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STMicroelectronics X0203NA 1BA2
,TO-226_straightlead.jpg)
- Part No.:
- X0203NA 1BA2
- Manufacturer:
- STMicroelectronics
- Category:
- SCRs
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
X0203NA 1BA2.pdf
- Description:
- SCR 800V 1.25A TO92-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,793
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Product details
Overview
X0203NA from STMicroelectronics is a sensitive-gate silicon-controlled rectifier (SCR) in TO-92 plastic package, rated for 400 V repetitive peak off-state voltage (VDRM), 1.25 A RMS on-state current (IT(RMS)), and 200 µA maximum gate trigger current (IGT). It operates across -40°C to +125°C junction temperature and is used in low-power AC phase-control circuits such as lamp dimmers and small appliance motor speed controllers.
For engineers reviewing the X0203NA datasheet, X0203NA pinout, X0203NA application, or X0203NA equivalent, key selection criteria include gate sensitivity (≤200 µA), low holding current (≤5 mA), fast turn-on delay (0.5 µs typ.), and thermal resistance (60 °C/W junction-to-leads) for reliable lead-soldered mounting in space-constrained consumer electronics.
Technical Context
This SCR employs TOP GLASS PNPN structure optimized for high dI/dt immunity (30 A/µs) and stable triggering at low gate drive. Its gate characteristics are specified with RL = 140 Ω and VD = 12 V DC, ensuring compatibility with microcontroller GPIOs and discrete transistor drivers.
The device features a 100 µs maximum turn-off time (tq) at 110°C junction temperature under 35 V reverse recovery conditions, and supports non-repetitive surge currents up to 22.5 A for 10 ms (I²t = 2.5 A²s), enabling robust transient handling in resistive and lightly inductive loads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VDRM | 400 V - Maximum repetitive blocking voltage before conduction; defines AC line voltage compatibility (e.g., 230 VAC RMS systems) |
| IT(RMS) | 1.25 A - Continuous RMS current capability at 60°C lead temperature; sets thermal design margin for TO-92 mounting |
| IGT | ≤200 µA - Max gate trigger current at 25°C; enables direct drive from low-current logic outputs |
| VGT | ≤0.8 V - Max gate trigger voltage; ensures reliable turn-on with minimal gate power dissipation |
| tq | ≤100 µs - Max turn-off time at 110°C; determines minimum commutation interval in phase-control timing |
| Rth(j-l) | 60 °C/W - Junction-to-leads thermal resistance; critical for calculating max average power (0.2 W) under DC lead cooling |
| IH | ≤5 mA - Max holding current at 25°C; defines minimum load current required to sustain conduction |
Pinout & Package
Package: TO-92 plastic (3-lead, straight lead configuration per mechanical drawing: A=1.35 mm, B=4.7 mm, C=2.54 mm, D=4.4–4.8 mm, E=12.7 mm, F=3.7 mm, a=0.45 mm; marking "X0203NA" on top face; weight 0.2 g).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Main current entry terminal during forward conduction | Connected to positive half-cycle AC source; must withstand full VDRM and ITSM stress |
| Cathode (K) | Main current exit terminal and reference for gate drive | Common return path; establishes gate-cathode voltage reference; tied to circuit ground in most configurations |
| Gate (G) | Control terminal initiating conduction | Receives low-energy pulse (≤200 µA, ≤0.8 V); polarity-sensitive (positive w.r.t. cathode for N-type gate) |
Key Features
| Feature | Design Value |
|---|---|
| Sensitive gate trigger | IGT ≤ 200 µA enables direct MCU GPIO control without external amplification |
| Low holding current | IH ≤ 5 mA allows stable latching even with light loads (e.g., indicator LEDs, small solenoids) |
| High dI/dt immunity | 30 A/µs rating prevents false triggering from fast current transients in noisy environments |
| TO-92 thermal performance | Rth(j-l) = 60 °C/W supports 0.2 W continuous dissipation with proper PCB copper pour on leads |
| Wide temperature operation | Junction range –40°C to +125°C ensures reliability in unventilated consumer enclosures |
Applications
| Lamp Dimmer Circuit | Small Appliance Motor Control |
|---|---|
Use Scenario: Phase-angle controlled 230 VAC incandescent lamp brightness adjustment using zero-crossing detection and pulse-triggered firing. IC Role / Device Role / Timing Role: SCR acts as bidirectional AC switch; triggered once per half-cycle to regulate power delivery based on firing angle. Use Value: Low IGT (≤200 µA) reduces gate driver complexity; 400 V VDRM provides 1.7× safety margin over 230 VAC peak (325 V). | Use Scenario: Speed regulation of universal motor in handheld vacuum cleaners or blenders via variable conduction angle. IC Role / Device Role / Timing Role: SCR serves as line-frequency AC power switch; gate pulse timing determines average torque and RPM. Use Value: IH ≤ 5 mA ensures motor remains energized through low-torque intervals; tq ≤ 100 µs permits tight firing window control. |
| AC Solid-State Relay Driver | Overvoltage Crowbar Protection |
Use Scenario: Low-power interface stage driving opto-TRIAC or transformer-isolated gate signal for industrial SSRs. IC Role / Device Role / Timing Role: Functions as isolated gate amplifier; converts logic-level trigger into robust SCR gate pulse. Use Value: PG(AV) = 0.2 W and PGM = 3 W (20 µs pulse) allow short high-energy gate pulses without thermal damage. | Use Scenario: Fast-acting crowbar across DC supply rail (e.g., 12–24 V) to short fault current during overvoltage events. IC Role / Device Role / Timing Role: SCR placed anode-to-rail, cathode-to-ground; triggered by comparator when voltage exceeds threshold. Use Value: ITSM = 22.5 A (10 ms) and I²t = 2.5 A²s ensure fuse coordination and safe energy clamping before system damage. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar sensitive-gate SCR applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ON Semiconductor MCR106-4 | VDRM = 400 V, IGT ≤ 500 µA, IT(RMS) = 1.25 A, TO-92 | Higher IGT requires stronger gate drive; otherwise identical voltage/current ratings | Select when gate drive capability ≥500 µA is available and cost is prioritized |
| Vishay S4006L | VDRM = 400 V, IGT ≤ 100 µA, IT(RMS) = 1.25 A, TO-220AB | Lower IGT but larger TO-220 package; higher thermal mass and Rth(j-a) = 65 °C/W | Select when board layout allows TO-220 and ultra-low gate drive (<100 µA) is required |
Compared with MCR106-4, X0203NA offers lower gate sensitivity for weaker drivers; versus S4006L, it trades smaller TO-92 footprint and easier hand-soldering for slightly higher IGT and better lead-based thermal management.
Availability
X0203NA is available at Aetrix Electronics and suitable for lamp dimmers, small-appliance motor controls, AC solid-state relay interfaces, and overvoltage crowbar protection circuits requiring stable component supply and long-term obsolescence support.
Supply support for X0203NA 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, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.
The X02xxxA series belongs to ST's legacy discrete power portfolio, developed specifically for cost-sensitive, low-power AC control applications where gate sensitivity, thermal efficiency in leaded packages, and long-term reliability are essential.
FAQ
What is the maximum allowable gate-cathode voltage (VGD) for X0203NA?
VGD is specified as ≥0.1 V at Tj = 125°C with RGK = 1 kΩ and VD = VDRM. This minimum value ensures gate-cathode junction integrity under worst-case blocking conditions and confirms that the gate remains reverse-biased during off-state operation to prevent leakage-induced misfiring.
Can X0203NA be used in DC switching applications?
Yes, but only with forced commutation. As a semi-controlled device, X0203NA lacks gate turn-off capability and relies on current interruption (e.g., series inductor + capacitor snubber or auxiliary switch) to reset conduction. It is not suitable for pure DC chopper topologies without external commutation circuitry.
What is the significance of the 0.5 µs typical gate delay time (tgd)?
tgd = 0.5 µs (typ.) is the time from gate pulse application to anode current reaching 10% of ITM. This fast response enables precise firing angle resolution in phase-control designs-e.g., achieving <1° timing accuracy at 50 Hz-and minimizes jitter in synchronized AC power regulation.
How does junction temperature affect gate trigger current (IGT)?
IGT increases with junction temperature: Fig.5 shows IGT[Tj] rises ~2.5× from 25°C to 125°C. At 125°C, IGT may reach ~500 µA. Designers must verify gate drive strength across the full operating range or implement temperature-compensated triggering to maintain reliability.
X0203NA 1BA2 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Packaging:
- Bulk
- Product Status:
- Active
- Voltage - Off State:
- 800 V
- Voltage - Gate Trigger (Vgt) (Max):
- 800 mV
- Current - Gate Trigger (Igt) (Max):
- 200 µA
- Voltage - On State (Vtm) (Max):
- 1.45 V
- Current - On State (It (AV)) (Max):
- 800 mA
- Current - On State (It (RMS)) (Max):
- 1.25 A
- Current - Hold (Ih) (Max):
- 5 mA
- Current - Off State (Max):
- 5 µA
- Current - Non Rep. Surge 50, 60Hz (Itsm):
- 22.5A, 25A
- SCR Type:
- Sensitive Gate
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
X0203NA 1BA2 FAQ
1.How can I place an order for X0203NA 1BA2 through Aetrix?
Please submit a Request for Quotation (RFQ) for X0203NA 1BA2 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 X0203NA 1BA2 reliable?
The price and inventory of X0203NA 1BA2 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for X0203NA 1BA2 is usually 5 days.
3.What payment methods are accepted for X0203NA 1BA2?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for X0203NA 1BA2 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for X0203NA 1BA2?
X0203NA 1BA2 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your X0203NA 1BA2 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 X0203NA 1BA2?
For technical support, including X0203NA 1BA2 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your X0203NA 1BA2 requirements.
6.How does Aetrix verify that X0203NA 1BA2 is sourced from the original manufacturer or authorized distributors?
All X0203NA 1BA2 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 X0203NA 1BA2 meets industry standards.
7.What is the process for return or replacement of X0203NA 1BA2?
All X0203NA 1BA2 units undergo pre-shipment inspection (PSI). If there is an issue with X0203NA 1BA2, 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 X0203NA 1BA2 part is unused and in its original packaging.
Return procedure for X0203NA 1BA2:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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