BSP135H6906XTSA1 - 600V N-Ch Depletion MOSFET | Infineon
MPN: BSP135H6906XTSA1 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.62 | $16.20 |
| 100 | $1.38 | $138.00 |
| 500 | $1.15 | $575.00 |
| 1,000 | $0.95 | $950.00 |
| 3,000 | $0.78 | $2,340.00 |
Drop-in alternatives for BSP135H6906XTSA1 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
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BSP135H6327XTSA1
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View Datasheet →BSP135L6327HTSA1
✅ Drop-In📋 Reference alternative (not in catalog)
BSP125H6327XTSA1
✅ Drop-In📋 Reference alternative (not in catalog)
BSP316PH6327XTSA1
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View Datasheet →BSP315PH6327XTSA1
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View Datasheet →BSP135H6906XTSA1 Maximum Ratings & Electrical Characteristics
| FET Type | N-Channel Depletion Mode |
| Drain-Source Voltage (VDS) Max | 600 V |
| Continuous Drain Current (ID) at TA=25C | 120 mA |
| RDS(on) Max at VGS=0V | 45 Ohm |
| Power Dissipation (PD) Max | 1.8 W |
| Gate Threshold Voltage (VGS(off)) | Depletion mode (normally-on) |
| Operating Temperature Range | -55C to +150C |
| Package | PG-SOT223-4 (SOT-223, 3+tab) |
| Mounting Type | Surface Mount |
| Pin Count | 4 (3 leads + drain tab) |
| Technology | SIPMOS (planar high-voltage) |
| MSL Level | 1 (unlimited) |
| RoHS Status | Compliant |
| Automotive Qualification | AEC-Q101 (per datasheets.com parametric record) |
| Lead-Free | Yes |
BSP135H6906XTSA1 Pin Configuration
| Pin 1 | Gate — Gate terminal; pull to VGS(off) (~-2 V) to switch off the depletion channel |
| Pin 2 | Drain — Drain terminal; also bonded to the metal tab on the rear of the package for thermal dissipation |
| Pin 3 | Source — Source terminal |
| Pin 4 | Source (Tab) — Source-connected tab on rear of package; solder to source copper pour for thermal relief |
Safe Operating Area - DC Continuous
Typical Applications
BSP135H6906XTSA1 is suitable for 6 applications: Offline SMPS Startup Bypass, Over-Voltage Protection Clamp, In-Rush Current Limiter, Offline Voltage Reference / Constant-Current Source, Automotive 12V/24V Auxiliary Supply, Active Dummy Load / Bleeder Circuit.
Offline SMPS Startup Bypass
The BSP135H6906XTSA1 fits offline SMPS startup bypass because it is normally-on at VGS=0 V and rated 600 V VDS. It carries the auxiliary winding bias current (typically 5-20 mA) from the rectified 310 VDC bulk rail to the controller VCC pin during cold-start, then is switched off by the controller once the auxiliary winding takes over. Using the BSP135 instead of a conventional startup resistor eliminates the continuous 0.5-2 W dissipation loss that plagues high-voltage supplies, often improving standby efficiency by 1-3 percent. The depletion characteristic means the circuit sees the auxiliary winding voltage from the moment AC is applied, no MCU initialization delay.
Recommended
Over-Voltage Protection Clamp
Used as an active over-voltage clamp, the BSP135H6906XTSA1 conducts the moment the rail exceeds its threshold, shunting fault current away from downstream components. Its 600 V rating comfortably covers 110/220 VAC rectified rails (peak 310 V) plus inductive transients, and its normally-on state means there is no firmware delay before protection engages. The gate can be pulled to a regulated negative rail (typically -5 V) by a Zener-resistor network to set the precise clamp voltage. This topology is common in industrial 24 V systems and offline appliance protection where response time is microseconds, not milliseconds.
Recommended
In-Rush Current Limiter
The BSP135H6906XTSA1 acts as an in-rush current limiter when placed in series with a bulk capacitor and a source resistor. At power-on, the depletion device is on and conducts the initial charging current; once VGS is pulled negative by a sensed voltage across the source resistor, the channel pinches off and limits the steady-state current. The 45 Ohm RDS(on) gives predictable current limiting around 30-50 mA without external feedback, and the 600 V rating supports universal AC input. This passive analog limiter is favored over PWM active limiters for its simplicity and zero quiescent draw in steady state.
Recommended
Offline Voltage Reference / Constant-Current Source
With a single source resistor, the BSP135H6906XTSA1 forms a simple two-terminal constant-current source suitable for offline biasing of optocouplers, Zener reference diodes, or low-power analog circuits. The 45 Ohm RDS(on) at VGS=0 V combined with a few kOhm of source resistance gives a regulated current of roughly 5-15 mA independent of drain voltage (above pinch-off). This is widely used as a passive current reference in isolated gate-drive bias supplies and as a stable pull-up element in 600 V analog front-ends.
Recommended
Automotive 12V/24V Auxiliary Supply
AEC-Q101-qualified depletion-mode variants of the BSP135 are used in automotive 12 V and 24 V body-electronics auxiliary supplies where normally-on behavior simplifies cold-start sequencing and redundant power paths. The part handles load-dump transients up to its 600 V rating, far above the 24 V system steady-state level, providing robust margin for inductive kickback and jump-start events. The SOT-223 (PG-SOT223-4) footprint is compatible with automotive PCB assembly standards and supports automated optical inspection.
Recommended
Active Dummy Load / Bleeder Circuit
In high-voltage test equipment and bleeder circuits, the BSP135H6906XTSA1 is used as an adjustable active load. By varying VGS between 0 V and the VGS(off) point, the designer can sweep drain current from full conduction (about 120 mA) down to microampere leakage. The 1.8 W SOT-223 package dissipates up to its rated power with adequate copper, and the depletion behavior means the load is engaged even when the test controller is unpowered - a useful safety feature for capacitor discharge applications.
Recommended
Recommended Products Summary
Engineering reference data for BSP135H6906XTSA1 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | BSP135H6327XTSA1 | BSP135L6327HTSA1 | BSP125H6327XTSA1 | BSP316PH6327XTSA1 | BSP315PH6327XTSA1 | BSD214SNH6327XTSA1 |
|---|---|---|---|---|---|---|---|
| Package | PG-SOT223-4 (SOT-223, 3+tab) | PG-SOT223-4 - same | PG-SOT223-4 - same | PG-SOT223-4 - same | PG-SOT223-4 - same | PG-SOT223-4 - same | PG-SOT223-4 - same |
| Brand | Infineon Technologies | Infineon Technologies | Infineon Technologies | Infineon Technologies | Infineon Technologies | Infineon Technologies | Infineon Technologies |
| FET Type / Polarity | N-Channel Depletion (normally-on) | N-Channel Depletion | N-Channel Depletion | N-Channel Depletion | P-Channel Enhancement | P-Channel Enhancement | N-Channel Enhancement |
| VDS Max | 600 V | 600 V | 600 V | 250 V | -60 V | -60 V | 250 V |
| Continuous Drain Current | 120 mA | 120 mA | 120 mA | 200 mA | -1.9 A | -1.9 A | 0.6 A |
| RDS(on) Max | 45 Ohm | 45 Ohm | 45 Ohm | 20 Ohm | 0.25 Ohm | 0.25 Ohm | 5 Ohm |
| Power Dissipation (PD) Max | 1.8 W | 1.8 W | 1.8 W | 1.8 W | 1.8 W | 1.8 W | 1.8 W |
| Operating Mode | Depletion (normally-on) | Depletion | Depletion | Depletion | Enhancement | Enhancement | Enhancement |
Key Differentiators
- Only Infineon N-channel depletion-mode MOSFET in PG-SOT223-4 at 600 V (vs BSP316PH6327XTSA1)
- Higher blocking voltage than lower-VDS depletion alternatives (vs BSP125H6327XTSA1)
- AEC-Q101 automotive-qualified option exists in same die (vs BSD214SNH6327XTSA1)
Design Notes
The BSP135H6906XTSA1 is normally-on at VGS=0 V. Engineers familiar with enhancement-mode MOSFETs may incorrectly assume the device is off when un-driven; in reality it conducts the moment the drain voltage exceeds 0 V. The circuit must tolerate this continuous conduction at power-up, and an explicit negative gate bias (typically derived from a Zener-resistor network on the drain) must be applied to switch the device off. Forgetting this is the most common design mistake and can result in permanently-on output rails.
At 100 mA drain current and 45 Ohm RDS(on), the part dissipates about 0.45 W in the SOT-223 (PG-SOT223-4) package, well within its 1.8 W rating. At full 120 mA with the drain tab soldered to a 1 square-inch copper pour, theta_JA drops to roughly 70 C/W, supporting full-rated current up to TA=125 C ambient. Without copper area, theta_JA rises to 150 C/W and continuous current should be limited to about 50 mA. The drain tab is pin 2 electrically and must be soldered for thermal relief.
Place the BSP135H6906XTSA1 with the drain tab connected to a copper pour of at least 1 square inch (about 645 square mm) on the top layer for thermal spreading. The SOT-223 footprint is non-standard (it is wider than SO-8), so verify the land pattern matches Infineon's PG-SOT223-4 reference. Keep the high-voltage drain trace away from low-voltage gate and source traces by at least 3 mm to prevent surface arcing at 600 V, and consider slotting the PCB between drain and gate to increase creepage.
For the offline SMPS startup bypass topology, route the gate bias Zener-resistor network close to the gate pin to minimize parasitic inductance. A 100 kOhm gate resistor plus a 5.6 V Zener to ground (referenced to source) provides a clean negative gate bias that turns the device off once the auxiliary winding takes over. The gate-source capacitance (Ciss typically 50-100 pF) is small enough that no extra gate drive buffer is required.
Compliance Information
RoHS and REACH compliant per Infineon product page. AEC-Q101 qualification noted by datasheets.com parametric record (variant dependent). Halogen-free status not explicitly stated in provided data.
