REV. 0

AD8369

–19–

Table III. AD8369 Evaluation Board Configuration Options

Component

Function

Default Condition

VPOS, GND

Supply and Ground Vector Pins

Not Applicable

SW1

Data Enable: Set to Position A when in serial mode of operation, set to Position B

Not Applicable

when in parallel mode of operation.

SW2

Device Enable: When in the PWDN position, the PWUP pin will be connected to

Not Applicable

ground and the AD8369 will be disabled. The device is enabled when the switch is

in the PWUP position, connecting the PWUP pin to VPOS.

SW3, R5

Serial/Parallel Selection. The device will respond to serial control inputs from

Not Applicable

connector P1 when the switch is in the SER position. Parallel operation is achieved

R5 = Open (Size 0603)

when in the PAR position. Device can be hardwired for parallel mode of operation by

placing the 0

W resistor in position R5.

SW4

Parallel Interface Control. Used to hardwire BIT0 through BIT3 to the desired gain

Not Applicable

code when in parallel mode of operation. The switch functions as a hexadecimal

to binary encoder (Gain Code 0 = 0000, Gain Code 15 = 1111).

J1, J2, J6, J7

Input and Output Signal Connectors. These SMA connectors provide a convenient

Not Applicable

way to interface the evaluation board with 50

W test equipment.

C1, C2, C3, C4

AC-Coupling Capacitors. Provides ac-coupling of the input and output signals.

C1, C2, C3, C4

= 1 nF (Size 0603)

T1, T2

Impedance Transformers. Used to transform the 200

W input and output

T1, T2 = TC4-1W

impedance to 50

W.

(MiniCircuits)

R1, R2, R11, R12

Single-Ended or Differential. R2 and R11 are used to ground the center tap of

R1, R2, R11, R12

the secondary windings on transformers T1 and T2. R1 and R12 should be used

= 0

W (Size 0603)

to ground J2 and J7 when used in single-ended applications. R1 and R12 should be

removed for differential operation.

R6, R7, R8, R9, R10 Control Interface Resistors. Simple series resistors for each control interface signal.

R6, R7, R8, R9,

R10 = 0

W (Size 0603)

C5, C6, C8

Power Supply Decoupling. Nominal supply decoupling consists of a 0.1

mF capacitor

C5 = 0.1

mF (Size 0603)

to ground followed by a 1 nF capacitor to ground positioned as close to the device

C6 = C8 = 1 nF

as possible. C8 provides additional decoupling of the input common-mode voltage.

(Size 0603)

C7

High-Pass Filter Capacitor. Used to set high-pass corner frequency of output.

C7 = 0.1

mF (Size 0603)

C9

Clock Filter Capacitor. May be required with some printer ports to minimize overshoot.

C9 = Open (Size 0603)

The clock waveform may be smoothed using a simple filter network established by

R7 and C9. Some experimentation may be necessary to determine optimum values.