MAX6034
Precision, Micropower, Low-Dropout, SC70
Series Voltage Reference
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Detailed Description
The MAX6034 family of precision bandgap references
use a proprietary temperature coefficient curvature-cor-
rection circuit and laser-trimmed, thin-film resistors,
resulting in a low temperature coefficient of less than
30ppm/°C and initial accuracy of better than 0.2%.
These devices can source up to 1mA and sink up to
200µA with less than 200mV of dropout voltage, making
them attractive for use in low-voltage applications.
Applications Information
Input Bypassing
For the best line-transient performance, decouple the
input with a 0.1µF ceramic capacitor as shown in the
Typical Operating Circuit. Locate the capacitor as
close to IN as possible.
Output/Load Capacitance
Devices in the MAX6034 family do not require an output
capacitor for frequency stability. They are stable for
capacitive loads from 0 to 1µF. However, in applica-
tions where the load or the supply can experience step
changes, an output capacitor reduces the amount of
overshoot (or undershoot) and improves the circuit’s
transient response. Many applications do not need an
external capacitor, and the MAX6034 can offer a signifi-
cant advantage in these applications when board
space is critical.
Supply Current
The quiescent supply current of the series-mode
MAX6034 family is typically 90µA and is virtually inde-
pendent of the supply voltage, with only a 16µA/V
(max) variation with supply voltage.
When the supply voltage is below the minimum-speci-
fied input voltage (as during turn-on), the device can
draw up to 50µA beyond the nominal supply current.
The input-voltage source must be capable of providing
this current to ensure reliable turn-on.
Output Voltage Hysteresis
Output voltage hysteresis is the change in the output
voltage at T
A
= +25°C before and after the device is
cycled over its entire operating temperature range.
Hysteresis is caused by differential package stress
appearing across the bandgap core transistors. The
typical temperature hysteresis value for the MAX6034
family is 100ppm.
Turn-On Time
These devices typically turn on and settle to within
0.1% of their final value in 85µs to 260µs depending on
the device. The turn-on time can increase up to 1.25ms
with the device operating at the minimum dropout volt-
age and the maximum load.
Temperature Coefficient vs.
Operating Temperature Range for a 1LSB
Maximum Error
In a data converter application, the reference voltage of
the converter 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 1
shows the maximum allowable reference voltage tem-
perature coefficient to keep the conversion error to less
than 1LSB, as a function of the operating temperature
range (T
MAX
- T
MIN
) with the converter resolution 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 con-
verter is dependent on the combination of many para-
meters such as integral nonlinearity, differential
nonlinearity, offset error, gain error, as well as voltage
reference changes.
