LM358, LM258, LM2904, LM2904V
Single Supply
Split Supplies
3.0 V to V
CC(max)
V
V
CC
CC
EE
1.5 V to V
CC(max)
1
2
1
2
1.5 V to V
EE(max)
V
V
/Gnd
EE
Representative Schematic Diagram
(One–Half of Circuit Shown)
Bias Circuitry
Common to Both
Amplifiers
Output
V
CC
Q15
Q22
Q16
Q14
Q13
40 k
Q19
5.0 pF
Q12
Q24
Q23
25
Q20
Q21
Q18
Inputs
Q11
Q9
Q17
Q25
Q6
Q7
Q2
Q5
Q1
2.4 k
Q8
Q10
Q3
Q4
Q26
2.0 k
V
/Gnd
EE
CIRCUIT DESCRIPTION
The LM258 series is made using two internally
compensated, two–stage operational amplifiers. The first
stage of each consists of differential input devices Q20 and
Q18 with input buffer transistors Q21 and Q17 and the
differential to single ended converter Q3 and Q4. The first
stage performs not only the first stage gain function but also
performs the level shifting and transconductance reduction
functions. By reducing the transconductance, a smaller
compensation capacitor (only 5.0 pF) can be employed, thus
saving chip area. The transconductance reduction is
accomplished by splitting the collectors of Q20 and Q18.
Another feature of this input stage is that the input common
mode range can include the negative supply or ground, in
single supply operation, without saturating either the input
devices or the differential to single–ended converter. The
second stage consists of a standard current source load
amplifier stage.
Large Signal Voltage
Follower Response
V
R
= 15 Vdc
CC
L
= 2.0 kΩ
T
= 25°C
A
5.0 µs/DIV
Each amplifier is biased from an internal–voltage regulator
which has a low temperature coefficient thus giving each
amplifier good temperature characteristics as well as
excellent power supply rejection.
3
MOTOROLA ANALOG IC DEVICE DATA
MOTOROLA [ MOTOROLA ]
