onsemi CM6126

Overview

CM6126 from onsemi is an Application Specific Integrated Passive (ASIP) transient voltage suppressor in a 4-bump WLCSP4 package (0.96 mm × 0.96 mm, 0.5 mm pitch). It provides ESD protection with ±30 kV contact/air discharge per IEC 61000−4−2, clamps transients to 20 V at 1 A, and delivers 280 pF line capacitance at 0 V bias for high-speed data line protection in USB 2.0 interfaces.

For engineers reviewing the CM6126 datasheet, pinout, applications, or equivalent options, key selection factors include its dual-channel TVS architecture, low clamping voltage under 1 A surge, RF insertion loss ≥11 dB (80 MHz–1 GHz), and verified compliance with IEC 61000−4−2 Level 4 ESD immunity requirements.

Technical Context

The CM6126 integrates two symmetrical TVS channels (A1/A2) referenced to a common ground plane (B1/B2), enabling bidirectional transient suppression on differential signal lines. Its silicon die structure includes daisy-chained junctions optimized for fast response (<1 ns) and low capacitance retention across bias voltages.

It operates within −30°C to +85°C ambient range and supports DC stand-off up to 10 V with <500 nA leakage. The device's 280 pF / 100–135 pF capacitance split between 0 V and 5 V bias enables stable RF performance in active signal paths without compromising ESD robustness.

Key Specifications

Pinout & Package

CM6126 uses a 4-bump Wafer-Level Chip Scale Package (WLCSP4, Case 567AW), measuring 0.96 mm × 0.96 mm with 0.5 mm pitch and solder bumps on a silicon die. Coplanarity applies to spherical crowns of solder balls per ASME Y14.5M.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient voltage suppression applications.

Compared with CM6125 and ESD5Z3.3T5G, the CM6126 uniquely delivers matched dual-channel suppression in one WLCSP footprint-reducing PCB real estate by 50% versus dual discrete solutions while maintaining lower capacitance and superior RF attenuation for high-speed differential interfaces.

Availability

CM6126 is available at Aetrix Electronics and suitable for USB 2.0 interface protection, MIPI D-PHY data line hardening, and HDMI DDC/CEC line safeguarding requiring stable component supply and long-term production continuity.

Supply support for CM6126 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 power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, medical, and IoT applications.

The CM6126 belongs to onsemi's Application Specific Integrated Passive (ASIP) product line, engineered to replace discrete TVS arrays with monolithic, space-optimized protection elements for high-density portable and automotive electronics.

FAQ

What is the primary function of the CM6126?

The CM6126 is an Application Specific Integrated Passive (ASIP) device designed specifically for transient voltage suppression and electrostatic discharge (ESD) protection. It functions as a dual-channel bidirectional TVS suppressor, clamping voltage excursions to 20 V at 1 A while providing ±30 kV IEC 61000−4−2 ESD immunity. Its role is to protect sensitive high-speed data lines such as USB 2.0 and MIPI D-PHY from electrical overstress without degrading signal integrity.

Does the CM6126 require external biasing or control signals?

No, the CM6126 is a fully passive device with no external biasing, enable pins, or control logic. It operates solely based on voltage threshold behavior: it remains high-impedance below 16 V breakdown voltage and conducts transient current above that threshold. The CM6126 relies entirely on its internal silicon junction characteristics and requires no power supply, configuration, or firmware-making it drop-in deployable in any analog or digital signal path needing robust ESD hardening.

Can the CM6126 be used for USB 3.0 or higher-speed interfaces?

No, the CM6126 is not suitable for USB 3.0 (5 Gbps) or higher-speed interfaces. Its 280 pF line capacitance at 0 V bias and ≥11 dB insertion loss up to 1 GHz are optimized for USB 2.0 (480 Mbps) and MIPI D-PHY (1.5 Gbps) applications. For SuperSpeed USB or PCIe Gen3+, lower-capacitance suppressors (<1 pF) with GHz-range bandwidth are required. The CM6126's specifications explicitly target sub-1 GHz signal environments, and using it on USB 3.0 lanes would cause unacceptable signal degradation.

What does the marking "X" indicate on the CM6126 top-side orientation mark?

The "X" in the CM6126 marking diagram denotes a single-digit date code indicating the year of manufacture-for example, "5" represents 2015, "6" represents 2016, etc.-per onsemi's standard coding convention. This digit appears adjacent to the orientation marking on the top surface of the WLCSP4 package and is laser-etched for traceability. The CM6126 itself contains no internal memory or programmable elements; the marking serves solely for lot and date identification during assembly and field failure analysis.

How is thermal dissipation managed in the CM6126 during repeated transient events?

The CM6126 relies on PCB copper pour and thermal vias connected to its B1/B2 ground terminals for heat removal, as it lacks an exposed thermal pad. Its silicon die thickness is 406 µm, and bump standoff is 240 µm-designed to transfer transient energy into the board's ground plane. The device is rated for 100 A I²t (10/1000 µs pulse), meaning it can safely absorb multiple low-energy transients without thermal runaway. Sustained high-frequency surges require careful PCB layout with ≥2 oz copper and ≥4 thermal vias under the CM6126 ground terminals to maintain junction temperature within −30°C to +85°C operating limits.