Data Sheet

AD7951

Rev. A | Page 19 of 32

TYPICAL CONNECTION DIAGRAM

Figure 27 shows a typical connection diagram for the AD7951 using the internal reference, serial data and serial configuration interfaces.

Different circuitry from that shown in Figure 27 is optional and is discussed in the following sections.

RD

CS

100nF

100nF

AVDD

10µF

100nF

AGND

DGND

DVDD

OVDD

OGND

CNVST

BUSY

SDOUT

SDCLK

RESET

PD

REFBUFIN

D

CLOCK

AD7951

MICROCONVERTER/

MICROPROCESSOR/

DSP

DIGITAL

INTERFACE

SUPPLY

(2.5V, 3.3V, OR 5V)

ANALOG

SUPPLY (5V)

OVDD

DIGITAL

SUPPLY (5V)

IN+

IN–

NOTE 5

ANALOG

INPUT+

2.7nF

U1

NOTE 1

SER/PAR

OB/2C

REFGND

REF

PDBUF

PDREF

100nF

NOTE 3

NOTE 4

NOTE 3

NOTE 7

10µF

10µF

22µF

NOTES

1. SEE ANALOG INPUT SECTION. ANALOG INPUT(–) IS REFERENCED TO AGND ±0.1V.

2. THE AD8021 IS RECOMMENDED. SEE DRIVER AMPLIFIER CHOICE SECTION.

3. THE CONFIGURATION SHOWN IS USING THE INTERNAL REFERENCE. SEE VOLTAGE REFERENCE INPUT SECTION.

4. A 22µF CERAMIC CAPACITOR (X5R, 1206 SIZE) IS RECOMMENDED (FOR EXAMPLE, PANASONIC ECJ4YB1A226M).

SEE VOLTAGE REFERENCE INPUT SECTION.

5. OPTION, SEE POWER SUPPLY SECTION.

6. THE VCC AND VEE SUPPLIES SHOULD BE VCC = [VIN(MAX) +2V] AND VEE = [VIN(MIN) –2V] FOR BIPOLAR INPUT RANGES.

FOR UNIPOLAR INPUT RANGES, VEE CAN BE 0V. SEE POWER SUPPLY SECTION.

7. OPTIONAL LOW JITTER CNVST, SEE CONVERSION CONTROL SECTION.

ANALOG

INPUT–

NOTE 2

VCC

VEE

10µF

100nF

+7V TO +15.75V

SUPPLY

10µF

100nF

–7V TO –15.75V

SUPPLY

NOTE 6

HW/SW

SCCS

SCCLK

SCIN

BIPOLAR

TEN

SERIAL

PORT 1

SERIAL

PORT 2

WARP

IMPULSE

50Ω

15Ω

10Ω

Figure 27. Typical Connection Diagram Shown with Serial Interface and Serial Programmable Port