RFSA3714 Datasheet, PDF (14/20 Pages) RF Micro Devices – 50MHz to 6000MHz, Digital Step Attenuator

RFSA3714
Latched Parallel Mode
This configuration allows the user to control the attenuator through the P1 connector using an external harness.
Remove the USB interface it if is currently installed on the evaluation board. Connect a user-supplied harness to the
P1 connector. The parallel bus signal names for P1 are indicated on the evaluation board. Programming jumper S2 is
set to ‘0’ to select parallel mode. All other programming jumpers are not required and can be set to any position. Apply
the supply voltage to P6. Send the appropriate signals onto the parallel bus lines in accordance with the Latched
Parallel Mode Timing Diagram. The attenuator is set to the desired state and measurements can be taken.
Direct Parallel Mode
This configuration allows the user to control the attenuator through the P1 connector using an external harness. When
using this mode the LE signal is held at logic high so that the attenuation will change immediately when there is a
change in logic state for any of the parallel bus signals. Remove the USB interface if it is currently installed on the
evaluation board. Connect a user-supplied harness to the P1 connector. The parallel bus signal names for P1 are
indicated on the evaluation board. Programming jumper S2 is set to ‘0’ to select parallel mode. All other programming
jumpers are not required and can be set to any position. Apply the supply voltage to P6. Send the appropriate signals
onto the parallel bus lines. The attenuator is set to the desired state and measurements can be taken.
Default Power-up State
The default attenuation state is maximum (31.75dB) when supply voltage is applied to the attenuator in both serial and
parallel modes. If a different attenuation state is desired during power up, this can be accomplished by applying signals
according to the Parallel Mode Truth Table. The attenuator will power up to the state applied to the parallel bus during
turn on. The LE signal must be held to logic ‘0’ during power up.
RF Micro Devices Inc. 7628 Thorndike Road, Greensboro, NC 27409-9421
DS141203
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The information in this publication is believed to be accurate. However, no responsibility is assumed by RF Micro Devices, Inc. ("RFMD") for its use, nor for any infringement of patents or other rights of
third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent rights of RFMD. RFMD reserves the right to change component circuitry, recommended
application circuitry and specifications at any time without prior notice.
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