MAX98357A Datasheet, PDF (1/38 Pages) Maxim Integrated Products – PCM Input Class D Audio Power Amplifiers

EVALUATION KIT AVAILABLE
MAX98357A/MAX98357B
PCM Input Class D Audio Power Amplifiers
General Description
The MAX98357A/MAX98357B 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) in I²S/left-justified
mode set by a single gain select input and a fixed 12dB
gain in TDM mode.
The digital audio interface is highly flexible with the
MAX98357A supporting I²S data and the MAX98357B sup-
porting left-justified data. Both ICs support 8 channel time
division multiplexed (TDM) data. The digital audio interface
accepts specified sample rates between 8kHz and 96kHz
for all supported data formats. The ICs can be configured
to produce a left channel, right channel, or (left/2 + 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 or 32-bit data 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 addition 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 9-pin WLP (1.345mm x 1.435mm
x 0.64mm) and 16-pin TQFN (3mm x 3mm x 0.75mm)
packages and are specified over the -40NC to +85NC
temperature range.
Applications
Notebook and Netbook Computers
Cellular Phones
Tablets
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.maximintegrated.com/MAX98357A.related.
Features
S Single-Supply Operation (2.5V to 5.5V)
S 3.2W Output Power into 4I at 5V
S 2.4mA Quiescent Current
S 92% Efficiency (R_L = 8I, P_OUT = 1W)
S 25µV_RMS Output Noise (A_V = 15dB)
S Low 0.015% THD+N at 1kHz
S No MCLK Required
S Sample Rates of 8kHz to 96kHz
S Supports Left, Right, or (Left/2 + Right/2) Output
S Sophisticated Edge Rate Control Enables
Filterless Class D Outputs
S 77dB PSRR at 1kHz
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 Packages:
1.345mm x 1.435mm WLP (0.4mm Pitch)
and 3mm x 3mm TQFN
Simplified Block Diagram
PCM
INPUT
SHUTDOWN
AND
CHANNEL
SELECT
MAX98357A
MAX98357B
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 Maxim Integrated’s website at www.maximintegrated.com.
19-6779; Rev 2; 8/14