MAX9776ETJ+ Maxim Integrated Products, MAX9776ETJ+ Datasheet - Page 33

• Manufacturer Part Number: MAX9776ETJ+
• Description: IC AMP AUDIO PWR 1.5W D 32TQFN
• Manufacturer: Maxim Integrated Products
• Series: DirectDrive™r
• Type: Class Dr

Specifications of MAX9776ETJ+

• Output Type: 1-Channel (Mono) with Stereo Headphones
• Max Output Power X Channels @ Load: 1.5W x 1 @ 4 Ohm; 60mW x 2 @ 16 Ohm
• Voltage - Supply: 2.7 V ~ 5.5 V
• Features: Depop, Differential Inputs, I²C, Mute, Short-Circuit and Thermal Protection, Shutdown, Volume Control
• Mounting Type: Surface Mount
• Package / Case: 32-TQFN Exposed Pad
• Product: Class-D
• Output Power: 1.5 W
• Common Mode Rejection Ratio (min): 45 dB
• Thd Plus Noise: 0.04 %
• Operating Supply Voltage: 2.7 V to 5.5 V
• Supply Current: 9.5 mA
• Maximum Power Dissipation: 1360 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Amplifier Class: D
• No. Of Channels: 3
• Supply Voltage Range: 2.7V To 5.5V
• Load Impedance: 4ohm
• Operating Temperature Range: -40°C To +85°C
• Amplifier Case Style: TQFN
• Rohs Compliant: Yes
• For Use With: MAX9776EVKIT+ - EVALUATION KIT FOR MAX9776
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Use capacitors with an ESR less than 100mΩ for opti-
mum performance. Low-ESR ceramic capacitors mini-
mize the output resistance of the charge pump. Most
surface-mount ceramic capacitors satisfy the ESR
requirement. For best performance over the extended
temperature range, select capacitors with an X7R dielec-
tric or better. Table 12 lists suggested manufacturers.
The value of the flying capacitor (C1) affects the output
resistance of the charge pump. A C1 value that is too
small degrades the device’s ability to provide sufficient
current drive, which leads to a loss of output voltage.
Increasing the value of C1 reduces the charge-pump out-
put resistance to an extent. Above 1µF, the on-resistance
of the switches and the ESR of C1 and C2 dominate.
The output capacitor value and ESR directly affect the
ripple at CPV
output ripple. Likewise, decreasing the ESR of C2
reduces both ripple and output resistance. Lower
capacitance values can be used in systems with low
maximum output power levels. See the Output Power
vs. Load Resistance and Charge-Pump Capacitor Size
graph in the Typical Operating Characteristics .
The CPV
impedance of the power supply and reduces the
impact of the MAX9775/MAX9776’s charge-pump
switching transients. Bypass CPV
and place it physically close to the CPV
Use a value for C3 that is equal to C1.
Proper layout and grounding are essential for optimum
performance. Use large traces for the power-supply
inputs and amplifier outputs to minimize losses due to
parasitic trace resistance. Large traces also aid in mov-
ing heat away from the package. Proper grounding
improves audio performance, minimizes crosstalk
between channels, and prevents any switching noise
from coupling into the audio signal. Connect PGND and
GND together at a single point on the PCB. Route all
traces that carry switching transients away from GND
and the traces/components in the audio signal path.
Table 12. Suggested Capacitor Manufacturers
Taiyo Yuden
TDK
Supply Bypassing, Layout, and Grounding
DD
SUPPLIER
bypass capacitor (C3) lowers the output
2 x 1.5W, Stereo Class D Audio Subsystem
SS
. Increasing the value of C2 reduces
______________________________________________________________________________________
Charge-Pump Capacitor Selection
CPV
with DirectDrive Headphone Amplifier
DD
Bypass Capacitor (C3)
Output Capacitor (C2)
Flying Capacitor (C1)
DD
800-348-2496
807-803-6100
with C3 to PGND
PHONE
DD
and PGND.
Connect all of the power-supply inputs (CPV
and PV
tor to CPGND. Bypass V
Bypass PV
0.1µF capacitor to PGND. Place the bypass capacitors
as close to the MAX9775/MAX9776 as possible. Place
a bulk capacitor between PV
Use large, low-resistance output traces. Current drawn
from the outputs increases as load impedance
decreases. High output trace resistance decreases the
power delivered to the load. Large output, supply, and
GND traces also allow more heat to move from the
MAX9775/MAX9776 to the PCB, decreasing the thermal
impedance of the circuit.
The MAX9776 TQFN-EP package features an exposed
thermal pad on its underside. This pad lowers the
package’s thermal impedance by providing a direct
heat conduction path from the die to the PCB. The
exposed pad is internally connected to GND. Connect
the exposed thermal pad to the PCB GND plane.
For the latest application details on WLP construction,
dimensions, tape carrier information, PCB techniques,
bump-pad layout, and recommended reflow tempera-
ture profile, as well as the latest information of reliability
testing results, refer to Application Note 1891:
Understanding the Basics of the Wafer-Level Chip-
Scale Package (WL-CSP) available on Maxim’s website
at www.maxim-ic.com/ucsp.
When operating at maximum output power, the WLP
thermal dissipation can become a limiting factor. The
WLP package does not dissipate as much power as a
TQFN and as a result will operate at a higher tempera-
ture. At peak output power into a 4Ω load, the
MAX9775/MAX9776 can exceed its thermal limit, trig-
gering thermal protection. As a result, do not choose
the WLP package when maximum output power into 4Ω
is required.
847-925-0899
847-390-4405
DD
WLP Applications Information
) together. Bypass CPV
FAX
DD
with a 1µF capacitor in parallel with a
TQFN Applications Information
DD
WLP Thermal Consideration
www.t-yuden.com
www.component.tdk.com
with 1µF capacitor to GND.
DD
and PGND if needed.
DD
with a 1µF capaci-
WEBSITE
DD
, V
DD
33
,