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Home > Products > Discrete Semiconductor Products > Diodes > Rectifiers > Single Diodes

STMicroelectronics STTH112A

Name: STTH112A
Brand: STMicroelectronics
SKU: STTH112A
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STTH112A

Manufacturer:: STMicroelectronics

Category:: Single Diodes

Package:: DO-214AC, SMA

Datasheet:: STTH112A.pdf

Description:: DIODE GEN PURP 1.2KV 1A SMA

Quantity:: RFQ Add To RFQ list

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Inventory:119,151

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Product details

Overview

STTH112A from STMicroelectronics is an ultrafast high-voltage planar silicon rectifier diode in SMA package, rated for 1200 V repetitive peak reverse voltage (V_RRM), 1 A average forward current (I_F(AV)), and 1.65 V maximum forward voltage drop at 125 °C - optimized for snubber, clamping, and freewheeling in offline switch-mode power supplies.

For engineers reviewing the STTH112A datasheet, STTH112A pinout, STTH112A application, or STTH112A equivalent, key selection criteria include reverse recovery time (75 ns), soft-switching behavior, thermal resistance (R_th(j-l) = 30 °C/W), junction temperature limit (+175 °C), and cathode-band polarity marking on the SMA body.

Technical Context

The STTH112A employs ST's proprietary planar ultrafast technology to achieve low stored charge and controlled minority-carrier lifetime, enabling soft reverse recovery with minimal EMI generation. Its 75 ns trr (at I_F = 0.5 A, I_RR = 0.25 A) and 500 ns t_fr support high-frequency operation up to 100 kHz in flyback and forward converters.

Thermal design is enabled by a low junction-to-lead thermal resistance of 30 °C/W (L = 10 mm), validated for epoxy FR4 PCBs with copper surface area ≥2 cm² per lead. The device operates reliably up to +175 °C junction temperature and withstands 18 A non-repetitive surge current (t = 8.3 ms).

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	1200 V - supports 850 V RMS input in universal AC-DC front-ends without derating
I_F(AV)	1 A at T_L = 115 °C - defines continuous conduction capability in TO-220-equivalent thermal conditions
V_F (max)	1.65 V at I_F = 1 A, T_j = 125 °C - sets conduction loss ceiling of ~1.65 W in worst-case thermal condition
t_rr	75 ns - enables clean turn-off in 100 kHz+ switching topologies with minimal voltage overshoot
R_th(j-l)	30 °C/W - allows direct thermal coupling to PCB copper for passive heatsinking without external metalwork
T_j(max)	+175 °C - permits operation in sealed industrial enclosures with ambient up to +105 °C
I_FSM	18 A (8.3 ms) - handles inrush and transient overloads in AC line rectification stages

Pinout & Package

The STTH112A is housed in an SMA (DO-214AC) surface-mount plastic package with cathode indicated by a band on the body. Lead length is specified at 10 mm for thermal testing; standard footprint matches JEDEC MS-013.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward current entry point	Connected to switching node (e.g., MOSFET drain) in freewheeling path
Cathode	Forward current exit / reverse-blocking terminal	Marked with band; ties to output rail or clamp capacitor in snubber circuits

Key Features

Feature	Design Value
Soft switching behavior	Controlled reverse recovery minimizes voltage ringing and EMI in high-dV/dt environments
High surge current rating	18 A single-pulse capability protects against line transients and startup surges
Low forward voltage drop	1.17 V typical at 125 °C reduces conduction losses vs. standard fast rectifiers
Planar junction construction	Ensures consistent trr and VF across production lots and temperature range
ECOPACK® compliant	Meets RoHS and halogen-free requirements without compromising thermal or electrical performance

Applications

AC-DC Adapter Output Rectification

Snubber Network Diode

Use Scenario: Secondary-side rectification in 12–24 V, 10–30 W offline adapters with universal AC input.

IC Role / Device Role / Timing Role: Freewheeling diode conducting during MOSFET off-time; synchronizes with primary-side PWM frequency (65–100 kHz).

Use Value: 75 ns trr prevents overlap conduction loss; 1.65 V VF limits dissipation to <1.7 W at full load.

Use Scenario: RCD snubber across MOSFET drain-source in flyback converters operating at 65 kHz.

IC Role / Device Role / Timing Role: Clamps voltage spikes during MOSFET turn-off; conducts only during brief energy transfer pulses.

Use Value: Soft recovery avoids secondary ringing; 1200 V V_RRM provides 2× margin over 600 V MOSFET breakdown.

DC-DC Converter Freewheeling

Inductive Load Demagnetization

Use Scenario: Output rectifier in isolated 48 V input telecom DC-DC modules delivering 3.3/5/12 V at ≤5 A.

IC Role / Device Role / Timing Role: Conducts freewheel current during synchronous rectifier off-phase; duty cycle dependent on load and regulation.

Use Value: 175 °C T_j(max) supports compact layout with limited airflow; 30 °C/W R_th(j-l) enables direct PCB thermal relief.

Use Scenario: Demagnetization path for relay coils or solenoid drivers in industrial PLC I/O modules.

IC Role / Device Role / Timing Role: Provides low-impedance path for inductive kickback; activated only during coil de-energization events.

Use Value: 18 A I_FSM safely absorbs 100 ms coil release energy; cathode band ensures unambiguous polarity mounting.

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultrafast high-voltage rectifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
ON Semiconductor MUR1120	V_RRM = 1200 V, I_F(AV) = 1 A, t_rr = 75 ns, VF = 1.7 V (max), DO-41/SMA	Higher VF increases conduction loss by ~3% at 1 A; identical trr and thermal specs	Select when DO-41 through-hole mounting is required or when sourcing diversity is prioritized
Vishay VS-1EWH12	V_RRM = 1200 V, I_F(AV) = 1 A, t_rr = 65 ns, VF = 1.6 V (max), SMA	10 ns faster trr improves EMI margin; slightly lower VF reduces loss but requires validation of softness	Prefer for noise-sensitive medical or audio power supplies where sub-70 ns recovery is critical

Compared with MUR1120 and VS-1EWH12, the STTH112A offers balanced softness and loss, verified thermal performance on FR4, and ECOPACK® compliance - making it optimal for cost-sensitive industrial adapters where reliability and manufacturability are prioritized over marginal speed gains.

Availability

STTH112A is available at Aetrix Electronics and suitable for AC-DC adapters, snubber networks, DC-DC converter freewheeling paths, and inductive load demagnetization circuits requiring stable component supply and long-term industrial availability.

Supply support for STTH112A 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, power, microcontroller, and sensor solutions for industrial, automotive, and consumer markets.

The STTH series belongs to ST's high-voltage rectifier product line, engineered specifically for efficiency-critical power conversion stages demanding ultrafast recovery, soft switching, and robust surge handling in compact packages.

FAQ

What is the cathode identification method for STTH112A?

The cathode is marked by a distinct color band on the SMA package body, aligned with the cathode terminal. This band must be oriented toward the positive rail or clamp capacitor in snubber/freewheeling configurations. Mechanical polarity is confirmed by the flat side of the SMA outline matching the cathode pad on the PCB footprint.

Can STTH112A replace standard fast recovery diodes in existing designs?

Yes - STTH112A can directly replace 1 A, 1200 V fast recovery diodes (e.g., UF4007) in most cases. Its lower trr (75 ns vs. 75–100 ns) and softer recovery reduce EMI, but layout parasitics must be reviewed to avoid unintended oscillation due to faster edge rates.

What is the minimum recommended copper area per lead for thermal performance?

ST specifies ≥2 cm² of 35 µm-thick copper per lead on FR4 for optimal R_th(j-a) performance. With 2 cm², R_th(j-a) drops to ~65 °C/W; below 1 cm², junction temperature rise exceeds safe margins at full I_F(AV).

Is STTH112A suitable for automotive under-hood applications?

No - STTH112A is not qualified to AEC-Q101 and lacks automotive-grade screening or extended temperature validation beyond +175 °C junction. It is intended for industrial, computing, and consumer power supplies where ambient temperatures remain ≤105 °C and no automotive qualification is mandated.

STTH112A Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: DO-214AC, SMA

Packaging:: Tape & Reel (TR)

Product Status:: Active

Technology:: Standard

Voltage - DC Reverse (Vr) (Max):: 1200 V

Current - Average Rectified (Io):: 1A

Voltage - Forward (Vf) (Max) @ If:: 1.9 V @ 1 A

Speed:: Fast Recovery =< 500ns, > 200mA (Io)

Reverse Recovery Time (trr):: 75 ns

Current - Reverse Leakage @ Vr:: 5 µA @ 1200 V

Capacitance @ Vr, F:: -

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SMA

Operating Temperature - Junction:: 175°C (Max)

STTH112A FAQ

1.How can I place an order for STTH112A through Aetrix?

Please submit a Request for Quotation (RFQ) for STTH112A 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 STTH112A reliable?

The price and inventory of STTH112A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STTH112A is usually 5 days.

3.What payment methods are accepted for STTH112A?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STTH112A transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STTH112A?

STTH112A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STTH112A 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 STTH112A?

For technical support, including STTH112A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STTH112A requirements.

6.How does Aetrix verify that STTH112A is sourced from the original manufacturer or authorized distributors?

All STTH112A 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 STTH112A meets industry standards.

7.What is the process for return or replacement of STTH112A?

All STTH112A units undergo pre-shipment inspection (PSI). If there is an issue with STTH112A, 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 STTH112A part is unused and in its original packaging.

Return procedure for STTH112A:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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