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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - DC DC Switching Regulators

onsemi FAN21SV06EMPX

Name: FAN21SV06EMPX
Brand: onsemi
SKU: FAN21SV06EMPX
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: FAN21SV06EMPX

Manufacturer:: onsemi

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 25-WQFN Exposed Pad

Datasheet:: FAN21SV06EMPX.pdf

Description:: IC REG BUCK ADJ 6A 25MLP

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Product details

Overview

FAN21SV06EMPX from onsemi is a 6 A, 24 V input integrated synchronous buck regulator in a 5 × 6 mm, 25-pin MLP package, featuring programmable 200–600 kHz switching frequency, internal 5 V bias regulator, and master/slave synchronization capability. It delivers up to 94% efficiency at 1.8 V/6 A output with ceramic-capacitor support and is used in point-of-load regulation for telecom and high-end computing systems.

For engineers reviewing the FAN21SV06EMPX datasheet, pinout, applications, or equivalent options, key selection criteria include its -40°C to +85°C operating range, integrated high- and low-side MOSFETs, external compensation flexibility, pre-bias startup capability, and programmable over-current protection with RILIM resistor interface.

Technical Context

The FAN21SV06EMPX implements summing-mode PWM control using an internally generated ramp signal combined with amplified current-sense feedback. Its dual-supply architecture supports VIN_Reg ≥ 6.5 V for single-input operation or separate low-power VIN_Reg supply down to 3.0 V.

It integrates a thermally optimized 5 V regulator (±3% output, 5 mA max load), programmable soft-start timing (T_0.8 = 2.5 ms, T_1.0 = 3.1 ms), and fault management with latched or auto-restart behavior controlled via EN pin configuration. Protection includes cycle-by-cycle over-current, over-voltage (115% V_REF), under-voltage (73% V_REF), and thermal shutdown at 155°C.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Current	6 A continuous - supports high-current PoL conversion without external MOSFETs or gate drivers.
Input Voltage Range	3.0 V to 24 V - enables dual-supply (VIN/VIN_Reg) or single-supply (>6.5 V) configurations.
Switching Frequency	200–600 kHz - programmable via RT resistor; supports all-ceramic designs and EMI optimization.
Reference Voltage	0.800 V ±0.6% - precise FB threshold enabling stable 0.8–19.2 V output range (up to 80% VIN).
Thermal Resistance	θ_J-PCB = 35 °C/W - validated on 4-layer, 2-oz copper PCB; enables 2.8 W dissipation at 25°C ambient.
Operating Temperature	-40°C to +85°C - extended industrial grade rating confirmed for FAN21SV06EMPX variant.
Protection Features	Over-current (7–11 A), over-voltage (110–120% V_OUT), under-voltage (68–78% V_OUT), thermal shutdown (155°C) - all latchable or auto-recover per EN configuration.

Pinout & Package

Package: 5 × 6 mm, 25-pin Molded Leadless Package (MLP) with three exposed thermal pads (P1, P2, P3) for enhanced heat dissipation. Pin numbering follows bottom-view layout per Figure 3.

Pin/Terminal	Circuit Role	Design Meaning
SW (P1, P6–P12)	Switching Node	Junction of integrated high- and low-side MOSFETs; connects to inductor and bootstrap capacitor (C_BOOT).
VIN (P2, P3–P5)	Main Power Input	Supplies power stage; accepts 3.0–24 V; decoupled with bulk and HF capacitors.
PGND (P3, P21–P23)	Power Ground	Low-side MOSFET source return; must be tied directly to thermal pad P3 for optimal thermal performance.
BOOT (Pin 1)	High-Side Gate Drive Supply	Internal bootstrap diode recharges C_BOOT; requires 10–100 nF ceramic capacitor between BOOT and SW.
VIN_Reg (Pin 2)	Bias Regulator Input	Input to internal 5 V regulator; must be ≥6.5 V for single-supply operation; bypassed with ≥1 µF X5R/X7R.
PGOOD (Pin 13)	Power-Good Monitor	Open-drain output asserting LOW when FB deviates >11% below or >13.5% above V_REF; delays HIGH assertion until soft-start completion.
EN (Pin 14)	Enable Control	Logic-high active; internal pull-up; toggling resets latched faults; discharge current enables auto-restart configuration.
5V_Reg (Pin 15)	Internal Regulator Output	5.0 V ±3% regulated supply for IC logic/analog circuits; requires ≥2.2 µF X5R/X7R to PGND; capable of 5 mA sourcing.
AGND (Pin 16)	Analog Ground Reference	Signal ground for error amplifier, COMP, FB, and compensation network; must connect to low-impedance ground plane.
ILIM (Pin 17)	Current Limit Programming	Connects to AGND via R_ILIM to set trip threshold below internal default (7–11 A); uses 10 µA current source.
RT (Pin 18)	Oscillator & Master/Slave Config	Resistor to AGND sets f_SW and configures CLK as master output; resistor to 5V_Reg configures slave mode with free-run fallback.
FB (Pin 19)	Feedback Input	Connects to resistor divider from V_OUT; 650 nA sink current enables open-circuit detection and precise 0.8 V reference tracking.
COMP (Pin 20)	Compensation Node	Error amplifier output; external RC network between COMP and FB sets loop stability and transient response.
CLK (Pin 24)	Synchronization Interface	Bi-directional: outputs synchronized clock (180° phase shift) in master mode; accepts external clock in slave mode.
RAMP (Pin 25)	Ramp Amplitude Control	Resistor to VIN sets internal ramp slope and provides voltage feedforward for improved line regulation.

Key Features

Feature	Design Value
Fully integrated synchronous buck	Includes matched high- and low-side MOSFETs with optimized interconnects - eliminates discrete driver, gate resistors, and external Schottky diode.
Single-supply operation	On-board 5 V regulator enables full functionality from VIN ≥ 6.5 V - reduces system BOM and simplifies power sequencing.
Pre-bias startup	Blocks low-side MOSFET conduction until soft-start reaches 95% V_REF - prevents output discharge during hot-insertion or multi-rail sequencing.
Flexible synchronization	CLK pin supports master (180° phase-shifted output) or slave (external clock input with 15% tolerance) modes - enables multi-phase interleaving or system-level clock alignment.
External compensation	COMP pin allows full control of loop gain, bandwidth, and phase margin - supports wide range of output capacitors, inductors, and load conditions.
Robust fault management	Configurable EN behavior (latched OFF, immediate restart, or auto-restart) plus independent UV/OV/OC/thermal protections - ensures reliable operation in mission-critical PoL applications.

Applications

Server Point-of-Load Regulation	Telecom Line Card Power
Use Scenario: Providing 1.2 V/6 A to FPGA core rails in dense 1U server blades with strict thermal and space constraints. IC Role / Device Role / Timing Role: Integrated buck regulator delivering tightly regulated output with programmable soft-start and PGOOD sequencing signal. Use Value: Eliminates need for external MOSFETs and drivers while maintaining >92% efficiency at full load across 12–24 V input range.	Use Scenario: Generating 3.3 V/4 A for DSP and PHY ICs on carrier-grade line cards requiring EMI-compliant, synchronized switching. IC Role / Device Role / Timing Role: Synchronized buck controller operating as slave to system clock - enables interleaved operation and reduced input ripple. Use Value: Achieves <15 mVpp output ripple with ceramic output caps and meets EN55022 Class B conducted emissions without shielding.
Graphics Card GPU Core Supply	High-End Gaming Console SoC Rail
Use Scenario: Delivering dynamic 0.8–1.3 V/6 A to GPU cores with rapid load transients (0–6 A in <1 µs) and thermal cycling. IC Role / Device Role / Timing Role: High-efficiency synchronous buck with external ramp feedforward and fast-response compensation network. Use Value: Maintains ±1.5% output regulation during 4 A/µs load steps and limits peak case temperature to <85°C at 6 A/24 V input.	Use Scenario: Powering application processor SoC in compact gaming console with limited board area and no forced airflow. IC Role / Device Role / Timing Role: Thermally efficient PoL regulator using MLP package with direct thermal pad connection to heatsink. Use Value: Dissipates 2.1 W at full load while sustaining -40°C to +85°C ambient operation without derating.

Server Point-of-Load Regulation

Telecom Line Card Power

Use Scenario: Providing 1.2 V/6 A to FPGA core rails in dense 1U server blades with strict thermal and space constraints.

IC Role / Device Role / Timing Role: Integrated buck regulator delivering tightly regulated output with programmable soft-start and PGOOD sequencing signal.

Use Value: Eliminates need for external MOSFETs and drivers while maintaining >92% efficiency at full load across 12–24 V input range.

Use Scenario: Generating 3.3 V/4 A for DSP and PHY ICs on carrier-grade line cards requiring EMI-compliant, synchronized switching.

IC Role / Device Role / Timing Role: Synchronized buck controller operating as slave to system clock - enables interleaved operation and reduced input ripple.

Use Value: Achieves <15 mVpp output ripple with ceramic output caps and meets EN55022 Class B conducted emissions without shielding.

Graphics Card GPU Core Supply

High-End Gaming Console SoC Rail

Use Scenario: Delivering dynamic 0.8–1.3 V/6 A to GPU cores with rapid load transients (0–6 A in <1 µs) and thermal cycling.

IC Role / Device Role / Timing Role: High-efficiency synchronous buck with external ramp feedforward and fast-response compensation network.

Use Value: Maintains ±1.5% output regulation during 4 A/µs load steps and limits peak case temperature to <85°C at 6 A/24 V input.

Use Scenario: Powering application processor SoC in compact gaming console with limited board area and no forced airflow.

IC Role / Device Role / Timing Role: Thermally efficient PoL regulator using MLP package with direct thermal pad connection to heatsink.

Use Value: Dissipates 2.1 W at full load while sustaining -40°C to +85°C ambient operation without derating.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MP2451DT-LF-Z	3 A rated, 2–36 V input, fixed 500 kHz f_SW, no synchronization or external compensation.	Limited to lower-current applications; lacks master/slave CLK, PGOOD, and adjustable current limit.	Select when cost-sensitive, low-complexity 3 A PoL is sufficient and synchronization is unnecessary.
TPS546B24RVFT	12 A rated, 4–18 V input, PMBus interface, digital loop compensation, 0.6 V reference.	Higher integration with telemetry and configurability; requires digital design expertise and firmware support.	Select for systems needing real-time telemetry, adaptive loop tuning, or multi-rail coordination via PMBus.

Compared with MP2451DT-LF-Z and TPS546B24RVFT, the FAN21SV06EMPX offers balanced integration-supporting 6 A loads, analog programmability (frequency, current limit, ramp), and hardware-based synchronization-without requiring digital infrastructure or sacrificing thermal performance in compact layouts.

Availability

FAN21SV06EMPX is available at Aetrix Electronics and suitable for server point-of-load regulation, telecom line card power, and high-end gaming console SoC rail applications requiring stable component supply across industrial temperature ranges.

Supply support for FAN21SV06EMPX 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

onsemi is a global semiconductor supplier focused on energy-efficient innovation, delivering silicon solutions for automotive, industrial, cloud, and IoT applications.

The FAN21SV06EMPX belongs to the TinyBuck™ family of integrated synchronous buck regulators, designed specifically for high-current, space-constrained point-of-load applications demanding minimal external components and robust thermal performance.

FAQ

What is the maximum output current supported by the FAN21SV06EMPX?

The FAN21SV06EMPX supports up to 6 A continuous output current under recommended operating conditions (T_A ≤ 85°C, proper PCB thermal design). Its internal MOSFETs and 35 °C/W junction-to-PCB thermal resistance enable this rating without external components. Derating may be required above 60°C ambient or with suboptimal copper layout. The FAN21SV06EMPX datasheet specifies 7–11 A over-current protection thresholds depending on R_ILIM configuration.

Does the FAN21SV06EMPX support startup into a pre-biased output?

Yes, the FAN21SV06EMPX supports startup into a pre-biased output. It inhibits low-side MOSFET conduction until the internal soft-start ramp reaches ~95% of the reference voltage (≈0.76 V), preventing reverse current flow and output discharge. This behavior is explicitly verified in the datasheet's Figure 20 ("Startup on Pre-Bias") and applies across the full -40°C to +85°C operating range of the FAN21SV06EMPX.

How is the switching frequency programmed on the FAN21SV06EMPX?

The switching frequency of the FAN21SV06EMPX is programmed using an external resistor (R_T) connected to Pin 18 (RT). In master mode (R_T to AGND), f_SW = 10⁶/(R_T + 65) kHz, yielding 200–600 kHz over 24–50 kΩ. In slave mode (R_T to 5V_Reg), the same resistor sets a free-running frequency ~10% slower, while allowing synchronization to an external clock on Pin 24 (CLK). The FAN21SV06EMPX requires R_T to be populated for startup in master mode.

What protection features does the FAN21SV06EMPX include?

The FAN21SV06EMPX includes cycle-by-cycle over-current protection (programmable via R_ILIM), over-voltage protection (110–120% V_OUT), under-voltage protection (68–78% V_OUT), thermal shutdown (155°C), and input UVLO (5.6–6.3 V). All protections are latched by default but can be configured for auto-restart via EN pin termination. These features are fully implemented in silicon and validated across the -40°C to +85°C range of the FAN21SV06EMPX.

Can the FAN21SV06EMPX operate with input voltages below 6.5 V?

Yes, the FAN21SV06EMPX can operate with input voltages as low as 3.0 V when configured in dual-supply mode: VIN (3.0–24 V) powers the power stage, while a separate ≥6.5 V supply is applied to VIN_Reg (Pin 2) to power the internal 5 V regulator and control circuitry. This configuration is documented in Figure 11 and the "Dual-Supply Application Circuit" section of the FAN21SV06EMPX datasheet.

FAN21SV06EMPX Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: TinyBuck®

Package/Case:: 25-WQFN Exposed Pad

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):: 3V

Voltage - Input (Max):: 24V

Voltage - Output (Min/Fixed):: 0.8V

Voltage - Output (Max):: 19.2V

Current - Output:: 6A

Frequency - Switching:: 200kHz ~ 600kHz

Synchronous Rectifier:: Yes

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 25-MLP (6x5)

FAN21SV06EMPX FAQ

1.How can I place an order for FAN21SV06EMPX through Aetrix?

Please submit a Request for Quotation (RFQ) for FAN21SV06EMPX 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 FAN21SV06EMPX reliable?

The price and inventory of FAN21SV06EMPX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FAN21SV06EMPX is usually 5 days.

3.What payment methods are accepted for FAN21SV06EMPX?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FAN21SV06EMPX transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for FAN21SV06EMPX?

FAN21SV06EMPX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your FAN21SV06EMPX 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 FAN21SV06EMPX?

For technical support, including FAN21SV06EMPX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FAN21SV06EMPX requirements.

6.How does Aetrix verify that FAN21SV06EMPX is sourced from the original manufacturer or authorized distributors?

All FAN21SV06EMPX 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 FAN21SV06EMPX meets industry standards.

7.What is the process for return or replacement of FAN21SV06EMPX?

All FAN21SV06EMPX units undergo pre-shipment inspection (PSI). If there is an issue with FAN21SV06EMPX, 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 FAN21SV06EMPX part is unused and in its original packaging.

Return procedure for FAN21SV06EMPX:

1.Submit a request within 90 days.

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

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