Datasheet

MAX6133
3ppm/°C, Low-Power, Low-Dropout
Voltage Reference
______________________________________________________________________________________ 11
TEMPERATURE
COEFFICIENT
(ppm/°C)
110
100
16 BIT
14 BIT
12 BIT
10 BIT
8 BIT
0.01
0.1
10
100
1000
1
10,000
18 BIT
20 BIT
OPERATING TEMPERATURE RANGE (T
MAX
- T
MIN
) (°C)
Figure 3. Temperature Coefficient vs. Operating Temperature Range for a 1LSB Maximum Error
Negative Low-Power Voltage Reference
As shown in Figure 2, the MAX6133 can be used to
develop a negative voltage reference using the
MAX400, a rail-to-rail op-amp with low power, low
noise, and low offset. The circuit only provides a good
negative reference and is ideal for space- and cost-
sensitive applications since it does not use resistors.
Temperature Coefficient vs.
Operating Temperature Range
for a 1LSB Maximum Error
In a data converter application, the converter’s refer-
ence voltage must stay within a certain limit to keep the
error in the data converter smaller than the resolution
limit through the operating temperature range. Figure 3
shows the maximum allowable reference-voltage tem-
perature coefficient that keeps the conversion error to
less than 1LSB. This is a function of the operating tem-
perature range (T
MAX
- T
MIN
) with the converter resolu-
tion as a parameter. The graph assumes the
reference-voltage temperature coefficient as the only
parameter affecting accuracy. In reality, the absolute
static accuracy of a data converter is dependent on the
combination of many parameters such as integral non-
linearity, differential nonlinearity, offset error, gain error,
as well as voltage reference changes.
Chip Information
TRANSISTOR COUNT: 656
PROCESS: BiCMOS
MAX6133
OUT
POSITIVE SUPPLY
GND
IN
-V
OUT
0.1µF
0.1µF
MAX400
V+
V-
0.1µF
0.1µF
Figure 2. Negative Low-Power Voltage Reference