SM5844 NPC [Nippon Precision Circuits Inc], SM5844 Datasheet - Page 14

• Manufacturer Part Number: SM5844
• Description: Asynchronous Sample Rate Converter
• Manufacturer: NPC [Nippon Precision Circuits Inc]

Table 2. Mode flag description
Deemphasis (DEEM, FSI1, FSI2 pins or FDEEM, FFSI1, FFSI2 flags)
The digital deemphasis filter is an IIR filter with var-
iable coefficients to faithfully reproduce the gain and
phase characteristics of standard analog deemphasis
filters.
The filter coefficients are selected by FSI1 (or FFSI1
flag) and FSI2 (or FFSI2 flag) to correspond to the
sampling frequencies fs = 44.1, 48.0 and 32.0 kHz.
Table 3. Deemphasis ON/OFF
W h e n M C O M = L OW
H I G H
B 1
D E E M = H I G H
D E E M = L OW
B2 to B5
B 1 0
B 1 1
B 1 2
Bit
B 6
B 7
B 8
B 9
M o d e fl ag
W h e n M C O M = H I G H
F D E E M
F R AT E
F T S T 1
F T S T 2
F 1 2 D B
FFSI1
FFSI2
F D E E M = H I G H
F D E E M = L OW
Not used
Test mode select 1
Test mode select 2
Input/output rate
Attenuator
Deemphasis filter fs
select 1
Deemphasis filter fs
select 2
Deemphasis control
O N / O F F
P arameter
D e e m p h a s i s
O F F
O N
SM5844AF
L O W / H I G H
H I G H
H I G H
H I G H
L O W
L O W
L O W
Mode function select
Table 4. Deemphasis fs select (FSI1, FSI2 pins or
FFSI1, FFSI2 flags)
FSI1 (FFSI1)
T S T 2 N = L OW
Input/output sample rate ratio check after every
output
Input/output sample rate ratio check for high
accuracy after every 2048 outputs
Nor mal operation (no shift)
+12 dB gain shift
Deemphasis filter OFF
Deemphasis filter ON
M C O M = L OW ( M C O M = H I G H )
H I G H
H I G H
L O W
L O W
F T S T 2
FFSI2
H I G H
H I G H
H I G H
H I G H
L O W
L O W
L O W
L O W
NIPPON PRECISION CIRCUITS—14
F T S T 1
Select
FFSI1
H I G H
H I G H
H I G H
H I G H
L O W
L O W
L O W
L O W
FSI2 (FFSI2)
H I G H
H I G H
L O W
L O W
44.1 kHz
48.0 kHz
32.0 kHz
M o d e
fsi
0
1
2
3
44.1 kHz
48.0 kHz
32.0 kHz
fs
Reset
m o d e
L O W
L O W
L O W
L O W
L O W
L O W
L O W