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

Diodes Incorporated AP3585AMPTR-G1

Name: AP3585AMPTR-G1
Brand: Diodes Incorporated
SKU: AP3585AMPTR-G1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP3585AMPTR-G1

Manufacturer:: Diodes Incorporated

Category:: DC DC Switching Controllers

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

Datasheet:: AP3585AMPTR-G1.pdf

Description:: IC REG CTRLR BUCK 8SO

Quantity:: RFQ Add To RFQ list

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Product details

Overview

AP3585AMPTR-G1 from Diodes Incorporated is a single-phase synchronous buck PWM controller in SO-8EP package, operating from 4.5V to 13.2V input and delivering regulated output down to 0.6V (AP3585B/C variant). It integrates dual MOSFET drivers with built-in bootstrap diode, supports lossless R_DS(ON)-based overcurrent protection, and features voltage-mode control with 10MHz error amplifier GBW and 6V/µs slew rate for fast transient response in DDR/SDRAM bus termination and graphics card subsystem supplies.

For engineers reviewing the AP3585AMPTR-G1 datasheet, AP3585AMPTR-G1 pinout, AP3585AMPTR-G1 application, or AP3585AMPTR-G1 equivalent, key selection criteria include fixed 200kHz/300kHz oscillator frequency, programmable OCSET threshold via external resistor, start-up into pre-biased load capability, thermal shutdown at +160°C, and compatibility with standard N-channel high-side/low-side MOSFETs in compact SO-8EP layout.

Technical Context

This controller implements voltage-mode PWM control with a single feedback loop referenced to an internal 0.6V bandgap reference (AP3585B/C), enabling precise output regulation across 3.3V–12V input range. The error amplifier delivers 10MHz gain-bandwidth and 6V/µs slew rate to support high converter bandwidth and sub-100µs load transient recovery.

It embeds adaptive shoot-through protection monitored on UGATE and PHASE pins, uses LGATE/OCSET as dual-function terminal for low-side gate drive and overcurrent threshold programming, and incorporates digital soft-start with 1.5ms ramp time (AP3585B) - confirmed by DS36819 Rev. 1–2 Section 5.2.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	4.5V to 13.2V VCC supply; supports 3.3V–12V VIN power input for buck stage
Output Voltage Range	0.6V to 80% of VIN - sets minimum 0.6V rail for DDR3/DDR4 termination and memory I/O
Oscillator Frequency	Fixed 200kHz (AP3585C) or 300kHz (AP3585A/B) - determines switching loss vs. filter size trade-off
Error Amplifier GBW	10MHz - enables >500kHz closed-loop bandwidth for <50µs 10A load step recovery
Overcurrent Protection	Lossless, R_DS(ON)-based using LGATE/OCSET pin; programmable via external resistor (10µA source)
Soft-Start Time	1.5ms (AP3585B) - prevents inrush current during power-up into pre-biased loads
Thermal Shutdown	+160°C with +20°C hysteresis - protects IC during sustained overload or poor heatsinking

Pinout & Package

AP3585AMPTR-G1 is housed in SO-8EP (exposed pad) package, where Pin 9 (exposed pad) must be soldered directly to PCB ground plane for thermal dissipation and EMI reduction. Package thermal resistance θ_JA is 70°C/W, enabling 1.43W power dissipation at T_A = +85°C.

Pin/Terminal	Circuit Role	Design Meaning
1: BOOT	Bootstrap capacitor connection node	Generates floating 12V+ gate drive for high-side N-MOSFET; requires 0.1µF ceramic cap to PHASE
2: UGATE	High-side MOSFET gate driver output	Drives upper switch with ±1.5A peak sink/source; monitored for adaptive shoot-through prevention
3: GND	Power and signal ground reference	Low-impedance return path for all currents; exposed pad (Pin 9) must connect to same ground plane
4: LGATE/OCSET	Low-side gate driver output & OC threshold input	Drives lower MOSFET gate; sets OCP trip point via external resistor (e.g., 30kΩ = ~30A limit)
5: VCC	Bias supply input	Accepts 4.5–13.2V; requires local 10µF + 0.1µF bypass to GND for stable operation
6: FB	Feedback input to error amplifier	Inverting input referenced to 0.6V internal VREF; used with resistor divider to set output voltage
7: COMP/EN	Compensation network node & enable input	Outputs error amplifier signal; pulled low disables controller; >0.3V initiates soft-start
8: PHASE	Switch node connection	Connects to source of high-side MOSFET and drain of low-side MOSFET; critical for shoot-through detection

Key Features

Feature	Design Value
Built-in bootstrap diode	Eliminates external diode, reducing BOM count and PCB area in high-density power modules
Voltage-mode control with 10MHz GBW	Enables stable loop compensation with minimal external components and robust phase margin >60°
Programmable R_DS(ON) overcurrent protection	Removes sense resistor, improving efficiency and eliminating power loss in current sensing path
Start-up into pre-biased output	Allows safe power sequencing in multi-rail systems where output voltage is already present at turn-on
Digital soft-start with 1.5ms ramp	Prevents output overshoot and inrush stress on input capacitors and downstream regulators

Applications

PCI/AGP Graphics Card Power

DDR3/DDR4 SDRAM Bus Termination

Use Scenario: Regulating 1.2V/1.35V termination voltage for high-speed GPU memory interfaces with tight ripple and transient requirements.

IC Role / Device Role / Timing Role: Primary synchronous buck controller managing power delivery to parallel SSTL-2/HSUL-12 termination networks.

Use Value: 6V/µs slew rate and 10MHz GBW ensure <100µs recovery from 10A load steps, maintaining signal integrity under dynamic GPU workloads.

Use Scenario: Providing stable 0.6V–1.5V VTT rails for DDR3/DDR4 memory modules in set-top boxes and industrial controllers.

IC Role / Device Role / Timing Role: Voltage-mode buck controller delivering tightly regulated termination supply synchronized to memory clock domains.

Use Value: Built-in 0.6V reference and 80% max duty cycle enable direct generation of JEDEC-compliant VTT without external DAC or trimming.

Cable Modem Power Subsystem

Industrial FPGA I/O Bank Supply

Use Scenario: Generating isolated 1.0V–1.8V auxiliary rails for DOCSIS 3.1 PHY and MAC processors in space-constrained cable modems.

IC Role / Device Role / Timing Role: Compact, integrated buck controller replacing discrete driver + controller solutions in legacy designs.

Use Value: SO-8EP package with 70°C/W θ_JA allows full 15A output in 12mm² footprint without heatsink, meeting ETSI thermal limits.

Use Scenario: Delivering configurable 1.2V/1.8V/2.5V I/O supply for Xilinx/Intel FPGA banks requiring independent voltage sequencing.

IC Role / Device Role / Timing Role: Programmable buck controller supporting multiple output voltages via FB divider and OCSET tuning.

Use Value: LGATE/OCSET pin enables per-rail current limiting; COMP/EN pin supports daisy-chained power-up sequencing with external logic.

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 (Monolithic Power)	Current-mode control; 500kHz switching; no integrated bootstrap diode; requires external OC sense resistor	Higher switching frequency enables smaller inductors but increases EMI filtering burden in noise-sensitive CATV systems	Select when higher frequency and current-mode stability outweigh need for reduced BOM count and R_DS(ON) sensing
RT8205AZSP (Richtek)	Voltage-mode control; 300kHz; 0.6V reference; no pre-bias start-up; thermal shutdown at +150°C	Lacks start-up into pre-biased load - unsuitable for hot-swap or multi-rail sequenced systems	Choose only for cost-sensitive, non-sequenced applications where soft-start timing and bias tolerance are not required

Compared with MP2238DJ-LF-Z and RT8205AZSP, AP3585AMPTR-G1 uniquely combines integrated bootstrap diode, R_DS(ON)-based OCP, and guaranteed pre-biased start-up - making it optimal for space-constrained, multi-rail embedded systems requiring minimal external components and robust power sequencing.

Availability

AP3585AMPTR-G1 is available at Aetrix Electronics and suitable for PCI graphics card power, DDR3/DDR4 bus termination, and cable modem subsystems requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for AP3585AMPTR-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 industrial, computing, and consumer markets.

The AP3585A/B/C product line delivers compact, integrated synchronous buck controllers targeting DDR/SDRAM termination, graphics subsystems, and broadband infrastructure - emphasizing reduced external component count, thermal robustness, and seamless integration with standard N-channel MOSFETs.

FAQ

What is the function of the LGATE/OCSET pin?

The LGATE/OCSET pin serves dual roles: it outputs the low-side MOSFET gate drive signal and accepts an external resistor to program the overcurrent protection threshold. A 10µA internal current source flows through this resistor to generate a voltage drop across the low-side MOSFET's R_DS(ON), enabling lossless current sensing without a dedicated sense resistor or shunt.

Does AP3585AMPTR-G1 support start-up into a pre-biased output?

Yes - AP3585AMPTR-G1 explicitly supports start-up into pre-biased loads, as confirmed in DS36819 Section 5.2. During soft-start initiation, the controller monitors the FB pin voltage and adjusts the COMP ramp to avoid reverse current flow, ensuring safe turn-on when the output rail is already energized by another source.

How does the built-in bootstrap diode simplify design?

The integrated bootstrap diode eliminates the need for an external discrete diode between BOOT and PHASE, reducing component count, PCB area, and potential failure points. It enables reliable high-side gate drive using a single 0.1µF ceramic capacitor, simplifying layout and improving reliability in high-volume consumer and industrial power supplies.

What is the maximum duty cycle and why is it limited to 80%?

The maximum duty cycle is 80%, as specified in DS36819 Section 4. This limit ensures sufficient off-time for accurate R_DS(ON)-based overcurrent detection during the low-side conduction period. Exceeding 80% would compromise OCP response time and risk undetected current faults during high-load conditions.

AP3585AMPTR-G1 Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

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

Packaging:: Tape & Reel (TR)

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):: 82%

Synchronous Rectifier:: Yes

Clock Sync:: Yes

Serial Interfaces:: -

Control Features:: Enable, Phase Control

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SO-EP

AP3585AMPTR-G1 FAQ

1.How can I place an order for AP3585AMPTR-G1 through Aetrix?

Please submit a Request for Quotation (RFQ) for AP3585AMPTR-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 AP3585AMPTR-G1 reliable?

The price and inventory of AP3585AMPTR-G1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP3585AMPTR-G1 is usually 5 days.

3.What payment methods are accepted for AP3585AMPTR-G1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP3585AMPTR-G1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP3585AMPTR-G1?

AP3585AMPTR-G1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP3585AMPTR-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 AP3585AMPTR-G1?

For technical support, including AP3585AMPTR-G1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP3585AMPTR-G1 requirements.

6.How does Aetrix verify that AP3585AMPTR-G1 is sourced from the original manufacturer or authorized distributors?

All AP3585AMPTR-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 AP3585AMPTR-G1 meets industry standards.

7.What is the process for return or replacement of AP3585AMPTR-G1?

All AP3585AMPTR-G1 units undergo pre-shipment inspection (PSI). If there is an issue with AP3585AMPTR-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 AP3585AMPTR-G1 part is unused and in its original packaging.

Return procedure for AP3585AMPTR-G1:

1.Submit a request within 90 days.

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

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