STUW81300 datasheet(41/63 Pages) STMICROELECTRONICS

41 / 63 page

DS11314 Rev 7

41/63

STuW81300

Circuit description

ST4 Register

Address:

STuW81300BaseAddress + 0x04

Type:

R/W

Description:

Lock det. control, Ref. Buffer, CP supply mode, VCO settings, Output power control

RW RW

RW RW RW RW RW

RW RW

[26:25] RESERVED: must be set to ‘0’

[24] CALB_3V3_MODE1: calibrator supply mode bit1

0: when VCC_VCO_Core = 4.5 V

1: when VCC_VCO_Core = 3.3 V

This feature is not available on product codes STUW81300-1T and STUW81300-1TR. This bit

must be set to ‘0’ on these.

[23] RF_OUT_3V3: RF output power control bit

0: when VCC_RFOUT = 4.5 V

1: when VCC_RFOUT = 3.3 V

[22:20] RESERVED: must be set to ‘0’

[19] EXT_VCO_EN: external VCO Buffer enable

0: external VCO buffer disabled; integrated VCOs are used

1: external VCO buffer enabled; external VCO required (internal VCOs are powered down)

[18] RESERVED: must be set to ‘0’

[17:15] VCO_AMP: set VCO signal amplitude at the internal oscillator circuit nodes; higher signal level

gives best phase noise performance while lower signal level gives low current consumption.

Different ranges of value are available, based upon the supply voltage provided to pin

VCC_VCO_core (pin #3).

Allowed settings:

000 to 010: (0-2) when VCO core is supplied at 3.3 V

000 to 111: (0-7) when VCO core is supplied at 4.5 V

[14] CALB_3V3_MODE0: calibrator supply mode bit0

0: when VCC_VCO_Core = 4.5 V

1: when VCC_VCO_Core = 3.3 V

This feature is not available on product codes STUW81300-1T and STUW81300-1TR. This bit

must be set to ‘0’ on these.

[13] RESERVED: must be set to ‘0’

STUW81300 Datasheet(PDF) 41 Page - STMicroelectronics