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Infineon Technologies IR3651STRPBF
- Part No.:
- IR3651STRPBF
- Manufacturer:
- Infineon Technologies
- Category:
- DC DC Switching Controllers
- Package:
- 14-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
IR3651STRPBF.pdf
- Description:
- IC REG CTRLR BUCK 14SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,597
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Product details
Overview
IR3651STRPBF from Infineon Technologies is a high-voltage synchronous PWM buck controller designed for non-isolated DC/DC conversion in 12–100V input systems. It drives external N-MOSFETs with 1A source/sink capability per gate driver, supports programmable switching frequency up to 400kHz, and regulates output voltage via an internal 1.25V reference. Used in telecom power supplies and distributed PoL architectures.
For engineers reviewing the IR3651STRPBF datasheet, IR3651STRPBF pinout, IR3651STRPBF application, or IR3651STRPBF equivalent, key selection criteria include high-side/low-side driver timing (30–100ns dead time), MOSFET RDS(on)-based hiccup current limiting, UVLO thresholds on Vcc/DRVcc/Vb, and SOIC-14 package thermal resistance (θJA = 88.2°C/W).
Technical Context
The IR3651STRPBF implements a voltage-mode PWM control architecture with an internal error amplifier, 1.25V precision reference, and oscillator synchronized via external clock or resistor (Rt). Its high-voltage level-shifting circuit enables direct drive of high-side N-MOSFETs referenced to the switch node (Vs), supporting bus voltages up to 100V.
Protection logic includes under-voltage lockout on three independent rails (Vcc, DRVcc, Vb), programmable overcurrent threshold via OCset pin, and hiccup-mode current limiting triggered by sensed MOSFET conduction loss. Soft-start is controlled by external capacitor on SS/SD pin with 15–25μA charging current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 12V to 100V - supports wide-range industrial and telecom DC inputs without pre-regulation |
| Switching Frequency | 100–400kHz - set by external Rt resistor or synchronized externally; enables EMI optimization and inductor size trade-off |
| Reference Voltage | 1.25V ±1.5% - enables precise output regulation down to sub-1V with resistor divider feedback |
| Gate Drive Current | 1.0A source/sink per driver - ensures fast MOSFET turn-on/turn-off with 10–20ns rise/fall times into 1.5nF load |
| UVLO Thresholds | Vcc: 4.17V (rising), DRVcc/Vb: 9.0V (rising) - prevents erratic operation during brown-out or startup transients |
| Dead Time | 30–100ns - hard-coded minimum off-time between high-side and low-side drivers to prevent shoot-through |
| Current Limit Sensing | MOSFET RDS(on)-based - eliminates sense resistor; OCset pin draws 7.5–12.5μA to set trip point |
Pinout & Package
IR3651STRPBF is housed in a 14-pin SOIC NB (narrow body) package with θJA = 88.2°C/W and θJC = 37°C/W. Pin 1 is Fb (feedback input); pin 14 is Rt (frequency-setting resistor connection). Power ground (PGnd) and signal ground (Gnd) are separated for noise immunity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 Fb | Inverting input to error amplifier | Connects to output voltage divider; sets regulated output via 1.25V reference |
| 2 Comp | Error amplifier output | Interface for loop compensation network (R+C to Gnd) to stabilize control loop |
| 3 SS/SD | Soft-start / shutdown control | Capacitor-to-ground sets ramp time; <0.3V forces shutdown |
| 4 SYNC | External clock synchronization input | Accepts TTL/CMOS clock up to 480kHz to align switching with system timing |
| 5 PGnd | Power ground return | Low-impedance path for gate driver currents; must connect to power plane near MOSFETs |
| 6 LDrv | Low-side MOSFET gate driver output | 1A capable driver; connects directly to gate of synchronous rectifier |
| 7 DRVcc | Low-side driver bias supply | Requires ≥0.1μF ceramic cap to PGnd; UVLO at 8.3–9.7V prevents weak drive |
| 8 Vb | High-side driver bootstrap supply | Must be >Vs +10V; cap to switch node enables floating high-side drive |
| 9 HDrv | High-side MOSFET gate driver output | 1A capable driver; referenced to Vs, not Gnd |
| 10 Vs | Switch node connection | Return path for high-side driver; connects to source of upper FET and drain of lower FET |
| 11 Vcc | Internal logic supply | Power for control blocks; requires ≥0.1μF ceramic cap to Gnd; UVLO at 4.0–4.35V |
| 12 OCset | Overcurrent threshold programming | Resistor to low-side FET drain sets current limit using RDS(on) sensing |
| 13 Gnd | Signal ground reference | Reference for internal bias, reference, and error amp; separate from PGnd |
| 14 Rt | Oscillator frequency setting | Resistor to Gnd sets free-running frequency (e.g., 120kΩ → ~200kHz) |
Key Features
| Feature | Design Value |
|---|---|
| High-voltage operation | Supports 100V bus input with integrated level-shifted high-side driver - eliminates need for external bootstrap IC or isolated supply |
| Hiccup-mode overcurrent protection | Self-resetting fault response using MOSFET RDS(on) sensing - avoids thermal runaway while maintaining system visibility of fault condition |
| Independent UVLO on three rails | Vcc, DRVcc, and Vb each have dedicated UVLO with hysteresis - ensures coordinated startup and safe gate drive sequencing |
| Programmable soft-start | Capacitor-controlled linear voltage ramp on SS/SD pin - prevents inrush current and output overshoot during power-up |
| Synchronization capability | SYNC pin accepts external clock up to 480kHz - enables multi-phase interleaving and EMI reduction in dense power systems |
Applications
| 48V Telecom Power Supply | Industrial PoL Converter |
|---|---|
|
Use Scenario: Primary 48V-to-12V step-down stage in carrier-grade base station power shelf. IC Role / Device Role / Timing Role: Synchronous buck controller managing dual-phase parallel operation with external MOSFETs and current-sharing control. Use Value: 100V input rating accommodates telecom transient surges (IEC 61000-4-5); hiccup OCP maintains system uptime during short-term overload events. |
Use Scenario: Point-of-load regulator powering FPGA I/O banks in factory automation PLC modules. IC Role / Device Role / Timing Role: High-efficiency buck controller delivering tightly regulated 1.8V/3.3V outputs with fast transient response. Use Value: 1.25V reference and error amplifier enable ±1% output accuracy; SOIC-14 package allows compact layout with minimal thermal vias. |
| Networking Switch Midplane Regulator | Server VRM Auxiliary Rail |
|
Use Scenario: 12V-to-3.3V conversion for PHY layer interfaces in 10GbE line cards. IC Role / Device Role / Timing Role: Synchronous buck controller operating at 300kHz to balance efficiency and filter size in space-constrained midplane designs. Use Value: External frequency sync allows alignment with system clock tree, reducing conducted EMI peaks across multiple rails. |
Use Scenario: Standby rail (5V/3.3V) generation in server motherboard VRM subsystems. IC Role / Device Role / Timing Role: Secondary buck controller powered from main 12V rail, providing always-on auxiliary power with low quiescent current. Use Value: 6–7mA dynamic supply current at 200kHz minimizes standby losses; SS/SD pin enables controlled sequencing with main CPU rail. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MP2918GL-Z | Integrated MOSFETs (40V max), no external high-side driver; fixed 500kHz frequency; no Vb/DRVcc separation | Better for low-input-voltage, space-constrained designs where integration outweighs voltage range needs | Select when input ≤40V and board area is critical; avoid for 48V+ telecom or industrial inputs |
| LM5116MHX/NOPB | Wide-input (6–100V), external N-MOSFET drive, but uses current-mode control and lacks hiccup OCP; requires external bootstrap diode | Preferred for designs requiring peak-current mode stability or multi-phase current sharing with external amplifiers | Select when current-mode loop dynamics are required or when hiccup mode is not mandatory; verify bootstrap reliability |
Compared with MP2918GL-Z and LM5116MHX/NOPB, IR3651STRPBF uniquely combines 100V input support, independent high-side/low-side gate drivers with dedicated bias rails, and RDS(on)-based hiccup protection-making it optimal for ruggedized 48V telecom and industrial PoL systems where reliability under fault conditions is critical.
Availability
IR3651STRPBF is available at Aetrix Electronics and suitable for 48V telecom power supplies, industrial point-of-load converters, and networking switch midplane regulators requiring stable component supply and long-term lifecycle support.
Supply support for IR3651STRPBF 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 global manufacturing and quality certification to ISO/TS 16949 and IECQ QC 080000.
The IR3651STRPBF belongs to Infineon's high-voltage analog power controller product line, engineered specifically for robust, high-efficiency synchronous buck conversion in telecom, industrial, and networking infrastructure equipment.
FAQ
What is the maximum allowable input voltage for IR3651STRPBF?
The absolute maximum Vs (switch node) voltage is 150V, but recommended operating input voltage is 12V to 100V. Operation above 100V violates the specified operating conditions and risks exceeding internal bias limits on Vb and DRVcc, potentially causing premature failure or erratic gate drive behavior.
How is overcurrent protection implemented without a sense resistor?
IR3651STRPBF uses MOSFET RDS(on) as the current-sense element. A resistor from OCset pin to the low-side MOSFET drain sets the trip threshold; the IC monitors voltage drop across RDS(on) during conduction and triggers hiccup-mode limiting when the threshold is exceeded.
Can IR3651STRPBF drive both high-side and low-side N-MOSFETs without external level shifters?
Yes. The IC integrates a high-voltage level-shifting circuit that references the high-side driver (HDrv) to the switch node (Vs), enabling direct drive of N-MOSFETs in the upper position. No external bootstrap diode or isolated supply is needed - only a capacitor from Vb to Vs.
What is the purpose of separating PGnd and Gnd pins?
PGnd carries high-frequency, high-current return paths for gate drivers; Gnd serves as the quiet reference for internal analog circuits (error amp, reference, oscillator). Separating them prevents switching noise from modulating regulation accuracy or causing false OCP triggering.
IR3651STRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Infineon Technologies
- Series:
- -
- Package/Case:
- 14-SOIC (0.154", 3.90mm Width)
- 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:
- 100kHz ~ 400kHz
- Duty Cycle (Max):
- 80%
- Synchronous Rectifier:
- Yes
- Clock Sync:
- Yes
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Enable, Soft Start
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-SOIC
IR3651STRPBF FAQ
1.How can I place an order for IR3651STRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for IR3651STRPBF 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 IR3651STRPBF reliable?
The price and inventory of IR3651STRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IR3651STRPBF is usually 5 days.
3.What payment methods are accepted for IR3651STRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IR3651STRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IR3651STRPBF?
IR3651STRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IR3651STRPBF 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 IR3651STRPBF?
For technical support, including IR3651STRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IR3651STRPBF requirements.
6.How does Aetrix verify that IR3651STRPBF is sourced from the original manufacturer or authorized distributors?
All IR3651STRPBF 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 IR3651STRPBF meets industry standards.
7.What is the process for return or replacement of IR3651STRPBF?
All IR3651STRPBF units undergo pre-shipment inspection (PSI). If there is an issue with IR3651STRPBF, 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 IR3651STRPBF part is unused and in its original packaging.
Return procedure for IR3651STRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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