MAX9728A Datasheet, PDF (1/19 Pages) Maxim Integrated Products – 60mW, DirectDrive, Stereo Headphone Amplifiers with Shutdown

19-3963; Rev 1; 7/09
EVAALVUAAILTAIOBNLEKIT
60mW, DirectDrive, Stereo
Headphone Amplifiers with Shutdown
General Description
The MAX9728A/MAX9728B stereo headphone ampli-
fiers are designed for display and notebook applica-
tions or portable equipment where board space is at a
premium. These devices use a unique, patented
DirectDrive™ architecture to produce a ground-refer-
enced output from a single supply, eliminating the need
for large DC-blocking capacitors, saving cost, board
space, and component height. The MAX9728A offers
an externally adjustable gain, while the MAX9728B has
an internally preset gain of -1.5V/V. The MAX9728A/
MAX9728B deliver up to 60mW per channel into a 32Ω
load and have low 0.02% THD+N. An 80dB at 1kHz
power-supply rejection ratio (PSRR) allows these
devices to operate from noisy digital supplies without
an additional linear regulator. Comprehensive click-
and-pop circuitry suppresses audible clicks and pops
on startup and shutdown.
The MAX9728A/MAX9728B operate from a single 4.5V
to 5.5V supply, consume only 3.5mA of supply current,
feature short-circuit and thermal-overload protection,
and are specified over the extended -40°C to +85°C
temperature range. The devices are available in tiny 12-
pin Thin QFN (3mm x 3mm x 0.8mm) and 14-pin
TSSOP packages (5mm x 4.4mm x 1.1mm).
Applications
Notebook PCs
DVD Players
LCD/PDP Displays
CRT TVs
Multimedia Monitors
Pin Configurations appear at end of data sheet.
Features
♦ No Bulky DC-Blocking Capacitors Required
♦ Low-Power Shutdown Mode, < 0.1µA
♦ Adjustable Gain (MAX9728A) or Fixed -1.5V/V
Gain (MAX9728B)
♦ Low 0.02% THD+N
♦ High PSRR (80dB at 1kHz) Eliminates LDO
♦ Integrated Click-and-Pop Suppression
♦ 4.5V to 5.5V Single-Supply Operation
♦ Low Quiescent Current (3.5mA)
♦ Available in Space-Saving Packages
12-Pin Thin QFN (3mm x 3mm x 0.8mm)
14-Pin TSSOP (5mm x 4.4mm x 1.1mm)
Ordering Information
PART
GAIN (V/V) PIN-PACKAGE TOP MARK
MAX9728AETC+
Adj. 12 TQFN-EP*
ABC
MAX9728AEUD+ Adj. 14 TSSOP
—
MAX9728BETC+
-1.5 12 TQFN-EP*
ABD
MAX9728BEUD+ -1.5 14 TSSOP
—
Note: All devices specified over the -40°C to +85°C operating
range.
+Denotes lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Block Diagrams
LEFT
AUDIO
INPUT
SHDN
RIGHT
AUDIO
INPUT
MAX9728A
DirectDrive OUTPUTS
ELIMINATE DC-BLOCKING
CAPACITORS
LEFT
AUDIO
INPUT
SHDN
RIGHT
AUDIO
INPUT
MAX9728B
DirectDrive OUTPUTS
ELIMINATE DC-BLOCKING
CAPACITORS
FIXED GAIN ELIMINATES
EXTERNAL RESISTOR
NETWORK
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.