Analog Devices Inc./Maxim Integrated MAX9890AEBL+T

Product Summary MAX9890AEBL+T Audio Click-and-Pop Eliminator

The MAX9890AEBL+T, developed by Analog Devices Inc./Maxim Integrated, is a highly specialized solution designed to eliminate audible transients — commonly known as clicks and pops — during the power-up and shutdown sequences of audio devices. Housed in a compact 9-bump UCSP (1.5mm x 1.5mm x 0.6mm) or 8-pin TDFN (3mm x 3mm x 0.8mm) package, the MAX9890AEBL+T targets space-constrained mobile and portable audio equipment such as notebook computers, PDAs, cell phones, portable DVD players, and MP3 players. It is ideal for engineers seeking to improve end-user perception of audio quality without significant compromise to board space or power consumption.

Key Features and Functions of MAX9890AEBL+T

At its core, the MAX9890AEBL+T provides seamless click-pop suppression for audio signal paths using coupling capacitors, such as those found in single-supply CODECs and headphone amplifiers. The device achieves this by carefully controlling the ramping of DC bias voltage across coupling capacitors during startup, using an S-shaped waveform to minimize spectral content in the audible range. Its integrated switches remain open during this ramping phase and only close once voltages stabilize, effectively ensuring that headphones or speakers are not exposed to unwanted transients.

A key differentiation between the MAX9890A and its MAX9890B variant is their ramp timing: the MAX9890AEBL+T supports a typical 200ms startup, optimized for coupling capacitors up to 100μF, while the B version extends this to 330ms for larger capacitors. Critical functions include ultra-low supply current (14μA during operation, dropping to just 0.001μA in shutdown), impressive total harmonic distortion plus noise (<0.003% THD+N into a 32Ω load), robust ±8kV ESD protection (Human Body Model), and a greatly simplified BOM that requires only one external 0.1μF capacitor for operation.

Electrical Characteristics and Operation Parameters of MAX9890AEBL+T

The electrical profile of the MAX9890AEBL+T addresses both efficiency and audio fidelity. Operating from a single 2.7V to 5.5V supply range, the device integrates an undervoltage lockout (UVLO) circuit that prevents malfunction below a typical 2.5V threshold. The robust on-resistance (RON) of its internal switches (0.5Ω) contributes negligibly to distortion, as validated by its low on-resistance flatness of just 2mΩ. This ensures the audio path remains transparent, minimizing coloration or signal degradation.

A notable power supply rejection ratio (PSRR) of -100dB (typ) over the operating voltage range shields the audio output from power rail noise, an essential attribute in mobile platforms with shared and often noisy supply lines. Maximum ratings include 6V on VCC and -40°C to +85°C operational temperature range, supporting flexible deployment in diverse climates and product classes.

Application Fields and Example Implementations for MAX9890AEBL+T

MAX9890AEBL+T’s main value proposition lies in consumer and mobile electronics where end-user experience hinges on noiseless startup and shutdown. Common integration points include the output coupling stage of CODECs and headphone amplifiers, especially where legacy or base designs lack native click-pop suppression. For example, in a premium notebook or a portable multimedia device, employing the MAX9890AEBL+T ensures headphones and external audio accessories are protected from abrupt transients, maintaining professional audio integrity throughout repeated power cycles.

The MAX9890AEBL+T is also advantageous in battery-powered applications thanks to its extraordinarily low quiescent and shutdown currents, extending operational life — a major consideration for portable device engineers.

Design Guidelines and Integration Tips for MAX9890AEBL+T

Successful deployment of the MAX9890AEBL+T revolves around sound component selection and PCB layout. The required external 0.1μF capacitor (CEXT) must be placed close to the device for effective ramp control and transient suppression. Since the exterior coupling capacitors dictate low-frequency response — forming a critical highpass filter with the headphone load — engineers must size these components to balance physical constraints against the desired bass extension. For typical 16Ω headphones and 100μF capacitors, the resulting -3dB bandwidth cutoff is approximately 100Hz.

Good layout practice further enhances performance, with short trace runs and close placement of decoupling and coupling capacitors around the MAX9890AEBL+T minimizing stray capacitance and external noise pickup. Given the excellent PSRR, the device is tolerant to moderate power rail variations, though standard decoupling (0.1μF close to the VCC pin) remains best practice.

Package Details, Dimensions, and Environmental Compliance of MAX9890AEBL+T

The MAX9890AEBL+T is available in two space-saving packages — a 9-bump UCSP (1.5mm x 1.5mm x 0.6mm) ideal for ultra-compact designs and an 8-pin TDFN (3mm x 3mm x 0.8mm) catering to standard assembly lines. Both packages are RoHS compliant and specified for a wide temperature range (-40°C to +85°C), covering most commercial and professional applications. ESD ratings of ±8kV (Human Body Model) substantially improve production robustness and in-field survivability.

Comparable Alternatives or Substitute Parts for MAX9890AEBL+T

In the context of second-sourcing or risk mitigation, engineers may consider analog click-pop suppressors with similar operational characteristics. Key comparative metrics should include supply current, startup/shutdown ramp timing, ESD robustness, THD+N levels, package options, and PSRR. Always assess whether alternative click-pop suppression devices match the MAX9890AEBL+T’s combination of timing flexibility, low-power credentials, and compact form factor. Additionally, closely related models within the MAX9890 series, such as the MAX9890B, may serve as drop-in replacements if their longer switch-on timing (330ms) aligns with application requirements.

Conclusion

: Assessing the Fit of MAX9890AEBL+T in Audio Applications

The MAX9890AEBL+T stands out as a highly integrated, low-power solution for audio click-pop suppression. Its efficient transient control, excellent audio fidelity, and compact packaging offer a strong value proposition for system designers and component specifiers aiming to enhance portable and battery-powered audio products. By providing a reliable interface between drive circuits and user-perceivable output stages, the MAX9890AEBL+T protects hardware investments, maintains sound quality, and reinforces consumer confidence in the end product.