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

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

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.

PIN

NAME

FUNCTION

1

IN

Supply Voltage Input

2

OUT

Reference Voltage Output

3

GND

Ground

Pin Description