SL2009 Ver la hoja de datos (PDF) - Zarlink Semiconductor Inc

Número de pieza

componentes Descripción

Fabricante

SL2009

Dual stage IF amplifier for cable tuners

Zarlink Semiconductor Inc 

SL2009

SAWF driver stage

Input operating range

Input NF, referred to 2kΩ

OPIP3

Gain

IF Amplifier stage

Input operating range

Input NF, referred to 2 kΩ

OPIP3

Gain

Characteristics

Table 1 - Quick reference data

30 - 50

4

4

14 - 28

30 - 50

6

8

20 - 40

Units

MHz

dB

dBV

dB

MHz

dB

dBV

dB

Functional Description

The SL2009 is an IF amplifier intended primarily for

application in cable tuners, and requiring a minimum

external component count to integrate the IF gain,

AGC facility and level detect.

The pin allocation is contained in figure (1) and the

block diagram in figure (2)

SAWF driver stage

In normal application the IF output of the tuner,

which is typically in the region of 30-50 MHz, is

interfaced to input preamplifier of the SAWF driver

stage, which is optimised for both signal handling

and NF referred to 2 kΩ.

The input preamplifier interfaces with the variable

gain stage, which is under control of the first AGC

sender and provides for 14 dB of gain control. The

typical gain characteristic is contained in figure (3).

The AGC stage then interfaces with the output buffer

amplifier, which presents a balanced 50 Ω drive to

the IF SAW filter and offers high signal handling to

minimise intermodulation distortions.

The SAWF amplifier also incorporates a level detect

block whose output AGCOUT, can be used to control

the gain of the SAWF amplifier or other gain stages

in front of the SL2009. This AGC characteristic can

be set up by a "current set" resistor connected

between the AGCBIAS input and Vee. The typical

characteristic curve for AGC set, output level under

different AGCBIAS conditions is contained in figure

(4).

See figures (5) and (6) for SAW amplifier input and

output impedances respectively.

IF amplifier section

In normal application the output of the SAW filter is

coupled differentially to the input preamplifier of the

IF amplifier, which presents a differential 2 kΩ 3 pF

load to the SAW filter and is optimised for both signal

handling and NF. See figure (8) for IF amplifier input

impedance.

The input preamplifier, then interfaces with the

variable gain stage which is under control of the

second AGC sender and this provides for 20 dB of

gain control. The typical AGC characteristic is

contained in figure (7)

The AGC output is then connected to the output

driver stage, which presents a low differential output

impedance, see figure (9) and is optimised for output

signal handling.

The typical key performance data at 5V Vcc and 25

deg C ambient are shown in the table entitled

'QUICK REFERENCE DATA'.

2

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