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RFFC5061/62

DS110614

7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical

support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.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

A0 and A1 are used to set the address of each part.

On power up, and after a reset, the devices ignore the address pins (A1 and A2, pins 15 and 16) and any data presented to the

serial bus will be programmed into all the devices. However, once the sipin 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 20mA load current. The output voltage of the GPO high state will drop with increased

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

again by approximately 25mV/mA.

External Modulation

The RFFC5061 and RFFC5062 fractional-N synthesizer can be used to modulate the frequency of the VCO. There are two ded-

icated 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 respec-

tively.

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 MOD-

ULATION bits, the VCO frequency is instantly updated. An arbitrary frequency modulation can then be performed dependant

only on the rate at which values are written into the FMOD register.

Slice2

(0)

Slice2

(1)

Slice2

(2)

Slice2

(3)

A1 A2

ENX

SDATA

SCLK

Vdd

Vdd

Vdd

Vdd

A1 A2

A1 A2

A1 A2

2

PD

MODULATION

 2

16





=