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onsemi 1PMT28AT1G
- Part No.:
- 1PMT28AT1G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-216AA
- Datasheet:
-
1PMT28AT1G.pdf
- Description:
- TVS DIODE 28VWM 45.4VC POWERMITE
- Quantity:
- Payment:
- Shipping:
Inventory:2,682
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Product details
Overview
1PMT28AT1G from onsemi is a unidirectional Zener transient voltage suppressor (TVS) in the POWERMITE® package, designed for clamping high-energy transients in DC power rails and signal lines. It features a 28 V working peak reverse voltage (VRWM), 32.8 V nominal breakdown voltage (VBR) at 1 mA, 45.4 V maximum clamping voltage (VC) at 4.4 A peak pulse current, and 200 W peak pulse power rating at 10/1000 µs. It is widely deployed in portable electronics power input protection.
For engineers reviewing the 1PMT28AT1G datasheet, pinout, applications, or equivalent options, key selection criteria include clamping performance under 10/1000 µs surge, thermal resistance to cathode tab (3.2 °C/W), JEDEC DO-216AA compliance, low-profile 1.1 mm height, and Pb-free RoHS-compliant packaging for space-constrained PCB layouts.
Technical Context
The 1PMT28AT1G operates as a unidirectional Zener TVS diode, leveraging avalanche breakdown to clamp transient overvoltages above its VRWM of 28 V. Its low Zener impedance and sub-1 ns response time ensure rapid suppression of ESD and lightning-induced surges before downstream ICs are damaged.
Thermally optimized via integral heatsink tabs and full metallic cathode tab, it achieves 3.2 °C/W junction-to-cathode thermal resistance - enabling sustained energy dissipation without derating in compact layouts. The POWERMITE package (DO-216AA) delivers SMA-equivalent thermal performance in 50% less footprint area (8.45 mm²).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Working Peak Reverse Voltage (VRWM) | 28 V - Maximum continuous DC or peak AC voltage the device blocks without clamping; sets minimum operating rail compatibility. |
| Breakdown Voltage (VBR) @ IT = 1 mA | 32.8 V (nominal) - Voltage at which avalanche conduction begins; defines threshold for reliable transient initiation. |
| Clamping Voltage (VC) @ IPP = 4.4 A | 45.4 V - Maximum voltage seen by protected circuit during 10/1000 µs surge; determines safe margin for 3.3 V/5 V logic rails. |
| Peak Pulse Power (Ppk) @ 10/1000 µs | 200 W - Energy-handling capacity for standard lightning/surge waveforms; enables IEC 61000-4-5 Level 3 compliance. |
| Junction-to-Cathode Thermal Resistance (RJcathode) | 3.2 °C/W - Enables direct mounting to copper pour or thermal pad for efficient heat extraction in high-duty-cycle applications. |
| ESD Rating (HBM) | Class 3 (>16 kV) - Meets stringent electrostatic discharge immunity requirements for handheld and consumer interface ports. |
| Package | POWERMITE® (DO-216AA) - JEDEC-registered surface-mount package with 1.1 mm max height, 8.45 mm² footprint, and full metallic cathode tab. |
Pinout & Package
1PMT28AT1G uses the POWERMITE® (DO-216AA) package: a 2-terminal surface-mount device with integral heatsink tabs and full metallic cathode bottom. Cathode is marked by a polarity band; lead orientation in tape places cathode (short lead) toward sprocket holes.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Cathode) | Transient current sink / clamping node | Connected to protected line (e.g., VBUS); carries full surge current to ground; thermally coupled to PCB copper via full-metallic bottom. |
| 2 (Anode) | Reference / ground return | Typically tied to system ground; low-inductance path required for fast transient response; junction-to-anode thermal resistance is 35 °C/W. |
Key Features
| Feature | Design Value |
|---|---|
| Low-profile thermal package | 1.1 mm max height with full metallic cathode tab enables placement under shields and in ultra-thin mobile designs while maintaining SMA-level thermal performance. |
| Sub-1 ns response time | Ensures clamping activation before transient energy couples into sensitive analog or digital ICs - critical for USB, HDMI, and battery-input protection. |
| JEDEC DO-216AA registration | Guarantees mechanical and soldering compatibility across qualified assembly processes and automated pick-and-place equipment. |
| Flux-trap-free construction | Full metallic bottom eliminates voids and flux entrapment during reflow, improving long-term reliability and thermal bond integrity. |
| Pb-free and RoHS compliant | Meets global environmental regulations without compromising surge performance or thermal capability. |
Applications
| USB Power Input Protection | Smartphone Battery Charging Circuit |
|---|---|
Use Scenario: Protects USB Type-C VBUS line from hot-plug transients, adapter surges, and ESD events during insertion/removal. IC Role / Device Role / Timing Role: Unidirectional TVS clamping element placed between VBUS and GND, upstream of load switch and charging IC. Use Value: Limits VBUS overshoot to ≤45.4 V during 4.4 A surges, preserving 5 V tolerant USB-PD controller and preventing latch-up in PMICs. |
Use Scenario: Shields lithium-ion battery charge path from reverse-polarity connection, charger fault conditions, and conducted surges. IC Role / Device Role / Timing Role: Primary overvoltage clamp on battery input rail, positioned before buck-boost charger IC and fuel gauge. Use Value: Withstands 200 W 10/1000 µs pulses without degradation, ensuring >100,000 mating cycles in ruggedized portable devices. |
| Industrial Sensor Node Power Rail | POS Terminal Serial Interface Protection |
Use Scenario: Secures 24 V DC input of wireless sensor nodes against induced lightning surges in factory automation environments. IC Role / Device Role / Timing Role: Standoff-rated TVS on main DC input, coordinated with upstream fuse and downstream LDO regulator. Use Value: 28 V VRWM matches common 24 V industrial bus tolerances; 3.2 °C/W RJcathode allows direct thermal coupling to chassis ground plane. |
Use Scenario: Guards RS-232/RS-485 data lines in point-of-sale terminals against ESD from operator contact and cable discharge events. IC Role / Device Role / Timing Role: Low-capacitance unidirectional TVS on TX/RX lines referenced to local ground, placed adjacent to connector. Use Value: Class 3 HBM rating (>16 kV) meets IEC 61000-4-2 Level 4; 1.1 mm profile fits tight connector keep-out zones without raising board stack height. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ28A | Same VRWM (28 V), but SMA package (2.5 mm height, 29.4 mm² footprint); 200 W rating; higher RJA (500 °C/W vs. 3.2 °C/W to cathode). | Requires larger PCB area and lacks integral heatsink tabs; less suitable for ultra-thin or thermally dense layouts. | Select when legacy SMA footprint compatibility is mandatory and thermal constraints are relaxed. |
| 1.5SMC28A | Higher peak power (1500 W @ 10/1000 µs), but SMC package (2.7 mm height, 42.5 mm²); no metallic cathode tab; RJA = 18 °C/W. | Better for high-energy surges but incompatible with space-constrained designs; no direct thermal path to PCB copper. | Choose only when surge threat level exceeds IEC 61000-4-5 Level 4 and board real estate permits larger package. |
Compared with SMAJ28A and 1.5SMC28A, the 1PMT28AT1G delivers identical 28 V clamping performance in a 50% smaller footprint and 1.1 mm profile, with superior thermal management via its full-metallic cathode tab - making it optimal for next-generation portable, wearable, and miniaturized industrial electronics where board space and thermal headroom are constrained.
Availability
1PMT28AT1G is available at Aetrix Electronics and suitable for USB power input protection, smartphone battery charging circuits, and industrial sensor node power rails requiring stable component supply, RoHS compliance, and consistent surge performance across production batches.
Supply support for 1PMT28AT1G 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 manufacturer specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The 1PMT28AT1G belongs to the 1PMT5.0AT1G/T3G Series of Zener transient voltage suppressors, engineered specifically for compact, high-reliability overvoltage protection in space- and thermally-constrained portable and industrial electronics.
FAQ
What is the clamping voltage of the 1PMT28AT1G at its rated peak pulse current?
The 1PMT28AT1G has a maximum clamping voltage (VC) of 45.4 V when subjected to its specified peak pulse current of 4.4 A under the standard 10/1000 µs waveform. This value is measured per Figure 2 in the official datasheet and ensures predictable overvoltage limiting for downstream 3.3 V or 5 V components. The 1PMT28AT1G maintains this clamping performance across its full operating temperature range of −55 °C to +150 °C.
Is the 1PMT28AT1G unidirectional or bidirectional, and how is polarity identified?
The 1PMT28AT1G is a unidirectional TVS diode, meaning it clamps only positive transients relative to its cathode terminal. Polarity is indicated by a visible cathode band on the device body, and in tape-and-reel packaging, the cathode (shorter lead) is oriented toward the sprocket holes. Pin 1 is cathode and must be connected to the line being protected; Pin 2 (anode) connects to ground.
What is the thermal resistance from junction to cathode tab for the 1PMT28AT1G, and why does it matter?
The 1PMT28AT1G has a junction-to-cathode thermal resistance (RJcathode) of 3.2 °C/W, measured at cathode tab temperature (Ttab = 75 °C). This exceptionally low value results from its full metallic cathode bottom and integral heatsink tabs, enabling direct thermal transfer to PCB copper pours. It matters because it allows the 1PMT28AT1G to sustain repeated surges without thermal runaway - critical in high-duty-cycle applications like industrial power inputs.
Can the 1PMT28AT1G replace SMAJ28A in an existing design without layout changes?
No - the 1PMT28AT1G cannot serve as a drop-in replacement for SMAJ28A due to fundamental package differences: 1PMT28AT1G uses POWERMITE® (DO-216AA, 2.0 × 1.9 mm), while SMAJ28A uses SMA (4.3 × 2.6 mm). Though both have identical VRWM and clamping specs, the 1PMT28AT1G requires a new footprint, stencil, and placement program. Its advantage lies in miniaturization and thermal performance, not mechanical interchangeability.
Does the 1PMT28AT1G meet industry ESD standards, and what test level does it support?
Yes, the 1PMT28AT1G is rated for Class 3 Human Body Model (HBM) ESD protection, exceeding 16 kV per ANSI/ESDA/JEDEC JS-001. This qualifies it for direct interface protection in handheld devices, USB ports, and exposed connectors subject to frequent operator contact. Its <1 ns response time ensures clamping occurs before ESD energy damages sensitive transceivers or microcontrollers downstream.
1PMT28AT1G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-216AA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 45.4V
- Current - Peak Pulse (10/1000µs):
- -
- Power - Peak Pulse:
- 1000W (1kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- Powermite
1PMT28AT1G FAQ
1.How can I place an order for 1PMT28AT1G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1PMT28AT1G 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 1PMT28AT1G reliable?
The price and inventory of 1PMT28AT1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1PMT28AT1G is usually 5 days.
3.What payment methods are accepted for 1PMT28AT1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1PMT28AT1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1PMT28AT1G?
1PMT28AT1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1PMT28AT1G 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 1PMT28AT1G?
For technical support, including 1PMT28AT1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1PMT28AT1G requirements.
6.How does Aetrix verify that 1PMT28AT1G is sourced from the original manufacturer or authorized distributors?
All 1PMT28AT1G 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 1PMT28AT1G meets industry standards.
7.What is the process for return or replacement of 1PMT28AT1G?
All 1PMT28AT1G units undergo pre-shipment inspection (PSI). If there is an issue with 1PMT28AT1G, 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 1PMT28AT1G part is unused and in its original packaging.
Return procedure for 1PMT28AT1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1PMT28AT1G Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
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