Product Specification

SP4308

Page 3 of 10

Evaluation Kit

The Digital Attenuator Evaluation Kit was designed to

ease customer evaluation of the SP4308 DSA.

J9 is used in conjunction with the supplied DC cable to

negative voltage generator is desired, then connect

is desired, then apply -3 V.

J1 should be connected to the LPT1 port of a PC with

the supplied control cable. The evaluation software is

written to operate the DSA in serial mode, so switch 7

(P/S) on the DIP switch SW1 should be ON with all

other switches off. Using the software, enable or

disable

each

attenuation

setting

to

the

desired

combined attenuation.

The software automatically

programs the DSA each time an attenuation state is

enabled or disabled. Note: Jumper J6 supplies power

to the evaluation board support circuits.

To evaluate the power up options, first disconnect the

control cable from the evaluation board. The control

cable must be removed to prevent the PC port from

biasing the control pins.

During power up with P/S=1 high and LE=1, the default

power-up signal attenuation is set to the value present

on the five control bits on the five parallel data inputs

(C1 to C16). This allows any one of the 32 attenuation

settings to be specified as the power-up state.

During power up with P/S=0 high and LE=0, the control

bits are automatically set to one of four possible values

presented through the PUP interface.

These four

values are selected by the two power-up control bits,

PUP1 and PUP2, as shown in the Table 6.

Pin 20 is open and can be connected to any bias.

Note: Resistors on pins 1 and 3 are

required and should be placed as close

to the part as possible to avoid package

resonance and meet error specifications

over frequency.

Figure 4. Evaluation Board Layout

Figure 5. Evaluation Board Schematic

Peregrine Specification 102/0142

Tel: +86-23-62808818

Fax: +86-23-62805284

www.sipatsaw.com / sawmkt@sipat.com