®
®
ADC-228
8-Bit, 20MHz, Complete
Flash A/D Converter
IN N O VA T IO N a n d E X C E L L E N C E
FEATURES
•
•
•
•
•
•
•
•
8-Bit flash A/D converter
20MHz sampling rate
Complete support circuitry
Low power, 1.5W
7MHz full power bandwidth
Sample-hold not required
Three-state outputs
MIL-STD-883 versions
GENERAL DESCRIPTION
The ADC-228 combines analog front-end circuitry and a flash
A/D converter to digitize high-speed analog signals at a rate of
20 million samples per second. The ADC-228 contains an
8-bit, 20MHz, flash A/D, a wideband analog input buffer, a
precision voltage reference, temperature compensation
circuitry, reference trims, and a three-state output buffer in a
24-pin package.
The ADC-228 offers significant savings by combining all of the
circuitry in a single package. Valuable board real estate is
saved, and design time and manufacturing costs are reduced.
The ADC-228 is housed in a 24-pin ceramic DDIP package
and is available in the commercial, 0 to +70°C, or military,
–55 to +125°C, temperature ranges. A MIL-STD-883 version
is also available. Operation is from ±15V and +5V power
supplies.
INPUT/OUTPUT CONNECTIONS
PIN
1
2
3
4
5
6
7
8
9
10
11
12
FUNCTION
+5V SUPPLY
GROUND
+5V REFERENCE OUT
GROUND
ANALOG INPUT
GROUND
GROUND
NLINV
NMINV
–15V SUPPLY
CS1
CS1
PIN
24
23
22
21
20
19
18
17
16
15
14
13
FUNCTION
BIT 8 (LSB)
BIT 7
BIT 6
BIT 5
NO CONNECTION
+15V SUPPLY
CLOCK INPUT
BIT 4
BIT 3
BIT 2
BIT 1 (MSB)
NO CONNECTION
CS1 11
CS1 12
NLINV 8
NMINV 9
CLOCK 18
ANALOG INPUT 5
INPUT
BUFFER
+15V SUPPLY 19
–15V SUPPLY 10
GROUND 7
GROUND 6
GROUND 4
GROUND 2
+5V SUPPLY 1
VOLTAGE
REFERENCE
NETWORK
LINEARIZATION
& TEMPERATURE
COMPENSATION
NETWORK
8-BIT
20MHz
FLASH
CONVERTER
TRI-STATE
BUFFER
13 NO CONNECTION
20 NO CONNECTION
14 BIT 1 (MSB)
15 BIT 2
16 BIT 3
17 BIT 4
21 BIT 5
22 BIT 6
23 BIT 7
24 BIT 8 (LSB)
3 +5V REF. OUT
Figure 1. Functional Block Diagram
DATEL, Inc., 11 Cabot Boulevard, Mansfield, MA 02048-1151 (U.S.A.)
•
Tel: (508) 339-3000 Fax: (508) 339-6356
•
For immediate assistance (800) 233-2765
®
®
ADC-228
ABSOLUTE MAXIMUM RATINGS
PARAMETER
Power Supply Voltage,
Pin 19
Pin 10
Digital Inputs, Pins 8,9,11,12,18
Analog Input, Pin 5
Digital Outputs
Lead Temp. (10 seconds)
LIMITS
Pin 1
–0.5 to +7V
–0.3 to +18V
+0.3 to –18V
–0.5 to +5.5V
–6 to +7.5V
–0.5 to +5.5V (short circuit protected to ground)
+300°C
DYNAMIC PERFORMANCE
Total Harm. Distortion, –0.5dB
DC to 2.5 MHz
2.5 MHz to 5 MHz
5 MHz to 10 MHz
Signal-to-Noise Ratio
and Distortion, –0.5dB
DC to 2.5 MHz
2.5 MHz to 5 MHz
5 MHz to 10 MHz
Signal-to-Noise Ratio
w/o Distortion, –0.5 dB
DC to 2.5 MHz
2.5 MHz to 5 MHz
5 MHz to 10 MHz
Effective Bits, –0.5dB
DC to 2.5 MHz
2.5 MHz to 5 MHz
5 MHz to 10 MHz
Input Bandwidth
Full Power
Small Signal (–20dB)
POWER SUPPLY
Power Supply Range
+15V Supply
–15V Supply
+5V Supply
Power Supply Current
+15V Supply
–15V Supply
+5V Supply
Power Dissipation
±12V, +5V Nominal
Over full supply range
±15V, +5V Nominal
PHYSICAL/ENVIRONMENTAL
Operating Temp. Range, Case
ADC-228MC
ADC-228MM, ADC-228/883
Storage Temp. Range
Package Type
Weight
Footnotes:
At full power input and chip selects enabled.
See Technical Note 3.
For 10-step, 40 IRE NTSC ramp test.
0 to +70°C
–55 to +125°C
–65 to +150°C
24-pin, ceramic DDIP
0.3 ounces (8.5 grams)
+11
–11
+4.75
—
—
—
—
—
—
+15
–15
+5
—
—
—
1.4
1.6
1.5
+15.75
–15.75
+5.25
+30
–10
+230
1.65
1.85
1.75
Volts
Volts
Volts
mA
mA
mA
Watts
Watts
Watts
MIN.
—
—
—
44
43
35
45
45
42
7.1
6.9
5.6
7
40
TYP.
–55
–50
–39
49
46
38
48
48
45
7.75
7.4
6.1
—
—
MAX.
–53
–48
–36
—
—
—
—
—
—
—
—
—
—
—
UNITS
dB
dB
dB
dB
dB
dB
dB
dB
dB
Bits
Bits
Bits
MHz
MHz
FUNCTIONAL SPECIFICATIONS
(Apply over the operating temperature range with 20MHz clock and ±15V and +5V
power supply voltages, unless otherwise specified.)
ANALOG INPUTS
Single-Ended, Non-Isolated
Input Range, dc-20MHz
Input Resistance
Input Capacitance
DIGITAL INPUTS
Logic Levels
Logic 1
Logic 0
Logic Loading
Logic 1
Logic 0
Clock Pulse Widths
"High"
"Low"
DIGITAL OUTPUTS
Coding
Resolution
Logic Levels
Logic 1
Logic 0
Logic Loading
Logic 1
Logic 0
Output Data Valid Delay
From Rising Edge
Output Hold Time
PERFORMANCE
Sampling Rate
Differential Linearity
Code Transitions
Code Centers
Integral Linearity, +25°C
End-point
Best-fit Line
Over Temperature End-point
Best-fit Line
Zero-Scale Offset
Code "0" to "1" Transition
+25°C
–55 to +125°C
Gain error
Full Scale Absolute Accuracy
Differential Gain
Differential Phase
Aperture Delay
Aperture Jitter
No Missing Codes
Power Supply Rejection
20
—
—
—
—
—
—
—
±0.5
±0.25
±0.5
±0.35
—
—
—
±0.75
±0.5
±0.75
±0.5
±1
±1
MHz
LSB
LSB
LSB
LSB
LSB
LSB
Straight bin., comp. bin., two's
comp.,
comp. two's comp.
8 bits
+2.4
—
—
Volts
—
—
+0.4
Volts
—
—
—
5
—
—
30
—
–1
+1
40
—
mA
mA
ns
ns
+2.0
—
—
—
25
19
—
—
—
—
—
—
—
+0.8
+160
–0.5
—
—
Volts
Volts
µA
mA
ns
ns
MIN.
0
2.45
—
TYP.
—
2.5
5
MAX.
+5.0
2.55
10
UNITS
Volts
kΩ
pF
—
—
±0.5
LSB
—
±0.5
±1.5
LSB
—
±0.5
±1.5
LSB
—
±0.5
±1.5
LSB
—
2
—
%
—
1
—
deg.
—
8
—
ns
—
50
—
ps
Over the operating temperature range
±0.02% FSR/ %V
S
maximum
2
®
®
ADC-228
TECHNICAL NOTES
1. Rated performance requires using good high-frequency
techniques. The analog and digital ground pins are
connected to each other internally. Avoid ground related
problems by connecting the grounds to one point, the
ground plane beneath the converter. Due to the inductance
and resistance of the power supply return paths, return the
analog and digital ground separately to the power supplies.
2. Bypass all the analog and digital supplies and the +5V
REFERENCE (pin 3) to ground with a 4.7µF, 25V tantalum
electrolytic capacitor in parallel with a 0.1µF ceramic
capacitor.
3. DATEL uses conservative definitions when specifying
integral linearity (end-point) and differential linearity (code
transition). The specifications using the less conservative
definitions have also been provided as a comparative
specification for products specified this way.
4. Single conversions (one-shot mode) would require another
clock edge to read out data. Users desiring to provide just
a single clock pulse could use the circuit shown in Figure 2
to obtain the data.
+5V
0.1µF
74HC86
4.7µF
+
1
CLOCK
IN
250
Ω
CLOCK
OUT
100pF
NLINV 8
–15V
0.1µF
10
4.7µF
+
14
15
B1 (MSB)
B2
B3
B4
B5
B6
B7
B8 (LSB)
NO CONNECTION
NMINV 9
16
17
50ns
CS1 11
21
ADC-228
CS1 12
CLOCK 18
ANALOG
INPUT
V
IN
5
DATA N
VALID
19
0.1µF
2, 4, 6, 7
22
23
24
13, 20
3
25ns
PULSES
DATA N
SAMPLED
+5V REFERENCE OUT
51
Ω
9k
Ω
*Optional
+
4.7µF
0.1µF
40ns
Figure 2. ADC-228 Single Clock Pulse
Circuit and Operation
* Use optional resistor only if
amp is not used to drive input.
R = V
EE
/1.667mA
+
4.7µF
+15V
Figure 3. ADC-228 Typical Connections
Table 1. ADC-228 Unipolar Output Coding
STRAIGHT BIN.
NMINV = 0
NLINV = 0
1111 1110
1100 0000
1000 0000
0100 0000
0000 0001
0000 0000
COMP. BIN.
NMINV = 1
NLINV = 1
0000 0001
0011 1111
0111 1111
1011 1111
1111 1110
1111 1111
Table 2. ADC-228 Bipolar Output Coding
(Assumes analog input is externally offset)
TWO’S
COMP.
NMINV = 1
NLINV = 0
0111 1111
0100 0000
0000 0001
0000 0000
1100 0000
1000 0001
1000 0000
COMP.
TWO’S COMP.
NMINV = 0
NLINV = 1
1000 0000
1011 1111
1111 1110
1111 1111
0011 1111
0111 1110
0111 1111
ANALOG
INPUT
+4.96V
+3.75V
+2.50V
+1.25V
+0.02V
0.00V
CODE
+FS – 1 LSB
+ 3/4 FS
+ 1/2 FS
+ 1/4 FS
+ 1 LSB
ZERO
ANALOG
INPUT
+2.480V
+1.250V
+0.020V
+0.000V
–1.250V
–2.480V
–2.500V
CODE
+FS – 1 LSB
+1/2 FS
+1 LSB
ZERO
–1/2 FS
–FS + 1 LSB
–FS
3
®
®
ADC-228
Table 3. Chip Select Truth Table
CS1
Pin 12
0
0
1
1
CS1
Pin 11
0
1
0
1
Bits 1-8
Three State Mode
Three State Mode
Data Outputted
Three State Mode
CLOCK
SAMPLE
N
SAMPLE
N+1
OUTPUT
DELAY
SAMPLE
N+2
DIGITAL
OUTPUT
DATA
N–1
DATA
N
DATA
N+1
OUTPUT
HOLD TIME
Figure 4. ADC-228 Timing Diagram
MECHANICAL DIMENSIONS
INCHES (mm)
1.31 MAX.
(33.27)
Dimension Tolerances
(unless otherwise indicated):
2 place decimal (.XX) ±0.010 (±0.254)
3 place decimal (.XXX) ±0.005 (±0.127)
0.80 MAX.
(20.32)
1
12
Lead Material:
Kovar alloy
Lead Finish:
50 microinches (minimum) gold plating
over 100 microinches (nominal) nickel plating
24
13
0.100 TYP.
(2.540)
1.100
(27.940)
0.235 MAX.
(5.969)
0.200 MAX.
(5.080)
0.010
–0.001
(0.254)
0.190 MAX.
(4.826)
0.018 ±0.002
(0.457)
0.100
(2.540)
0.040
(1.016)
+0.002
SEATING
PLANE
0.025
(0.635)
0.600 ±0.010
(15.240)
0.100
(2.540)
ORDERING INFORMATION
MODEL
ADC-228MC
ADC-228MM
ADC-228/883
TEMPERATURE RANGE
0 to +70°C
–55 to +125°C
–55 to +125°C
Receptacle for PC board mounting can be ordered through AMP Inc., part # 3-331272-8
(component lead socket), 24 required. Contact DATEL for 883 product specifications
®
®
ISO 9001
R
E
G
I
S
T
E
R
E
D
IN N O VA T IO N a n d E X C E L L E N C E
DS-0211B
10/96
DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151
Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356
Internet: www.datel.com E-mail:sales@datel.com
Data Sheet Fax Back: (508) 261-2857
DATEL (UK) LTD. Tadley, England Tel: (01256)-880444
DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: 1-34-60-01-01
DATEL GmbH München, Germany Tel: 89-544334-0
DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-354-2025
DATEL makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein
do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. The DATEL logo is a registered DATEL, Inc. trademark.
京公网安备 11010802033920号
EEWORLD
