LM1117IMPX-3.3 National Semiconductor, LM1117IMPX-3.3 Datasheet - Page 5

• Manufacturer Part Number: LM1117IMPX-3.3
• Description: IC,VOLT REGULATOR,FIXED,+3.3V,BIPOLAR,SOT-223,3PIN,PLASTIC
• Manufacturer: National Semiconductor

Specifications of LM1117IMPX-3.3

• Rohs Compliant: NO

Random Variable Theory vs. Worst Case Over PVT
Substituting into equations 7 and 8:
∆V
∆V
∆V
±
±
±
±
±
±
±
±
±
±
±
±
ref
ref
ref
0.5
1.0
2.0
5.0
0.5
1.0
2.0
5.0
0.5
1.0
2.0
5.0
[%]
[%]
[%]
E(V
Partial Derivatives of Equation 1
out
) ) V
∆V
∆V
∆V
TABLE 2. Equivalent Six Sigma Output Tolerance for V
0.5%
0.5%
0.5%
0.54
1.02
2.01
5.00
0.66
1.09
2.05
5.02
0.81
1.18
2.10
5.04
out
out
out
out
+ V[R
[%]
[%]
[%]
V
V
V
out
out
out
Resistor Tolerance
Resistor Tolerance
Resistor Tolerance
= 1.8 V
= 3.3 V
1
= 12 V
] x R
∆V
∆V
∆V
2
0.65
1.08
2.04
5.02
1.00
1.32
2.18
5.07
1.36
1.61
2.37
5.16
out
out
out
1%
1%
1%
/ R
[%]
[%]
[%]
1
3
x V
ref
∆V
∆V
∆V
2.12
2.29
2.87
5.41
4.37
4.45
4.78
6.62
6.34
6.40
6.63
8.06
out
out
out
5%
5%
5%
(V
(10)
(9)
[%]
[%]
[%]
ref
= 1.275 V)
5
∆V
∆V
∆V
Using equation 10, the six-sigma based error for common
V
this method are far more practical than those obtained with
the worst case method and a six sigma paradigm is still
assured for the resulting output voltage.
Values for E(V
from the calculated value of V
case for this error occurs at high output voltages. For ex-
ample, with V
= 1.275 V the expected value of the output voltage will only
be 40 µV higher than predicted with equation 1. This is an
error of only 0.000254%. As such, this error predicted by
equation 9 is ignored.
±
±
±
±
±
±
±
±
±
±
±
±
out
ref
ref
ref
0.5
1.0
2.0
5.0
0.5
1.0
2.0
5.0
0.5
1.0
2.0
5.0
’s is tabulated in Table 2. Notice that the results using
[%]
[%]
[%]
out
out
out
[%] for Common V
∆V
∆V
∆V
= 15 V, R1 = 10 kΩ, R2 = 107 kΩ, and V
) are not tabulated because the difference
0.5%
0.5%
0.5%
0.61
1.06
2.03
5.01
0.73
1.13
2.07
5.03
0.82
1.19
2.10
5.04
out
out
out
(Continued)
[%]
[%]
[%]
V
V
V
out
out
out
Resistor Tolerance
Resistor Tolerance
Resistor Tolerance
= 2.5 V
= 5.0 V
= 15 V
∆V
∆V
∆V
out
0.85
1.22
2.12
5.05
1.17
1.45
2.26
5.11
1.39
1.64
2.38
5.16
out
out
out
1%
1%
1%
is very small. The worst
out
[%]
[%]
[%]
’s
∆V
∆V
∆V
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3.50
3.61
4.00
6.08
5.29
5.36
5.63
7.26
6.49
6.55
6.77
8.18
out
out
out
5%
5%
5%
[%]
[%]
[%]
ref