ML13055 查看數據表（PDF） - LANSDALE Semiconductor Inc.

零件编号

产品描述 (功能)

生产厂家

ML13055

Wideband FSK Receiver

LANSDALE Semiconductor Inc. 

ML13055

LANSDALE Semiconductor, Inc.

GENERAL DESCRIPTION

The ML13055 is an extended frequency range FM IF,

quadrature detector, signal strength detector and data

shaper. It is intended primarily for FSK data systems.

The design is very similar to ML3356 except that the

oscillator/mixer has been removed, and the frequency

capability of the IF has been raised about 2:1. The

detector output configuration has been changed to a

balanced, open-collector type to permit symmetrical

drive of the data shaper (comparator). Meter drive and

squelch features have been retained.

The limiting IF is a high frequency type, capable of

being operated up to 100 MHz. It is expected to be used

at 40 MHz in most cases. The quadrature detector is

internally coupled to the IF, and a 2.0 pF quadrature

capacitor is internally provided. The 20 dB quieting sen-

sitivity is approximately 20 µ V, tuned input, and the IF

can accept signals up to 220 mVrms without distortion

or change of detector quiescent DC level.

The IF is unusual in that each of the last 5 stages of the

6 stage limiter contains a signal strength sensitive, cur-

rent sinking device. These are parallel connected and

buffered to produce a signal strength meter drive which

is fairly linear for IF input signals of 20 µ V to 20

mVrms (see Figure 4).

A simple squelch arrangement is provided whereby the

meter current flowing through the meter load resistance

flips a comparator at about 0.8 Vdc above ground. The

signal strength at which this occurs can be adjusted by

changing the meter load resistor. The comparator (+)

input and output are available to permit control of hys-

teresis. Good positive action can be obtained for IF

input signals of above 20 µVrms. A resistor (R) from

Pin 13 to Pin 12 will provide VCC/R of feedback cur-

rent. This current can be correlated to an amount of sig-

nal strength hysteresis by using Figure 4.

The squelch is internally connected to the data shaper.

Squelch causes the data shaper to produce a high

(VCC) output.

The data shaper is a complete “floating” comparator,

with diodes across its inputs. The outputs of the quadra-

ture detector can be fed directly to either or preferably

both inputs of the comparator to produce a squared out-

put swinging from VCC to ground in inverted or nonin-

verted form.

Page 8 of 9

www.lansdale.com

Issue B

Share Link: