STA381BWSTR STMicroelectronics, STA381BWSTR Datasheet - Page 154

• Manufacturer Part Number: STA381BWSTR
• Description: Audio DSPs Sound Terminal 2.1 High EFF Dig Audio
• Manufacturer: STMicroelectronics

Specifications of STA381BWSTR

• Product Category: Audio DSPs
• Rohs: yes
• Operating Supply Voltage: 4.5 V to 25.5 V
• Operating Temperature Range: 0 C to + 150 C
• Mounting Style: SMD/SMT
• Package / Case: VQFN-48
• Snr: 100 dB

Register description: Sound Terminal compatibility
7.23
154/171
Bad PWM detection registers (address 0x4D, 0x4E, 0x4F)
The STA381BWS implements a detection on the PWM outputs able to verify if the output
signal has no zero-crossing in a configurable time window. This check can be useful to
detect DC levels in the PWM outputs. To be noted that the checks are performed on logic
level PWM (i.e. not the power bridge ones, nor the PWM on DDX3 and DDX4 I/Os).
In case of ternary modulation, the detection threshold is computed as:
If the measured PWM duty cycle is detected greater than or equal to TH for more than
BPTIM PWM periods, the corresponding PWM bit will be set in register 0x4E.
In case of binary modulation, there are two thresholds:
In this case if the measured PWM duty cycle is outside the TH1-TH2 range for more than
BPTIM PWM periods, the corresponding bit will be set in register 0x4E.
BPTIM[7]
BPTH[5]
BP4B
D7
D7
D7
0
0
0
TH=[(BPTH*2+1)/128]*100%
TH1=[(64+BPTH)/128]*100%
TH2=[(64-BPTH)/128]*100%
BPTIM[6]
BPTH[4]
BP4A
D6
D6
D6
0
0
1
BPTIM[5]
BPTH[3]
BP3B
D5
D5
D5
1
0
0
Doc ID 018937 Rev 6
BPTIM[4]
BPTH[2]
BP3A
D4
D4
D4
1
0
1
BPTIM[3]
BPTH[1]
BP2B
D3
D3
D3
0
0
1
BPTIM[2]
BPTH[0]
BP2A
D2
D2
D2
0
0
1
BPTIM[1]
reserved
BP1B
D1
D1
D1
1
0
1
STA381BWS
BPTIM[0]
reserved
BP1A
D0
D0
D0
0
0
0