sta335bw STMicroelectronics, sta335bw Datasheet - Page 20

• Manufacturer Part Number: sta335bw
• Description: 2.1 Channels High Efficiency Digital Audio System
• Manufacturer: STMicroelectronics

Register description
5.1.3
5.1.4
5.1.5
20/54
Thermal warning recovery bypass
If the thermal warning adjustment is enabled(TWAB=0), then the thermal warning recovery
determines if the -3 dB output limit is removed when thermal warning is negative.
If TWRB=0 and TWAB=0, then when a thermal warning disappears the -3 dB output limit is
removed and the gain is added back to the system. If TWRB=1 and TWAB=0, then when a
thermal warning disappears the -3 dB output limit remains until TWRB is changed to zero or
the device is reset.
Thermal warning adjustment bypass
The on-chip STA335BW power output block provides feedback to the digital controller using
inputs to the power control block. The TWARN input is used to indicate a thermal warning
condition. When TWARN is asserted (set to 0) for a period of time greater than 400 ms, the
power control block forces a -3 dB output limit (determined by TWOCL in Coeff RAM) to the
modulation limit in an attempt to eliminate the thermal warning condition. Once the thermal
warning output limit adjustment is applied, it remains in this state until reset, unless
FDRB = 0.
Fault detect recovery bypass
The on-chip STA335BW power output block provides feedback to the digital controller using
inputs to the Power Control block. The FAULT input is used to indicate a fault condition
(either over-current or thermal). When FAULT is asserted (set to 0), the power control block
attempts a recovery from the fault by asserting the tri-state output (setting it to 0 which
directs the power output block to begin recovery), holds it at 0 for period of time in the range
of 0.1 ms to 1 second as defined by the Fault-Detect Recovery Constant register (FDRC
registers 29-2Ah), then toggles it back to 1. This sequence is repeated as log as the fault
indication exists. This feature is enabled by default but can be bypassed by setting the
FDRB control bit to 1.
Bit
Bit
Bit
5
6
7
R/W
R/W
R/W
R/W
R/W
R/W
RST
RST
RST
1
1
0
TWRB
TWAB
Name
Name
Name
FDRB
0 – Thermal warning Recovery enabled
1 – Thermal warning Recovery disabled
0 – Thermal warning adjustment enabled
1 – Thermal warning adjustment disabled
0 – Fault Detect Recovery enabled
1 – Fault Detect Recovery disabled
Description
Description
Description
STA335BW