TMP464 datasheet(29/42 Pages) TI2

29 / 42 page

Processor, FPGA, or ASIC

TMP464

D+

D-

CDIFF

(3)

(2)

PNP Transistor-Connected Configuration

(1)

PNP Diode-Connected Configuration

(1)

Series Resistance

(2)

NPN Diode-Connected Configuration

(1)

Series Resistance

(2)

Integrated PNP Transistor-Connected Configuration

(1)

Internal and PCB

Series Resistance

(2)

TMP464

www.ti.com

SBOS835C – MAY 2017 – REVISED OCTOBER 2019

Product Folder Links: TMP464

Submit Documentation Feedback

Typical Application (continued)

Figure 21. TMP464 Remote Transistor Configuration Options

8.2.1 Design Requirements

The TMP464 device is designed to be used with either discrete transistors or substrate transistors built into

processor chips, field programmable gate arrays (FPGAs), and application-specific integrated circuits (ASICs) ;

see Figure 21. Either NPN or PNP transistors can be used, as long as the base-emitter junction is used as the

remote temperature sensor. NPN transistors must be diode-connected. PNP transistors can either be transistor-

or diode-connected (see Figure 21).

Errors in remote temperature sensor readings are typically the consequence of the ideality factor (η-factor) and

current excitation used by the TMP464 device versus the manufacturer-specified operating current for a given

transistor. Some manufacturers specify a high-level and low-level current for the temperature-sensing substrate

transistors. The TMP464 uses 7.5 μA (typical) for ILOW and 120 μA (typical) for IHIGH.

The ideality factor (η-factor) is a measured characteristic of a remote temperature sensor diode as compared to

an ideal diode. The TMP464 allows for different η-factor values; see the η-Factor Correction Register section.

The η-factor for the TMP464 device is trimmed to 1.008. For transistors that have an ideality factor that does not

match the TMP464 device, Equation 4 can be used to calculate the temperature error.

NOTE

For Equation 4 to be used correctly, the actual temperature (°C) must be converted to

Kelvin (K).

TMP464 Datasheet(PDF) 29 Page - Texas Instruments

TMP464 Datasheet(HTML) 29 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

Datasheet Download

Link URL