CDB44800 Cirrus Logic Inc, CDB44800 Datasheet - Page 75

• Manufacturer Part Number: CDB44800
• Description: BOARD EVAL FOR CS44800 PWM CTRL
• Manufacturer: Cirrus Logic Inc
• Series: Popguard®r

Specifications of CDB44800

• Amplifier Type: Class D
• Output Type: 8-Channel
• Voltage - Supply: 20 V ~ 50 V
• Operating Temperature: -10°C ~ 70°C
• Board Type: Fully Populated
• Utilized Ic / Part: CS44800
• Description/function: Audio DSPs
• Operating Supply Voltage: 5 V
• Product: Audio Modules
• For Use With/related Products: CS44800
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Max Output Power X Channels @ Load: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 598-1532; CDB-44800

DS632F1
7.33.2 Decimator Scale (DEC_SCALE[18:0])
7.34
7.34.1 Decimator Outd (DEC_OUTD[23:0])
DEC_OUTD23
DEC_OUTD15
DEC_OUTD07
7
7
7
Decimator Outd (addresses 3Bh, 3Ch, 3Dh)
Default = 25868h
Function:
These bits are used to scale the power supply reading
ing the PSR feedback calibration sequence. DEC_SCALE[18:0] has 19-bit precision, formatted as signed
1.18 with decimal values from -1 to 1-2^(-18). The combination of shift and scale factors
(DEC_SCALE[18:0]*2^(DEC_SHIFT[2:0])) can be viewed as a floating point coefficient. The floating point
coefficient will be determined during the PSR feedback calibration sequence. See
(DEC_SHIFT[2:0])
Default = 000000h (Read Only)
Function:
These bits reflect the real-time power supply value as measured by the external PSR feedback circuit.
DEC_OUTD[23:0] has 24-bit precision, formatted as signed 2.22 with decimal values from -4 to 4-2^(-22).
Calibration needs to be done to correlate the value of DEC_OUTD[23:0] with the real power supply value.
A quiet DC power supply without any ripple is treated as 1.0 with DEC_OUTD[23:0] calibrated at 400000h.
See
“Recommended PSR Calibration Sequence” on page
DEC_OUTD22
DEC_OUTD14
DEC_OUTD06
6
6
6
20000h=0.5
28851h=0.6331
DEC_SCALE[18:0]
Table 18. Decimator Shift/Scale Coefficient Calculation Examples
register description and
DEC_OUTD21
DEC_OUTD13
DEC_OUTD05
5
5
5
001b=1
010b=2
DEC_OUTD20
DEC_OUTD12
DEC_OUTD04
DEC_SHIFT[2:0]
4
4
4
“Recommended PSR Calibration Sequence” on page
DEC_OUTD19
DEC_OUTD03
DEC_OUTD11
0.5*2^(1)=1
0.6331*2^(2)=2.5325
Calculated Coefficient (C
3
3
3
(Decimator Outd (addresses 3Bh, 3Ch,
44.
DEC_OUTD18
DEC_OUTD10
DEC_OUTD02
2
2
2
PSR
DEC_OUTD17
DEC_OUTD09
DEC_OUTD01
)
1
1
1
Decimator Shift
CS44800
DEC_OUTD16
DEC_OUTD08
DEC_OUTD00
3Dh)) dur-
0
0
0
44.
75