MAX97000EVKIT+ Maxim Integrated Products, MAX97000EVKIT+ Datasheet - Page 32

• Manufacturer Part Number: MAX97000EVKIT+
• Description: KIT EVALUATION FOR MAX97000
• Manufacturer: Maxim Integrated Products

Specifications of MAX97000EVKIT+

• Description/function: Audio Amplifiers
• Operating Supply Voltage: 2.7 V to 5.5 V
• Product: Audio Development Tools
• Supply Current: 1 A
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: MAX97000

Audio Subsystem with Mono Class D
Speaker and Class H Headphone Amplifier
Use capacitors with an ESR less than 100mI for optimum
performance. Low-ESR ceramic capacitors minimize 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 dielectric.
The value of the flying capacitor (connected between
C1N and C1P) affects the output resistance of the
charge pump. A 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 the flying capacitor reduces the charge-pump output
resistance to an extent. Above 1FF, the on-resistance
of the internal switches and the ESR of external charge-
pump capacitors dominate.
The holding capacitor (bypassing HPVDD and HPVSS)
value and ESR directly affect the ripple on the supply.
Increasing the capacitor’s value reduces output ripple.
Likewise, decreasing the ESR 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 graph in the Typical
Operating Characteristics section for more information.
Proper layout and grounding are essential for optimum
performance. Use a large continuous ground plane on
a dedicated layer of the PCB to minimize loop areas.
Connect GND and PGND directly to the ground plane
using the shortest trace length possible. Proper ground-
ing improves audio performance, minimizes crosstalk
between channels, and prevents any digital noise from
coupling into the analog audio signals.
Place the capacitor between C1P and C1N as close
as possible to the MAX97000 to minimize trace length
from C1P to C1N. Inductance and resistance added
between C1P and C1N reduce the output power of
the headphone amplifier. Bypass HPVDD and HPVSS
with capacitors located close to the pins with a short
trace length to PGND. Close decoupling of HPVDD and
HPVSS minimizes supply ripple and maximizes output
power from the headphone amplifier.
32
Supply Bypassing, Layout, and Grounding
Charge-Pump Capacitor Selection
Charge-Pump Holding Capacitor
Charge-Pump Flying Capacitor
Bypass PVDD to PGND with as little trace length as pos-
sible. Connect OUTP and OUTN to the speaker using
the shortest and widest traces possible. Reducing trace
length minimizes radiated EMI. Route OUTP/OUTN as
a differential pair on the PCB to minimize the loop area
and thereby the inductance of the circuit. If filter compo-
nents are used on the speaker outputs, be sure to locate
them as close to the MAX97000 as possible to ensure
maximum effectiveness. Minimize the trace length from
any ground tied passive components to PGND to further
minimize radiated EMI.
An evaluation kit (EV kit) is available to provide an
example layout for the MAX97000. The EV kit allows
quick setup of the MAX97000 and includes easy-to-use
software allowing all internal registers to be controlled.
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 on reliability
testing results, refer to the Application Note: UCSP - A
Wafer-Level Chip-Scale Package on Maxim’s website at
www.maxim-ic.com/ucsp. See Figure 15 for the recom-
mended PCB footprint for the MAX97000.
Figure 15. Recommended PCB Footprint
WLP Applications Information
0.24mm
0.21mm