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onsemi CM1249-04S9
- Part No.:
- CM1249-04S9
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- SOT-953
- Datasheet:
-
CM1249-04S9.pdf
- Description:
- LOW CAPACITANCE TRANSIENT VOLTAG
- Quantity:
- Payment:
- Shipping:
Inventory:5,786
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Product details
Overview
CM1249-04S9 from onsemi is a low-capacitance transient voltage suppressor (TVS) array providing ESD protection for four high-speed I/O lines, with 5 pF typical input capacitance, ±8 kV contact ESD rating per IEC 61000-4-2, and 0.75 µA leakage at 3.5 V - deployed in USB 2.0, serial, and docking port interfaces.
For engineers reviewing the CM1249-04S9 datasheet, pinout, applications, or equivalent options, key selection criteria include channel count, clamping voltage under ±5 mA, dynamic resistance, diode capacitance vs. reverse voltage behavior, and SOT-953 package compatibility with high-density PCB layouts.
Technical Context
The CM1249-04S9 integrates four independent bidirectional TVS diodes in a single SOT-953 package, each configured as a cathode-to-line (CHx) and common anode (VN) structure. It operates within –40°C to +85°C and supports transient suppression without signal integrity degradation due to its low 5 pF typical capacitance and sub-1 Ω forward dynamic resistance.
Clamping occurs at 6.1 V (positive) and –0.4 V (negative) under ±5 mA test current, enabling robust protection of 3.3 V interface rails. The device meets IEC 61000-4-2 Level 4 (±8 kV contact) and MIL-STD-883 HBM (±15 kV), with no external capacitor required on CH pins per specification notes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Channel Count | 4 independent ESD-protected I/O channels |
| Input Capacitance | 5 pF typical at 1 MHz, 0 VDC - preserves signal integrity in USB 2.0 and IEEE 1394 applications |
| ESD Rating | ±8 kV contact discharge per IEC 61000-4-2 - meets industrial and consumer immunity requirements |
| Clamp Voltage | +6.1 V / –0.4 V at ±5 mA - limits voltage excursion on 3.3 V data lines during transients |
| Leakage Current | 0.75 µA max at 3.5 VDC - avoids loading of low-power interface receivers |
| Dynamic Resistance | 0.7 Ω forward, 2.1 Ω reverse - ensures fast, low-impedance clamping path during ESD events |
Pinout & Package
SOT-953 is a 5-pin, ultra-compact surface-mount package (1.00 × 0.80 × 0.45 mm) with gull-wing leads, optimized for space-constrained portable electronics and high-density routing near connectors.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | CH1 cathode | Protected I/O line 1 - connects directly to USB D+ or other high-speed signal |
| 2 | CH2 cathode | Protected I/O line 2 - e.g., USB D– or serial TX |
| 3 | VN anode | Common TVS anode - tied to ground plane for bidirectional clamping |
| 4 | CH3 cathode | Protected I/O line 3 - e.g., VBUS sense or auxiliary control line |
| 5 | CH4 cathode | Protected I/O line 4 - e.g., ID pin or sideband signal |
Key Features
| Feature | Design Value |
|---|---|
| Low I/O capacitance | 5 pF typical enables use in 480 Mbps USB 2.0 without signal rise-time degradation |
| IEC 61000-4-2 compliance | ±8 kV contact discharge rating verified per standard test setup with VN grounded |
| ESD endurance | Withstands >1000 ESD strikes per channel - supports long-term reliability in field-deployed ports |
| SOT-953 footprint | 1.0 mm × 0.8 mm body saves >60% board area vs. SOIC-8 TVS arrays |
Applications
| USB 2.0 Interface Protection | Industrial Serial Port Protection |
|---|---|
Use Scenario: Protecting D+/D– lines and VBUS/ID pins on USB 2.0 host/device connectors exposed to frequent handling and static discharge. IC Role / Device Role / Timing Role: Bidirectional TVS array clamping transients before they reach the USB transceiver IC. Use Value: Prevents latch-up or damage to PHY-level circuitry while maintaining <1 ns response time and minimal signal distortion. | Use Scenario: Securing RS-232/RS-485 transceiver I/O pins in factory automation panels subject to operator ESD and cable-induced surges. IC Role / Device Role / Timing Role: Low-leakage transient suppressor placed at connector entry point to shunt energy to chassis ground. Use Value: Enables reliable operation at 115.2 kbps without added series impedance or timing skew from higher-capacitance protectors. |
| Docking Station Port Protection | Consumer Docking/Proprietary Port Protection |
Use Scenario: Shielding multi-signal docking connectors (e.g., DisplayPort Alt Mode, USB-C sideband use cases) where multiple high-speed and power lines coexist. IC Role / Device Role / Timing Role: Four-channel discrete TVS array assigned to critical signal pairs and configuration lines. Use Value: Delivers simultaneous protection across mixed-signal paths without cross-talk or shared-clamp interference. | Use Scenario: Hardening proprietary high-speed data ports on gaming peripherals, VR headsets, or smart home hubs with frequent plug/unplug cycles. IC Role / Device Role / Timing Role: ESD front-end protector placed immediately adjacent to edge connector pads. Use Value: Achieves system-level ESD pass rate >99.5% in production testing using standard IEC 61000-4-2 test fixtures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ESD protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPD4E05U06DQAR | 4-channel, 0.5 pF typical capacitance, lower clamping voltage (+3.6 V / –1.2 V), 5-pin X2SON package | Better suited for USB 3.0/PCIe Gen1+ where sub-1 pF is mandatory; requires tighter layout control due to smaller pad pitch | Select when signal bandwidth exceeds 1 GHz and board space allows X2SON rework capability |
| ESD5Z4.5T5G | Single-channel, 4.5 V working voltage, SOD-523 package, 12 pF capacitance | Limited to one line per device; higher capacitance restricts use to low-speed GPIO or power rails, not high-speed data | Choose only for cost-sensitive, low-density designs where multi-channel integration is unnecessary |
Compared with TPD4E05U06DQAR and ESD5Z4.5T5G, the CM1249-04S9 delivers optimal balance of 4-channel integration, 5 pF capacitance, and proven USB 2.0 interoperability - making it preferred for mid-speed interface protection where layout simplicity and qualification history matter.
Availability
CM1249-04S9 is available at Aetrix Electronics and suitable for USB 2.0 interface protection, industrial serial port hardening, and docking station signal line safeguarding requiring stable component supply and RoHS-compliant sourcing.
Supply support for CM1249-04S9 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 delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The CM1249-04S9 belongs to onsemi's low-capacitance TVS portfolio designed specifically for high-speed digital interface protection - emphasizing minimal signal loading, repeatable ESD survivability, and compact packaging for next-generation portable electronics.
FAQ
What is the maximum operating temperature range for the CM1249-04S9?
The CM1249-04S9 is rated for continuous operation from –40°C to +85°C, matching standard industrial ambient requirements. This range is validated across all electrical parameters including leakage current, clamping voltage, and capacitance. Thermal derating is not required within this span, and the device maintains full IEC 61000-4-2 ESD performance throughout. The CM1249-04S9's silicon structure and SOT-953 package enable stable behavior even under thermal cycling conditions typical of portable electronics.
Does the CM1249-04S9 require an external capacitor for proper ESD protection?
No, the CM1249-04S9 does not require an external capacitor for basic ESD protection functionality. Per the datasheet Note 4, all ESD and electrical characteristics - including ±8 kV contact rating and 5 pF capacitance - are specified with no external capacitor on the CH pins. Adding capacitance may degrade high-frequency transient response and is discouraged unless explicitly modeled for a specific system-level surge profile. The CM1249-04S9's internal diode structure provides sufficient charge-handling capability for standard IEC 61000-4-2 waveforms.
How many ESD strikes can the CM1249-04S9 withstand per channel?
Each channel of the CM1249-04S9 is rated to withstand over 1000 ESD strikes at ±8 kV contact discharge level, as confirmed in the device's Features section. This endurance is measured under standard IEC 61000-4-2 test conditions with VN grounded and applies independently to all four CHx terminals. Post-strike verification shows no parametric shift beyond specification limits, supporting long-term deployment in high-touch consumer interfaces. The CM1249-04S9's robustness stems from its low dynamic resistance and optimized junction design.
What is the significance of the VN pin on the CM1249-04S9?
The VN pin is the common anode node for all four TVS diodes in the CM1249-04S9 and must be connected directly to a low-impedance ground plane. It enables bidirectional clamping: positive transients are shunted from CHx to VN (ground), while negative transients pull VN below ground and conduct through the reverse-biased diode path. Proper VN grounding is essential for achieving the specified ±8 kV ESD rating and 6.1 V / –0.4 V clamp voltages. The CM1249-04S9's performance degrades significantly if VN is routed with inductance or shared with noisy power domains.
Is the CM1249-04S9 RoHS compliant and lead-free?
Yes, the CM1249-04S9 is RoHS compliant and features a lead-free finish, as explicitly stated in the Features section and Ordering Information table. The "S9" suffix denotes lead-free, halogen-free, and RoHS-compliant construction per EU Directive 2011/65/EU. All materials, plating, and assembly processes meet JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1) requirements. The CM1249-04S9's SOT-953 package uses matte tin over nickel underplate, fully compatible with standard Pb-free reflow profiles.
CM1249-04S9 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- SOT-953
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Discontinued at Digi-Key
- Type:
- Zener
- Unidirectional Channels:
- 4
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 3.5V (Max)
- Voltage - Breakdown (Min):
- 6.47V
- Voltage - Clamping (Max) @ Ipp:
- -
- Current - Peak Pulse (10/1000µs):
- -
- Power - Peak Pulse:
- 10W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 12pF @ 1MHz
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-953
CM1249-04S9 FAQ
1.How can I place an order for CM1249-04S9 through Aetrix?
Please submit a Request for Quotation (RFQ) for CM1249-04S9 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 CM1249-04S9 reliable?
The price and inventory of CM1249-04S9 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CM1249-04S9 is usually 5 days.
3.What payment methods are accepted for CM1249-04S9?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CM1249-04S9 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CM1249-04S9?
CM1249-04S9 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CM1249-04S9 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 CM1249-04S9?
For technical support, including CM1249-04S9 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CM1249-04S9 requirements.
6.How does Aetrix verify that CM1249-04S9 is sourced from the original manufacturer or authorized distributors?
All CM1249-04S9 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 CM1249-04S9 meets industry standards.
7.What is the process for return or replacement of CM1249-04S9?
All CM1249-04S9 units undergo pre-shipment inspection (PSI). If there is an issue with CM1249-04S9, 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 CM1249-04S9 part is unused and in its original packaging.
Return procedure for CM1249-04S9:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
CM1249-04S9 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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