ML13055 Datasheet(数据表) 8 Page - LANSDALE Semiconductor Inc.
LANSDALE [LANSDALE Semiconductor Inc.]
ML13055 Datasheet(HTML) 8 Page - LANSDALE Semiconductor Inc.
LANSDALE Semiconductor, Inc.
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
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-
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