Product Specification

SP4304

Page 3 of 10

Evaluation Kit

The Digital Attenuator Evaluation Kit board was

designed to ease customer evaluation of the

SP4304 Digital Step Attenuator.

J9 is used in conjunction with the supplied DC cable

negative voltage generator is desired, then do not

J1 should be connected to the parallel port of a PC

with the supplied ribbon cable. The evaluation

software is written to operate the DSA in serial

mode, so Switch 7 (P/S) 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.

To evaluate the Power up options, first disconnect

the parallel ribbon cable from the evaluation board.

The parallel cable must be removed to prevent the

PC parallel port from biasing the control pins to

unknown states. During power up in serial mode (P/

S=1 and LE=0) or in parallel mode with P/S=0 and

LE=1, the default power-up signal attenuation is set

to the value present on the six control bits on the six

parallel data inputs (C0.5 to C16). This allows any

one of the 64 attenuation settings to be specified as

the power-up state.

To power up in Parallel mode (P/S=0) with LE=0, the

control bits are automatically set to one of four

possible values. These four values are selected by

the two power-up control bits, PUP1 and PUP2, as

shown in the Parallel PUP Truth Table (Table 6).

Figure 4. Evaluation Board Layout

Figure 5. Evaluation Board Schematic

Note: Resistors on pins 1 and 3

are required to avoid package

resonance and meet error

specifications over frequency.

Tel: +86-23-62808818

Fax: +86-23-62805284

www.sipatsaw.com / sawmkt@sipat.com