Detailed Description

The MAX6610/MAX6611 combine a temperature sensor

with a low-power voltage reference. The reference volt-

age and temperature sensor gain give convenient LSB

weights when used with an ADC.

For example, when an 8-bit ADC is used with the

MAX6610/MAX6611, an LSB is equivalent to 1°C and a

10-bit ADC LSB is equivalent to 0.25°C.

The reference output features a proprietary tempera-

ture-coefficient, curvature-correction circuit and laser-

trimmed thin-film resistors that result in a low

temperature coefficient (50ppm/°C max) and initial

accuracy of ±0.5% max. The maximum supply current

is 250µA during normal operation and 1µA max during

shutdown. The supply voltage range is 3.0V to 5.5V for

the MAX6610 and 4.5V to 5.5V for the MAX6611.

Voltage Reference

The MAX6610/MAX6611 REF output provides a voltage

reference for ADCs or other system subcircuits. REF is

capable of driving loads of up to 1mA. An output

capacitor can be as large as 1µF.

The voltage reference provides scaled ADC conver-

sions with bit weights that are in convenient units.

For the MAX6610 (2.56V REF output), an 8-bit ADC

yields 10mV/bit or 2.5mV/bit for a 10-bit ADC. The

MAX6611 (4.096V REF output) yields 16mV/bit for an 8-

bit ADC or 4mV/bit for a 10-bit ADC.

Temperature Sensor

The MAX6610/MAX6611 TEMP output provides an ana-

log output voltage that is a linear function of its die tem-

perature as defined by:

and

(16mV/°C for the MAX6611 and 10mV/°C for the

MAX6610). There is a +75°C offset on the temperature

output (The MAX6611’s output is 1.2V and, the

MAX6610’s output is 0.75V) at 0°C. The temperature error

+125°C.

Shutdown

The MAX6610/MAX6611 are equipped with a shutdown

feature that, when driven low, shuts down all internal cir-

cuitry and reduces supply current to 1µA (max). When in

shutdown, REF is pulled to GND through a 150k

Ω resis-

tor and TEMP goes to a high-impedance state. For nor-

Applications Information

Output/Load Capacitance

The MAX6610/MAX6611 TEMP output can drive capac-

itive loads up to 0.2µF. The MAX6610/MAX6611 REF

output can drive capacitive loads up to 1µF. Devices in

this family do not require an output capacitance for

dynamic stability. However, in applications where the

load or the supply can experience step changes, an

output capacitor within the specified range reduces the

amount of overshoot (or undershoot) and assists the

circuit’s transient response. Many applications do not

need an external capacitor, and this family can offer a

significant advantage in these applications when board

space is critical.

Supply Current

The quiescent supply current of the MAX6610/

MAX6611 is typically 150µA and is virtually indepen-

dent of the supply voltage. Unlike shunt-mode refer-

ences, the load current of series-mode references is

drawn from the supply voltage only when required, so

supply current is not wasted and efficiency is maxi-

mized over the entire supply voltage range. This

improved efficiency can help reduce power dissipation

and extend battery life.

Precision, Low-Power, 6-Pin SOT23

Temperature Sensors and Voltage References

4

_______________________________________________________________________________________

PIN

NAME

FUNCTION

Supply Voltage Input. Bypass to GND

with a 0.1µF capacitor.

2

GND

Ground

3

SHDN

Logic Level Shutdown Input (Active

Low). Driving SHDN with a logic low

turns off internal circuitry to reduce

supply current to 1µA (max).

4

TEMP

Temperature Output Pin. Voltage at

TEMP varies linearly with temperature.

5

REF

Reference Voltage Output

6

GND

Must be connected to pin 2.

Pin Description