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

STMicroelectronics STTH212U

Name: STTH212U
Brand: STMicroelectronics
SKU: STTH212U
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STTH212U

Manufacturer:: STMicroelectronics

Category:: Single Diodes

Package:: DO-214AA, SMB

Datasheet:: STTH212U.pdf

Description:: DIODE GEN PURP 1.2KV 2A SMB

Quantity:: RFQ Add To RFQ list

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Inventory:15,055

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Product details

Overview

STTH212U from STMicroelectronics is a high-voltage ultrafast recovery rectifier diode in SMB package, rated for 1200 V repetitive peak reverse voltage (V_RRM), 2 A average forward current (I_F(AV)), and 75 ns maximum reverse recovery time (t_rr). It delivers low conduction loss (V_F = 1.07 V typ. at 125 °C, 2 A) and soft switching behavior for EMI reduction in high-frequency power converters.

For engineers reviewing the STTH212U datasheet, STTH212U pinout, STTH212U application, or STTH212U equivalent, key selection criteria include its 175 °C maximum junction temperature, 25 °C/W junction-to-lead thermal resistance (SMB), softness factor >4.5 at 200 A/µs, and suitability for freewheeling/clamping in PFC stages and offline SMPS.

Technical Context

This diode employs planar silicon technology to achieve stable ultrafast recovery with controlled minority-carrier lifetime, enabling predictable t_rr ≤ 75 ns and low Q_RR (≤ 400 nC typical at 600 V, 125 °C). Its soft recovery (softness factor ≥ 4.5) minimizes voltage overshoot and ringing during turn-off.

The device operates up to 175 °C junction temperature and supports surge currents up to 40 A (8.3 ms sine half-wave), with thermal impedance optimized for SMB footprint on FR4 PCBs (R_th(j-l) = 25 °C/W).

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	1200 V - blocks line transients in 800 V AC-input PFC and industrial DC-link applications
I_F(AV)	2 A at T_lead = 90 °C - supports continuous conduction mode operation in compact 30–65 W adapters
t_rr (max)	75 ns - enables switching frequencies up to 300 kHz without excessive switching loss or EMI
V_F (typ.)	1.07 V at 125 °C, 2 A - reduces conduction loss to ~2.1 W in 2 A average-current path
T_j(max)	175 °C - allows derated operation in sealed enclosures or high ambient environments
R_th(j-l)	25 °C/W (SMB) - defines thermal path from junction to PCB copper via leadframe, critical for layout design
I_FSM	40 A (8.3 ms) - withstands inrush and overload surges in unregulated input stages

Pinout & Package

Housed in an SMB (DO-214AA) surface-mount package with two terminals: cathode (marked band) and anode. The package meets UL94 V0 flammability rating and supports automated reflow assembly.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward current entry point	Connected to switch node (e.g., MOSFET drain) in flyback/freewheeling paths
Cathode	Forward current exit / reverse-blocking terminal	Connected to output rail or snubber network; marked with band for orientation

Key Features

Feature	Design Value
Soft switching behavior	Softness factor ≥ 4.5 at 200 A/µs - suppresses voltage spikes and EMI in hard-switched topologies
High surge robustness	40 A non-repetitive surge (8.3 ms) - survives cold-start and short-circuit events without degradation
Low thermal resistance	R_th(j-l) = 25 °C/W - enables 2 A operation with < 50 °C junction rise over lead on standard FR4
High-temperature capability	Rated to 175 °C junction - supports operation in enclosed power supplies and industrial controls
Planar silicon construction	Stable t_rr and V_F across temperature - eliminates parameter drift in wide ambient ranges

Applications

AC-DC Power Factor Correction (PFC)

Offline Switch-Mode Power Supplies (SMPS)

Use Scenario: Boost diode in continuous conduction mode (CCM) PFC stage operating from 85–265 V AC input.

IC Role / Device Role / Timing Role: Freewheeling diode conducting during MOSFET off-time; handles 2 A average current at 100 kHz switching.

Use Value: Soft recovery limits dV/dt-induced EMI, while 1200 V rating ensures margin against 1.2 kV line transients.

Use Scenario: Output rectifier in 36 W flyback adapter powering IoT gateways.

IC Role / Device Role / Timing Role: Secondary-side rectifier delivering 5 V/3 A; conducts during transformer reset phase.

Use Value: 75 ns t_rr prevents reverse conduction overlap with synchronous FET, reducing cross-conduction loss.

Snubber Networks

Inductive Load Demagnetization

Use Scenario: RCD snubber diode clamping voltage spikes across MOSFETs in LLC resonant converters.

IC Role / Device Role / Timing Role: Fast turn-on/turn-off clamp element absorbing leakage inductance energy in < 100 ns windows.

Use Value: Low V_F (1.07 V) minimizes snubber power dissipation; soft recovery avoids secondary ringing.

Use Scenario: Freewheeling diode across solenoid valves or relay coils in PLC output modules.

IC Role / Device Role / Timing Role: Provides low-impedance path for coil current decay after driver turn-off.

Use Value: 40 A I_FSM safely absorbs 30 A coil dump pulses; 175 °C rating supports operation near heat-generating logic ICs.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
STTH2R012DJ	Same V_RRM (1200 V), lower I_F(AV) (1.2 A), DPAK package, R_th(j-l) = 15 °C/W	Better thermal performance but lower current rating; requires larger PCB area	Select when board space permits and thermal budget is tighter than current demand
ES1J	Lower V_RRM (600 V), same SMB package, t_rr = 35 ns, I_F(AV) = 1 A	Insufficient for 800 V AC-line applications; suitable only for 230 V AC or DC-fed systems	Use only in cost-sensitive, lower-voltage (< 400 V DC) designs where 1200 V margin is unnecessary

Compared with STTH2R012DJ and ES1J, STTH212U uniquely balances 1200 V blocking, 2 A average current, SMB footprint, and soft recovery-making it optimal for space-constrained, high-input-voltage offline converters requiring EMI control.

Availability

STTH212U is available at Aetrix Electronics and suitable for AC-DC power factor correction, offline switch-mode power supplies, snubber networks, and inductive load demagnetization requiring stable component supply and consistent parametric performance across production lots.

Supply support for STTH212U 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 automotive, industrial, and consumer markets.

The STTH series targets high-efficiency power conversion, with STTH212U specifically engineered for ultrafast, soft-recovery rectification in high-voltage, high-frequency switching applications.

FAQ

What is the maximum allowable PCB copper area under each lead for optimal thermal performance?

Per Figure 13 in the datasheet, R_th(j-a) improves with increasing copper surface area (S_Cu). For SMB-packaged STTH212U, using ≥ 2 cm² of 35 µm-thick copper per lead reduces R_th(j-a) to ~55 °C/W. Thermal relief patterns should avoid isolating leads from inner-layer planes.

Does STTH212U support reflow soldering per JEDEC J-STD-020?

Yes. STTH212U's SMB package is qualified for standard Pb-free reflow profiles (peak temperature ≤ 260 °C, 20–40 s above 217 °C), as confirmed by ST's ECOPACK® compliance documentation and package mechanical data in Rev 2 of DocID11497.

How does softness factor affect EMI in a boost PFC stage?

A softness factor ≥ 4.5 means reverse recovery current decays gradually, limiting di/dt and associated magnetic field generation. In boost PFC, this reduces common-mode noise on input EMI filters and lowers conducted emissions above 150 kHz-critical for meeting EN55022 Class B limits.

Can STTH212U replace STTH212S in the same PCB footprint?

No. STTH212U (SMB) and STTH212S (SMC) have different land patterns: SMB uses 5.84 mm × 2.18 mm pads; SMC requires 8.19 mm × 3.14 mm. Mechanical interference and solder joint reliability would be compromised if substituted without layout revision.

STTH212U Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: DO-214AA, SMB

Packaging:: Tape & Reel (TR)

Product Status:: Active

Technology:: Standard

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

Current - Average Rectified (Io):: 2A

Voltage - Forward (Vf) (Max) @ If:: 1.75 V @ 2 A

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

Reverse Recovery Time (trr):: 75 ns

Current - Reverse Leakage @ Vr:: 10 µA @ 1200 V

Capacitance @ Vr, F:: -

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SMB

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

STTH212U FAQ

1.How can I place an order for STTH212U through Aetrix?

Please submit a Request for Quotation (RFQ) for STTH212U 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 STTH212U reliable?

The price and inventory of STTH212U are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STTH212U is usually 5 days.

3.What payment methods are accepted for STTH212U?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STTH212U transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STTH212U?

STTH212U orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STTH212U 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 STTH212U?

For technical support, including STTH212U datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STTH212U requirements.

6.How does Aetrix verify that STTH212U is sourced from the original manufacturer or authorized distributors?

All STTH212U 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 STTH212U meets industry standards.

7.What is the process for return or replacement of STTH212U?

All STTH212U units undergo pre-shipment inspection (PSI). If there is an issue with STTH212U, 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 STTH212U part is unused and in its original packaging.

Return procedure for STTH212U:

1.Submit a request within 90 days.

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

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