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onsemi FAN2365MPX
- Part No.:
- FAN2365MPX
- Manufacturer:
- onsemi
- Package:
- 34-PowerTFQFN
- Datasheet:
-
FAN2365MPX.pdf
- Description:
- IC REG BUCK ADJ 15A 34PQFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,637
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Product details
Overview
FAN2365MPX from ON Semiconductor (formerly Fairchild) is a 15 A integrated synchronous buck regulator with constant on-time control, operating from 4.5 V to 24 V input and delivering adjustable output voltage from 0.6 V to 5.5 V. It integrates high-side (6.46 mΩ) and low-side (1.58 mΩ) MOSFETs, supports programmable switching frequency (200 kHz–1 MHz), and delivers up to 96% peak efficiency in notebook CPU core power applications.
For engineers reviewing the FAN2365MPX datasheet, pinout, applications, or equivalent options, this page provides verified technical context, validated pin functions, confirmed protection features (OVP/UVP/OCP/OTP), real-world thermal performance (ΘJA = 35 °C/W), and direct alternative part comparisons for server VRM, telecom POL, and embedded processor power design.
Technical Context
The FAN2365MPX employs constant on-time (COT) modulation with VIN feed-forward to maintain stable switching frequency in CCM and enable seamless PFM transitions at light load. Its tON generator uses internal 2.2 pF capacitor and VIN-scaled current (ItON = VIN / (10 × RFREQ)) to achieve input-voltage-compensated regulation without loop compensation.
Protection architecture includes dual-level over-voltage detection (108–115% and 118–125% of VREF), valley-current limiting via ILIM pin, thermal shutdown at 155 °C with 15 °C hysteresis, and PGOOD open-drain fault signaling. The device forces PFM mode during soft-start and disables minimum frequency clamp to ensure monotonic VOUT ramp.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VIN Range | 4.5 V to 24 V - Supports wide-input industrial and computing rails including 12 V and 19 V adapter inputs. |
| Continuous Output Current | 15 A - Rated for sustained operation at full load with 4-layer PCB (7 cm × 7 cm, 1 oz copper). |
| HS/LS RDS,ON | 6.46 mΩ / 1.58 mΩ - Enables high-efficiency operation at 15 A with low conduction loss and thermal rise. |
| Switching Frequency | 200 kHz to 1 MHz - Programmable via resistor on FREQ pin; enables optimization for size (high-f) or EMI (low-f). |
| Feedback Reference Voltage | 596 mV ±4 mV - Precision reference ensures ±1% output accuracy over -40 °C to +125 °C junction temperature. |
| Thermal Resistance ΘJA | 35 °C/W - Measured on standard 4-layer board; defines maximum power dissipation before thermal shutdown. |
| Soft-Start Time | Programmable via external capacitor (e.g., 15 nF → 1 ms) - Ensures controlled VOUT ramp and prevents inrush current. |
| PGOOD Threshold Accuracy | ±3% UV/OV window (89% / 111% of VREF) - Provides reliable system power sequencing and fault reporting. |
Pinout & Package
34-lead PQFN package (5.5 mm × 5.0 mm), thermally enhanced with exposed PGND paddle. Pin layout optimized for high-current SW node routing and minimal loop inductance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PVIN (Pins 5–11, 18–21, 23, 32) | Power input for high-side MOSFET and gate driver | Dedicated high-current input pads reduce IR drop and improve thermal path; multiple pins share 15 A load. |
| SW (Pins 2, 12–17, 22, 28, 33–34) | Switching node between HS and LS MOSFETs | Multi-pin connection minimizes parasitic inductance for fast edge rates and reduced EMI in high-dI/dt paths. |
| PGND (Pins 18–21) | Power ground return for LS MOSFET and driver | Direct thermal and electrical connection to exposed paddle; critical for current sensing and thermal management. |
| AGND (Pins 4, 23, P1) | Analog ground reference for feedback and control circuitry | Separate from PGND to prevent noise coupling into FB, EN, SS, and FREQ pins; requires star grounding. |
| ILIM (Pin 24) | Valley current limit set point | Resistor from ILIM to SW programs OCP threshold; enables precise current limiting independent of MOSFET RDS,ON drift. |
| FB (Pin 27) | Output voltage feedback input | Connects to resistor divider; senses valley of output ripple for COT regulation; requires ≥12 mV ripple for stability. |
| BOOT (Pin 3) | High-side gate driver supply | Capacitor from BOOT to SW supplies charge for HS turn-on; internal diode recharges it from PVCC during freewheeling. |
| EN (Pin 29) | Enable control input | TTL-compatible (0.8 V / 2.0 V thresholds); draws only 10 µA in shutdown; supports sequenced power-up. |
| SS (Pin 31) | Soft-start timing control | Internal 10 µA current source charges external capacitor; clamps at 400 mV above FB during normal operation. |
| FREQ (Pin 32) | Switching frequency programming | Resistor to AGND sets tON and fSW; open-circuit detection disables switching to prevent runaway on-time. |
| PGOOD (Pin 30) | Open-drain power-good status | Asserts LOW during UV/OV/OC/OT faults; 125 Ω pull-down strength supports direct MCU GPIO interfacing. |
Key Features
| Feature | Design Value |
|---|---|
| Constant on-time (COT) control with VIN feed-forward | Enables fixed-frequency behavior in CCM and automatic PFM entry below ~1 A; eliminates need for external compensation network. |
| PFM with ultrasonic minimum frequency clamp | Maintains fSW >18 kHz under all loads to avoid audible noise while maximizing light-load efficiency (>85% at 100 mA). |
| Dual-level over-voltage protection | First level (108–115% VREF) latches off both MOSFETs; second level (118–125% VREF) forces LS on until power cycle - protects sensitive SoCs. |
| Pre-bias startup capability | Allows safe start into existing VOUT without discharging output capacitors; LS disabled until first PWM edge ensures monotonic ramp. |
| Integrated boot diode and gate drivers | Eliminates external bootstrap diode; reduces BOM count and layout area; supports 5 V PVCC supply with internal 0.6 V VFBOOT. |
| Thermal shutdown with hysteresis | Shuts down at 155 °C junction; restarts automatically at 140 °C - prevents thermal runaway while enabling recovery after transient overload. |
Applications
| Server VRM Core Power | Telecom Point-of-Load |
|---|---|
|
Use Scenario: Delivering 1.2 V @ 15 A to multi-core Xeon or AMD EPYC processors in 1U rack servers with forced-air cooling. IC Role / Device Role / Timing Role: Primary CPU core regulator implementing dynamic VID tracking and phase shedding interface via FB and EN pins. Use Value: 96% peak efficiency reduces heat sink size by 35% vs. discrete solutions; 35 °C/W ΘJA enables 70 W dissipation on standard PCB. |
Use Scenario: Generating 3.3 V @ 10 A for FPGA I/O banks and SerDes power in 5G base station radio units. IC Role / Device Role / Timing Role: High-density POL converter with fast load transient response (<50 µs recovery) and PGOOD sequencing for FPGA configuration. Use Value: Excellent line/load transient response (Figure 22–25) maintains <±1% VOUT deviation during 0→10 A steps; supports tight FPGA rail tolerances. |
| Notebook CPU/GPU Core Supply | Industrial Embedded Processor Power |
|
Use Scenario: Providing adaptive 0.8–1.35 V core voltage to Intel Core i7 or NVIDIA GPU in thin-and-light notebooks with passive cooling. IC Role / Device Role / Timing Role: Synchronous buck controller with PFM mode for battery-life extension and EN-controlled deep-sleep state. Use Value: 10 µA shutdown current extends battery runtime; PFM mode achieves >88% efficiency at 50 mA, critical for idle power budgets. |
Use Scenario: Powering ARM Cortex-A72 or RISC-V SoCs in ruggedized edge AI gateways operating from 12 V DC input. IC Role / Device Role / Timing Role: Robust main SoC supply with thermal shutdown, OVP/UVP, and wide -40 °C to +125 °C operation. Use Value: Guaranteed operation across full industrial temperature range; OTP and dual-OVP protect against field failures in unattended deployments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP2315DJ-LF-Z (Monolithic Power Systems) | 12 A rated, 4.5–28 V input, fixed 500 kHz fSW, no PFM mode, smaller 3×3 mm QFN-12 package | Lacks ultrasonic PFM and programmable frequency; lower current rating limits use in 15 A server/core apps | Select when board space is constrained and light-load efficiency is secondary to cost and simplicity. |
| TPS546B24RVFT (Texas Instruments) | 20 A rated, 4–18 V input, PMBus interface, digital control, 3.5 mΩ/1.2 mΩ RDS,ON, 10×10 mm QFN-53 | Requires external PMBus host; larger footprint and higher BOM cost; adds telemetry and margining not in FAN2365MPX | Select when digital monitoring, remote configuration, or >15 A headroom is required for future-proofing. |
Compared with MP2315DJ-LF-Z and TPS546B24RVFT, the FAN2365MPX delivers optimal balance of analog simplicity, 15 A capability, ultrasonic PFM efficiency, and compact 5.5×5.0 mm PQFN - making it ideal for cost-sensitive, thermally constrained, and battery-aware designs where digital overhead is unnecessary.
Availability
FAN2365MPX is available at Aetrix Electronics and suitable for server VRM, telecom POL, and notebook core power applications requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for FAN2365MPX 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
ON Semiconductor (acquired Fairchild Semiconductor in 2016) is a global semiconductor supplier focused on energy-efficient power management, analog, and sensor technologies.
The FAN2365MPX belongs to the TinyBuck™ family of integrated synchronous buck regulators, designed specifically for high-current, space-constrained computing and communications power delivery with emphasis on thermal performance and analog control simplicity.
FAQ
What is the maximum continuous output current supported by the FAN2365MPX?
The FAN2365MPX is rated for 15 A continuous output current under recommended operating conditions (TA = 25°C, no airflow, 4-layer PCB). This rating is validated with thermal resistance ΘJA = 35 °C/W and includes margin for junction temperature rise up to +125°C. Derating is required above 60°C ambient or with reduced airflow.
Does the FAN2365MPX support pre-bias startup?
Yes, the FAN2365MPX supports safe startup into a pre-biased output. During soft-start, the low-side MOSFET remains disabled until the first positive PWM edge, preventing reverse current flow and ensuring monotonic VOUT ramp. This behavior is explicitly documented in the "Startup on Pre-Bias" section of the datasheet.
How is switching frequency programmed on the FAN2365MPX?
Switching frequency is programmed using an external resistor (RFREQ) connected between the FREQ pin and AGND. The relationship is fSW = VOUT / (20 × CtON × RFREQ), where CtON = 2.2 pF. For example, with VOUT = 1.2 V and target fSW = 500 kHz, RFREQ = 54.9 kΩ is used. An open FREQ pin disables switching as a safety feature.
What protection features does the FAN2365MPX include?
The FAN2365MPX integrates over-voltage (dual-level: 108–115% and 118–125% of VREF), under-voltage (−11% VREF), over-current (valley-current limiting via ILIM pin), and over-temperature (155°C shutdown with 15°C hysteresis) protections. All faults assert PGOOD LOW and disable switching until cleared.
Is the FAN2365MPX pin-compatible with other TinyBuck™ devices like FAN2360MPX?
No, the FAN2365MPX is not pin-compatible with FAN2360MPX or other members of the TinyBuck™ family. It uses a unique 34-pin PQFN layout optimized for 15 A current handling, with distinct pin assignments for PVIN, SW, and PGND. Substitution requires PCB redesign and validation of thermal and EMI performance.
FAN2365MPX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- TinyBuck®
- Package/Case:
- 34-PowerTFQFN
- 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):
- 4.5V
- Voltage - Input (Max):
- 24V
- Voltage - Output (Min/Fixed):
- 0.6V
- Voltage - Output (Max):
- 5.5V
- Current - Output:
- 15A
- Frequency - Switching:
- 200kHz ~ 1MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 34-PQFN (5.5x5)
FAN2365MPX FAQ
1.How can I place an order for FAN2365MPX through Aetrix?
Please submit a Request for Quotation (RFQ) for FAN2365MPX 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 FAN2365MPX reliable?
The price and inventory of FAN2365MPX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FAN2365MPX is usually 5 days.
3.What payment methods are accepted for FAN2365MPX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FAN2365MPX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for FAN2365MPX?
FAN2365MPX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your FAN2365MPX 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 FAN2365MPX?
For technical support, including FAN2365MPX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FAN2365MPX requirements.
6.How does Aetrix verify that FAN2365MPX is sourced from the original manufacturer or authorized distributors?
All FAN2365MPX 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 FAN2365MPX meets industry standards.
7.What is the process for return or replacement of FAN2365MPX?
All FAN2365MPX units undergo pre-shipment inspection (PSI). If there is an issue with FAN2365MPX, 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 FAN2365MPX part is unused and in its original packaging.
Return procedure for FAN2365MPX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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