RFFC5071A/2A

WIDEBAND SYNTHESIZER/VCO WITH

INTEGRATED 6 GHz MIXER

Data Sheet Rev. D, August 22, 2019 | Subject to change without notice

10 of 27

www.qorvo.com

®

Multi-Slice Mode

The Multi-Slice mode of operation allows up to four chips to be controlled from a common serial bus. The device address pins

(15 and 16) ADD1 and ADD2 are used to set the address of each part.

On power up, and after a reset, the devices ignore the address pins ADD1 and ADD2 and any data presented to the serial bus will be

programmed into all the devices. However, once the ADDR bit in the SDI_CTRL register is set, each device then adopts an address

according to the state of the address pins on the device.

General Purpose Outputs

The general purpose outputs (GPOs) can be controlled via the GPO register and will depend on the state of MODE since they can be set

in different states corresponding to either mixer path 1 or 2. For example, the GPOs can be used to drive LEDs or to control external

circuitry such as switches or low power LNAs.

Each GPO pin can supply approximately 20 mA load current. The output voltage of the GPO high state will drop with increased current

drive by approximately 25 mV/mA. Similarly, the output voltage of the GPO low state will rise with increased current, again by

approximately 25 mV/mA.

External Modulation

The RFFC5071A and RFFC5072A fractional-N synthesizer can be used to modulate the frequency of the VCO. There are two dedicated

registers, EXT_MOD and FMOD, which can be used to configure the device as a modulator. It is possible to modulate the VCO in

two ways:

1.Binary FSK

The MODSETUP bits in the EXT_MOD register are set to 11. GPO3 is then configured as an input and used to control the signal

frequency. The frequency deviation is set by the MODSTEP and MODULATION bits in the EXT_MOD and FMOD registers respectively.

The modulation frequency is calculated according to the following formula:

2.Continuous Modulation

The MODSETUP bits in the EXT_MOD register are set to 01. The frequency deviation is set by the MODSTEP and MODULATION bits

in the EXT_MOD and FMOD registers respectively. The VCO frequency is then changed by writing a new value into the MODULATION

bits, the VCO frequency is instantly updated. An arbitrary frequency modulation can then be performed dependent only on the rate at

which values are written into the FMOD register.

Slice 2

(0)

Slice 2

(1)

A1

A2

A1

A2

Vdd

Slice 2

(2)

A2

A1

Vdd

Slice 2

(3)

A2

A1

Vdd

Vdd

ENX

SDATA

SCLK