ADC-228A/883 - C&D Technologies, Inc.

FEATURES

• 8-Bit flash A/D converter

• 20MHz sampling rate

• Complete support circuitry

• Low power, 900mW

• Sample-hold not required

• Three-state outputs

• MIL-STD-883 versions

GENERAL DESCRIPTION

The ADC-228A 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-228A 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-228A 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-228A 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.

INNOVATION and EX C ELL E N C

ADC-228A

8-Bit, 20MHz, Complete

Flash A/D Converter

Figure 1. Functional Block Diagram

PIN FUNCTION PIN FUNCTION

1 +5V SUPPLY 24 BIT 8 (LSB)

2 GROUND 23 BIT 7

3 +5V REFERENCE OUT 22 BIT 6

4 GROUND 21 BIT 5

5 ANALOG INPUT 20 NO CONNECTION

6 GROUND 19 +15V SUPPLY

7 GROUND 18 CLOCK INPUT

8 NO CONNECTION 17 BIT 4

9 NO CONNECTION 16 BIT 3

10 –15V SUPPLY 15 BIT 2

11 CS1 14 BIT 1 (MSB)

12 CS2 13 NO CONNECTION

INPUT/OUTPUT CONNECTIONS

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

1 3 N O C O N N E C T I O N

2 0 N O C O N N E C T I O N

1 4 B I T 1 ( M S B )

1 5 B I T 2

1 6 B I T 3

1 7 B I T 4

2 1 B I T 5

2 2 B I T 6

2 3 B I T 7

2 4 B I T 8 ( L S B )

3 + 5 V R E F . O U T

T R I - S T A T E

B U F F E R

8 - B I T

2 0 M H z

F L A S H

C O N V E R T E R

L I N E A R I Z A T I O N

& T E M P E R A T U R E

C O M P E N S A T I O N

N E T W O R K

I N P U T

B U F F E R

C S 1 1 1

C S 2 1 2

N O C O N N E C T I O N 8

N O C O N N E C T I O N 9

C L O C K 1 8

A N A L O G I N P U T 5

+ 1 5 V S U P P L Y 1 9

G R O U N D 4

G R O U N D 7

G R O U N D 6

 1 5 V S U P P L Y 1 0

+ 5 V S U P P L Y 1

V O L T A G E

R E F E R E N C E

N E T W O R K

G R O U N D 2

PRELIMINARY PRODUCT DATA

ADC-228A

FUNCTIONAL SPECIFICATIONS

(Apply over the operating temperature range with 20MHz clock and ±15V and +5V

power supply voltages, unless otherwise specified.)

ANALOG INPUTS MIN. TYP. MAX. UNITS

Single-Ended, Non-Isolated

Input Range, dc-20MHz 0 — +5.0 Volts

Input Resistance 1.95 2 — k

Ω

Input Capacitance —510 pF

DIGITAL INPUTS

Logic Levels

Logic 1 +2.0 — — Volts

Logic 0 — — +0.8 Volts

Logic Loading

Logic 1 — — +160 µA

Logic 0 — — –0.5 mA

Clock Pulse Widths

"High" 20 — — ns

"Low" 20 — — ns

DIGITAL OUTPUTS

Coding

Resolution

Logic Levels

Logic 1 +2.4 — — Volts

Logic 0 — — +0.4 Volts

Logic Loading

Logic 1 — — –1 mA

Logic 0 — — +1 mA

Output Data Valid Delay

From Rising Edge — — 40 ns

Output Hold Time 6——ns

PERFORMANCE

Sampling Rate

➀

20 — — MHz

Differential Linearity

Code Transitions,

+25°C — ±0.5 ±0.75 LSB

0 to +70°C — ±0.5 ±0.75 LSB

–55 to +125°C — ±0.5 ±0.85 LSB

Integral Linearity, +25°C

End-point — ±0.5 ±1 LSB

Best-fit Line — ±0.35 ±0.75 LSB

Over Temperature End-point — — ±1.75 LSB

Best-fit Line — — ±1 LSB

Zero-Scale Offset

Code "0" to "1" Transition

+25°C — ±0.5 ±1 LSB

–55 to +125°C — ±0.5 ±1.5 LSB

PERFORMANCE MIN. TYP. MAX. UNITS

Gain error — ±0.5 ±1.5 LSB

Full Scale Absolute Accuracy — ±0.5 ±1.5 LSB

Differential Gain

➁

—2—%

Differential Phase

➁

— 1 — deg.

Aperture Delay —8—ns

Aperture Jitter —50—ps

No Missing Codes

Power Supply Rejection

DYNAMIC PERFORMANCE

Total Harm. Distortion, –0.5dB

DC to 2.5 MHz — –55 –53 dB

2.5 MHz to 5 MHz — –49 –44 dB

5 MHz to 10 MHz — –39 –36 dB

Signal-to-Noise Ratio

and Distortion, –0.5dB

DC to 2.5 MHz 44 49 — dB

2.5 MHz to 5 MHz 41 46 — dB

5 MHz to 10 MHz 35 38 — dB

Signal-to-Noise Ratio

w/o Distortion, –0.5 dB

DC to 2.5 MHz 45 48 — dB

2.5 MHz to 5 MHz 44 49 — dB

5 MHz to 10 MHz 42 45 — dB

Effective Bits, –0.5dB

DC to 2.5 MHz 7.1 7.75 — Bits

2.5 MHz to 5 MHz 6.8 7.4 — Bits

5 MHz to 10 MHz 5.6 6.1 — Bits

Input Bandwidth

Large Signal (–3dB) 15 — — MHz

Small Signal (–20dB) 40 — — MHz

POWER SUPPLY

Power Supply Range

+15V Supply +11 +15 +15.75 Volts

–15V Supply –11 –15 –15.75 Volts

+5V Supply +4.75 +5 +5.25 Volts

Power Supply Current

+15V Supply — +12 +20 mA

–15V Supply — –13 –20 mA

+5V Supply — +70 +80 mA

Power Dissipation

±15V, +5V Nominal — 0.7 0.9 Watts

PHYSICAL/ENVIRONMENTAL

Operating Temp. Range, Case

ADC-228AMC 0 to +70°C

ADC-228AMM, ADC-228A/883 –55 to +125°C

Storage Temp. Range –65 to +150°C

Package Type 24-pin, ceramic DDIP

Weight 0.3 ounces (8.5 grams)

Footnotes:

➀

At full power input and chip selects enabled.

➁

For 10-step, 40 IRE NTSC ramp test.

ABSOLUTE MAXIMUM RATINGS

PARAMETER LIMITS

Power Supply Voltage, Pin 1 –0.3 to +7V

Pin 19 –0.3 to +18V

Pin 10 +0.3 to –18V

Digital Inputs, Pins 8,9,11,12,18 –0.5 to +5.5V

Analog Input, Pin 5 –3.8 to +6.6V

Digital Outputs –0.5 to +5.5V

(short circuit protected to ground)

Lead Temp. (10 seconds)+300°C Over the operating temperature range

±0.02% FSR/%VS maximum

Straight Binary

8 Bits

ADC-228A

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.

ANALOG

INPUT CODE STRAIGHT BIN.

+4.96V +FS – 1 LSB 1111 1110

+3.75V + 3/4 FS 1100 0000

+2.50V + 1/2 FS 1000 0000

+1.25V + 1/4 FS 0100 0000

+0.02V + 1 LSB 0000 0001

0.00V ZERO 0000 0000

Table 1. ADC-228A Unipolar Output Coding

Table 2. Chip Select Truth Table

Figure 2. ADC-228A Timing Diagram

CS2 CS1

Pin 12 Pin 11 Bits 1-8

0 0 Three State Mode

0 1 Three State Mode

1 0 Data Outputted

1 1 Three State Mode

Figure 3. ADC-228A Typical Connections

S A M P L E

N + 2

S A M P L E

N + 1

S A M P L E

O U T P U T

H O L D T I M E

D A T A

N + 1

D A T A

N + 2

C L O C K

D I G I T A L

O U T P U T

D E L A Y

2 4

2 3

B 8 ( L S B )

B 7

9 k

5 1

1 9

I N

+ 1 5 V

* O p t i o n a l +

2 , 4 , 6 , 7

+ 5 V R E F E R E N C E O U T

N O C O N N E C T I O N

8 , 9 , 1 3 , 2 0

2 2 B 6

2 1 B 5

1 7 B 4

1 6 B 3

C S 1 1 2

C L O C K 1 8

A N A L O G

I N P U T

1 5 B 2

1 4

B 1 ( M S B )

4 . 7 µ F

0 . 1 µ F

1 01

 1 5 V

+ 5 V

C S 1 1 1

* U s e o p t i o n a l r e s i s t o r o n l y i f

a m p i s n o t u s e d t o d r i v e i n p u t .

A D C - 2 2 8 A

0 . 1 µ F

4 . 7 µ F

R = V / 1 . 6 6 7 m A

ADC-228A

MECHANICAL DIMENSIONS INCHES (mm)

0.200 MAX.

(5.080)

0.235 MAX.

(5.969)

0.600 ±0.010

(15.240)

0.80 MAX.

(20.32)

0.100 TYP.

(2.540)

0.100

(2.540)

0.018 ±0.002

(0.457)

0.100

(2.540)

0.040

(1.016)

1.31 MAX.

(33.27)

112

1.100

(27.940)

0.190 MAX.

(4.826)

0.010

(0.254)

+0.002

–0.001

SEATING

PLANE

0.025

(

0.635

)

Dimension Tolerances

(unless otherwise indicated):

2 place decimal (.XX) ±0.010 (±0.254)

3 place decimal (.XXX) ±0.005 (±0.127)

Lead Material:

Kovar alloy

Lead Finish:

50 microinches (minimum) gold plating

over 100 microinches (nominal) nickel plating

ORDERING INFORMATION

MODEL TEMPERATURE RANGE SAMPLING RATE

ADC-228AMC 0 to +70°C 20MSPS

ADC-228AMM –55 to +125°C 20MSPS

ADC-228A/883 * –55 to +105°C 15MSPS

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

INNOVATION and EX C ELL E N C

®®

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.

DS-0513 Preliminary 10/03

ISO 9001

REGISTERED

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

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: 6-6354-2025

DATEL's initial qualification was done at 15MSPS and as a Mil-STD-883 Class G product per

customer request. Mil-STD-883 Class G allows for a reduced temperature range (–55°C to

+105°C) that applies to this device. Contact DATEL if a 20MSPS rate or a Mil-STD-883

Class H (–55°C to +125°C) temperature range is desired.