onsemi \u7684 ESD7951ST5G \u662f\u4e00\u6b3e\u53cc\u5411\u8d85\u4f4e\u7535\u5bb9 ESD \u4fdd\u62a4\u4e8c\u6781\u7ba1\uff0c\u91c7\u7528 2 \u5f15\u811a SOD-923 \u5c01\u88c5 (1.0 x 0.6 mm)\u3002\u5b83\u63d0\u4f9b 5 V \u5de5\u4f5c\u7535\u538b\u30011 A \u5cf0\u503c\u8109\u51b2\u7535\u6d41\u4e0b 12.9 V \u7684\u7b9d\u4f4d\u7535\u538b\u30010.5 pF \u7ed3\u7535\u5bb9\u548c 1 \u00b5A \u6700\u5927\u6f0f\u7535\u6d41\u3002\u8be5\u5668\u4ef6\u53ef\u9632\u6b62 IEC 61000-4-2 ESD \u4e8b\u4ef6\u3002\u5176\u8d85\u4f4e\u7535\u5bb9\u4f7f\u5176\u9002\u7528\u4e8e USB 2.0 \u9ad8\u901f\u548c\u5929\u7ebf\u8def\u5f84\u7b49\u9ad8\u9891\u4fe1\u53f7\u7ebf\u8def\u3002\u5de5\u4f5c\u6e29\u5ea6\u8303\u56f4\u4e3a -55\u00b0C \u81f3 +125\u00b0C\u3002\u540e\u7f00 T5G \u8868\u793a 8000 \u4ef6\u5e26\u5377\u5305\u88c5\u3002.<\/p>","protected":false},"excerpt":{"rendered":"
The ESD7951ST5G from onsemi is a bidirectional ultra-low capacitance ESD protection diode in a 2-pin SOD-923 package (1.0 x 0.6 mm). It provides 5 V working voltage, 12.9 V clamping voltage at 1 A peak pulse current, 0.5 pF junction capacitance, and 1 \u00b5A maximum leakage current. The device protects against IEC 61000-4-2 ESD events. […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[54,13],"tags":[],"chip_brand":[144],"class_list":["post-2058","post","type-post","status-publish","format-standard","hentry","category-diodes","category-integrated-circuits-ics","chip_brand-on"],"acf":{"brief_explanation":"Bidirectional ESD diode, 5V Vrwm, 0.5pF, 12.9V clamp@1A, SOD-923, USB\/antenna protection","date_code":"","package_case":"SOD-923 (1.0 x 0.6 x 0.5 mm, 0.65mm pitch)","in_stock":696,"datasheet":"https:\/\/www.onsemi.com\/pdf\/datasheet\/esd7951-d.pdf","price":"$0.14 (8K+ pcs)","product_introduction":"The ESD7951 from onsemi is a bidirectional ESD protection diode designed for ultra-low capacitance applications. The ESD7951ST5G is the SOD-923 tape-and-reel version with 8000 units per reel. With only 0.5 pF junction capacitance, the device is optimized for high-frequency signal paths where capacitive loading must be minimized \u2014 USB 2.0 High-Speed (480 Mbps), HDMI, RF antenna lines, and other impedance-controlled interfaces.\n\nThe bidirectional configuration protects signal lines that swing both above and below ground, making it suitable for AC-coupled and differential pair interfaces. The 5 V reverse working voltage (VRWM) covers 3.3 V and 5 V logic rails, while the 12.9 V clamping voltage at 1 A ensures the protected IC sees a limited voltage during an ESD strike.\n\nThe SOD-923 package occupies only 0.6 mm\u00b2 of board area with a 0.5 mm profile, making it one of the smallest ESD protection packages available. This is critical for smartphones, tablets, and wearables where PCB real estate is extremely limited.\n\nThe ESD7951 is also available in an automotive-qualified version (SZESD7951ST5G) with AEC-Q101 compliance for automotive applications.\n\nNote: The LCSC listing marks this part as discontinued, but onsemi's ESD7951 product family remains in production. Verify current availability with authorized distributors before designing into new products.","working_principle":"**Bidirectional TVS Diode Structure:** The ESD7951 uses back-to-back Zener diodes in a single chip, providing symmetric clamping for both positive and negative ESD transients. In normal operation (voltage between -VRWM and +VRWM), both diodes are reverse-biased and draw only leakage current (1 \u00b5A max). When a positive transient exceeds VBR, the upper Zener diode avalanches and clamps the voltage. When a negative transient exceeds -VBR, the lower Zener diode conducts.\n\n**Ultra-Low Capacitance Design:** The 0.5 pF capacitance is achieved through a specialized junction geometry that minimizes the depletion region area while maintaining adequate avalanche energy absorption. This is critical for USB 2.0 High-Speed where the specification limits total capacitive loading per D+\/D- line.\n\n**Clamping Mechanism:** During an IEC 61000-4-2 ESD event (8 kV contact, 15 kV air), the diode avalanches within sub-nanoseconds, diverting the ESD current away from the protected IC. The clamping voltage (12.9 V at 1 A) represents the voltage the protected device experiences during the event. Lower clamping voltage provides better protection.","pin_description":"
| Pin<\/th> | Name<\/th> | Type<\/th> | Description<\/th><\/tr><\/thead> | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1<\/td> | I\/O<\/td> | I\/O<\/td> | ESD protection terminal; connect to protected signal line; bidirectional; 5V working voltage; 0.5pF capacitance to GND<\/td><\/tr> | ||||||||||||||||||||||||
| 2<\/td> | GND<\/td> | G<\/td> | Ground reference; connect to PCB ground plane via shortest path; via-in-pad recommended for low inductance<\/td><\/tr><\/tbody><\/table>","application_scenarios":"
|