TFA9815 NXP Semiconductors, TFA9815 Datasheet - Page 6

• Manufacturer Part Number: TFA9815
• Description: The TFA9815 is a 2-channel power comparator for high-efficiency class D audio amplifiersystems
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TFA9815_1
Preliminary data sheet
8.3 Input comparators
8.4 Diagnostic
Table 4.
The device has two modes: Sleep and Operating.
In Sleep mode the TFA9815 is not biased and has a very low supply current. Sleep mode
can also be used to quickly mute the device.
When the TFA9815 is set into Operating mode the device is started via the start-up
sequence, which provides a pop-free start-up behavior. After start-up the STABn
reference voltages are present and the outputs start switching.
Table 5.
The input stages have a differential input and are optimized for low noise and offset. This
results in maximum flexibility in the application.
Operating in self-oscillating configuration the inputs (IN1P, IN1N, IN2P, IN2N) of the
comparators are internally set to a voltage level of V
sequence. In Operating mode the inputs are high-ohmic.
Operating in open-loop configuration, no internal voltages are applied to the inputs. The
input pins (IN1P, IN1N, IN2P, IN2N) are pulled down to V
resistors.
The DIAG output is an open-drain output. The maximum current is 2 mA. When one of the
protections is activated the DIAG output is set LOW. The DIAG output refers to V
Interfacing
SO/OL connected to:
V
Open
Interfacing
ENABLE (V)
ENABLE < 0.8 V
ENABLE > 3 V
Fig 3.
SSD(HW)
Timing diagram
SO/OL connections
Start-up
Rev. 01 — 16 December 2008
Protection
Active
DIAG
High
LOW
5 s
Configuration
Self-oscillating
Open-loop
Mode
Sleep mode
Operating mode
Amplifier
restart
P
010aaa377
, but only during the start-up
SSA1
t
t
and V
Audio amplifier 2 x 17 W
SSA2
© NXP B.V. 2008. All rights reserved.
TFA9815
level by internal
SSD
6 of 26
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