onsemi CM1218-05SO

Overview

CM1218-05SO from onsemi is a 5-channel low-capacitance transient voltage suppressor (TVS) array designed for ESD protection of high-speed data lines. It delivers ±15 kV IEC 61000−4−2 contact discharge immunity, 7 pF typical channel input capacitance, and 5.5 V reverse stand-off voltage in an SOT-23-6 package. It is used to safeguard USB, serial, and IEEE1394 interface pins against electrostatic discharge.

For engineers reviewing the CM1218-05SO datasheet, pinout, applications, or equivalent options, key selection criteria include channel count, clamping voltage under 10 mA (±0.8 V / +6.8 V), leakage current ≤1 µA at 5 V, and compatibility with space-constrained PCB layouts requiring compact SMT ESD protection.

Technical Context

The CM1218-05SO integrates five bidirectional TVS diodes sharing a common anode (VN) terminal, enabling simultaneous protection of five signal lines with minimal parasitic capacitance. Its architecture uses silicon avalanche diodes optimized for fast response (<1 ns) to ESD transients while maintaining low dynamic resistance (1.1 Ω forward, 2.7 Ω reverse).

It operates across −40°C to +85°C and supports system-level ESD compliance without external components-each channel withstands >1000 ESD strikes per IEC 61000−4−2. The device is Pb-free and qualified per JEDEC MO-178 for SOT-23-6 packaging.

Key Specifications

Pinout & Package

SOT-23-6 package (Case 527AJ), surface-mount, Pb-free, JEDEC-compliant. Dimensions: 2.90 mm × 2.80 mm × 1.45 mm. Seating plane defined per ASME Y14.5M.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ESD protection applications.

Compared with CM1218-05SO, TPD2E001DRYR offers lower capacitance but halves channel density, increasing assembly cost and routing complexity; ESD5Z5.0T1G provides lower unit cost but sacrifices high-speed performance and increases PCB area by >3× due to discrete implementation.

Availability

CM1218-05SO is available at Aetrix Electronics and suitable for USB port protection, industrial serial interface hardening, and embedded camera module ESD mitigation requiring stable component supply and long-term manufacturability.

Supply support for CM1218-05SO 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 CM1218 family was developed specifically for high-density, low-capacitance ESD protection of high-speed digital interfaces - targeting design-in in portable electronics, docking systems, and industrial I/O modules.

FAQ

What is the maximum operating temperature range for CM1218-05SO?

The CM1218-05SO is rated for continuous operation from −40°C to +85°C, as specified in Table 2 of the official datasheet. This range covers standard commercial and extended industrial ambient conditions. Thermal derating is not required within this span, and the device maintains full ESD performance (±15 kV IEC 61000−4−2) across the entire range. CM1218-05SO must not be operated beyond these limits to ensure reliability.

Does CM1218-05SO require external components for basic ESD protection?

No, CM1218-05SO functions as a standalone ESD protection device with no external components needed. Its internal TVS diodes provide complete bidirectional clamping from each cathode (CH1–CH5) to the shared anode (VN), which connects directly to system ground. Note 4 in Table 3 confirms measurements were performed with no external capacitor on CHX, validating its self-contained operation. CM1218-05SO is designed for direct placement adjacent to protected I/O traces.

How many ESD strikes can CM1218-05SO withstand before degradation?

Each I/O pin of CM1218-05SO is rated to withstand over 1000 ESD strikes per the IEC 61000−4−2 contact discharge test at ±15 kV, as stated in the Features section of the datasheet. This endurance applies individually to CH1 through CH5 under standard test conditions (C_discharge = 150 pF, R_discharge = 330 Ω). CM1218-05SO retains full electrical specifications after this stress, making it suitable for high-touch consumer interfaces.

Is CM1218-05SO compatible with lead-free reflow soldering processes?

Yes, CM1218-05SO is Pb-free and qualified for lead-free reflow per IPC/JEDEC J-STD-020. Its SOT-23-6 package (Case 527AJ) supports peak reflow temperatures up to 260°C for 10 seconds. The device meets JEDEC moisture sensitivity level (MSL) 1, meaning it can be stored indefinitely at ≤30°C/85% RH without baking. CM1218-05SO's thermal profile compliance is documented in onsemi's Soldering and Mounting Techniques Reference Manual.

What is the leakage current specification for CM1218-05SO at 5 V?

CM1218-05SO exhibits ≤1 µA leakage current at V_IN = 5.0 VDC and T_A = 25°C, as specified in Table 3 (I_LEAK). This ultra-low leakage prevents unintended loading of weak-drive I/O circuits such as GPIOs or open-drain bus lines. The value remains stable across temperature and ensures compatibility with battery-powered devices where standby current is critical. CM1218-05SO maintains this performance without external biasing or trimming.