MAX98355A Datasheet, PDF(1/34 Page) Maxim Integrated Products – PCM Input Class D Audio Power Amplifiers

19-6278; Rev 0; 5/12

EVALUATION KIT AVAILABLE

MAX98355A/MAX98355B

PCM Input Class D Audio Power Amplifiers

General Description

The MAX98355A/MAX98355B are digital pulse-code

modulation (PCM) input Class D power amplifiers that

provide Class AB audio performance with Class D effi-

ciency. These ICs offer five selectable gain settings

(3dB, 6dB, 9dB, 12dB, and 15dB) set by a single gain-

select input (GAIN).

The digital audio interface is highly flexible with the

MAX98355A supporting I2S data and the MAX98355B

supporting left-justified data. Both ICs support time divi-

sion multiplexed (TDM) data. The digital audio interface

accepts sample rates ranging from 8kHz to 96kHz for all

supported data formats. The ICs can be configured to

produce a left channel, right channel, or (left + right)/2

output from the stereo input data. The ICs operate using

16/24/32-bit data for I2S and left justified modes as well

as 16-bit data with up to four slots when using TDM

mode. The ICs eliminate the need for the external MCLK

signal that is typically used for PCM communication. This

reduces EMI and possible board coupling issues in addi-

tion to reducing the size and pin count of the ICs.

The ICs also feature a very high wideband jitter tolerance

(12ns typ) on BCLK and LRCLK to provide robust operation.

Active emissions-limiting, edge-rate limiting, and over-

shoot control circuitry greatly reduce EMI. A filterless

spread-spectrum modulation scheme eliminates the

need for output filtering found in traditional Class D

devices and reduces the component count of the solution.

The ICs are available in a 9-pin WLP package (1.345mm

x 1.435mm x 0.64mm) and are specified over the -40NC

to +85NC temperature range.

Applications

Cellular Phones

Tablets

Portable Media Players

Notebook Computers

Ordering Information appears at end of data sheet.

Functional Diagram appears at end of data sheet.

For related parts and recommended products to use with this part,

refer to www.maxim-ic.com/MAX98355A.related.

Features

S Single-Supply Operation (2.5V to 5.5V)

S 3.2W Output Power into 4I at 5V

S 2.2mA Quiescent Current

S 92% Efficiency (RL = 8I, POUT = 900mW,

VDD = 3.7V)

S 25ÂµVRMS Output Noise (AV = 15dB)

S Low 0.013% THD+N at 1kHz

S No MCLK Required

S Sample Rates of 8kHz to 96kHz

S Supports Left, Right, or (Left + Right)/2 Outputs

S Sophisticated Edge Rate Control Enables

Filterless Class D Outputs

S 77dB PSRR at 217Hz

S Low RF Susceptibility Rejects TDMA

Noise from GSM Radios

S Extensive Click-and-Pop Reduction Circuitry

S Robust Short-Circuit and Thermal Protection

S Available in Space-Saving Package:

1.345mm x 1.435mm WLP (0.4mm Pitch)

Simplified Block Diagram

PCM

INPUT

SHUTDOWN

AND

CHANNEL

SELECT

MAX98355A

MAX98355B

DIGITAL

AUDIO

DAC

INTERFACE

GAIN

CONTROL

CLASS D

OUTPUT

STAGE

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maximâs website at www.maxim-ic.com.

▷