My Inquiry
My Account
Diodes Incorporated ZTX949STZ
,TO-226_straightlead.jpg)
- Part No.:
- ZTX949STZ
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- E-Line-3, Formed Leads
- Datasheet:
-
ZTX949STZ.pdf
- Description:
- TRANS PNP 30V 4.5A E-LINE
- Quantity:
- Payment:
- Shipping:
Inventory:1,875
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
ZTX949STZ from Diodes Incorporated is a PNP silicon planar medium-power high-current transistor designed for switching and linear amplification in industrial power control circuits. It delivers −4.5 A continuous collector current, −20 A peak pulse current, and exhibits very low VCE(sat) (−100 mV at −2 A/−200 mA), excellent hFE linearity down to 10 mA, and operates up to +200°C junction temperature - used in DC-DC converter output stages and motor drive H-bridge high-side switches.
For engineers reviewing the ZTX949STZ datasheet, ZTX949STZ pinout, ZTX949STZ application, or ZTX949STZ equivalent, key selection criteria include verified PNP polarity, TO-92-compatible E-Line package thermal resistance (Rth(j-amb) = 150°C/W), −30 V VCEO, −4.5 A IC, and Spice model availability for transient simulation of high-current switching waveforms.
Technical Context
The ZTX949STZ is a discrete PNP bipolar junction transistor optimized for medium-power switching with robust safe operating area (SOA) up to 100 V and 20 A in single-pulse mode. Its gain linearity across 10 mA–20 A and low leakage (ICBO ≤ −1 nA at 100°C) support precision current regulation in analog feedback loops and stable operation in thermally demanding environments.
It features a TO-92-compatible E-Line (3-312) package with emitter-base-collector (E-B-C) terminal order, rated for −55°C to +200°C operation, and achieves fT = 100 MHz at −100 mA/−10 V - enabling use in high-speed switching above 100 kHz while maintaining predictable saturation behavior under pulsed loads.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −30 V - Maximum sustainable collector-emitter voltage before breakdown in common-emitter configuration; defines upper rail limit in high-side switch designs. |
| IC (continuous) | −4.5 A - Continuous DC current handling capability; determines heatsink sizing for steady-state power dissipation (Ptot = 1.2 W @ 25°C). |
| VCE(sat) | −100 mV @ −2 A/−200 mA - Low saturation voltage minimizes conduction loss and self-heating during on-state operation in power switches. |
| hFE | 100–300 @ −10 mA to −5 A - Wide, linear current gain range supports both small-signal biasing and high-current drive without gain collapse. |
| fT | 100 MHz @ −100 mA/−10 V - Transition frequency enables reliable switching up to ~10–20 MHz with controlled rise/fall times in pulse applications. |
| Rth(j-amb) | 150 °C/W - Thermal resistance from junction to ambient on standard 1-inch² PCB copper; sets maximum allowable power at elevated ambient temperatures. |
Pinout & Package
Package: E-Line TO-92-compatible (3-312), epoxy-molded, through-hole mounting. Dimensions and lead spacing match standard TO-92 footprint for drop-in replacement in legacy designs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Emitter (E) | Current sink terminal for PNP device | Connected to higher potential rail (e.g., VCC) in high-side switch; carries full load current into the device. |
| Base (B) | Control input for minority-carrier injection | Requires negative current (−20 mA typical) to saturate; base resistor must be sized for required IB/IC ratio (e.g., 10:1). |
| Collector (C) | Output current source terminal | Connected to load and ground; voltage swing limited by VCEO (−30 V); handles reverse current flow in inductive flyback. |
Key Features
| Feature | Design Value |
|---|---|
| Very low VCE(sat) | −100 mV at −2 A ensures <0.2 W conduction loss, reducing thermal stress in compact PCB layouts. |
| Exceptional hFE linearity | Gain remains stable from 10 mA to 20 A, enabling accurate current mirroring and analog amplifier stages without gain compensation. |
| High-temperature operation | Junction rating up to +200°C allows deployment in engine control units, industrial motor drives, and sealed power supplies without derating. |
| Spice model available | Validated behavioral model supports accurate transient simulation of switching losses, turn-on delay, and thermal coupling in system-level design. |
Applications
| DC-DC Converter Output Stage | Industrial Motor Drive H-Bridge |
|---|---|
Use Scenario: High-side switch in non-synchronous buck converter output stage delivering 3–5 A load current. IC Role / Device Role / Timing Role: PNP transistor configured as saturated switch controlling power delivery to output inductor and filter capacitor. Use Value: Low VCE(sat) reduces conduction loss by >30% vs. comparable transistors, improving efficiency at 12 V input and 5 V/4 A output. | Use Scenario: Upper-leg switch in brushed DC motor H-bridge driving 24 V, 3 A stall current loads. IC Role / Device Role / Timing Role: High-side PNP switch enabling bidirectional motor control with fast turn-off via base pull-up and flyback clamping. Use Value: Robust SOA and −20 A peak rating withstand inductive kickback during PWM commutation without secondary snubbing. |
| Thermal Management Circuit | Overcurrent Protection Latch |
Use Scenario: Current-sense amplifier front-end in fan controller monitoring 0.5–4 A airflow load. IC Role / Device Role / Timing Role: Linear-mode PNP transistor biased for precise current amplification with minimal thermal drift. Use Value: Gain linearity down to 10 mA and low leakage (<−1 nA @ 100°C) ensure stable sensing accuracy over full industrial temperature range. | Use Scenario: Latching shutdown element in power supply overcurrent protection circuit. IC Role / Device Role / Timing Role: PNP transistor used in cross-coupled latch that holds off main power path after fault detection. Use Value: Very low ICBO and high VCEO prevent false triggering due to leakage or voltage transients during sustained overload conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP high-current switching applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ZTX951 | Higher VCEO (−60 V), lower IC (−3 A), same TO-92 package | Better suited for 48 V bus systems but limited to lower continuous current | Select when higher voltage margin is critical and load current stays below 3 A. |
| MJD2955T4G | TO-220 package, −10 A IC, −60 V VCEO, Rth(j-amb) = 40°C/W | Requires heatsink; supports higher power but occupies more board space | Choose for >5 A continuous loads where thermal management infrastructure exists. |
Compared with ZTX949STZ, ZTX951 trades current capacity for voltage headroom in the same footprint, while MJD2955T4G provides scalable power handling at the cost of board area and thermal design complexity - making ZTX949STZ optimal for space-constrained 24–30 V systems needing 4–5 A with minimal external thermal mass.
Availability
ZTX949STZ is available at Aetrix Electronics and suitable for industrial motor drives, DC-DC converter output stages, and thermal management circuits requiring stable component supply and long-term production continuity.
Supply support for ZTX949STZ 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 power management, signal integrity, and protection devices for industrial and automotive markets.
The ZTX949STZ belongs to Diodes' ZTX series of high-current bipolar transistors, engineered specifically for ruggedized switching and linear applications in harsh-temperature environments where gain stability and low saturation loss are critical.
FAQ
What is the correct pinout orientation for ZTX949STZ when viewed from the flat side with leads down?
When viewing the ZTX949STZ from the flat side with leads pointing downward, the pin order left-to-right is Emitter (E), Base (B), Collector (C). This matches the E-Line TO-92-compatible 3-312 mechanical drawing and is confirmed by Diodes Incorporated's official packaging documentation and marking layout (ZTX949 printed on top surface).
Can ZTX949STZ be used in parallel configurations for higher current handling?
Parallel operation is not recommended without individual emitter resistors due to gain mismatch and thermal runaway risk. The device's hFE variation (100–300) and positive temperature coefficient of VBE(sat) require careful balancing; Diodes does not characterize or guarantee performance in paralleled configurations per the datasheet.
What is the maximum allowable base drive current for reliable long-term operation?
The absolute maximum peak base current is −300 mA (per ICM rating), but continuous base current should be limited to −50 mA to avoid bond wire degradation. For −4.5 A IC, a design target of −225 mA (IB/IC = 5) with 20% margin ensures saturation while preserving reliability over 10+ years at 100°C junction temperature.
Does ZTX949STZ have qualified AEC-Q101 automotive grade variants?
No - ZTX949STZ is not AEC-Q101 qualified. Diodes offers the ZTX949Q variant (same die, enhanced test screening) for automotive applications, which undergoes stress testing per AEC-Q101 Rev D including HTGB, HTRB, and temperature cycling. Standard ZTX949STZ is intended for industrial and commercial use only.
ZTX949STZ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- E-Line-3, Formed Leads
- Packaging:
- Cut Tape (CT)
- Product Status:
- Active
- Transistor Type:
- PNP
- Current - Collector (Ic) (Max):
- 4.5 A
- Voltage - Collector Emitter Breakdown (Max):
- 30 V
- Vce Saturation (Max) @ Ib, Ic:
- 320mV @ 300mA, 5A
- Current - Collector Cutoff (Max):
- 50nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 100 @ 1A, 1V
- Power - Max:
- 1.58 W
- Frequency - Transition:
- 100MHz
- Operating Temperature:
- -55°C ~ 200°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- E-Line (TO-92 compatible)
ZTX949STZ FAQ
1.How can I place an order for ZTX949STZ through Aetrix?
Please submit a Request for Quotation (RFQ) for ZTX949STZ 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 ZTX949STZ reliable?
The price and inventory of ZTX949STZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ZTX949STZ is usually 5 days.
3.What payment methods are accepted for ZTX949STZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ZTX949STZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ZTX949STZ?
ZTX949STZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ZTX949STZ 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 ZTX949STZ?
For technical support, including ZTX949STZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ZTX949STZ requirements.
6.How does Aetrix verify that ZTX949STZ is sourced from the original manufacturer or authorized distributors?
All ZTX949STZ 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 ZTX949STZ meets industry standards.
7.What is the process for return or replacement of ZTX949STZ?
All ZTX949STZ units undergo pre-shipment inspection (PSI). If there is an issue with ZTX949STZ, 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 ZTX949STZ part is unused and in its original packaging.
Return procedure for ZTX949STZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ZTX949STZ Tags
-
MMBT3906LT1G
onsemi
-
MMBT3904-7-F
Diodes Incorporated
-
MMBT3904LT1G
onsemi
-
MMBT3906-7-F
Diodes Incorporated
-
MMBT3904-TP
Micro Commercial Co
-
MMBT2222A-7-F
Diodes Incorporated
-
BC846BLT1G
onsemi
-
BC847B,215
Nexperia USA Inc.
-
SMMBT3904LT1G
onsemi
-
MMBT2222A-TP
Micro Commercial Co
-
MMBTA06LT1G
onsemi
-
MMBT2222ALT1G
onsemi
Tech Hub
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…
Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…
A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…
