UAA2062 Просмотр технического описания (PDF) - Philips Electronics

Номер в каталоге

Компоненты Описание

Список матч

UAA2062

Analog cordless telephone IC

Philips Electronics 

Philips Semiconductors

Analog cordless telephone IC

Product specification

UAA2062

The synthesizer

The synthesizer has been designed to support most

country channel frequencies between 25 and 50 MHz

(see Chapter “Channel frequencies”).

The local oscillator LO2 and the reference divider provide

the reference frequency for the RX and TX PLL loops.

A single bit programmes the divider value for the reference

divider. A 5 kHz reference frequency (respectively

12.5 kHz) is used with a 10.24 MHz crystal frequency

(respectively 11.15 MHz). The clock divider ratio can be

programmed to 2.5 or to 80. The ratio 80 can be chosen

when the IC is in sleep mode to obtain current saving in the

microcontroller. The clock output is a CMOS output

inverter, supplied by Vref(PLL).

The 14-bit TX counter is programmed for the desired

transmit channel frequency. The 14-bit RX counter is

programmed for the desired RX VCO frequency.

All counters power-up in the proper default state and for a

10.24 MHz reference crystal. Both RX and TX phase

detectors have current drive type outputs of 400 µA.

The RX VCO is connected to an external capacitor and

inductor as illustrated in Fig.5. The varicaps are integrated.

Operating in the 25 US channels, there is a large

frequency difference between the minimum and the

maximum channel frequencies. The sensitivity of the

RX VCO is not large enough to accommodate this large

frequency range. Internal programmable capacitors can

be connected across the RX VCO tank circuit to change

the RX VCO sensitivity. The TX VCO also has internal

programmable capacitors to accommodate a large

frequency range. Chapter “Channel frequencies” shows

the frequency selection for all countries.

andbook, full pagewidth

CLKO 22

CLOCK

DIVIDER

1-BIT PROGRAMMABLE

REFERENCE COUNTER

/2048 or /892

crystal oscillator

14-BIT

PROGRAMMABLE

RX COUNTER

C1

RXPD 47

R2

C2

R3

43

C3

RXLF

RX PHASE

DETECTOR

TX PHASE

DETECTOR

14-BIT

PROGRAMMABLE

TX COUNTER

RX VCO

24 LO2I

23 LO2O

9 LO3I

TX

VCO

3 TXLF

R6

2 TXPD

44 LO1I

45 LO1O

C6

R5 C5

C4

Fig.5 Synthesizer schematic diagram.

FCA123

2000 Aug 10

9

Share Link: