MAX9702EVCMODU Maxim Integrated Products, MAX9702EVCMODU Datasheet - Page 5

• Manufacturer Part Number: MAX9702EVCMODU
• Description: Audio Modules & Development Tools 1.8W Filterless Ster eo Class D Audio Pow
• Manufacturer: Maxim Integrated Products

Table 1. Hardware Shutdown
*Default configuration
The MAX9702 EV kit provides three sets of differential
outputs. The first set of differential outputs (SR+/- and
SL+/-) can be connected directly to a speaker load
without any filtering. There are two optional filters that
can be added to ease evaluation. The second set of
differential outputs (FOUTR1+/- and FOUTL1+/-) for the
common-mode choke filter requires the following com-
ponents: T1, T2, C2, C7, C16, and C21. The last set is
the LCR filtered outputs (FOUTR2+/- and FOUTL2+/-)
require the following components: L1–L4, C1, C3, C4, C8,
C9, C14, C17, C18, C22, C23, R1, R4, R6, and R8. See
Table 2 for the suggested filtering component values for
an 8Ω load and 30kHz cutoff frequency.
Table 2. Suggested LCR Filter Components
for an 8Ω Load and 30kHz Cutoff
The MAX9702 is designed to pass FCC RF emissions
without additional filtering when using 10cm of cable to
connect the speaker. In applications where more margin
and/or cable length is required, use the common-mode
choke filter with capacitors C2, C7, C16, C21, and com-
mon-mode choke T1 and T2 to reduce the radiated emis-
sion. The value of these four capacitors is 100pF. Table 3
lists the cable length versus the required output filters.
JUMPER
JU1
C3, C9, C17, C22
C1, C8, C14, C23
COMPONENT
R1, R4, R6, R8
C4, C18
MAX9702 Evaluation System/Evaluation Kit
L1–L4
POSITION
SHUNT
Open
1-2*
2-3
_______________________________________________________________________________________
HIGH (Powered up)
LOW (Enable hardware shutdown)
Controlled by SHDN pad
SHDN HARDWARE INPUT PIN
Optional Class D Filter
LOGIC LEVEL
0.033µF
0.068µF
VALUE
0.15µF
(SHDN)
15µH
22Ω
The MAX9702 features a total of four oscillator frequen-
cy operating modes that include two fixed-frequency
modes, one spread-spectrum mode, and one external
clock mode. Table 4 shows how to use jumper JU2 to
configure these four operating modes.
The MAX9702 features a headphone sense input that
monitors whether a headphone is present and automat-
ically configures the device. Jumper JU3 gives the user
a choice of how to handle the headphone sense as
shown in Table 5.
Table 3. Cable Length vs. Suggested
Output Filters
Table 4. Oscillator Frequency Operating
Modes
*Default configuration
Table 5. Headphone Sense (HPS)
*Default configuration
JUMPER
CABLE LENGTH
JUMPER
JU2
JU3
3 < X < 6
X [in]
X ≤ 3
X ≥ 6
POSITION
SHUNT
POSITION
1-4*
SHUNT
1-2
1-3
1-5
Open
1-2*
COMMON-MODE
CHOKE FILTER
Unconnected FFM with f
Externally
Required
clocked
Disable speaker amplifier and
enable headphone amplifier
Headphone jack automatically
configures the MAX9702
HEADPHONE SENSE FUNCTION
SYNC
GND
V
—
—
DD
FFM with f
SSM with f
1150kHz ±50kHz
FFM with f
clock frequency
LCR FILTER
MODE
Required
S
S
S
S
—
—
= 1100kHz
= 1340kHz
= external
=
5