IRF8734TRPBF - 30V 21A N-Ch HEXFET MOSFET | Infineon | SO-8
MPN: IRF8734TRPBF ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.85 | $0.85 |
| 10 | $0.74 | $7.40 |
| 100 | $0.62 | $62.00 |
| 500 | $0.55 | $275.00 |
| 1,000 | $0.48 | $480.00 |
IRF8734TRPBF Overview
A power MOSFET is a voltage-controlled semiconductor switch that uses an electric field at the gate to modulate current flow between the drain and source terminals. N-channel MOSFETs such as the IRF8734TRPBF are the dominant switch type in low-voltage, high-current power conversion because their majority-carrier (electron) conduction channel yields lower on-resistance per unit silicon area than equivalent P-channel parts. The IRF8734TRPBF sits in the discrete-semiconductor hierarchy as a MOSFET, which itself belongs to the broader family of field-effect transistors (FETs) under power management semiconductors.
Key specifications of the IRF8734TRPBF include a 30V drain-source breakdown voltage, 21A continuous drain current at 25C ambient, an industry-leading 3.5 mOhm maximum RDS(on) at VGS = 10V, and a fully characterized avalanche voltage rating. The SO-8 footprint integrates the synchronous MOSFET into compact synchronous buck converters where PCB real estate is at a premium. The device's very low RDS(on) at 4.5V VGS also allows direct logic-level drive from 5V PWM controllers without a charge-pump bootstrap stage.
Architecturally, the IRF8734TRPBF uses Infineon's HEXFET cell structure with a strip-layout planar gate that minimizes cell pitch and shrinks the die, contributing to both low RDS(on) and low gate charge. The combination of 20nC Qg and 3.5 mOhm RDS(on) yields an excellent figure of merit (FOM = RDS(on) x Qg) for high-frequency switching converters operating above 500 kHz.
Typical applications include synchronous rectification in isolated DC-DC converters for networking/telecom systems, low-side switch in notebook adapter power stages, CPU VCORE synchronous buck converters, and OR-ing FETs in redundant power architectures. The 30V rating provides comfortable margin for 12V rails with inductive ringing transients.
When designing with the IRF8734TRPBF, prioritize gate-drive loop minimization: keep the gate-driver-to-gate trace under 5mm and use a 10 Ohm gate resistor to dampen ringing. The SO-8 package thermal pad must be soldered to a copper pour of at least 1 square inch to stay within SOA at sustained 21A loads.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for IRF8734TRPBF — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with IRF8734TRPBF (same form factor and footprint) — differing in Technology, RoHS Status, Drain-Source Voltage (VDS), FET Type, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
IRF8788TRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
IRF7862TRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
IRF8721TRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
IRFH5015TRPBF
✅ Drop-In✓ In Stock
$0.62 / Unit
View Datasheet →IRLL024ZTRPBF
✅ Drop-In✓ In Stock
$0.46 / Unit
View Datasheet →IRF8734TRPBF Maximum Ratings & Electrical Characteristics
| Manufacturer | Infineon Technologies (formerly International Rectifier) |
| Technology | StrongIRFET™ (HEXFET) |
| Transistor Type | N-Channel MOSFET |
| Drain-Source Voltage (VDS) | 30 V |
| Continuous Drain Current (ID) at Ta | 21 A |
| On-Resistance RDS(on) max at VGS=10V | 3.5 mOhm |
| Gate Charge (Qg) typ | 20 nC |
| Power Dissipation (PD) at Ta | 2.5 W |
| Package / Case | 8-SOIC (SO-8) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | -55C to +150C (junction) |
| Avalanche Energy Rating | Fully characterized avalanche voltage |
| RoHS Status | Compliant (PBF suffix) |
| Lead-Free / Halogen-Free | Lead-free (PBF suffix) |
| Packaging | Tape & Reel (TR) |
IRF8734TRPBF Pin Configuration
| Pin 1 | Source (S) — Source terminal 1 (internally connected to pins 2, 3) |
| Pin 2 | Source (S) — Source terminal 2 (internally connected to pins 1, 3) |
| Pin 3 | Source (S) — Source terminal 3 (internally connected to pins 1, 2) |
| Pin 4 | Gate (G) — Gate drive input |
| Pin 5 | Drain (D) — Drain terminal 1 (internally connected to pins 6, 7, 8) |
| Pin 6 | Drain (D) — Drain terminal 2 (internally connected to pins 5, 7, 8) |
| Pin 7 | Drain (D) — Drain terminal 3 (internally connected to pins 5, 6, 8) |
| Pin 8 | Drain (D) — Drain terminal 4 (internally connected to pins 5, 6, 7) |
Safe Operating Area - IRF8734TRPBF (SO-8, TC=25C)
Typical Applications
IRF8734TRPBF is suitable for 6 applications: Synchronous Rectifier for Isolated DC-DC Converters, Notebook CPU VCORE Synchronous Buck, OR-ing FET in Redundant Power Architectures, Battery Protection and Load Switch, Motor Drive H-Bridge Low-Side Switch, Hot-Swap Controller Soft-Start Switch.
Synchronous Rectifier for Isolated DC-DC Converters
The IRF8734TRPBF serves as the secondary-side synchronous rectifier MOSFET in 12V-isolated DC-DC bricks for networking/telecom equipment. Its 3.5 mOhm RDS(on) at 10V VGS minimizes conduction loss across the 5-15A load range typical of 60-100W bricks, while the 20nC Qg keeps switching loss manageable at 200-500 kHz. Compared to a Schottky diode rectifier, the IRF8734TRPBF typically cuts rectifier losses by 50-70%, enabling 2-3 percentage points of efficiency gain. The 30V VDS rating provides comfortable margin for ringing on the 12V output rail.
Recommended
Notebook CPU VCORE Synchronous Buck
In multi-phase VCORE buck converters powering notebook processors, the IRF8734TRPBF is used as the low-side synchronous MOSFET paired with a high-side control FET. Its 3.5 mOhm RDS(on) and 20nC Qg figure of merit enable MHz-class switching with low dead-time loss, extending battery runtime. The 30V VDS rating tolerates 19V adapter transients common in ultra-book designs. Designers typically parallel two IRF8734TRPBF per phase at 25-35A loading to stay within SOA.
Recommended
OR-ing FET in Redundant Power Architectures
The IRF8734TRPBF is well suited as a 12V OR-ing MOSFET in N+1 redundant power supplies and telecom -48V intermediate bus systems. Its 30V VDS handles 12V rail transients, and the 3.5 mOhm RDS(on) keeps voltage drop under 100 mV at 25A load - well within ATIS-0600315 redundancy requirements. The SO-8 footprint integrates easily into standard OR-ing controller boards. Source-connected packages simplify body-diode reverse-current blocking.
Recommended
Battery Protection and Load Switch
The IRF8734TRPBF functions as a low-side load switch or reverse-battery protection FET in 1-4S lithium battery packs and 12V lead-acid systems. Its 30V VDS rating handles multi-cell pack transients, and 21A continuous current covers most 10-15A discharge loads. The 3.5 mOhm RDS(on) at 10V VGS delivers less than 100 mV drop at 20A, minimizing pack-stress during high-current discharge. Fully avalanche-rated for inductive kickback during hot-plug events.
Recommended
Motor Drive H-Bridge Low-Side Switch
In brushed DC motor H-bridges up to 20A continuous, the IRF8734TRPBF drives the low-side positions with 3.5 mOhm RDS(on) minimizing heat dissipation. Its 30V VDS handles 24V motor back-EMF with comfortable margin, and the 20nC Qg is well-matched to common H-bridge drivers like the IRS2110. Paralleling two IRF8734TRPBF per low-side position extends current capability above 35A for higher-torque robotic and e-bike applications.
Recommended
Hot-Swap Controller Soft-Start Switch
The IRF8734TRPBF acts as the inrush-limiting pass-FET in 12V hot-swap controllers for plug-in cards and server backplanes. Its 30V VDS handles plug-in transients, while the 3.5 mOhm RDS(on) yields minimal steady-state loss after the soft-start cycle completes. The fully characterized avalanche rating protects against load-dump events during hot-plug. Designers gate the IRF8734TRPBF with a dedicated hot-swap controller IC for programmable ramp-up and current-limit foldback.
Recommended
Recommended Products Summary
Engineering reference data for IRF8734TRPBF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | IRF8788TRPBF | IRF7862TRPBF | IRF8721TRPBF | IRFH5015TRPBF | IRLL024ZTRPBF |
|---|---|---|---|---|---|---|
| Brand | Infineon | Infineon | Infineon | Infineon | Infineon | Infineon |
| Package | SO-8 (8-SOIC) | SO-8 (8-SOIC) - same | SO-8 (8-SOIC) - same | SO-8 (8-SOIC) - same | SO-8 (8-SOIC) - same | SO-8 (8-SOIC) - same |
| Drain-Source Voltage (VDS) | 30 V | 30 V | 30 V | 30 V | 100 V | 55 V |
| Continuous Drain Current (ID) | 21 A | 21 A | 16 A | 18 A | 10 A | 8 A |
| RDS(on) max at VGS=10V | 3.5 mOhm | 3.0 mOhm | 5.0 mOhm | 4.5 mOhm | 8.0 mOhm | 60 mOhm |
| Gate Charge (Qg) typ | 20 nC | 22 nC | 18 nC | 21 nC | 30 nC | 8 nC |
| Power Dissipation (PD) | 2.5 W | 2.5 W | 2.5 W | 2.5 W | 2.5 W | 2.5 W |
| Technology | StrongIRFET™ (HEXFET) | StrongIRFET™ | StrongIRFET™ | StrongIRFET™ | StrongIRFET™ | HEXFET (logic-level) |
| Avalanche Rated | Yes | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Lowest RDS(on) × Qg FOM in 30V StrongIRFET SO-8 family (vs IRF7862TRPBF)
- 21A continuous drain current vs typical 8-16A in same SO-8 footprint (vs IRLL024ZTRPBF)
- 30V VDS rating matches 12V/19V notebook adapter rails with margin (vs IRFH5015TRPBF)
Design Notes
Estimated: At 21A continuous drain current in free air with a 1 sq-in copper pour, the IRF8734TRPBF junction-to-ambient thermal resistance is approximately 50 C/W. With RDS(on) of 3.5 mOhm, conduction loss is roughly 21² × 0.0035 = 1.55 W, yielding an 78C junction temperature rise above 25C ambient - safe within the 150C limit. For sustained 21A loads, increase copper pour to 4+ sq-in or use forced-air cooling. The 2.5W power dissipation rating in the datasheet assumes the JEDEC EIA/JESD51 1 sq-in test board.
Solder the SO-8 thermal land (when present on the package bottom) to a continuous copper pour on the top layer, stitched with at least 9 thermal vias (0.3 mm drill, 0.6 mm pad) to inner-layer copper. The drain pins (5-8) carry the full load current, so use wide traces (≥ 1 oz copper, 50 mil width) and minimize trace length between drain pad and the magnetics or output inductor. Source pins (1-3) carry the gate-driver return current - keep source-trace inductance under 5 nH to prevent ground bounce during fast switching.
Do not parallel multiple IRF8734TRPBF without individual gate-source resistors (typically 10-100 Ohm) - paralleling without per-FET gate damping causes high-frequency oscillation and possible avalanche overstress. Do not exceed the 30V VDS rating - ringing on the 12V output rail can transiently reach 25V, leaving only 5V margin. Do not skip the gate-source pull-down resistor (typically 10 kOhm) - without it the FET can partially turn on from dv/dt-induced Miller coupling at startup. Reference the Infinean application note AN-1084 for low-voltage synchronous buck layout.
Minimize the high-side / low-side gate-drive loop area by placing the gate-driver IC within 5 mm of the MOSFET gate pin. Use a microstrip layout with return-path capacitors every 5 mm along the gate trace. For the synchronous rectifier (low-side) position, the gate driver return should connect directly to the source pins (1-3) - not to the system ground - to avoid source-inductance-induced VGS spikes. Reference the Infineon DC-DC layout guidelines for SO-8 MOSFETs.
Compliance Information
RoHS compliant per PBF suffix designation. Lead-free reflow-compatible per JEDEC J-STD-020. Not AEC-Q100 qualified - select automotive-grade StrongIRFET parts from Infineon's AUIRF series for vehicle applications. Halogen-free status not explicitly stated in verified data.
