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STMicroelectronics STTA1212D
- Part No.:
- STTA1212D
- Manufacturer:
- STMicroelectronics
- Category:
- Single Diodes
- Package:
- TO-220-2
- Datasheet:
-
STTA1212D.pdf
- Description:
- DIODE GEN PURP 1.2KV 12A TO220AC
- Quantity:
- Payment:
- Shipping:
Inventory:2,994
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Product details
Overview
STTA1212D from STMicroelectronics is an ultra-fast, soft-recovery 1200 V / 12 A high-voltage power diode in TO-220AC package, optimized for freewheeling, snubber, clamping, and high-voltage rectification in SMPS and motor control. It delivers typ. 50 ns reverse recovery time, max 2.0 V forward voltage at 12 A/25°C, and 1.9 °C/W junction-to-case thermal resistance.
For engineers reviewing the STTA1212D datasheet, STTA1212D pinout, STTA1212D application, or STTA1212D equivalent, key selection criteria include softness factor (S = 1.2), low conduction losses (P1 = 29.2 W @ δ = 0.5), high dIF/dt immunity (up to –500 A/µs), and compatibility with IGBT/MOSFET companion switching in high-frequency hard-switched topologies.
Technical Context
The STTA1212D employs a proprietary TURBOSWITCH silicon process enabling ultra-fast turn-off with controlled soft recovery-minimizing voltage overshoot and EMI during commutation. Its dynamic parameters are characterized across temperature (Tj = 25–125°C) and dIF/dt (–50 to –500 A/µs), supporting stable operation under pulsed current stress.
It features a low threshold voltage (Vto = 1.57 V @ 125°C) and dynamic resistance (Rd = 36 mΩ), enabling accurate conduction loss modeling via P = Vto × IF(AV) + Rd × IF²(RMS). Reverse leakage remains ≤5.0 mA at 125°C and 960 V, ensuring reliability in high-temperature HVDC link applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRRM | 1200 V - Withstands repetitive reverse voltage up to 1200 V without breakdown, suitable for 800 V DC bus systems with safety margin. |
| IF(AV) | 12 A - Average forward current rating defines continuous conduction capability in rectifier or freewheel paths. |
| trr (typ) | 50 ns - Ultra-fast reverse recovery minimizes switching losses and EMI in 50–500 kHz SMPS primary-side snubbers. |
| S factor | 1.2 - Soft recovery ratio (tb/ta) reduces voltage ringing and stress on companion IGBTs during turn-off. |
| Rth(j-c) | 1.9 °C/W - Enables 29.2 W conduction dissipation at Tc = 95°C, supporting compact heatsink designs. |
| IRM (max) | 30 A - Peak reverse recovery current at 125°C/600 V determines snubber energy handling and gate drive stress. |
| VF (max) | 2.0 V @ 12 A/25°C - Directly impacts conduction loss and thermal rise in high-duty-cycle rectification. |
Pinout & Package
TO-220AC package: single-ended, isolated tab (cathode-connected metal flange), 3-pin outline with center tab as cathode terminal. Mounting via M3 screw (0.55 N·m recommended torque); epoxy meets UL94 V0.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Lead 1) | Forward current entry point | Connected to load or switch node; must withstand surge current up to 100 A (10 ms sine). |
| Cathode (Tab) | Forward current exit / thermal path | Electrically and thermally coupled to heatsink; electrically tied to cathode potential. |
| No-Connect (Lead 2) | Unused mechanical support | Non-functional lead; omitted in some variants; no electrical connection or thermal role. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-fast soft recovery | trr = 50 ns typ., S = 1.2 - Reduces voltage spikes and EMI in hard-switched IGBT circuits. |
| Low conduction loss architecture | Vto = 1.57 V & Rd = 36 mΩ @ 125°C - Enables precise loss modeling and <29.2 W steady-state dissipation. |
| High dIF/dt immunity | Rated to –500 A/µs - Maintains stable recovery behavior under aggressive switching edge rates. |
| High-temperature reliability | Tj(max) = 150°C & IR ≤ 5.0 mA @ 125°C/960 V - Ensures stability in enclosed industrial power modules. |
Applications
| Motor Drive Freewheeling | SMPS Primary Snubber |
|---|---|
Use Scenario: Used across IGBT collector-emitter in 3-phase inverter legs to recirculate inductive motor current during PWM off-time. IC Role / Device Role / Timing Role: Ultra-fast freewheeling diode with soft recovery prevents voltage overshoot during IGBT turn-off. Use Value: Reduces IGBT switching losses by >35% and eliminates need for external RC snubbers in 10–20 kHz drives. | Use Scenario: Placed across primary winding of flyback or forward converter transformers to clamp voltage spikes. IC Role / Device Role / Timing Role: Snubber diode absorbing leakage inductance energy during MOSFET turn-off. Use Value: Limits peak voltage to <1.2×VDC with <50 ns recovery, enabling use of 650 V MOSFETs in 400 V systems. |
| SMPS Primary Demagnetizing | SMPS Secondary Rectification |
Use Scenario: Connected in series with primary winding to reset transformer core in RCD or active clamp topologies. IC Role / Device Role / Timing Role: Demagnetizing diode conducting only during core reset interval with minimal reverse recovery tail. Use Value: Prevents core saturation and enables >90% duty cycle operation while maintaining <100 ns trr consistency. | Use Scenario: High-voltage output rectifier in telecom or industrial 48 V/120 V DC-DC converters with 600–800 V output isolation. IC Role / Device Role / Timing Role: High-VRRM rectifier handling 1200 V transient surges and 12 A average output current. Use Value: Delivers 2.0 V VF at full load with 1.9 °C/W Rth(j-c), reducing secondary-side thermal footprint by 40% vs. standard FRDs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ultra-fast high-voltage diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STTH1212D | Same VRRM (1200 V), IF(AV) (12 A), but trr = 65 ns (typ), S = 1.0, Rth(j-c) = 2.0 °C/W | Higher recovery loss in >200 kHz snubbers; less soft turn-off increases IGBT voltage stress | Preferred where cost sensitivity outweighs EMI constraints; not recommended for <100 ns critical timing. |
| IXYS MUR1220CT | VRRM = 200 V lower (1000 V), trr = 35 ns (typ), but IF(AV) = 12 A, TO-220AC, no softness spec | Unsuitable for 800 V DC bus; faster but uncontrolled recovery risks oscillation with IGBTs | Only viable in lower-voltage (<700 V) SMPS with tight layout and added damping. |
Compared with STTH1212D and MUR1220CT, the STTA1212D uniquely balances 1200 V rating, 50 ns soft recovery, and validated S-factor performance-making it the only option qualified for noise-sensitive motor drive freewheeling and high-dV/dt snubber roles in industrial inverters.
Availability
STTA1212D is available at Aetrix Electronics and suitable for motor control inverters, telecom SMPS primary-side protection, and industrial HV rectification requiring stable component supply and long-term lifecycle continuity.
Supply support for STTA1212D 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.
The TURBOSWITCH product line was engineered specifically for ultra-low-loss, soft-switching power conversion-targeting high-frequency SMPS, motor drives, and renewable energy inverters where diode-induced switching stress limits system efficiency.
FAQ
What is the maximum junction temperature and how does it affect derating?
The STTA1212D has a maximum operating junction temperature of 150°C. At Tj = 125°C, forward voltage rises to 2.2 V and reverse leakage reaches 5.0 mA, requiring thermal design that maintains Tc ≤ 89°C for full 32.1 W total dissipation. Derating curves in Fig. 1 show IF(AV) drops to ~9.5 A at Tc = 100°C.
Is the TO-220AC package electrically insulated?
No-the TO-220AC package has an electrically conductive metal tab tied directly to the cathode. The mounting surface must be isolated from other potentials unless referenced to cathode potential. Insulating pads or shoulder washers are required when mounting to grounded heatsinks.
How is softness factor (S = tb/ta) measured and why does it matter?
S is calculated from reverse recovery waveform: tb is tail time after peak IRM, ta is time to peak. An S = 1.2 indicates gradual current decay, reducing di/dt-induced voltage spikes across stray inductance. This lowers EMI and prevents false triggering of overvoltage protection in IGBT gate drivers.
Can STTA1212D replace standard FRD or UF diodes in existing designs?
Yes-if VRRM, IF(AV), and package fit requirements are met-but verify dIF/dt conditions and layout parasitics. Its softer recovery may reduce snubber losses, but its higher VF at high Tj could increase conduction loss versus newer SiC Schottky alternatives in low-voltage outputs.
STTA1212D Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- TURBOSWITCH™
- Package/Case:
- TO-220-2
- Packaging:
- Tube
- Product Status:
- Obsolete
- Technology:
- Standard
- Voltage - DC Reverse (Vr) (Max):
- 1200 V
- Current - Average Rectified (Io):
- 12A
- Voltage - Forward (Vf) (Max) @ If:
- 2.2 V @ 12 A
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- 100 ns
- Current - Reverse Leakage @ Vr:
- 100 µA @ 1200 V
- Capacitance @ Vr, F:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220AC
- Operating Temperature - Junction:
- 150°C (Max)
STTA1212D FAQ
1.How can I place an order for STTA1212D through Aetrix?
Please submit a Request for Quotation (RFQ) for STTA1212D 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 STTA1212D reliable?
The price and inventory of STTA1212D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STTA1212D is usually 5 days.
3.What payment methods are accepted for STTA1212D?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STTA1212D transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STTA1212D?
STTA1212D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STTA1212D 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 STTA1212D?
For technical support, including STTA1212D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STTA1212D requirements.
6.How does Aetrix verify that STTA1212D is sourced from the original manufacturer or authorized distributors?
All STTA1212D 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 STTA1212D meets industry standards.
7.What is the process for return or replacement of STTA1212D?
All STTA1212D units undergo pre-shipment inspection (PSI). If there is an issue with STTA1212D, 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 STTA1212D part is unused and in its original packaging.
Return procedure for STTA1212D:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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