Electronic Components Datasheet Search |
|
RFFC5061SB Datasheet(PDF) 6 Page - RF Micro Devices |
|
RFFC5061SB Datasheet(HTML) 6 Page - RF Micro Devices |
6 / 25 page 6 of 25 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. The synthesizer step size is typically 1.5Hz when using a 26MHz reference frequency. The exact step size for any reference and LO frequency can be calculated using the following formula: (FREF * P) / (R * 224 * LO_DIV) Where FREF is the reference frequency, R is the reference division ratio, P is the prescalar division ratio, and LO_DIV is the LO divider value. Pin 26 (GPO4) can be configured as a lock detect pin. The lock status is also available in the read-back register. The lock detect function is a window detector on the VCO tuning voltage. The lock flag will be high to show PLL lock which corresponds to the VCO tuning voltage being within the specified range, typically 0.30V to 1.25V. Phase Detector and Charge Pump The phase detector provides a current output to drive an active loop filter. The charge pump output current is set by the value contained in the P1_CP_DEF and P2_CP_DEF fields in the loop filter configuration register. The charge pump current is given by approximately 3uA/bit, and the fields are 6 bits long. This gives default value (31) of 93uA and maximum value (63) of 189uA. If the automatic loop bandwidth calibration is enabled the charge pump current is set by the calibration algorithm based upon the VCO gain. The phase detector will operate with a maximum input frequency of 26MHz. Loop Filter The active loop filter is implemented using the on-chip low noise op-amp with external resistors and capacitors. The internal configuration of the chip is shown below with the recommended active loop filter. The op-amp gives a tuning voltage range of typically +0.1V to +2.4V. The recommended loop filter shown is designed to give the lowest integrated phase noise for refer- ence frequency of 26MHz. The external loop filter gives the flexibility to optimize the loop response for any particular applica- tion and combination of reference and VCO frequencies. Crystal Oscillator The RFFC5061 and RFFC5062 have been designed to use a standard, low cost, external crystal of typically 26MHz. The crystal oscillator circuit contains internal loading capacitors. No external loading capacitors are required, assuming crystal load speci- fication of between 8pF and 10pF. The internal loading capacitors are a combination of fixed capacitance, and an array of switched capacitors. The switched capacitors can be used to tune the crystal oscillator onto the required center frequency and minimize frequency error. The capacitance steps are approximately 0.25pF (fine) and 0.55pF (coarse) and the total differential capacitance range is from LFILT1 8p2 180p 22K 470R 470R 330p 330p LFILT2 LFILT3 +1.1V |
Similar Part No. - RFFC5061SB |
|
Similar Description - RFFC5061SB |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |