lt1055s8-pbf Linear Technology Corporation, lt1055s8-pbf Datasheet - Page 11

• Manufacturer Part Number: lt1055s8-pbf
• Description: Lt1056 - Precision, High Speed, Jfet Input Operational Amplifiers
• Manufacturer: Linear Technology Corporation

APPLICATIONS
Phase Reversal Protection
Most industry standard JFET input op amps (e.g., LF155/
LF156, LF351, LF411, OP15/16) exhibit phase reversal at
the output when the negitive common mode limit at the
input is exceeded (i.e., from –12V to –15V with ±15V
supplies). This can cause lock-up in servo systems. As
shown below, the LT1055/LT1056 does not have this
problem due to unique phase reversal protection circuitry
(Q1 on simplified schematic).
TYPICAL APPLICATIONS
SCALE FACTOR
1V IN OCTAVE OUT
*1% METAL FILM RESISTOR
PIN NUMBERED TRANSISTORS = CA3096 ARRAY
15V
0.5ms/DIV
Input
EXPONENT
U
2500Ω*
ZERO TRIM
562Ω*
TRIM
3.57k*
INFORMATION
0V TO 10V
U
INPUT
Exponential Voltage-to-Frequency Converter for Music Synthesizers
11.3k*
LT1055/56 AI06
U
10k*
1k*
W
4.7k
500k
†
2
6
1
5
4
3
(LF155/LF56, LF441, OP-15/OP-16)
1.1k
U
10k*
2
3
2
3
TEMPERATURE CONTROL LOOP
–15V
+
–
+
–
POLYSTYRENE
LM301A
LT1055
4
–15V
1
15V
15V
0.01µF
7
7
500pF
0.5ms/DIV
Output
8
6
6
1N148
3k
Voltage Follower with Input Exceeding the Negative
LM329
2N3906
2N3904
LT1055/56 AI07
500Ω*
15 2.2k
13
SINE WAVE
14
INPUT
±15V
1k*
4.7k
8
Common Mode Range
SAWTOOTH
OUTPUT
15V
LT1055/56 TA03
9
7
2
3
33Ω
–
+
LT1055/56
–15V
15V
7
4
LT1055/LT1056
†
LT1055 and LT1056, please see the LTC1043
data sheet and Application Note 3.
For ten additional applications utilizing the
6
LT1055/LT1056
2k
LT1055/56 AI05
0.5ms/DIV
Output
OUTPUT
11
LT1055/56 AI08
10556fc