MP7228
BiCMOS
Fixed, Octal, Voltage Output, Single or Dual
Supply, 8-Bit Digital-to-Analog Converter
FEATURES
•
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•
•
•
•
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APPLICATIONS
MPS Pioneered Segmented DAC Approach
•
Function Generators
Eight 8-Bit DACs with Buffer Amplifiers
•
Automatic Test Equipment
Bipolar Amplifier Inputs for Low Noise and Drift
•
Process Controls
Operates with Single or Dual Supplies
BENEFITS
µP
Compatible (95ns WR)
No External Adjustments Required
•
Reduced Board Space; Lower System Cost
Power-on-Reset Function
•
Reduced System Errors due to Excellent DAC-to-DAC
Specified for 5 to 15 V Operation
Matching and Tracking
ESD Protection: 2000 Volts Minimum
•
Easy to Design with Microprocessors
Latch-Up Proof
•
Stable, High Reliability through Advanced Processing
Quad Available: MP7226
•
Lower 1/f Noise Increases Useful Dynamic Range
GENERAL DESCRIPTION
The MP7228 contains eight 8-bit voltage-output Digital-to-
Analog Converters, with BiCMOS output buffer amplifiers and
interface logic on a monolithic chip. Separate on-chip latches
are provided for each of the eight D/A converters. The control
logic is speed compatible with most 8-bit microprocessors. All
digital inputs are TTL/CMOS(5V) compatible.
The MP7228 is manufactured using EXAR’s advanced thin
film resistors on a double metal BiCMOS process. The MP7228
incorporates a unique bit decoding technique yielding lower
glitch, higher speed and excellent accuracy over temperature
and time. The MP7228 maintains 8-Bit accuracy over the full op-
erating temperature range without laser trim or external adjust-
ments.
SIMPLIFIED BLOCK DIAGRAM
V
REF
V
DD
–
+ 1
–
+ 2
–
+ 3
–
+ 4
–
+ 5
–
+ 6
–
+ 7
–
+ 8
LATCH 1
DAC 1
V
OUT1
V
OUT2
V
OUT3
V
OUT4
V
OUT5
V
OUT6
V
OUT7
V
OUT8
MSB
DATA
(8 BIT)
LSB
D
A
T
A
B
U
S
D
A
T
A
B
U
S
LATCH 2
DAC 2
LATCH 3
DAC 3
LATCH 4
DAC 4
LATCH 5
DAC 5
LATCH 6
DAC 6
LATCH 7
DAC 7
WR
LATCH 8
DAC 8
A2
A1
A0
V
SS
GND
CONTROL
LOGIC
Rev. 2.00
1
MP7228
ORDERING INFORMATION
Package
Type
Plastic Dip
Plastic Dip
PLCC
PLCC
SOIC
SOIC
Ceramic Dip
Ceramic Dip
Temperature
Range
–40 to +85
°
C
–40 to +85
°
C
–40 to +85
°
C
–40 to +85
°
C
–40 to +85
°
C
–40 to +85
°
C
–55 to +125
°
C
–55 to +125
°
C
Part No.
MP7228KN
MP7228LN
MP7228KP
MP7228LP
MP7228KS
MP7228LS
MP7228TD*
MP7228UD*
INL
(LSB)
1
1/2
1
1/2
1
1/2
1
1/2
DNL
(LSB)
1/2
1/2
1/2
1/2
1/2
1/2
1/2
1/2
Full Scale Error
(LSB)
1
1/2
1
1/2
1
1/2
1
1/2
*Contact factory for availability.
PIN CONFIGURATIONS
See Packaging Section for Package Dimensions
V
DD
V
OUT8
V
OUT7
V
OUT6
V
OUT5
V
OUT4
V
OUT3
V
OUT2
V
OUT1
V
SS
V
REF
GND
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
A2
A0
V
OUT7
V
DD
A1
V
OUT8
N/C
4
3
2
1
28
27
26
A0
A1
A2
WR
DB0 (LSB)
DB1
DB2
DB3
DB4
DB5
DB6
DB7 (MSB)
1
2
3
4
24
23
22
V
OUT6
V
OUT5
V
OUT4
N/C
V
OUT3
V
OUT2
V
OUT1
5
6
7
8
9
10
11
12
13
14
15
16
17
18
25
24
23
22
21
20
19
WR
DB0
DB1
N/C
DB2
DB3
DB4
21
See Pin
Labels
20
5
at left for Pin
6
Descriptions
19
7
18
8
9
10
11
12
17
16
15
14
13
DB7
DB5
V
SS
GND
DB6
V
REF
N/C
24 Pin CDIP, PDIP (0.300”)
DN24, NN24
24 Pin SOIC (Jedec, 0.300”)
S24
28 Pin PLCC
P28
PIN OUT DEFINITIONS
DIP
PLCC
1
2
3
4
5
6
7
8
9
10
11
12
13
14
NAME
N/C
V
DD
V
OUT8
V
OUT7
V
OUT6
V
OUT5
V
OUT4
N/C
V
OUT3
V
OUT2
V
OUT1
V
SS
V
REF
GND
DESCRIPTION
No Connection
Positive Power Supply (+5V to +15V)
DAC 8 Voltage Output
DAC 7 Voltage Output
DAC 6 Voltage Output
DAC 5 Voltage Output
DAC 4 Voltage Output
No Connection
DAC 3 Voltage Output
DAC 2 Voltage Output
DAC 1 Voltage Output
Negative Power Supply (0V to –5V)
Reference Input Voltage
Ground
DIP
PLCC
15
16
17
18
19
20
21
22
23
24
25
26
27
28
NAME
N/C
DB7
DB6
DB5
DB4
DB3
DB2
N/C
DB1
DB0
WR
A2
A1
A0
DESCRIPTION
No Connection
Data Input Bit 7 (MSB)
Data Input Bit 6
Data Input Bit 5
Data Input Bit 4
Data Input Bit 3
Data Input Bit 2
No Connection
Data Input Bit 1
Data Input Bit 0 (LSB)
Write (Active Low)
DAC address Bit 2
DAC address Bit 1
DAC address Bit 0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Rev. 2.00
2
MP7228
ELECTRICAL CHARACTERISTICS
Single or Dual Supply Operation (V
DD
= +10.8 V to 16.5 V, V
SS
= 0 V or –5 V
10%,
GND = 0
V, V
REF
= +2 V to +10 V, R
L
= 2kΩ, C
L
= 100pF unless otherwise noted)
Parameter
STATIC PERFORMANCE
Resolution (All Grades)
Integral Non-Linearity
(Relative Accuracy)
K, T
L, U
Differential Non-Linearity
K, T
L, U
Total Unadjusted Error
2
K, T
L, U
Full Scale Error
3
K, T
L, U
Zero Code Error
K, T
L, U
Output Load Resistance
DYNAMIC PERFORMANCE
4
Voltage Output Slew Rate
Voltage Output Settling Time
Digital Feedthrough
Digital Crosstalk
5
2
4
4
25
25
2
5
V/µs
µs
nVs
nVs
2
N
INL
1
1/2
DNL
1/2
1/2
2
1
1
1/2
20
15
2
3/4
3/4
LSB
2
1
LSB
1
1/2
mV
30
20
kΩ
1
1/2
LSB
8
8
Bits
LSB
End Point Linearity Spec
Symbol
Min
25
°
C
Typ
Max
Tmin to Tmax
Min
Max
Units
Test Conditions/Comments
All grades monotonic over full
temperature range.
V
DD
= 15 V
10%,
V
REF
= +10 V
V
REF
= +10 V typ. Tempco is
5 ppm/°C
TA = 25°C typ. Tempco is
10µV/°C
V
OUT
= +10 V
V
REF
= +10 V; Settling Time to
1/2
LSB
Code transition all 0s to all 1s
V
REF
= 0 V, WR = V
DD
Code transition all 0s to all 1s
V
REF
= +10 V, WR = 0 V
REFERENCE INPUT
Reference Input Range
1
Reference Input Resistance
Reference Input Capacitance
4
AC Feedthrough
DIGITAL INPUTS
Input High Voltage
Input Low Voltage
Input Leakage Current
Input Capacitance
4
Input Coding
V
INH
V
INL
I
LKG
2.4
0.8
1
8
2.4
0.8
1
8
V
V
µA
pF
1
2
500
–70
10
1
2
10
V
kΩ
pF
dB
*Limitation: V
REF
– V
SS
< 11 V
Min R
IN
at code 149
10
Occurs when all DACS are loaded
with all 1s
V
REF
= 10 kHz, 5 V p-p sinewave
R
IN
V
IN
= 0 V or V
DD
Binary
Rev. 2.00
3
MP7228
ELECTRICAL CHARACTERISTICS (CONT’D)
Parameter
POWER SUPPLY
V
DD
Range
V
SS
Range (Dual Supplies)
8
I
DD
I
SS
(Dual Supplies)
TA = 25°C
SWITCHING
CHARACTERISTICS
4, 6, 7
Address to WR Setup Time
Address to WR Hold Time
Data Valid to WR Setup Time
Data Valid to WR Hold Time
WR Pulse Width
t
AS
t
AH
t
DS
t
DH
t
WR
0
0
70
10
95
0
0
95
10
120
ns
ns
ns
ns
ns
10.8
0
16.5
–5.5
16
10.8
0
16.5
–5.5
20
V
V
mA
For specified performance
For specified performance
Outputs unloaded;
V
IN
=V
INL
or V
INH
Outputs unloaded;
V
IN
=V
INL
or V
INH
Symbol
Min
25
°
C
Typ
Max
Tmin to Tmax
Min
Max
Units
Test Conditions/Comments
14
18
NOTES:
1
V
OUT
must be less than V
DD
by 3.5 V to ensure correct operation.
2
Total Unadjusted Error includes zero code error, relative accuracy and full-scale error.
3
Calculated after zero code error has been adjusted out.
4
Sample tested at 25°C to ensure compliance.
5
The glitch impulse transferred to the output of one converter (not adjusted) due to a change in the digital input code to another
addressed converter.
6
All input rise and fall times are measured from 10% to 90% of +5 V, t
R
= t
F
= 5 ns.
7
Timing measurement reference level is (V
INH
+ V
INL
)/2.
Specifications are subject to change without notice
Rev. 2.00
4
MP7228
ELECTRICAL CHARACTERISTICS
Single & Dual
5
V Supply Operation (V
DD
= +5 V
5%,
V
SS
= 0 V to –5 V
10%,
V
REF
= +1.25 V,
R
L
= 2kΩ, C
L
= 100pF, GND = 0 V unless otherwise noted)
Parameter
STATIC PERFORMANCE
Resolution (All Grades)
Integral Non-Linearity
(Relative Accuracy)
K, T
L, U
Differential Non-Linearity
K, T
L, U
Total Unadjusted Error
2
Full Scale Error
3
K, T
L, U
Zero Code Error
Output Load Resistance
DYNAMIC PERFORMANCE
4
Voltage Output Slew Rate
Voltage Output Settling Time
Digital Feedthrough
Digital Crosstalk
5
2
4
4
25
25
V/µs
µs
nVs
nVs
2
N
INL
2
1
DNL
1
1
4
4
2
20
4
2
mV
kΩ
V
OUT
= +10 V
R
L
=100Ω, C
L
=13pF
V
REF
= +1.25 V; Settling Time to
1/2
LSB
Code transition all 0s to all 1s
V
REF
= 0 V, WR = V
DD
Code transition all 0s to all 1s
V
REF
= +1.25 V, WR = 0 V
1
1
LSB
LSB
2
1
LSB
8
8
Bits
LSB
End Point Linearity Spec
Symbol
Min
25
°
C
Typ
Max
Tmin to Tmax
Min
Max
Units
Test Conditions/Comments
All grades monotonic over full
temperature range.
V
DD
= 5 V
5%,
V
REF
= 1.25 V
V
REF
= +1.25 V
REFERENCE INPUT
Reference Input Range
Reference Input Resistance
Reference Input Capacitance
4
AC Feedthrough
DIGITAL INPUTS
Input High Voltage
Input Low Voltage
Input Leakage Current
Input Capacitance
4
Input Coding
V
INH
V
INL
I
LKG
2.4
0.8
1
8
2.4
0.8
1
8
V
V
µA
pF
1
2
500
–70
1.6
1
2
1.6
V
kΩ
pF
dB
V
OUT
must be < V
DD
by 3.2V
Min R
IN
at code 149
10
Occurs when all DACs are loaded
with all 1s
V
REF
= 10 kHz, 1/2 V p-p sinewave
R
IN
V
IN
= 0 V or V
DD
Binary
Rev. 2.00
5
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