feedback loop - enables stable compensation using standard Type-II/III networks
Reference Voltage	0.6V ±1% - sets output as low as 0.6V via external resistor divider; tight tolerance reduces output regulation error
Switching Frequency	300kHz (±10%) - balances efficiency and size for mid-power applications; stable over temperature and line
Error Amplifier GBW	10MHz - supports >500kHz closed-loop bandwidth for fast transient response in CPU/GPU core rails
Max Duty Cycle	80% - allows ≥0.6V output from 5V input (e.g., 0.6V @ 5V = 12% duty); sufficient for common low-V_OUT applications
Overcurrent Protection	Lossless, R_DS(ON)-based via OPS pin - eliminates sense resistor; sets trip point with external ROCSET resistor
Startup Support	Pre-biased output compatible - prevents reverse current during hot-insertion or multi-rail sequencing

Pinout & Package

AP3581AMP-G1 is housed in a PSOP-8 package with exposed thermal pad (GND) for enhanced power dissipation. The 8-pin layout supports compact synchronous buck implementation with dedicated high- and low-side gate drivers, integrated bootstrap circuitry, and adaptive shoot-through protection sensing.

Pin/Terminal	Circuit Role	Design Meaning
1 BOOT	Bootstrap capacitor node	Connects 0.1–0.47µF capacitor to PHASE to generate >12V gate drive for upper N-MOSFET
2 UGATE	High-side gate driver output	Drives upper MOSFET gate; monitored for adaptive shoot-through prevention
3 OPS	Overcurrent threshold setting	Resistor to GND programs current limit using lower MOSFET R_DS(ON) - no sense resistor needed
4 LGATE	Low-side gate driver output	Drives lower MOSFET gate; monitored for adaptive shoot-through prevention
5 VCC	Bias supply input	Accepts 4.5–13.2V input; powers internal circuitry and gate drivers; requires local bypass capacitor
6 FB	Inverting error amplifier input	Connects to resistor divider from output; compares against 0.6V reference to regulate output voltage
7 COMP/EN	Error amp output & enable/disable	Compensation node for loop stability; pulled low to disable converter and enter shutdown mode
8 PHASE	Switch node	Connects to source of upper MOSFET and drain of lower MOSFET; monitored for timing and protection
9 GND	Signal & power ground	Exposed thermal pad - must be soldered to PCB ground plane for thermal and EMI performance

Key Features

Feature	Design Value
Integrated bootstrap diode	Eliminates external diode; reduces BOM count and layout area while maintaining 12V gate drive capability
10MHz error amplifier	Enables >500kHz control loop bandwidth - critical for <10µs recovery from 0→5A load steps in DDR3/DDR4 termination rails
Lossless overcurrent protection	Uses lower MOSFET R_DS(ON) as current sense element - avoids power loss and cost of discrete sense resistor
Pre-biased output startup	Allows safe turn-on when output capacitor is pre-charged - essential for hot-swap and multi-rail sequencing in servers
Adaptive shoot-through protection	Monitors UGATE, LGATE, and PHASE timing in real time - prevents simultaneous conduction without fixed dead-time programming

Applications

Microprocessor Core Supply

DDR SDRAM Termination

Use Scenario: Powering 1.2V/1.35V CPU or GPU cores in embedded controllers and industrial PCs.

IC Role / Device Role / Timing Role: Primary voltage-mode buck controller regulating core rail with fast transient response and precise 0.6V reference scaling.

Use Value: 10MHz error amplifier and 300kHz switching enable <10µs recovery from 0→10A load transients, minimizing voltage droop below ±3%.

Use Scenario: Providing SSTL-2 or DDR3/DDR4 VTT termination voltage (typically 0.6V or 0.9V) with tight regulation.

IC Role / Device Role / Timing Role: Low-noise, pre-biased-capable buck controller delivering stable termination voltage synchronized with data bus activity.

Use Value: Built-in soft-start and pre-biased startup prevent reverse current into termination network during system power-up sequencing.

PCI/AGP Graphics Card Rail

Industrial 5V/12V DC-DC Regulator

Use Scenario: Generating auxiliary 1.5V or 1.8V rails on PCIe or AGP graphics cards with space-constrained layouts.

IC Role / Device Role / Timing Role: Compact synchronous buck controller with integrated boot diode and PSOP-8 footprint minimizing board area.

Use Value: PSOP-8 package with exposed GND pad achieves ≤50°C/W θ_JA, supporting continuous 5A output without heatsink in 2-layer designs.

Use Scenario: General-purpose 5V-to-3.3V or 12V-to-5V regulation in industrial PLCs and HMIs where reliability and long-term availability matter.

IC Role / Device Role / Timing Role: Robust PWM controller with UVLO (4.2V), OVP, OTP (160°C), and R_DS(ON)-based OCP for field-deployed equipment.

Use Value: RoHS-compliant "G1" suffix and –40°C to +85°C operation ensure compliance with industrial environmental and regulatory requirements.

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck controller applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MP2238DJ-LF-Z	Current-mode control; 500kHz switching; no integrated boot diode; requires external bootstrap diode	Lacks pre-biased startup; higher switching frequency increases EMI filtering complexity	Preferred where higher frequency and current-mode stability outweigh boot diode integration benefits
RT8205AZSP	Voltage-mode control; 600kHz; 0.6V reference; no integrated boot diode; separate EN pin (vs. COMP/EN combo)	Higher f_SW demands smaller magnetics but reduces efficiency at high load; lacks adaptive shoot-through protection	Chosen when faster transient response is prioritized and external diode layout is acceptable

Compared with MP2238DJ-LF-Z and RT8205AZSP, AP3581AMP-G1 offers unique integration of boot diode and adaptive shoot-through protection in PSOP-8, simplifying layout and improving reliability in space-constrained, pre-biased, or thermally demanding applications - at the trade-off of fixed 300kHz frequency and no current-mode option.

Availability

AP3581AMP-G1 is available at Aetrix Electronics and suitable for microprocessor core supplies, DDR termination rails, PCI graphics card power, and industrial 5V/12V DC-DC regulators requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for AP3581AMP-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 design house specializing in high-performance, cost-optimized power management solutions for computing, communications, and industrial markets.

The AP3581A/B/C series was developed to deliver compact, integrated synchronous buck control for core and I/O rail regulation in space- and cost-sensitive applications - emphasizing ease of use, protection robustness, and thermal efficiency in PSOP-8.

FAQ

What is the function of the COMP/EN pin on AP3581AMP-G1?

The COMP/EN pin serves dual functions: it is the output node of the internal error amplifier used for loop compensation, and acts as the enable/disable control. Pulling this pin below 0.3V shuts down the controller, halting switching and reducing quiescent current to 4mA. External RC networks on this pin set phase margin and transient response characteristics per application requirements.

Does AP3581AMP-G1 support start-up into a pre-biased output?

Yes, AP3581AMP-G1 supports pre-biased output startup. Its control architecture prevents reverse current flow during turn-on when the output capacitor is already charged, making it suitable for hot-swap and multi-rail sequencing environments such as server motherboards and telecom line cards where rail ordering is critical.

How is overcurrent protection implemented without a sense resistor?

AP3581AMP-G1 uses lossless overcurrent protection by monitoring the voltage drop across the lower MOSFET's R_DS(ON). A resistor (ROCSET) connected between the OPS pin and GND sets the current threshold. This eliminates the power loss and board area associated with discrete current-sense resistors while maintaining accurate, temperature-compensated trip points.

What thermal considerations apply to the PSOP-8 package?

The PSOP-8 package features an exposed GND pad that must be soldered to a large PCB copper pour for effective heat dissipation. With θ_JA = 50°C/W, the device sustains continuous 5A output at ambient up to 60°C without forced airflow. Thermal shutdown triggers at 160°C with 20°C hysteresis, protecting against sustained overload or poor layout conditions.

AP3581AMP-G1 Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: 8-SOIC (0.154", 3.90mm Width) Exposed Pad

Packaging:: Tube

Product Status:: Obsolete

Output Type:: Transistor Driver

Function:: Step-Down

Output Configuration:: Positive

Topology:: Buck

Number of Outputs:: 1

Output Phases:: 1

Voltage - Supply (Vcc/Vdd):: 4.5V ~ 13.2V

Frequency - Switching:: 300kHz

Duty Cycle (Max):: 80%

Synchronous Rectifier:: Yes

Clock Sync:: No

Serial Interfaces:: -

Control Features:: Enable, Phase Control

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-PSOP

AP3581AMP-G1 FAQ

1.How can I place an order for AP3581AMP-G1 through Aetrix?

Please submit a Request for Quotation (RFQ) for AP3581AMP-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 AP3581AMP-G1 reliable?

The price and inventory of AP3581AMP-G1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP3581AMP-G1 is usually 5 days.

3.What payment methods are accepted for AP3581AMP-G1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP3581AMP-G1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP3581AMP-G1?

AP3581AMP-G1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP3581AMP-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 AP3581AMP-G1?

For technical support, including AP3581AMP-G1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP3581AMP-G1 requirements.

6.How does Aetrix verify that AP3581AMP-G1 is sourced from the original manufacturer or authorized distributors?

All AP3581AMP-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 AP3581AMP-G1 meets industry standards.

7.What is the process for return or replacement of AP3581AMP-G1?

All AP3581AMP-G1 units undergo pre-shipment inspection (PSI). If there is an issue with AP3581AMP-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 AP3581AMP-G1 part is unused and in its original packaging.

Return procedure for AP3581AMP-G1:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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