SL161 ZARLINK [Zarlink Semiconductor Inc], SL161 Datasheet - Page 6

• Manufacturer Part Number: SL161
• Description: WIDEBAND LOG IF STRIP AMPLIFIER
• Manufacturer: ZARLINK [Zarlink Semiconductor Inc]

OPERATING NOTES
shown in Fig. 8.
virtually full output on noise.
the chain. As there is a large mismatch between stages a
simple parallel or series circuit cannot be used. This choice of
network is also controlled by the need to avoid distorting the
logarithmic law: the network must give unity voltage transfer at
resonance. A suitable network is shown in Fig. 9. The value of
C3 must be chosen so that at resonance its admittance equals
the total loss conductance across the tuned circuit. Resistor
R12 may be introduced to improve the symmetry of filter
response, providing other values are adjusted for unity gain at
resonance.
output line if many stages and fast rise times are required.
SL1615
The amplifiers are intended for use directly coupled, as
The seventh stage in an untuned cascade will be giving
Noise may be reduced by inserting a single tuned circuit in
A single capacitor may not be suitable for decoupling the
Fig.9 Circuit diagram of low strip
Fig.8 Direct coupled amplifiers
Values of supply line decoupling capacitor required for
untuned cascades are given below. Smaller values can be
used in high frequency tuned cascades.
avoid the introduction of common ground lead inductance
between input and output circuits. the equipment designer
should take care to aviod the subsequent introduction of such
inductance.
resistance of, typically 10 . It is a junction type having a low
breakdown voltage and consequently the positive supply
current will increase rapidly if the supply voltage exceeds
7.5V. (See Absolute Maximum Ratings).
Minimum capacitance
The amplifiers have been provided with two ground leads to
The on-chip 500pF supply decoupling capacitor has a
Centre frequency
Dynamic Range
Video rise time
Bandwidth
Output voltage
Typical log accuracy
6 or more
30nF
Number of stages
-75dBm to +15dBm
approx. 20MHz
10nF
5
0 - 1.5V
70nSec
60MHz
3nF lnF
4
2dB
3