TFA9812_2
© NXP B.V. 2009. All rights reserved.
Preliminary data sheet
Rev. 02 — 22 January 2009
9 of 66
NXP Semiconductors
TFA9812
BTL stereo Class-D audio amplifier with I
2
S input
The block control defines the operational control settings of the TFA9812 in line with the
actual I
2
C settings and the pin-controlled settings.
The PLL block creates the system clock and can take the I
2
S BCK, the MCLK or an
external crystal as reference source.
The following protections are built into the TFA9812:
•
Thermal Foldback (TF)
•
OverTemperature Protection (OTP)
•
OverCurrent Protection (OCP)
•
OverVoltage Protection (OVP)
•
UnderVoltage Protection (UVP)
•
Window Protection (WP)
•
Lock Protection (LP)
•
UnderFrequency Protection (UFP)
•
OverFrequency Protection (OFP)
•
Invalid BCK Protection (IBP)
•
DC-blocking
•
ElectroStatic Discharge (ESD)
8.2 Functional modes
8.2.1 Control modes
The two control modes of the TFA9812 are I
2
C and legacy.
•
In I
2
C mode the I
2
C format control is enabled.
•
In Legacy mode a pin-based subset of the control options is available. The control
settings for features which are not available in Legacy mode are set to the default I
2
C
register settings.
The control mode is selected via pin CSEL as shown in
In the functional descriptions below the control for the various functions will be described
for each control mode.
summarizes the support given by each control mode
for the various TFA9812 functions.
8.2.2 Key operating modes
There are six key operating modes:
•
In Sleep mode the voltage supplies are present, but power consumption for the whole
device is reduced to the minimum level. The output stages in Sleep mode are 3-state
and I
2
C communication is disabled.
Table 4.
Control mode selection
CSEL Pin value
Control mode
0
Legacy (no I
2
C)
1
I
2
C
