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Diodes Incorporated ZTX658STOA
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- Part No.:
- ZTX658STOA
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- E-Line-3, Formed Leads
- Datasheet:
-
ZTX658STOA.pdf
- Description:
- TRANS NPN 400V 0.5A E-LINE
- Quantity:
- Payment:
- Shipping:
Inventory:3,293
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Product details
Overview
ZTX658STOA from Diodes Incorporated is an NPN silicon planar medium-power high-voltage transistor with VCEO = 400 V, IC = 500 mA continuous, Ptot = 1 W at Tamb = 25°C, and fT = 50 MHz - designed for telephone dialler circuits requiring robust voltage blocking and reliable switching under pulsed loads.
For engineers reviewing the ZTX658STOA datasheet, ZTX658STOA pinout, ZTX658STOA application, or ZTX658STOA equivalent, key selection criteria include verified 400 V VCEO rating, hFE ≥ 50 at IC = 1 mA, VCE(sat) ≤ 0.5 V at IC = 100 mA / IB = 10 mA, thermal resistance Rth(j-amb) = 175 °C/W (PCB-mounted), and TO-92-compatible E-Line package compliance.
Technical Context
This NPN bipolar junction transistor operates in linear and switching modes with guaranteed breakdown voltages of 400 V across both C–B and C–E junctions, enabling use in off-line telephony interface stages where transient overvoltage immunity is critical. Its fT = 50 MHz at IC = 20 mA / VCE = 20 V supports moderate-speed pulse amplification and dial pulse shaping.
Switching performance is characterized by ton = 130 ns and toff = 3300 ns under defined pulsed conditions (IC = 100 mA, VC = 100 V, IB1 = 10 mA, IB2 = −20 mA), with safe operating area validated up to 100 V and 1 A in single-pulse mode at Tamb = 25°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 400 V - Sustains full line voltage transients in telephone ring signal generation without breakdown |
| IC (continuous) | 500 mA - Supports sustained current drive for electromechanical dial pulsing and relay control |
| Ptot | 1 W at 25°C - Requires derating above 25°C (5.7 mW/°C) for stable thermal operation on standard PCB |
| hFE | 50 min at IC = 1 mA - Ensures predictable base drive requirements in low-current bias networks |
| VCE(sat) | 0.5 V max at IC = 100 mA / IB = 10 mA - Limits conduction loss and self-heating during active switching |
| fT | 50 MHz - Enables faithful reproduction of 10–20 kHz dial pulse edges without phase distortion |
| Rth(j-amb) | 175 °C/W - Defines maximum allowable ambient temperature rise for 1 W dissipation on 1 in² copper PCB |
Pinout & Package
Package: TO-92 compatible E-Line (3-lead, straight lead form, JEDEC TO-92 outline). Pin identification confirmed per device marking and mechanical drawing ZTX658 C B E - Collector (lead 1), Base (lead 2), Emitter (lead 3).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Lead 1 (C) | Collector | Main high-voltage current sink node; rated for 400 V reverse bias and 1 A pulsed current |
| Lead 2 (B) | Base | Current-controlled input; requires 10 mA drive for full saturation at 100 mA collector load |
| Lead 3 (E) | Emitter | Reference terminal for bias network; VEB rating limited to 5 V reverse |
Key Features
| Feature | Design Value |
|---|---|
| High-voltage blocking capability | Guaranteed 400 V VCEO and VCBO enables direct connection to telephone line interfaces without external snubbing |
| Controlled saturation behavior | VCE(sat) ≤ 0.5 V at IC/IB = 10 ensures low power loss and minimal self-heating in pulsed dial applications |
| Thermal robustness | Junction temperature range −55°C to +200°C supports operation in unregulated telecom enclosures and industrial dialling systems |
| Standardized mechanical fit | E-Line TO-92 footprint allows drop-in replacement in legacy telephone hardware using existing PCB land patterns |
Applications
| Telephone Dialler Circuits | Ring Signal Generators |
|---|---|
Use Scenario: Generating standardized 10–20 pulse-per-second DC interruptions on POTS lines to emulate rotary dial operation. IC Role / Device Role / Timing Role: High-voltage NPN switch controlling loop current through telephone line transformer primary. Use Value: 400 V VCEO withstands 170 V RMS ring voltage peaks plus transients; 130 ns ton ensures clean pulse edge definition. | Use Scenario: Driving electromechanical ringers or LED indicators in analog telephone sets during incoming call detection. IC Role / Device Role / Timing Role: Medium-power amplifier stage converting low-level ring detect logic into isolated AC-coupled ringer drive. Use Value: 1 W Ptot and 500 mA IC support sustained 75 V/30 mA ringer coil excitation without thermal runaway. |
| Off-Hook Detection Interfaces | Line Monitoring Circuits |
Use Scenario: Sensing subscriber line current draw to determine handset lift status in PBX or key system units. IC Role / Device Role / Timing Role: Linear-mode current amplifier feeding precision ADC input with gain stability across −55°C to +100°C. Use Value: hFE ≥ 50 at IC = 1 mA ensures consistent amplification factor for <1 mA loop current sensing. | Use Scenario: Detecting line faults (short/open) and supervisory signals (busy tone, dial tone) in central office line cards. IC Role / Device Role / Timing Role: High-impedance buffer and level translator isolating sensitive monitoring circuitry from 48 V nominal line potential. Use Value: 5 V VEBO and 100 nA ICBO at 320 V enable stable DC biasing under varying line leakage conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN high-voltage switching applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ZTX653STOA | VCEO = 300 V (100 V lower); hFE = 100 min at IC = 10 mA | Not suitable for 400 V line transients; better for lower-voltage dial interfaces with higher gain needs | Select only if system peak voltage remains below 300 V and higher DC current gain is prioritized |
| BCV61B | VCEO = 300 V; SOT-23 package; Ptot = 250 mW | Surface-mount only; insufficient power handling for sustained dial pulse loads | Use only in space-constrained, low-duty-cycle monitoring functions-not for primary dial switching |
Compared with ZTX658STOA, ZTX653STOA trades voltage margin for higher hFE, while BCV61B sacrifices power and voltage capability for miniaturization - neither replicates the 400 V/1 W/TO-92 combination required for legacy telephone dialler reliability.
Availability
ZTX658STOA is available at Aetrix Electronics and suitable for telephone dialler circuits, ring signal generators, off-hook detection interfaces, and line monitoring circuits requiring stable component supply across extended temperature and voltage stress conditions.
Supply support for ZTX658STOA 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability components for industrial, automotive, and communications infrastructure.
ZTX658STOA belongs to the ZTX series of high-voltage bipolar transistors engineered specifically for legacy telephony interface and pulse-generation applications where long-term stability and voltage ruggedness are mandatory.
FAQ
What is the maximum safe operating voltage for ZTX658STOA in continuous DC mode?
The ZTX658STOA is rated for continuous collector-emitter voltage (VCEO) of 400 V at Tj ≤ 150°C. Operation above this value risks avalanche breakdown. Derating is required above 25°C ambient per the 5.7 mW/°C curve, and PCB layout must provide ≥1 in² copper for thermal management to sustain rated voltage at full current.
Can ZTX658STOA be used in linear amplifier configurations?
Yes - its hFE stability across IC = 1 mA to 200 mA and VCE = 5–10 V, combined with −55°C to +200°C junction range, supports Class-A and AB linear amplification in low-frequency (<50 kHz) analog stages such as ringer driver preamps or line supervision buffers.
Is ZTX658STOA RoHS compliant and halogen-free?
Yes - Diodes Incorporated confirms ZTX658STOA meets RoHS Directive 2011/65/EU and is halogen-free per IEC 61249-2-21. The device carries the "HF" suffix in official documentation and conforms to JEDEC J-STD-609A for marking of halogen content.
Does ZTX658STOA require a heatsink for 1 W operation?
No external heatsink is required if mounted on a PCB with ≥1 in² of 2 oz copper per layer, as specified in the Rth(j-amb) = 175 °C/W condition. Without that copper area, junction temperature will exceed 150°C at 1 W, risking parametric shift or failure - thermal simulation or IR measurement is recommended for non-standard layouts.
ZTX658STOA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- E-Line-3, Formed Leads
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 500 mA
- Voltage - Collector Emitter Breakdown (Max):
- 400 V
- Vce Saturation (Max) @ Ib, Ic:
- 500mV @ 10mA, 100mA
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 50 @ 100mA, 5V
- Power - Max:
- 1 W
- Frequency - Transition:
- 50MHz
- Operating Temperature:
- -55°C ~ 200°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- E-Line (TO-92 compatible)
ZTX658STOA FAQ
1.How can I place an order for ZTX658STOA through Aetrix?
Please submit a Request for Quotation (RFQ) for ZTX658STOA 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 ZTX658STOA reliable?
The price and inventory of ZTX658STOA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZTX658STOA is usually 5 days.
3.What payment methods are accepted for ZTX658STOA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZTX658STOA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ZTX658STOA?
ZTX658STOA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ZTX658STOA 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 ZTX658STOA?
For technical support, including ZTX658STOA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZTX658STOA requirements.
6.How does Aetrix verify that ZTX658STOA is sourced from the original manufacturer or authorized distributors?
All ZTX658STOA 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 ZTX658STOA meets industry standards.
7.What is the process for return or replacement of ZTX658STOA?
All ZTX658STOA units undergo pre-shipment inspection (PSI). If there is an issue with ZTX658STOA, 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 ZTX658STOA part is unused and in its original packaging.
Return procedure for ZTX658STOA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ZTX658STOA Tags
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