IS31AP2121
Integrated Silicon Solution, Inc. – www.issi.com
19
Rev. C, 10/20/2015
temperature drops to 125°C. The temperature
values may vary around 10%.
Short-Circuit Protection
The short-circuit protection circuit protects the output
stage when the wires connected to loudspeakers are
shorted to each other or GND/VDD. For normal 24V
operations, the current flowing through the power
stage will be less than 7A for stereo configuration or
less than 14A for mono configuration. Otherwise, the
short-circuit detectors may pull the ERRORB pin to
DGND, disabling the output stages. When the over-
temperature or short-circuit condition occurs, the
open-drain ERRORB pin will be pulled low and
latched into ERROR state.
Once the over-temperature or short-circuit condition
is removed, IS31AP2121 will exit ERROR state
when one of the following conditions is met: (1)
RSTB pin is pulled low. (2) PDB pin is pulled low. (3)
Master mute is enabled through the I2C interface.
Under-voltage Protection
Once the V
DD
voltage is lower than 2.7V,
IS31AP2121 will turn off its loudspeaker power
stages and cease the operation of digital processing
circuits. When V
DD
becomes larger than 2.8V,
IS31AP2121 will return to normal operation.
ANTI-POP DESIGN
IS31AP2121 will generate appropriate control
signals to suppress pop sounds during initial power
on/off, power down/up, mute, and volume level
changes.
3D SURROUND SOUND
IS31AP2121 provides the virtual surround sound
technology with greater separation and depth voice
quality for stereo signals.
I2C CHIP SELECT
ERRORB is an input pin during power. It can be
pulled High (15k
Ω
pull up) or Low (15k
Ω
pull down).
Low indicates an I2C address of 0x30, and high an
address of 0x31.
OUTPUT CONFIGURATION
The bit 4 [SEM] of address 0X11 and PBTL pin
defines the configuration mode. IS31AP2121 can be
configured to stereo, mono via PBTL pin (the bit 4
[SEM] of address 0X11 default is low). 2.1CH output
mode configuration, user can via I2C to program it
from the bit 4 [SEM] of address 0X11. Table 2
provides a reference of available configuration.
Table 2
Output Configurations
[SEM]
PBTL
Configuration Mode
0 0
Stereo
0 1
Mono
1 x
2.1CH
Figure 32
Output Configurations