TDA8735T 查看數據表（PDF） - Philips Electronics

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TDA8735T

PLL frequency synthesizer

Philips Electronics 

Philips Semiconductors

PLL frequency synthesizer

Product specification

TDA8735

PINNING

SYMBOL

XTAL1

XTAL2

VCC1

VEE

n.c.

DEC

VCOFI

BS

n.c.

SDA

SCL

AS

n.c.

LOOPI

LOOPO

VCC2

PIN

DESCRIPTION

1 reference oscillator output

2 reference oscillator input

3 supply voltage 1

4 ground

5 not connected

6 prescaler decoupling

7 VCO input frequency

8 band switch output

9 not connected

10 serial data input (I2C-bus)

11 serial clock input (I2C-bus)

12 address select input (I2C-bus)

13 not connected

14 tuning voltage amplifier input

15 external loop filter output

16 supply voltage 2

handbook, halfpage

XTAL1 1

XTAL2 2

VCC1 3

VEE 4

n.c. 5

16 VCC2

15 LOOPO

14 LOOPI

13 n.c.

TDA8735

12 AS

DEC 6

11 SCL

VCOFI 7

10 SDA

BS 8

9 n.c.

MGH650

Fig.2 Pin configuration.

FUNCTIONAL DESCRIPTION

The TDA8735 contains the following parts and facilities:

• Input amplifier VCO signal

• A prescaler with the divisors 3 : 4 and a 2-bit

programmable swallow counter

• A 13-bit programmable counter

• A digital memory phase detector

• A reference frequency channel comprised of a 4 MHz

crystal oscillator followed by a reference counter; the

reference frequency can be 1, 10 or 25 kHz and is

applied to the digital memory phase detector

• An I2C-bus interface with data latches and control logic;

the I2C-bus is intended for communication between

microcontrollers and different ICs or modules. Detailed

information on the I2C-bus specification is available on

request.

• A software-controlled switch output

• A programmable current amplifier (charge pump) which

consists of a 5 and a 500 µA current source, this allows

adjustment of loop gain, thus providing high-current

high-speed tuning and low current-stable tuning.

The output at the loop amplifier can deliver a tuning

voltage of up to 10.5 V (VCC2 − 1.5 V).

Controls

The TDA8735 is controlled via the 2-wire I2C-bus. As slave

receiver for programming there is one module address, a

logic 0 (R/W bit), a subaddress byte and four data bytes.

The subaddress determines which one of the four data

bytes is transmitted first. The module address contains a

programmable address bit (D1) which with address select

input AS (pin 12) makes it possible to operate two

TDA8735 in one system.

The auto increment facility of the I2C-bus allows

programming of the TDA8735 within one transmission

(address + subaddress + 4 data bytes).

The TDA8735 can also be partially programmed.

Transmission must then be ended by a stop condition.

The bit organization of the 4 data bytes is illustrated in

Fig.3 and is described below.

The divider number is defined by 15-bit words, bits

S0 to S14. To calculate the lock frequency, the divider

number has to be multiplied by the selected reference

frequency.

1998 Oct 23

4

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