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onsemi NST857AMX2T5G
- Part No.:
- NST857AMX2T5G
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- 0402 (1006 Metric)
- Datasheet:
-
NST857AMX2T5G.pdf
- Description:
- TRANS PNP 45V 0.1A 3X2DFN
- Quantity:
- Payment:
- Shipping:
Inventory:7,940
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Product details
Overview
NST857AMX2T5G from onsemi is a PNP silicon general-purpose transistor in a 1.0 × 0.6 mm X2DFN3 package, rated for −45 V VCEO, −100 mA IC, and 166 mW power dissipation on standard FR4 (0.6 mm² Cu pad), with hFE = 180–250 at IC = −2 mA and fT = 100 MHz - used in low-power signal switching and biasing circuits in portable consumer electronics.
For engineers reviewing the NST857AMX2T5G datasheet, pinout, applications, or equivalent options, key selection considerations include its −0.3 V VCE(sat) at −10 mA/−0.5 mA drive, −5.0 V VEBO rating, thermal resistance of 722 °C/W (standard layout), and RoHS-compliant Pb-free/halogen-free construction.
Technical Context
This device operates as a discrete PNP bipolar junction transistor optimized for low-voltage, medium-speed switching and linear amplification in compact portable systems. Its design supports forced β = 10 operation with fast turn-on (typ. 12 ns) and fall time (typ. 35 ns) under −20 V VCC, and exhibits stable hFE across −55 °C to +150 °C.
The NST857AMX2T5G uses a surface-mount X2DFN3 package with three terminals: Collector (Pin 3), Base (Pin 1), Emitter (Pin 2). Its safe operating area (SOA) is defined up to 100 mA and −40 V with 1 ms pulse limit, and it achieves 4.5 pF output capacitance at −10 V VCB, supporting RF-coupled audio and timing applications below 100 MHz.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −45 V - Maximum collector-emitter voltage before breakdown under open-base conditions; sets upper rail limit in negative-rail switch designs. |
| IC (cont.) | −100 mA - Continuous collector current rating; defines maximum load-handling capability in DC bias or switching paths. |
| hFE | 180–250 @ IC = −2 mA - DC current gain range enabling predictable base drive sizing for low-current amplification or logic-level interfacing. |
| fT | 100 MHz - Current-gain bandwidth product; supports small-signal amplification and switching up to ~10–20 MHz practical frequency range. |
| VCE(sat) | −0.3 V @ IC = −10 mA, IB = −0.5 mA - Low saturation voltage minimizes conduction loss in high-efficiency low-side switches or level shifters. |
| RJA | 722 °C/W - Junction-to-ambient thermal resistance on 0.6 mm² Cu pad; requires careful PCB copper area planning for >50 mW continuous operation. |
| Cob | 4.5 pF @ VCB = −10 V - Output capacitance impacts high-frequency response and switching speed in tuned or fast-switching circuits. |
Pinout & Package
Package: X2DFN3 (1.0 × 0.6 mm, 0.35 mm pitch), case 714AC, surface-mount, leadless. Thermal pad not electrically connected; no exposed thermal slug.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (left) | Base | Control terminal; accepts forward-biased current to enable conduction between emitter and collector; requires series resistor for current limiting. |
| Pin 2 (center) | Emitter | Current source terminal in PNP configuration; connects to higher potential rail (e.g., VCC or battery +); polarity critical for correct biasing. |
| Pin 3 (right) | Collector | Current sink terminal; delivers load current to ground or lower-potential node; must remain ≤ VE − |VCEO| to avoid breakdown. |
Key Features
| Feature | Design Value |
|---|---|
| Pb-free, halogen-free, RoHS-compliant | Meets global environmental compliance requirements without requiring special handling or exemptions for industrial or consumer shipments. |
| Low VCE(sat) (−0.3 V) | Reduces power loss and self-heating in battery-powered switching nodes, extending runtime in wearables and remote sensors. |
| High fT (100 MHz) | Enables use in audio preamplifiers, oscillator buffers, and clock distribution stages where gain stability above 10 MHz is required. |
| Wide TJ range (−55 to +150 °C) | Supports deployment in automotive cabin modules, industrial controllers, and outdoor IoT edge nodes without derating at extremes. |
| Low Cob (4.5 pF) | Minimizes Miller effect in high-gain common-emitter stages, improving stability and bandwidth in feedback amplifier designs. |
Applications
| Portable Audio Amplifier Stage | Low-Voltage Logic Level Shifter |
|---|---|
|
Use Scenario: Amplifying line-level analog signals from DACs or codecs in Bluetooth earbuds and hearing aids. IC Role / Device Role / Timing Role: PNP small-signal amplifier in common-emitter configuration with emitter degeneration for gain control and distortion reduction. Use Value: 100 MHz fT and 180–250 hFE ensure flat 20 Hz–20 kHz response with <0.5% THD at −10 mA quiescent current. |
Use Scenario: Translating 1.8 V GPIO outputs to interface with 3.3 V or 5 V peripherals in microcontroller-based sensor hubs. IC Role / Device Role / Timing Role: Active-low level shifter using saturated PNP switch with grounded emitter and pull-up collector load. Use Value: −0.3 V VCE(sat) ensures <100 mV logic LOW voltage at 5 mA sink current, meeting TTL and CMOS input thresholds reliably. |
| Thermal Sensor Bias Circuit | LED Current Sink Driver |
|
Use Scenario: Providing stable bias current to NTC thermistors or bandgap reference diodes in temperature-compensated power supplies. IC Role / Device Role / Timing Role: Constant-current source configured with emitter resistor and base voltage divider for precision current regulation. Use Value: Tight hFE tolerance (180–250) and low VBE(on) drift (−0.6 to −0.75 V) enable ±2% current accuracy over −40 to +85 °C. |
Use Scenario: Driving indicator LEDs in smart home panels and medical device status displays with minimal board space. IC Role / Device Role / Timing Role: Low-side current sink switch controlling LED anode via collector-emitter path with fixed base drive. Use Value: −100 mA IC rating and −0.65 V VCE(sat) at full load allow driving up to 3 parallel LEDs at 20 mA each with <150 mW dissipation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP general-purpose transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMBT3906LT1G | Same X2DFN3 package, but VCEO = −40 V, hFE = 100–300, RJA = 625 °C/W (0.6 mm²), VCE(sat) = −0.4 V @ −10 mA. | Slightly lower voltage rating and higher saturation voltage; less suitable for −45 V rail designs or ultra-low-loss switching. | Select when cost sensitivity outweighs marginal VCEO and VCE(sat) advantages of NST857AMX2T5G. |
| DXT3906PSQ-13 | DFN1006-3 package (same footprint), VCEO = −40 V, hFE = 150–300, RJA = 600 °C/W, fT = 250 MHz. | Higher fT but lower VCEO; better for RF coupling but unsuitable for −45 V bias networks. | Prefer for high-frequency signal routing where bandwidth >100 MHz is critical and voltage margin is relaxed. |
Compared with MMBT3906LT1G and DXT3906PSQ-13, the NST857AMX2T5G offers superior −45 V breakdown margin and lowest VCE(sat) among X2DFN3 PNP transistors, making it optimal for space-constrained, high-reliability negative-rail switching where thermal headroom and voltage safety are prioritized.
Availability
NST857AMX2T5G is available at Aetrix Electronics and suitable for portable audio amplifiers, low-voltage logic level shifters, thermal sensor bias circuits, LED current sink drivers, and battery management system monitoring nodes requiring stable component supply and long-term manufacturability.
Supply support for NST857AMX2T5G 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The NST857AMX2T5G belongs to onsemi's general-purpose bipolar transistor family designed for compact, high-reliability signal switching and amplification in space-constrained portable and embedded systems.
FAQ
What is the maximum continuous collector current for NST857AMX2T5G?
The NST857AMX2T5G has a maximum continuous collector current (IC) rating of −100 mA at TA = 25°C. This value assumes operation on a standard FR4 PCB with a 0.6 mm², 2 oz. copper pad. Derating is required above 25°C at 1.39 mW/°C, and actual usable current depends on thermal layout and ambient conditions. The NST857AMX2T5G must not exceed this limit to maintain reliability and avoid parametric shift.
Does NST857AMX2T5G support operation at elevated temperatures?
Yes, the NST857AMX2T5G is specified for junction and storage temperatures from −55 °C to +150 °C. Its hFE remains functional across this range, with typical values of 180–250 at 25°C and reduced but stable gain at extremes. The device maintains VCEO = −45 V and VCE(sat) ≤ −0.65 V even at +150 °C, making NST857AMX2T5G suitable for under-hood automotive modules and industrial controllers.
What is the thermal resistance of NST857AMX2T5G on a standard PCB layout?
The NST857AMX2T5G has a junction-to-ambient thermal resistance (RJA) of 722 °C/W when mounted on FR4 with a 0.6 mm², 2 oz. copper pad - the baseline layout referenced in its datasheet. This value increases significantly with smaller copper areas or non-thermal-pad layouts. For higher power operation, designers should use the 100 mm² pad option (RJA = 185 °C/W), but that requires larger PCB real estate. The NST857AMX2T5G's thermal performance must be validated per actual board stackup.
Is NST857AMX2T5G pin-compatible with other X2DFN3 PNP transistors?
The NST857AMX2T5G uses the standard X2DFN3 (Case 714AC) footprint with Collector (Pin 3), Base (Pin 1), and Emitter (Pin 2) arranged left-to-right. It shares identical pinout and mechanical dimensions with MMBT3906LT1G and DXT3906PSQ-13, enabling direct PCB footprint reuse. However, electrical parameters differ - especially VCEO, hFE, and VCE(sat) - so circuit validation is required before substitution. The NST857AMX2T5G is not a drop-in replacement without design review.
What does the "T5G" suffix indicate in NST857AMX2T5G?
The "T5G" suffix in NST857AMX2T5G denotes tape-and-reel packaging: "T" = tape and reel, "5" = 8,000 units per reel, and "G" = Pb-free/RoHS-compliant finish. This matches onsemi's standard ordering nomenclature and confirms the device meets environmental compliance requirements without exemptions. The NST857AMX2T5G is supplied in moisture-sensitive packaging per J-STD-020, requiring appropriate handling prior to reflow.
NST857AMX2T5G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- 0402 (1006 Metric)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Transistor Type:
- PNP
- Current - Collector (Ic) (Max):
- 100 mA
- Voltage - Collector Emitter Breakdown (Max):
- 45 V
- Vce Saturation (Max) @ Ib, Ic:
- 650mV @ 5mA, 100mA
- Current - Collector Cutoff (Max):
- 15nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 125 @ 2mA, 5V
- Power - Max:
- 225 mW
- Frequency - Transition:
- 100MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 3-X2DFN (1x0.6)
NST857AMX2T5G FAQ
1.How can I place an order for NST857AMX2T5G through Aetrix?
Please submit a Request for Quotation (RFQ) for NST857AMX2T5G 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 NST857AMX2T5G reliable?
The price and inventory of NST857AMX2T5G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for NST857AMX2T5G is usually 5 days.
3.What payment methods are accepted for NST857AMX2T5G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for NST857AMX2T5G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for NST857AMX2T5G?
NST857AMX2T5G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your NST857AMX2T5G 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 NST857AMX2T5G?
For technical support, including NST857AMX2T5G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your NST857AMX2T5G requirements.
6.How does Aetrix verify that NST857AMX2T5G is sourced from the original manufacturer or authorized distributors?
All NST857AMX2T5G 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 NST857AMX2T5G meets industry standards.
7.What is the process for return or replacement of NST857AMX2T5G?
All NST857AMX2T5G units undergo pre-shipment inspection (PSI). If there is an issue with NST857AMX2T5G, 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 NST857AMX2T5G part is unused and in its original packaging.
Return procedure for NST857AMX2T5G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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