1
A/D, D/C Converters for Image Signal Processing
MN6556A, MN6556AS
Low Power 8-Bit CMOS D/A Converters for Image Processing
Overview
The MN6556A and MN6556AS are 8-bit CMOS digi-
tal-to-analog converters with a maximum conversion rate
of 20 MSPS.
They use both a matrix cell and weighted current tech-
nology to achieve a low power consumption of only 50
mW. Output has an amplitude of one volt above the ground
level.
Features
Maximum conversion rate: 20 MSPS (min.)
Linearity error:
±
0.3 LSB (typ.)
Differential linearity error:
±
0.3 LSB (typ.)
Power supply voltage: 5.0
±
0.5 V
Power consumption: 50 mW (typ.)
Full scale current: 5 mA (typ.)
Applications
Digital television
Digital video equipment
Digital image processing equipment
Measuring instrument
Pin Assignment
MN6556A : DIP022-P-0400
MN6556AS : SOP022-P-0375
(TOP VIEW)
AV
DD
AV
DD
I
O
VC
VIB
COMP
V
REF
I
REF
AV
SS
N.C.
N.C.
DV
SS
DB8
DB7
DB6
DB5
DB4
DB3
DB2
DB1
CLK
DV
DD
1
2
3
4
5
6
7
8
9
10
11
22
21
20
19
18
17
16
15
14
13
12
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MN6556A, MN6556AS
A/D, D/C Converters for Image Signal Processing
Block Diagram
+
+
X-Decoder
Y-Decoder
Latch
Latch
Latch
Current
Source
V
REF
I
REF
DB3
DB2
DB1
(MSB)
R
REF
N.C.
DV
DD
DV
SS
AV
DD
AV
DD
AV
SS
1/2
1/4
VIB
Matrix Current Cell
VC
I
O
R
OUT
3
7
8
16
15
14
6
13
17
18
19
20
21
COMP
CLK
DB4
DB5
DB6
DB7
DB8 (LSB)
10
11
12
22
1
2
9
5
4
N.C.
3
A/D, D/C Converters for Image Signal Processing
MN6556A, MN6556AS
Pin Descriptions
Pin No.
Symbol
Function Description
1
AV
DD
Power supply for analog circuits
2
AV
DD
Power supply for analog circuits
3
I
O
Analog current output
4
VC
Capacitor connection
5
VIB
Capacitor connection
6
COMP
Phase compensation
7
V
REF
Reference voltage input pin
8
I
REF
Reference resistor
9
AV
SS
Ground for analog circuits
10
N.C.
No connection
11
N.C.
No connection
12
DV
DD
Ground for digital circuits
13
CLK
Sampling clock
14
DB1
Digital input (MSB)
15
DB2
Digital input
16
DB3
Digital input
17
DB4
Digital input
18
DB5
Digital input
19
DB6
Digital input
20
DB7
Digital input
21
DB8
Digital input (LSB)
22
DV
SS
Power supply for digital circuits
Absolute Maximum Ratings
Ta=25°C
Parameter
Symbol
Rating
Unit
Power supply voltage for digital circuits
DV
DD
0.3 to +7.0
V
Power supply voltage for analog circuits
AV
DD
0.3 to +7.0
V
Input voltage
V
I
DV
SS
0.3 to DV
DD
+0.3
V
Output voltage
V
O
AV
SS
0.3 to AV
DD
+0.3
V
Operating ambient temperature
T
opr
20 to +70
°C
Storage temperature
T
stg
55 to +125
°C
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MN6556A, MN6556AS
A/D, D/C Converters for Image Signal Processing
Recommended Operating Conditions
V
DD
=AV
DD
=DV
DD
=5.0V, V
SS
=AV
SS
=DV
SS
=0V, Ta=25°C
Parameter
Symbol
min
typ
max
Unit
Power supply voltage
V
DD
4.5
5.0
5.5
V
Reference voltage
V
REF
1.8
V
Reference resistance
R
REF
1.5
k
External compensation capacitor
C
COMP
1
µ
F
Output load resistance
R
OUT
200
Digital input
"H" level
V
IH
2.4
V
DD
V
voltage
"L" level
V
IL
V
SS
0.8
V
Clock
"H" level pulse width
t
WH
20
ns
"L" level pulse width
t
WL
20
ns
Electrical Characteristics
DV
DD
=AV
DD
=5.0V, DV
SS
=AV
SS
=0V, Ta=25°C
Parameter
Symbol Conditions
min
typ
max
Unit
Power supply voltage
I
DD
10
20
mA
Resolution
RES
8
bit
Linearity error
E
L
R
REF
=1.5k
, R
OUT
=200
±
0.3
±
0.5
LSB
Differential linearity error
E
D
V
REF
=1.8V
±
0.3
±
0.5
LSB
Full scale current
I
FS
R
REF
=1.5k
, V
REF
=1.8V
4.5
5.0
5.5
mA
Setup time
t
S
15
ns
Hold time
t
H
15
ns
Settling time
t
ST
R
REF
=1.5k
, R
OUT
=200
50
ns
Maximum conversion speed
F
C(max.)
V
REF
=1.8V
20
MSPS
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A/D, D/C Converters for Image Signal Processing
MN6556A, MN6556AS
Timing Chart
CLK
Data
Analog Output
(Settling waveform)
Dn-1
Dn
Dn+1
t
S
t
H
t
WH
t
WL
±1/2LSB
±1/2LSB
An
t
d
t
ST
t
d
t
ST
2.4V
0.8V
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