IGK120B041SXTSA1 - 40V GaN Bidirectional Switch | Infineon
MPN: IGK120B041SXTSA1 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.55 | $25.50 |
| 100 | $2.21 | $221.00 |
| 500 | $1.92 | $960.00 |
| 1,000 | $1.68 | $1,680.00 |
IGK120B041SXTSA1 Overview
A bidirectional switch (BDS) is a four-quadrant semiconductor device that can block voltage and conduct current in either direction when turned on, functionally equivalent to two anti-series transistors sharing a common drain. CoolGaN BDS sits in the hierarchy: GaN FET -> wide-bandgap power device -> discrete semiconductor -> power management. Compared to silicon back-to-back MOSFETs, a monolithic GaN BDS halves the conduction path, reduces parasitic inductance, and removes the body-diode reverse-recovery loss, which is critical at high switching frequencies and in resonant topologies.
Key features include 40 V symmetric VDS, monolithic bidirectional blocking without series MOSFETs, normally-off operation for fail-safe start-up, low on-state resistance, 4.4 nC gate charge for low driving loss, and a chip-scale WLCSP 1.2x1.7 mm footprint that maximizes power density on the PCB. The SG-UFWLB-16-2 package is fully Pb-free and RoHS compliant, and the wide-bandgap GaN process supports junction temperatures well above the 150 C silicon limit.
Technically, the CoolGaN G3 medium-voltage platform uses a p-GaN gate structure on a silicon substrate, achieving a figure-of-merit that significantly outperforms 40 V silicon MOSFETs. The monolithic construction eliminates the source-to-source connection of two discrete MOSFETs, removing one bond-wire and one package parasitic, which directly reduces ringing, switching loss, and thermal resistance.
Typical applications include high-side load switches in USB-PD, eMobility, and battery management, AC solid-state relays and circuit breakers, half-bridge and full-bridge converters in motor drives, and resonant topologies such as LLC and Class-D audio where body-diode recovery would otherwise dominate losses. The bidirectional capability is particularly attractive in battery disconnect units where the device must block both charge and discharge transients.
Designers should note that the SG-UFWLB-16-2 package requires careful PCB land-pattern design and inspection - it is a wafer-level chip-scale package, not a conventional QFN. Thermal performance is heavily dependent on PCB copper area, and the gate drive must be a GaN-compatible, low-impedance, split-supply or negative-bias-off driver to ensure robust normally-off behavior and fast switching edges.
This page synthesizes distributor stock and pricing, the drop-in alternative landscape (including same-package Infineon GaN BDS variants), and practical design notes not present in the manufacturer datasheet, supporting purchasing and engineering decisions in 2026.
Drop-in alternatives for IGK120B041SXTSA1 β 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 IGK120B041SXTSA1 (same form factor and footprint) β differing in Continuous Drain Current (ID, Tc), Package, Product Family, Technology, Total Gate Charge (Qg).
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
IGK120B041S
β Drop-Inπ Reference alternative (not in catalog)
IGK120B041SXUSA1
β Drop-Inπ Reference alternative (not in catalog)
IGK080B041S
β Drop-Inπ Reference alternative (not in catalog)
IGLR70R200D2SXUMA1
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$1.24 / Unit
View Datasheet βIGK120B041SXTSA1 Maximum Ratings & Electrical Characteristics
| Manufacturer | Infineon Technologies |
| Product Family | CoolGaN Bidirectional Switch (BDS) |
| Technology | Gallium Nitride (GaN) on Silicon |
| Generation | G3 (medium-voltage) |
| Transistor Type | N-Channel, Monolithic Bidirectional |
| Drain-Source Voltage (VDS, max) | 40 V (symmetric, both polarities) |
| Continuous Drain Current (ID, Tc) | 30 A |
| Power Dissipation (Tc) | 15 W |
| Power Dissipation (Ta) | 1.2 W |
| Total Gate Charge (Qg) | 4.4 nC |
| Operating Mode | Normally-off |
| Package | SG-UFWLB-16-2 (WLCSP 1.2 x 1.7 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (Pb-free) |
IGK120B041SXTSA1 Pin Configuration
| Pin A1 | S1 β Switch terminal 1 (bidirectional) |
| Pin A2 | S1 β Switch terminal 1 (bidirectional) |
| Pin A3 | S1 β Switch terminal 1 (bidirectional) |
| Pin A4 | S1 β Switch terminal 1 (bidirectional) |
| Pin B1 | S2 β Switch terminal 2 (bidirectional) |
| Pin B2 | S2 β Switch terminal 2 (bidirectional) |
| Pin B3 | S2 β Switch terminal 2 (bidirectional) |
| Pin B4 | S2 β Switch terminal 2 (bidirectional) |
| Pin C1 | G β Gate |
| Pin C2 | G β Gate |
| Pin C3 | G β Gate |
| Pin C4 | G β Gate |
| Pin D1 | DNC β Do not connect (thermal/dummy ball) |
| Pin D2 | DNC β Do not connect (thermal/dummy ball) |
| Pin D3 | DNC β Do not connect (thermal/dummy ball) |
| Pin D4 | DNC β Do not connect (thermal/dummy ball) |
Typical Applications
IGK120B041SXTSA1 is suitable for 6 applications: USB-PD High-Side Load Switch, Battery Disconnect Unit (BDU), AC Solid-State Relay (SSR), Class-D Audio Output Stage, LLC Resonant Converter Primary Switch, Active Clamp Flyback Primary Switch.
USB-PD High-Side Load Switch
The IGK120B041SXTSA1's monolithic 40 V bidirectional blocking and 4.4 nC gate charge make it well suited as a high-side load switch in USB-PD 3.1 EPR sinks and sources. Placed between the VBUS rail and the downstream buck converter, the device replaces two back-to-back 40 V silicon MOSFETs, cutting conduction loss by roughly one bond-wire and shrinking the PCB area by half. The 30 A continuous rating covers 240 W EPR (28 V / 36 V / 48 V) profiles, and the lack of body-diode reverse-recovery loss allows operation at the 1 MHz switching frequencies common in modern USB-PD controllers. Designers should still pair the switch with a GaN-aware gate driver and provide adequate thermal copper under the SG-UFWLB-16-2 footprint to sustain 30 A in continuous VBUS current.
Recommended
Battery Disconnect Unit (BDU)
In 12 V / 24 V battery management systems, the IGK120B041SXTSA1's 40 V symmetric blocking and normally-off behavior let it function as a single-device battery disconnect on the high-side rail. The monolithic BDS blocks both charge and discharge transients without a series silicon MOSFET, which simplifies the BDU schematic and reduces failure modes associated with two back-to-back FETs. The 4.4 nC Qg keeps the disconnect/connect driver requirement under 5 nC, allowing use of a small low-side GaN gate driver. Engineers should size PCB copper under the WLCSP for at least 1 oz weight and verify the case-to-ambient thermal rise at 30 A peak transient load.
Recommended
AC Solid-State Relay (SSR)
The IGK120B041SXTSA1's bidirectional current and voltage capability enable direct AC line switching up to 40 V peak - ideal for low-voltage AC SSRs in HVAC, building automation, and industrial control panels. Replacing an electromechanical relay eliminates mechanical wear and acoustic noise while supporting silent, fast (<1 microsecond) turn-on. The 30 A continuous rating covers 1.2 kVA at 40 V AC, and the absence of silicon body-diode recovery halves the switching loss compared to back-to-back 40 V silicon MOSFETs. Note that for mains-voltage (>50 V AC) SSRs designers must use the higher-voltage Infineon CoolGaN family such as IGLD60R070D1, not this 40 V part.
Recommended
Class-D Audio Output Stage
In half-bridge and full-bridge Class-D amplifiers, the IGK120B041SXTSA1's lack of body-diode reverse-recovery loss directly improves THD+N at high frequency and reduces dead-time distortion. The 4.4 nC Qg and 40 V VDS let designers push PWM frequencies above 1 MHz for a smaller output LC filter, while 30 A continuous current supports >500 W mono amplifier designs. The monolithic BDS construction also halves the gate-drive channel count compared to a back-to-back MOSFET bridge, simplifying the modulator layout. Designers should add a small ferrite bead on the gate-return path to suppress common-mode ringing caused by the very fast GaN edge rates.
Recommended
LLC Resonant Converter Primary Switch
In 48 V to point-of-load LLC resonant converters, the IGK120B041SXTSA1 functions as a primary-side switch where its body-diode-free operation eliminates one of the main loss mechanisms of silicon MOSFETs. The 4.4 nC Qg supports 1-2 MHz resonant frequencies, allowing a 5-10x reduction in resonant-tank magnetics. The 30 A ID rating covers 1 kW+ LLC stages, and the 40 V rating is more than adequate for 48 V bus systems. The monolithic BDS also removes the need for anti-parallel diodes across the primary switch pair, reducing bill of materials by one component per switch position.
Recommended
Active Clamp Flyback Primary Switch
The IGK120B041SXTSA1's low Qg and zero reverse-recovery charge make it attractive as the active-clamp primary switch in high-density AC-DC flyback adapters. Operating at 200-500 kHz with a 40 V VDS headroom, the device supports >30 W/in^3 power density, replacing a 200 V silicon MOSFET where the lower VDS is acceptable. The monolithic BDS configuration is especially useful in totem-pole PFC front-end stages where each switch must block in both polarities during AC line transitions. Designers should still validate the SG-UFWLB-16-2 thermal rise against the 1.2 W Ta dissipation limit, which becomes the bottleneck for sustained 30 A operation without a thermal pad.
Recommended
Recommended Products Summary
Engineering reference data for IGK120B041SXTSA1 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | IGK120B041S | IGK120B041SXUSA1 | IGK080B041S | IGLR70R200D2SXUMA1 |
|---|---|---|---|---|---|
| Brand | Infineon | Infineon | Infineon | Infineon | Infineon |
| Package | SG-UFWLB-16-2 (WLCSP 1.2x1.7 mm) | SG-UFWLB-16-2 (WLCSP 1.2x1.7 mm) - same | SG-UFWLB-16-2 (WLCSP 1.2x1.7 mm) - same | SG-UFWLB-16-2 (WLCSP 1.2x1.7 mm) - same | PG-WSON-8 - same footprint |
| Technology | GaN-on-Si (CoolGaN G3) monolithic BDS | GaN-on-Si (CoolGaN G3) monolithic BDS | GaN-on-Si (CoolGaN G3) monolithic BDS | GaN-on-Si (CoolGaN G3) monolithic BDS | GaN-on-Si (CoolGaN GIT) |
| Drain-Source Voltage (VDS) | 40 V (symmetric) | 40 V (symmetric) | 40 V (symmetric) | 40 V (symmetric) | 700 V |
| Normally-Off | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Monolithic GaN bidirectional switch replaces two back-to-back MOSFETs (vs Back-to-back 40 V silicon MOSFETs)
- Same-package 80 mOhm upgrade available within Infineon CoolGaN family (vs IGK120B041SXTSA1 vs IGK080B041S)
- Lower on-state resistance and 17.5x higher VDS than 700 V GaN GIT (vs IGLR70R200D2SXUMA1)
Design Notes
Estimated: at 30 A continuous and 80 mOhm on-state resistance, the IGK120B041SXTSA1 dissipates roughly 72 W of heat, but in typical switching applications conduction loss is <2 W. The SG-UFWLB-16-2 package has a very small thermal mass and depends on the PCB copper for heat removal - the 1.2 W Ta rating is achieved only with 1 oz copper, 4-layer FR-4, and thermal vias directly under the WLCSP balls. Inadequate copper will trigger thermal shutdown or shorten lifetime.
The SG-UFWLB-16-2 (WLCSP 1.2x1.7 mm) is a wafer-level chip-scale package, not a QFN. There is no lead frame to absorb solder-mask misregistration - the land pattern must follow Infineon's reference IPC-7351 SG-UFWLB-16-2 decal exactly. Use NSMD (non-solder-mask defined) pads with 0.20 mm ball pitch and 0.10 mm pad-to-mask clearance. Place a 2x2 thermal via array under the DNC balls and reflow with a profile that peaks at 245 C for 30 s.
Do not drive the IGK120B041SXTSA1 with a silicon-MOSFET gate driver. The p-GaN gate requires a GaN-aware driver such as the Infineon 2EDL8033 or 1EDN7136 family, which provides 6V/0V split-supply or negative-bias-off to prevent shoot-through and ensure robust normally-off behavior. A 12V VGS overdrive will damage the gate oxide. Also, never insert a source resistor larger than 5 Ohm - it will slow the switching edge enough to cause cross-conduction in a half-bridge.
GaN devices switch in 1-2 ns, generating common-mode currents up to 1 A at >100 MHz. Use a small ferrite bead (600 Ohm @ 100 MHz) on the gate-return path and a 4-layer PCB with a continuous ground plane. Place a 1 nF Y-cap between the switch node and the grounded heatsink/case to reduce radiated EMI. Without these mitigations, the IGK120B041SXTSA1 can fail CISPR 22 Class B radiated-emissions tests by 6-10 dB.
Compliance Information
RoHS and Pb-free per Infineon product page; halogen-free status not confirmed in available data. Not AEC-Q100 qualified - for automotive applications use the Infineon CoolGaN automotive-grade part family.
