LT1632 LINER [Linear Technology], LT1632 Datasheet - Page 12

• Manufacturer Part Number: LT1632
• Description: 45MHz, 45V/us, Dual/Quad Rail-to-Rail Input and Output Precision Op Amps
• Manufacturer: LINER [Linear Technology]

APPLICATIONS
LT1632/LT1633
amplifiers operate over a very wide supply range, it is
possible to exceed the maximum junction temperature of
150 C in plastic packages under certain conditions. Junc-
tion temperature T
perature T
The power dissipation in the IC is the function of the supply
voltage, output voltage and load resistance. For a given
supply voltage, the worst-case power dissipation P
occurs at the maximum supply current and when the
output voltage is at half of either supply voltage (or the
maximum swing if less than 1/2 supply voltage). There-
fore P
To ensure that the LT1632/LT1633 are used properly,
calculate the worst-case power dissipation, use the ther-
mal resistance for a chosen package and its maximum
junction temperature to derive the maximum ambient
temperature.
Example: An LT1632CS8 operating on 15V supplies and
driving a 500 , the worst-case power dissipation per
amplifier is given by:
12
LT1632CN8: T
LT1632CS8: T
LT1633CS: T
P
DMAX
DMAX
+ IN
– IN
= (V
A
is given by:
and power dissipation P
225
225
R6
R7
S
J
• I
J
J
= T
SMAX
= T
J
= T
U
D6
D5
is calculated from the ambient tem-
A
A
A
+ (P
) + (V
+ (P
+ (P
D8
D7
INFORMATION
U
D
V
V
+
–
D
D
• 150 C/W)
S
• 190 C/W)
• 130 C/W)
/2)
Q4
Q7
D1
D2
2
/R
Q3
W
L
D
Figure 1. LT1632 Simplified Schematic Diagram
as follows:
Q5
Q6
U
V
BIAS
Q1
DMAX
D3
D4
+
Q2
I
1
If both amplifiers are loaded simultaneously, then the total
power dissipation is 0.562W. The SO-8 package has a
junction-to-ambient thermal resistance of 190 C/W in still
air. Therefore, the maximum ambient temperature that the
part is allowed to operate is:
For a higher operating temperature, lower the supply
voltage or use the DIP package part.
Input Offset Voltage
The offset voltage changes depending upon which input
stage is active, and the maximum offset voltages are
trimmed to less than 1350 V. To maintain the precision
characteristics of the amplifier, the change of V
entire input common mode range (CMRR) is guaranteed
to be less than 1500 V on a single 5V supply.
Input Bias Current
The input bias current polarity depends on the input
common mode voltage. When the PNP differential pair is
active, the input bias currents flow out of the input pins.
P
T
T
Q11
A
A
DMAX
= T
= 150 C – (0.562W • 190 C/W) = 43 C
Q9
R1
R3
Q12
J
= (30V • 5.6mA) + (15V – 7.5V)(7.5/500)
= 0.168 + 0.113 = 0.281W
– (P
Q8
R4
R2
DMAX
V
Q13
–
+
R5
I
• 190 C/W)
2
OUTPUT BIAS
C
BUFFER
C
AND
C2
C1
Q15
Q14
1632/33 F01
OUT
OS
over the