MAX9768EVKIT+ Maxim Integrated Products, MAX9768EVKIT+ Datasheet - Page 15

• Manufacturer Part Number: MAX9768EVKIT+
• Description: EVALUATION KIT FOR MAX9768
• Manufacturer: Maxim Integrated Products

Specifications of MAX9768EVKIT+

• Amplifier Type: Class D
• Output Type: 1-Channel (Mono)
• Max Output Power X Channels @ Load: 10W x 1 @ 8 Ohm
• Voltage - Supply: 4.5 V ~ 14 V
• Operating Temperature: -40°C ~ 85°C
• Board Type: Fully Populated
• Utilized Ic / Part: MAX9768
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

When the output current exceeds the hard current limit,
2.5A (typ), the MAX9768 disables the outputs and initi-
ates a startup sequence. This startup sequence takes
220ms for the MAX9768 and 15ms for the MAX9768B.
The shutdown and startup sequence is repeated until
the output fault is removed. When in hard current limit,
the output may make a soft clicking sound. The aver-
age supply current is relatively low, as the duty cycle of
the output short is brief. Most applications will not enter
hard current-limit mode unless the output is short cir-
cuited or incorrectly connected.
When the die temperature exceeds the thermal shut-
down threshold, +150°C (typ), the MAX9768 outputs
are disabled. When the die temperature decreases
below +135°C (typ), normal operation resumes. The
effect of thermal shutdown is an output signal turning
off for approximately 3s in most applications, depend-
ing on the thermal time constant of the audio system.
Most applications should never enter thermal shut-
down. Some of the possible causes of thermal shut-
down are too low of a load impedance, high ambient
temperature, poor PCB layout and assembly, or exces-
sive output overdrive.
The MAX9768 features a shutdown mode that reduces
power consumption and extends battery life. Driving
SHDN low places the device in low-power (0.5µA) shut-
down mode. Connect SHDN to digital high for normal
operation. In shutdown mode, the outputs are high
impedance, SYNCOUT is pulled high, the BIAS voltage
decays to zero, and the common-mode input voltage
decays to zero. The I
during shutdown.
The MAX9768 features an undervoltage lockout protec-
tion that shuts down the device if either of the supplies
are too low. The device will go into shutdown if V
less than 2.5V (V
than 4V (PV
The MAX9768 features a clickless/popless mute mode.
When the device is muted, the outputs do not stop
switching, only the volume level is muted to the speak-
er. To mute the MAX9768, drive MUTE to logic-high.
DD
UVLO = 4V).
Undervoltage Lockout (UVLO)
DD
______________________________________________________________________________________
UVLO = 2.5V) or if PV
2
C register retains its contents
Thermal Shutdown
Hard Current Limit
Mute Function
Shutdown
Amplifier with Volume Control
DD
is less
10W Mono Class D Speaker
DD
is
MUTE should be held high during system power-up
and power-down to ensure optimum click-and-pop
performance.
The volume control operates from either an analog volt-
age input or through the I
trol has 64 levels, with the lowest setting equal to mute.
To set the device to analog mode, connect ADDR1 and
ADDR2 to GND. In analog mode, SDA/VOL is an ana-
log input for volume control, see the Functional
Diagram/Typical Application Circuit . The analog input
range is ratiometric between 0.9 x V
where 0.9 x V
(Table 6).
In I
separately by the command register (Tables 4, 5, 6). See
the Write Data Format section for more information
regarding formatting data and tables to set volume levels.
The MAX9768 features an I
consisting of a serial data line (SDA) and a serial clock
line (SCL). SDA and SCL facilitate communication
between the MAX9768 and the master at clock rates up
to 400kHz. When the MAX9768 is used on an I
with multiple devices, the V
ered on to ensure proper I
ter, typically a microcontroller, generates SCL and
initiates data transfer on the bus. Figure 3 shows the 2-
wire interface timing diagram.
A master device communicates to the MAX9768 by trans-
mitting the proper address followed by the data word.
Each transmit sequence is framed by a START (S) or
REPEATED START (S
tion. Each word transmitted over the bus is 8 bits long
and is always followed by an acknowledge clock pulse.
The MAX9768 SDA line operates as both an input and
an open-drain output. A pullup resistor, greater than
500Ω, is required on the SDA bus. The MAX9768 SCL
line operates as an input only. A pullup resistor, greater
than 500Ω, is required on SCL if there are multiple mas-
ters on the bus, or if the master in a single-master sys-
tem has an open-drain SCL output. Series resistors in
line with SDA and SCL are optional. The SCL and SDA
inputs suppress noise spikes to assure proper device
operation even on a noisy bus.
2
C mode, volume control for the speaker is controlled
DD
= full mute and 0.1 x V
r
) condition and a STOP (P) condi-
2
C interface. The volume con-
2
C bus operation. The mas-
DD
2
C 2-wire serial interface
supply must stay pow-
Volume Control
DD
I
DD
2
and 0.1 x V
C Interface
= full volume
2
C bus
DD
15
,