Ultra-Low-Power Precision Series

Voltage Reference

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13

Applications Information

Input Bypassing

The MAX6029 does not require an input bypass capac-

itor. For improved transient performance, bypass the

input to ground with a 0.1µF ceramic capacitor. Place

the capacitor as close to IN as possible.

Load Capacitance

The MAX6029 does not require an output capacitor for

stability. The MAX6029 is stable driving capacitive

loads from 0 to 100pF and 0.1µF to 10µF when sourc-

ing current and from 0 to 0.4µF when sinking current. In

applications where the load or the supply can experi-

ence step changes, an output capacitor reduces the

amount of overshoot (undershoot) and improves the cir-

cuit’s transient response. Many applications do not

require an external capacitor, and the MAX6029 offers

a significant advantage in applications where board

space is critical.

Supply Current

The quiescent supply current of the series-mode

MAX6029 is very small, 5.25µA (max), and is very sta-

ble against changes in the supply voltage with only

1.5µA/V (max) variation with supply voltage. The

MAX6029 family draws load current from the input volt-

age source only when required, so supply current is not

wasted and efficiency is maximized at all input volt-

ages. This improved efficiency reduces power dissipa-

tion and extends battery life.

Output Thermal Hysteresis

Output thermal hysteresis is the change of the output

cycled over its entire operating temperature range.

Hysteresis is caused by differential package stress

appearing across the device.

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 temper-

ature coefficient to keep the conversion error to less than

1 LSB, as a function of the operating temperature range

ter. The graph assumes the reference-voltage tempera-

ture coefficient as the only parameter affecting accuracy.

In reality, the absolute static accuracy of a data convert-

er is dependent on the combination of many parameters

such as integral nonlinearity, differential nonlinearity, off-

set error, gain error, as well as voltage reference

changes.

Turn-On Time

These devices turn on and settle to within 0.1% of their

final value in less than 1ms. The turn-on time increases

when heavily loaded and operating close to dropout.

Pin Description

PIN

SOT23

SO

NAME

FUNCTION

12

IN

Positive Voltage Supply

24

GND

Ground

3, 4

1, 3, 5, 7,

8

N.C.

No Connection. Leave

unconnected or connect to

ground.

56

OUT

Reference Output

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

°C)

Figure 1. Temperature Coefficient vs. Operating Temperature Range for a 1 LSB Maximum Error