Differential Input DirectDrive Line Drivers/Headphone Amplifiers

The MAX97220 is a differential input DirectDrive® line driver/headphone amplifier. This device is capable of driving line level loads with 3VRMS into 1kΩ with a 5V supply and 2VRMS into 600Ω loads from a 3.3V supply. A headphone load is capable of being driven with 125mW into 32Ω with a 5V supply. The IC is offered with an internally fixed 6dB gain or an externally set gain through external resistors. The external gain setting nodes can also be used to configure filters for set-top box applications. The IC has exceptional THD+N over the full audio bandwidth.

Two versions of the IC are available with different turn-on times (tON). The A, C, and E versions for headphone applications feature a tON of 5.5ms while the B and D versions, intended for set-top-box applications, feature a 130ms tON. An on-chip charge pump inverts the power-supply input, creating a negative rail. The output stage of the amplifier is powered between the positive input supply and the output of the charge pump. The bipolar supplies bias the output about ground, eliminating the need for large, distortion-introducing output coupling capacitors. The IC powers on and off without clicks or pops.

The IC is available in a 3mm x 3mm x 0.8mm, 16-pin TQFN and is specified over the extended -40°C to +85°C temperature range.

Applications

* Blu-ray™ and DVD Players * LCD Televisions * Prosumer Audio Devices * Set-Top Boxes * Simple Multimedia Interfaces

* Output Power 125mW into 32Ω with a 5V Supply

* 3VRMS Output Drive into 1kΩ with a 5V Supply

* 2VRMS Output Drive into 600Ω with a 3.3V Supply

* Fully Differential Inputs

* Fixed or Externally Adjustable Gain with No Clicks or Pops

* Wide 2.5V to 5.5V Operating Range

* DirectDrive Outputs Eliminate DC-Blocking Capacitors

* Flat THD+N, Better Than 90dB in the Audio Band

* 18-Bit SNR Performance, 112dB

* Footprint Compatible with the MAX9722