TL852 Datasheet, PDF (4/7 Pages) Texas Instruments – Overall Gain Adjustable With One External Resistor

TL852
SONAR RANGING RECEIVER
SLSS003 – SEPTEMBER 1983 – REVISED MARCH 1988
APPLICATION INFORMATION
detect level versus gain step
Detect level is measured by applying a 15-cycle burst of 49.4 kHz square wave just after the beginning of the
gain step to be tested. The least burst amplitude that makes REC reach the trip level is defined to be the detect
level. System gain is then inversely proportional to detect level. See the test circuit in Figure 1.
VCC
68 kΩ
TL331
15-Cycle
49.4-kHz
Variable-Amplitude
Burst Generator
490 kΩ
L1
1 mH
0.01 µF
0.01 µF
21 mH
R1
5 kΩ
0.0022 µF
500 pF
5 kΩ
8
BIAS
7 _G2IN
6
G1OUT
5
VCC
4
LC
3
GADJ
2 _XIN
1 _G1IN
REC ⁹
NC ¹⁰
11
NC
12
GCC
13
GCB
14
GCA
15
GCD
16
GND
1000 pF
Trip
Level
Detect
All Resistors ±1%, 1/4 W
All Capacitors ±1%, Film
L1 Q > 60 at 50 kHz
C1 Q > 500 at 50 kHz
Input
Signal
15 Pulses
Rec
Output
Trip Level
Comparator
Output
Figure 1. Detect-Level Measurement Circuit and Waveforms
4
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