monitored voltage. IN2 powers all other options for the

MAX6710 and is a monitored voltage. When any supply

drops below its threshold, the reset output asserts low

and remains low while either IN1 or IN2 is above 1.0V.

Adjustable Thresholds

The MAX6700/MAX6710 offer several monitor options

with adjustable reset thresholds. The threshold voltage at

each adjustable IN_ input is typically 0.62V. To monitor a

voltage > 0.62V, connect a resistor-divider network to the

circuit as shown in Figure 5.

or, solved in terms of R1:

Because the MAX6700/MAX6710 have a guaranteed

input current of ±0.2µA (±0.4µA for IN1) on their

adjustable inputs, resistor values up to 100k

Ω can be

used for R2 with < 1% error. The MAX6700/MAX6710Q

include an internal voltage clamp (1.5V typ) at each of

the adjustable voltage inputs. An input voltage higher

than 1.5V induces a higher input current.

Unused Inputs

Connect unused monitor inputs to a supply voltage

greater in magnitude than their specified threshold volt-

ages. For unused IN_ adjustable inputs, connect a 1M

Ω

series resistor between the unused input and IN2 (or

tion (device power-supply pin). Do not connect unused

monitor inputs to ground or allow them to float.

Adding Manual Reset Capability

(MAX6710)

Figure 6 shows an application circuit adding manual reset

to the MAX6710. Depressing the pushbutton switch short-

circuits the analog input to ground and initiates a RESET

pulse. The switch must be open for at least 140ms in

order to deassert the RESET output. No external switch

debounce is required. Use a small capacitor to improve

noise immunity when using long leads from the pushbut-

ton switch to the adjustable input.

Power-Supply Bypassing and Grounding

The MAX6700/MAX6710 are normally powered from the

inputs are immune to short supply transients. For higher

immunity in noisy applications, connect a 0.1µF bypass

capacitor from the IN2 input to ground. Add capacitance

to IN1, IN3, and IN4 to increase their noise immunity.

Low-Voltage, High-Accuracy, Triple/Quad

Voltage µP Supervisory Circuits in SOT Package

_______________________________________________________________________________________

7

Figure 5. Setting the Auxiliary Monitor

90%

10%

IN_

RESET

R2

R1

R1 = R2

(

- 1

)

0.62V

Figure 4. Interfacing to Different Logic-Supply Voltage

IN2

GND

IN2 = +3.3V

+5V

MAX6700

MAX6710

GND

RESET

RESET

100k

Ω