AD7868

–14–

REV. B

LK4, DAC Reference Selection

The DAC reference may be connected to either the ADC refer-

ence output (RO ADC) or to the DAC reference (RO DAC).

LK5, ADC Internal Clock Selection

This link configures the ADC for continuous or noncontinuous

internal clock operation.

LK6, DAC Updating

The DAC, LDAC input may asserted independently of the

ADC CONVST signal or it may be tied to CONVST or it may

tied to GND.

LK7, ADC Clock Source

This link provides the option for the ADC to use its own inter-

nal clock oscillator or an external TTL compatible clock.

LK8 Frame Synchronous Option

LK8 provides the option of tying the ADC RFS output to the

DAC TFS input.

LK9 Transmit/Receive Clock Option

LK9 provides the option to connect the ADC RCLK to the

DAC TCLK.

COMPONENT LIST

IC1

AD7868

IC2, IC3

2X AD711

IC4,

ADG201HS

IC5,

MC78L05

IC6,

MC79L05

IC7,

74HC4050

IC8,

74HC221

C1, C3, C5, C7

C9, C11, C13, C15

10

µF Capacitor

C17, C19, C23

C2, C4, C6, C8

C10, C12, C14, C16

0.1

µF Capacitor

C18, C20, C24

C21

330 pF Capacitor

C22

68 pF Capacitor

R1, R2, R4

2 k

Ω Resistor

R3, R5

4.7 k

Ω Resistor

R6

15 k

Ω Resistor

R7

200

Ω Resistor

LK1, LK2, LK3,

LK4, LK5, LK6,

LK7, LK8

Shorting Plugs

LK9

SKT1, SKT2, SKT3,

SKT4, SKT5

BNC Sockets

SKT6

9-Contact D-Type Connector

Figure 21. Silkscreen for the Circuit Diagram of Figure 19