Analogue, Mixed Signal, LSI


Headphone amp operates down to 0,9 V

10 March 2004 Analogue, Mixed Signal, LSI

Maxim has extended its DirectDrive headphone amplifier series with the introduction of the MAX9721A/B/C devices. The MAX9721 operates from a 0,9 to 1,8 V single supply, allowing the device to be powered directly from a single AA or AAA battery.

These headphone amps employ a ground-referenced output from a single supply, eliminating the two bulky DC-blocking capacitors typically required between the amplifier and headphone. Eliminating the DC-blocking capacitors also improves the low-frequency response, allowing full-range audio reproduction - especially important for music playback.

The MAX9721 is ideal for single-cell portable audio equipment. Like Maxim's other DirectDrive headphone amps, it does not require a DC bias voltage to be applied to the headphone-jack ground pin, thus simplifying end-product design and reliability.

An 80 dB at 1 kHz power-supply rejection ratio allows the devices to operate from noisy digital supplies without an additional linear regulator. They consume only 2,2 mA of supply current, has short-circuit and thermal-overload protection, and is specified over -40 to +85°C. Internal fixed gains of -2 V/V (MAX9721A), -1,5 V/V (MAX9721B), and -1 V/V (MAX9721C) further reduce external component count.

The devices deliver 20 mW per channel into a 32 Ω load with VDD of 1,5 V. The typical THD+N is 0,006% and the outputs include ±8 kV ESD protection. Comprehensive click-and-pop circuitry suppresses audible clicks and pops on start-up and shutdown. A low-power shutdown mode reduces supply current to 1,0 µA to extend battery life. The MAX9721 is available in a tiny 12-bump (1,54 x 2,02 x 0,6 mm) UCSP and a 12-pin (4 x 4 x 0,8 mm) TQFN package.



Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

IMU with dual-sensing capability
EBV Electrolink Analogue, Mixed Signal, LSI
ST’s 6-axis inertial measurement unit integrates a dual accelerometer up to 320g and embedded AI for activity tracking and high-impact sensing.

Read more...
Plural data converter series
Analogue, Mixed Signal, LSI
Silanna Semiconductor has announced the launch of Plural, a new generation of data converters for customers eager to find a more available, affordable, high-performance alternative to existing brands.

Read more...
Telemetry retrofit for sustainable resource management
CST Electronics Test & Measurement
AquaMeter is a cost-effective secure telemetry retrofit that can easily be added to hundreds of millions of legacy mechanical water meters.

Read more...
Precision JFET op-amp
Altron Arrow Analogue, Mixed Signal, LSI
The specifications of the ADA4620 make it optimal as a front-end amplifier in a data-acquisition system, or for a TIA circuit with high input impedance.

Read more...
A new era in modular I/O solutions
Rugged Interconnect Technologies Analogue, Mixed Signal, LSI
Aerospace and defence system designers are demanding scalable and high-performance I/O solutions and while traditional mezzanine standards have proven reliable, they often fall short of meeting modern bandwidth, size, and flexibility requirements.

Read more...
High voltage instrument op-amp
iCorp Technologies Analogue, Mixed Signal, LSI
The SGM621B is a high accuracy, high voltage instrumentation amplifier, which is designed to set any gain from 1 to 10 000 with one external resistor.

Read more...
High-speed SAR ADC simplifies design
Altron Arrow Analogue, Mixed Signal, LSI
The ADI AD4080 simplifies data converter integration by integrating a low drift reference buffer, low dropout regulators and a 16K result data FIFO buffer.

Read more...
Achieving lowest cost, scalable and dynamic wireless mesh network installations
CST Electronics Editor's Choice Telecoms, Datacoms, Wireless, IoT
In many situations it is desirable for sensors to be connected wirelessly in a mesh network as this saves infrastructure and cost since long cabling runs are not required.

Read more...
2-wire quad voltage output DAC
Altron Arrow Analogue, Mixed Signal, LSI
The DAC has a 2-wire serial interface that operates at clock rates up to 400 kHz, and this interface is SMBus compatible, allowing multiple devices to be placed on the same bus.

Read more...
Dual-channel ADC for RF applications
RFiber Solutions Analogue, Mixed Signal, LSI
The ARF0471 from Advanced RF is a dual-channel, 14-bit, 3 GSPS ADC, which features an on-chip buffer and sample-and-hold circuit.

Read more...