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Infineon Technologies IR3846MTRPBF
- Part No.:
- IR3846MTRPBF
- Manufacturer:
- Infineon Technologies
- Package:
- 34-PowerVFQFN
- Datasheet:
-
IR3846MTRPBF.pdf
- Description:
- IC REG BUCK ADJ 35A 34PQFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,050
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Product details
Overview
IR3846MTRPBF from Infineon Technologies is a highly integrated synchronous buck DC/DC regulator with integrated high- and low-side MOSFETs, delivering up to 35A output current at 0.6V–0.86×PVin. It operates from 1.5V–21V input (with external Vcc) or 5V–21V single-input, features 0.5% reference accuracy, programmable 300–1500kHz switching frequency, and supports remote differential sensing for precision load regulation in server point-of-load applications.
For engineers reviewing the IR3846MTRPBF datasheet, IR3846MTRPBF pinout, IR3846MTRPBF application, or IR3846MTRPBF equivalent, key selection criteria include its thermally compensated hiccup-mode overcurrent protection, post-package trimmed dead-time, Smart LDO biasing, true differential remote sense amplifier (±1.5mV offset), and dedicated Vp/Vref pins for voltage tracking and margining in multi-rail systems.
Technical Context
The IR3846 implements a voltage-mode PWM controller with feed-forward compensation, enabling enhanced line regulation across wide input ranges. Its error amplifier delivers 100–120dB DC gain and 20–40MHz GBWP, supporting stable loop response with external RC compensation on COMP.
It integrates a digital soft-start clock (180–220kHz), body braking for improved transient response, and independent overvoltage protection on Vsns that remains active even when Enable is low. The remote sense amplifier provides 3–9MHz unity-gain bandwidth and 110dB DC gain, with ±2mV offset over –40°C to +125°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 35A continuous - supports high-current CPU/GPU core rails without external MOSFETs |
| Reference Accuracy | ±0.5% (0°C–105°C), ±1.0% (–40°C–125°C) - enables tight output tolerance for advanced processors |
| Switching Frequency | 300–1500kHz programmable via Rt/Sync - allows optimization of size vs. efficiency in dense PCB layouts |
| Rds(on) Top/Bottom | 3.1/1.27mΩ typical - minimizes conduction loss at 35A, reducing thermal stress in 5mm×7mm PQFN |
| Remote Sense Offset | ±1.5mV (0°C–85°C), ±2mV (–40°C–125°C) - ensures sub-10mV total sensing error at load under thermal variation |
| Junction Temp Range | –40°C to +125°C - validated for sustained operation in server and telecom baseplate environments |
| Thermal Resistance θJA | 14.3°C/W - measured on high-thermal-conductivity test board, guides heatsink/no-heatsink design decisions |
Pinout & Package
IR3846MTRPBF uses a thermally enhanced 5mm × 7mm Power QFN (PQFN) package with exposed thermal pad, optimized for high-current DC/DC conversion in space-constrained server and networking boards.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PVin (Pin 1) | Main power input to high-side FET | Bypass caps must be placed adjacent to PVin/PGND; also feeds feed-forward path for line regulation |
| Boot (Pin 4) | High-side gate driver supply | Requires bootstrap capacitor between Boot and SW; supports 4.5–7.5V drive for top FET |
| Enable (Pin 5) | Global IC enable/disable control | UVLO thresholds: 1.14–1.36V start, 0.9–1.06V stop - supports precise power sequencing |
| Rt/Sync (Pin 6) | Frequency setting / external sync input | Resistor-to-LGND sets fSW; accepts 270–1650kHz external clock with 100–200ns pulse width |
| OCset (Pin 7) | Current limit configuration | Three trip points: float (default), tie to VCC (high), tie to PGND (low) - no external resistor needed |
| Vsns (Pin 8) | OVP and Power Good sensing input | Dedicated OVP path remains active even when Enable = low - critical for system-level fault containment |
| FB (Pin 9) | Error amplifier inverting input | Connects to output or remote sense amp; sets VOUT via resistor divider referenced to 0.6V internal Vref |
| COMP (Pin 10) | Error amplifier output | External RC network here sets loop compensation - enables stability tuning for varied output capacitors |
| RS+ / RS− (Pins 16/15) | Differential remote sense inputs | True differential measurement at load; rejects common-mode noise and IR drop in PCB traces |
| Vref (Pin 17) | External reference access | Enables margining (0.4–1.2V range); tie to LGND for tracking mode with Vp |
| Vp (Pin 18) | Voltage tracking/sequencing node | Used with Vref to coordinate startup/shutdown timing across multiple rails; leave open if unused |
| PGD (Pin 19) | Open-drain Power Good output | Asserts after soft-start and VOUT regulation; requires external pull-up to VCC |
| Vin (Pin 20) | LDO input supply | Must be connected when VCC is externally regulated - powers internal logic and drivers |
| VCC/LDO_out (Pin 21) | Internal LDO output | Supplies control circuitry and gate drivers; requires ≥4.7µF bypass cap to PGND |
| SW (Pin 24) | Power switch node | Connects to output inductor; voltage swing up to 25V (DC), –4V to 25V (AC, 100ns) |
Key Features
| Feature | Design Value |
|---|---|
| Integrated MOSFET drivers + bootstrap diode | Eliminates need for external gate driver ICs or discrete bootstrap components - reduces BOM count and layout complexity |
| Enhanced pre-bias start-up | Allows safe startup into pre-charged output capacitors without reverse current - essential for hot-swap and multi-rail sequencing |
| Body braking during light-load transients | Actively discharges output inductor energy to improve undershoot recovery - reduces required output capacitance by up to 30% |
| Smart LDO for VCC generation | Self-biased LDO improves light-load efficiency by >15% vs. traditional linear regulators - extends battery life in standby modes |
| Thermally compensated hiccup-mode OCP | Current limit adapts to junction temperature; hiccup restart prevents thermal runaway during sustained overload |
Applications
| Server Core Voltage Regulation | Telecom Line Card PoL |
|---|---|
Use Scenario: Delivering 1.2V @ 35A to dual-socket Xeon processors in 1U rack servers with strict thermal envelope. IC Role / Device Role / Timing Role: Primary point-of-load regulator with integrated power stage and remote sensing for <10mV output deviation under dynamic load steps. Use Value: Eliminates external MOSFETs and drivers, reducing solution size by 40% while maintaining ±0.5% regulation accuracy across –40°C to +125°C. | Use Scenario: Powering FPGA, DSP, and SerDes supplies on carrier-grade line cards requiring rail sequencing and margining. IC Role / Device Role / Timing Role: Sequenced multi-rail controller using Vp/Vref pins to coordinate startup with auxiliary supplies and support in-system voltage margin testing. Use Value: Enables full-system validation at ±5% VOUT margin without hardware changes - accelerates qualification cycles by 30%. |
| Network Switch ASIC Supply | Storage Controller Power |
Use Scenario: Providing 0.85V @ 25A to 12.8Tbps switch ASICs with fast transient response requirements. IC Role / Device Role / Timing Role: High-bandwidth buck regulator leveraging body braking and 1500kHz max fSW to achieve <500ns load-step recovery. Use Value: Reduces peak undershoot to <25mV under 20A/µs load step - avoids ASIC reset and maintains link integrity. | Use Scenario: Powering NVMe SSD controllers and DRAM buffers in enterprise storage enclosures with ambient temperatures up to 70°C. IC Role / Device Role / Timing Role: Thermally robust PoL converter using θJA = 14.3°C/W and thermal shutdown to sustain 35A output at 70°C ambient. Use Value: Maintains full rated current without derating - eliminates need for forced air cooling in sealed chassis designs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP2960GQ-Z (Monolithic Power) | 30A rating, 0.6V ref, 4.5–18V input, no integrated remote sense amp or Vp pin | Lacks true differential remote sensing and rail tracking capability - unsuitable for high-accuracy multi-rail sequencing | Select when cost sensitivity outweighs precision sensing and sequencing needs |
| TPS53689T (Texas Instruments) | 40A rating, 0.5V ref, 4.5–24V input, D-CAP3 control, no Smart LDO or body braking | Higher current but lacks body braking and Smart LDO - exhibits larger undershoot and lower light-load efficiency | Select when maximum output current is primary requirement and transient performance is secondary |
Compared with MP2960GQ-Z and TPS53689T, IR3846MTRPBF uniquely combines 35A capability with integrated remote sense amplification, Vp-based tracking, and body braking - making it optimal for server and telecom applications demanding simultaneous precision, density, and transient robustness.
Availability
IR3846MTRPBF is available at Aetrix Electronics and suitable for server core voltage regulation, telecom line card PoL, network switch ASIC supply, and enterprise storage controller power requiring stable component supply and long-term lifecycle support.
Supply support for IR3846MTRPBF 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
Infineon Technologies is a German semiconductor manufacturer specializing in power management, automotive, and industrial control ICs, with leadership in silicon and GaN-based power solutions.
The SupIRBuck® product line delivers fully integrated, high-current DC/DC regulators targeting space-constrained, high-efficiency point-of-load applications in datacenter, networking, and telecom infrastructure.
FAQ
What is the minimum recommended output capacitance for stable operation at 35A?
The IR3846MTRPBF datasheet specifies a minimum 330µF ceramic or polymer output capacitor for 35A operation at 600kHz. This value ensures sufficient phase margin with the internal error amplifier's 100–120dB DC gain and 20–40MHz GBWP. Lower values may cause instability under heavy load transients, especially when combined with high-ESR bulk capacitors.
Can IR3846MTRPBF operate without an external Vcc supply?
Yes - IR3846MTRPBF supports single-input operation from 5V to 21V applied to PVin, with the internal Smart LDO generating VCC/LDO_out from Vin (Pin 20). However, when using external Vcc, Vin must still be connected per datasheet Note 4 to ensure proper biasing of control circuitry and gate drivers.
How does the OCset pin configure current limit thresholds?
The OCset pin offers three factory-trimmed current limit settings: floating (default 35A), tied to VCC (≈42A), or tied to PGND (≈28A). These correspond to different internal RDS(on) scaling factors applied to the bottom-FET current sense signal. No external resistor is required - configuration is purely connection-based and verified across temperature.
Is remote sensing mandatory, or can FB be used directly for local feedback?
Remote sensing is optional - FB (Pin 9) can be connected directly to the output for local regulation. However, using RS+/RS− enables true differential measurement at the load, rejecting PCB trace IR drop and improving regulation accuracy to ±0.5% across board temperature gradients, which is critical for CPU/GPU core rails.
IR3846MTRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Infineon Technologies
- Series:
- SupIRBuck®
- Package/Case:
- 34-PowerVFQFN
- 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):
- 1.5V
- Voltage - Input (Max):
- 21V
- Voltage - Output (Min/Fixed):
- 0.6V
- Voltage - Output (Max):
- 18.06V
- Current - Output:
- 35A
- Frequency - Switching:
- 300kHz ~ 1.5MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 34-PQFN (5x7)
IR3846MTRPBF FAQ
1.How can I place an order for IR3846MTRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for IR3846MTRPBF 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 IR3846MTRPBF reliable?
The price and inventory of IR3846MTRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IR3846MTRPBF is usually 5 days.
3.What payment methods are accepted for IR3846MTRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IR3846MTRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IR3846MTRPBF?
IR3846MTRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IR3846MTRPBF 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 IR3846MTRPBF?
For technical support, including IR3846MTRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IR3846MTRPBF requirements.
6.How does Aetrix verify that IR3846MTRPBF is sourced from the original manufacturer or authorized distributors?
All IR3846MTRPBF 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 IR3846MTRPBF meets industry standards.
7.What is the process for return or replacement of IR3846MTRPBF?
All IR3846MTRPBF units undergo pre-shipment inspection (PSI). If there is an issue with IR3846MTRPBF, 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 IR3846MTRPBF part is unused and in its original packaging.
Return procedure for IR3846MTRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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