DNC

TEMP

V

OUT

V

IN

GND

DNC

NC

TRIM/NR

REF50xx

V

TEMP

2.6mV/ C

°

NOTE:(1)Lowdriftopamp,suchastheOPA333,OPA335,orOPA376.

+V

V

=

HYST

6

(

(

|V

V

|

V

PRE

POST

NOM

-

REF5020-Q1, REF5025-Q1, REF5030-Q1

REF5040-Q1, REF5045-Q1, REF5050-Q1

www.ti.com

SBOS456G – SEPTEMBER 2008 – REVISED OCTOBER 2013

THERMAL HYSTERESIS

Thermal hysteresis for the REF50xx is defined as the change in output voltage after operating the device at

+25°C, cycling the device through the specified temperature range, and returning to +25°C. It can be expressed

as Equation 2:

where

•

•

•

•

temperature range of –40°C to +125°C and returned to +25°C

(2)

TEMPERATURE MONITORING

The temperature output terminal (TEMP, pin 3) provides a temperature-dependent voltage output with

approximately 60-k

Ω source impedance. As seen in Figure 8, the output voltage follows the nominal relationship:

(3)

This pin indicates general chip temperature, accurate to approximately ±15°C. Although it is not generally

suitable for accurate temperature measurements, it can be used to indicate temperature changes or for

temperature compensation of analog circuitry. A temperature change of 30°C corresponds to an approximate 79-

mV change in voltage at the TEMP pin.

The TEMP pin has high output impedance (see Figure 25). Loading this pin with a low-impedance circuit induces

To avoid errors caused by low-impedance loading, buffer the TEMP pin output with a suitable low-temperature

drift op amp, such as the OPA333, OPA335, or OPA376, as shown in Figure 29.

Figure 29. Buffering the TEMP Pin Output

POWER DISSIPATION

The REF50xx family is specified to deliver current loads of ±10 mA over the specified input voltage range. The

temperature of the device increases according to the equation:

where

•

•

•

•

(4)

The REF50xx junction temperature must not exceed the absolute maximum rating of 150°C.

Copyright © 2008–2013, Texas Instruments Incorporated

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