PMB2347 データシートの表示（PDF） - Infineon Technologies

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PMB2347

RF/IF Double PLL Frequency Synthesizer

Infineon Technologies 

PMB 2347

preliminary

Functional Description

3.4 Circuit Description

1. General Description

The PMB 2347 consists of two fully programmable PLLs, one for the RF and

one for the IF frequency range. Each PLL contains a high frequency dual mod-

ulus prescaler, an A- and a N-counter with dual modulus control logic, a refer-

ence- (R-) counter, and a phase detector with charge pump output. The two

synthesizers are controlled via the common serial 3-wire interface.

The reference frequency is applied at the common RI-input and divided by the

R-counter of each PLL. Its maximum value is 45 MHz. The RF and IF input fre-

quencies will be divided by the corresponding prescalers with a programmable

32/32 or 64/65 (RF) and 8/9 or 16/17 (IF) divide ratio and the following program-

mable A/N-counters. The maximum RF frequency value is 2.8 GHz and 500

MHz for the IF frequency.

The phase and frequency detectors with the charge pumps have a linear oper-

ating range without a dead zone for very small phase deviations.

The multifunctional output port LD/fo can be programmed as lock detector and

test output.

2. Programming

Programming of the IC is done via the serial data interface. The content of the

bus telegram (serial data format) is assigned to the functional units according

to the address.

The most significant bit (MSB) of the serial data formats is shifted first.

The short control data format allows a fast PD-current change.

The long control data format allows the programming of asynchronous or syn-

chronous data acquisition of PLL1 (RF), 4 different PD-output current modes for

the PLL1 and 1 PD-output current modes for PLL2, polarity setting of the PD-

output signals, 2 standby modes, charge pump pulse width and the prescaler

divide ratio.

The A/N-counter data format of PLL1 contains the A/N-counter value.. The data

format of PLL2 comprise the counter values as well.

The R-counter data format contains the R-counter values.

The PLL1 (RF) of PMB 2347 offers the possibility of synchronous counter and

charge pump current programming to avoid phase errors at the phase detector

when R- and A-/N-counter are programmed one after another or the charge

pump current is altered.

Asynchronous Mode:

The serial data is written directly to the data registers of the addressed counter

with the Enable pulse. As each counter is loading the new starting value after it

is decremented to „zero“, the counters changes therefore their counter values

asynchronously to the others.

Wireless Components

3-7

Specification, August 1999

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