SP4308 Datasheet, PDF (3/10 Pages) SIPAT Co,Ltd – 75 Ω RF Digital Attenuator

SP4308
Product Specification
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
supply V_DD, GND, and –V_DD. If use of the internal
negative voltage generator is desired, then connect
–V_DD (black banana plug) to ground. If an external –V_DD
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.
Figure 4. Evaluation Board Layout
Figure 5. Evaluation Board Schematic
Peregrine Specification 102/0142
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.
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