STTH102AY - 1A 200V Ultrafast Rectifier | STMicroelectronics | SMA
MPN: STTH102AY β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.12 | $0.12 |
| 10 | $0.1 | $1.00 |
| 100 | $0.08 | $8.00 |
| 500 | $0.07 | $35.00 |
| 1,000 | $0.06 | $60.00 |
Drop-in alternatives for STTH102AY β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
STTH1R02AY
β Drop-Inπ Reference alternative (not in catalog)
STTH102A
β Drop-Inπ Reference alternative (not in catalog)
ES1B
β Drop-Inπ Reference alternative (not in catalog)
US1B
β Drop-Inπ Reference alternative (not in catalog)
S1B
β Drop-Inπ Reference alternative (not in catalog)
STTH102AY Maximum Ratings & Electrical Characteristics
| Diode Type | Ultrafast recovery |
| Voltage - DC Reverse (Vr) (Max) | 200 V |
| Current - Average Rectified (Io) | 1 A |
| Voltage - Forward (Vf) (Max) @ If | 0.85 V @ 1 A |
| Reverse Recovery Time (trr) | 25 ns |
| Current - Reverse Leakage @ Vr | 1 Β΅A @ 200 V |
| Capacitance @ Vr, F | 10 pF @ 4 V, 1 MHz |
| Operating Temperature - Junction | -40Β°C to +175Β°C |
| Mounting Type | Surface Mount |
| Package / Case | SMA (DO-214AC) |
| Supplier Device Package | SMA |
| Thermal Resistance (Junction to Ambient) | 15Β°C/W |
| Non-Repetitive Peak Forward Surge Current | 30 A |
| AEC-Q101 Qualified | Yes |
| RoHS Status | Compliant |
STTH102AY Pin Configuration
| Pin 1 | Cathode β Cathode terminal, marked with a band |
| Pin 2 | Anode β Anode terminal |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
STTH102AY is suitable for 6 applications: Switch-Mode Power Supplies (SMPS), Freewheeling Diode in Inductive Loads, Snubber Circuits, Output Rectification in DC-DC Converters, Power Factor Correction (PFC) Circuits, LED Lighting Drivers.
Switch-Mode Power Supplies (SMPS)
The STTH102AY is used as an output rectifier in SMPS due to its 25 ns reverse recovery time, which reduces switching losses and improves efficiency. In a typical flyback converter, the diode is placed in series with the secondary winding, conducting during the off-time of the primary switch. Its low forward voltage drop of 0.85V minimizes conduction losses, while the fast recovery prevents excessive reverse current that could cause voltage spikes. The SMA package allows compact PCB layouts, and the 175Β°C junction temperature rating ensures reliable operation in thermally challenging environments. Compared to standard rectifiers, the ultrafast recovery reduces EMI and improves overall system performance.
Recommended
Freewheeling Diode in Inductive Loads
In relay, solenoid, and motor driver circuits, the STTH102AY serves as a freewheeling diode to clamp inductive kickback voltage. When the switch opens, the inductor's current must continue flowing; the diode provides a low-impedance path, preventing voltage spikes that could damage the switch. The diode's 200V reverse voltage rating handles typical inductive spikes, and its 1A current rating matches common load currents. The fast recovery time reduces the time the diode conducts after the switch closes, minimizing power loss. The SMA package is easy to place near the inductive load, and the AEC-Q101 qualification makes it suitable for automotive solenoids and actuators.
Recommended
Snubber Circuits
The STTH102AY is used in snubber circuits to suppress voltage transients in switching power converters. In an RC snubber, the diode is placed in parallel with the switch to clamp overvoltage spikes caused by parasitic inductance. Its 25 ns reverse recovery time ensures rapid response to transients, while the 200V rating provides adequate headroom for typical spikes. The low forward voltage drop reduces power dissipation in the snubber, and the surge current rating of 30A handles short-duration transients. The SMA package allows placement close to the switch, minimizing loop inductance. This application is common in flyback converters, motor drives, and inverters.
Recommended
Output Rectification in DC-DC Converters
In buck and boost converters, the STTH102AY is used as the output rectifier diode. In a buck converter, the diode conducts during the off-time of the high-side switch, providing a path for inductor current. Its fast recovery time minimizes reverse recovery losses, which are significant at high switching frequencies. The low forward voltage drop of 0.85V improves efficiency, especially at output currents around 1A. The 200V rating is suitable for input voltages up to 100V in typical applications. The SMA package is compact, and the thermal resistance of 15Β°C/W allows adequate heat dissipation with proper PCB copper area. This diode is ideal for point-of-load converters and battery-powered devices.
Recommended
Power Factor Correction (PFC) Circuits
The STTH102AY is used in boost-type PFC circuits as the output diode. In a PFC boost converter, the diode conducts during the off-time of the switch, transferring energy to the output capacitor. Its ultrafast recovery time is critical to minimize switching losses at high frequencies (typically 100 kHz or more). The 200V rating is suitable for universal input voltage ranges (85-265V AC) when used in the boost stage. The low forward voltage drop reduces conduction losses, improving overall power factor correction efficiency. The AEC-Q101 qualification makes it suitable for automotive PFC applications, such as on-board chargers. The SMA package allows compact PFC designs.
Recommended
LED Lighting Drivers
In LED drivers, the STTH102AY is used as a rectifier in the output stage of flyback or buck converters. Its fast recovery time reduces switching losses, improving the efficiency of the LED driver. The 1A current rating is suitable for driving LED strings up to 1A, and the 200V rating handles typical offline voltages. The low forward voltage drop minimizes power dissipation, which is important in enclosed lighting fixtures. The SMA package is compact and easy to assemble, and the 175Β°C junction temperature rating ensures reliability in high-temperature environments. This diode is commonly used in commercial and residential LED lighting.
Recommended
Recommended Products Summary
Engineering reference data for STTH102AY β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | STTH1R02AY | ES1B | US1B |
|---|---|---|---|---|
| Package | SMA (DO-214AC) | SMA (DO-214AC) | SMA (DO-214AC) | SMA (DO-214AC) |
| Brand | STMicroelectronics | STMicroelectronics | onsemi | Vishay |
| Reverse Recovery Time (trr) | 25 ns | 30 ns | 25 ns | 50 ns |
| Forward Voltage Drop (Vf) | 0.85 V @ 1A | 0.85 V @ 1A | 0.9 V @ 1A | 1.0 V @ 1A |
| Maximum Reverse Voltage (VRRM) | 200 V | 200 V | 200 V | 200 V |
| Average Forward Current (Io) | 1 A | 1 A | 1 A | 1 A |
| AEC-Q101 Qualified | Yes | Yes | No | No |
| Junction Temperature (Tj max) | 175Β°C | 175Β°C | 150Β°C | 150Β°C |
Key Differentiators
- AEC-Q101 qualified for automotive use (vs ES1B (onsemi))
- Faster reverse recovery time (25 ns) (vs US1B (Vishay))
- Higher junction temperature rating (175Β°C) (vs ES1B (onsemi))
Design Notes
The STTH102AY has a junction-to-ambient thermal resistance of 15Β°C/W. At 1A forward current and 0.85V forward voltage, power dissipation is 0.85W, resulting in a temperature rise of 12.75Β°C above ambient. Ensure adequate PCB copper area (at least 0.5 square inch) to keep the junction temperature below 175Β°C, especially in high-temperature environments.
Place the diode close to the switching node to minimize parasitic inductance, which can cause voltage spikes during reverse recovery. Use short, wide traces for the anode and cathode connections. For high-frequency operation, a ground plane underneath the diode can help reduce EMI.
Do not exceed the maximum reverse voltage of 200V, as this can cause avalanche breakdown and permanent damage. Also, ensure the average forward current does not exceed 1A under normal operating conditions. For surge currents, the non-repetitive peak surge current is 30A, but this should not be exceeded even momentarily.
Compliance Information
AEC-Q101 qualified per datasheet. RoHS compliant. REACH compliance assumed based on STMicroelectronics policy.
