HD49330AF_15 Datasheet, PDF (11/22 Pages) Renesas Technology Corp – CDS/PGA & 12-bit A/D Converter

HD49330AF/AHF
7. Adjustment of Black-Level S/H Response Frequency Characteristics
The CR time constant that is used for sampling/hold (S/H) at the black level can be adjusted by changing the
register settings, as shown in table 6.
Table 6 SHSW CR Time Constant Setting
SHSW-fsel (Register setting)
[0] [1] [2] [3] [0] [1] [2] [3] [0] [1] [2] [3] [0] [1] [2] [3] [0] [1] [2] [3] [0] [1] [2] [3] [0] [1] [2] [3] [0] [1] [2] [3]
L L L LHL L L LHL LHHL L L LHLHLHL LHHLHHHL
CR Time Constant (Typ) 2.20 nsec 2.30 nsec 2.51 nsec 2.64 nsec 2.93 nsec 3.11 nsec 3.52 nsec 3.77 nsec
(cutoff frequency conversion) (72 MHz) (69 MHz) (63 MHz) (60 MHz) (54 MHz) (51 MHz) (45 MHz) (42 MHz)
SHSW-fsel (Register setting)
[0] [1] [2] [3] [0] [1] [2] [3] [0] [1] [2] [3] [0] [1] [2] [3] [0] [1] [2] [3] [0] [1] [2] [3] [0] [1] [2] [3] [0] [1] [2] [3]
L L LHHL LHLHLHHHLHL LHHHLHHLHHHHHHH
CR Time Constant (Typ) 4.40 nsec 4.80 nsec 5.87 nsec 6.60 nsec 8.80 nsec 10.6 nsec 17.6 nsec 26.4 nsec
(cutoff frequency conversion) (36 MHz) (33 MHz) (27 MHz) (24 MHz) (18 MHz) (15 MHz) (9 MHz) (6 MHz)
8. The SHAMP frequency characteristics can be adjusted by changing the register settings
and the C4 value of the external 31st pin.
The settings are shown in table 7.
Values other than those shown in the table 7 cannot be used.
BLKC
31
C4
Table 7 SHAMP Frequency Characteristics Setting
LoPwr
[0]
(Register setting)
H
SHA-fsel (Register setting)
[1]
[0]
[1]
L
L
H
"Lo"
116 MHz
10000 pF
(270 pF)
75 MHz
13000 pF
(300 pF)
"Hi"
49 MHz
15000 pF
(620 pF)
32 MHz
22000 pF
(750 pF)
Note: Upper line : SHAMP cutoff frequency (Typ)
Middle line : Standard value of C4 (maximum value is not defined)
Lower line : Minimum value of C4 (do not set below this value)
[0]
[1]
H
H
56 MHz
18000 pF
(360 pF)
24 MHz
27000 pF
(820 pF)
Rev.1.0, Apr.05.2004, page 9 of 19