RF Micro Devices Inc.

7628 Thorndike Road, Greensboro, NC 27409-9421

DS150205

For sales or technical support, contact RFMD at +1.336.678.5570 or customerservice@rfmd.com.

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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RFSA3715

Evaluation Board Programming Using External Bus

Serial Addressable Mode

This configuration allows the user to control the attenuator through the P5 connector using an external harness.

Remove the USB interface board if it is currently installed on the evaluation board. Connect a user-supplied harness to

the P5 connector. Note that the top row of P5 contains the serial bus signals and the bottom row is ground.

Programming jumper S1 is set to ‘0’ and S2 is set to ‘1’. External address jumpers S3 through S5 can be set to any

value desired by the user. Jumper S6 is installed and allows the LE signal to be routed from the P5 connector to the

attenuator. Apply the supply voltage to P6. Send the appropriate signals onto the serial bus lines in accordance with

the Serial Addressable Mode Timing Diagram. The attenuator is set to the desired state and measurements can be

taken.

Latched Parallel Mode

This configuration allows the user to control the attenuator through the P1 connector using an external harness.

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 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. Pro

gramming 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

This 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.