I EEE Catalog Number: CFP10OLT-CDR
I SBN: 978-1-4244-7722-7
5 – 7 July 2010
Corfu Island, Greece
D. Gizopoulos, A. Chatterjee,
M. Nicolaidis and A. Paschalis
W elcome Message
Keynote/ I nvited Talks
TTTC I nformation 2010
Author I ndex
2010 IEEE 16th International On-Line Testing Symposium
1 de 222/11/2010 13:23
Thermal Coupling in ICs: Applications to the Test
and Characterization of Analogue and RF Circuits
Josep Altet, Diego Mateo, Eduardo Aldrete-Vidrio
Electronic Engineering Department
Universitat Politècnica de Catalunya
Abstract—In this presentation we cover how to use low frequency
or DC temperature measurements to observe figures of merit of
high frequency analogue circuits.
I.INTRODUCTION: THERMAL COUPLING
Thermal coupling is defined as the temperature increase at
the vicinity of a circuit or device due to its power consumption.
Temperature and power dissipation can be related with a linear
transfer function behaving as a low pas filter, with a cut-off
frequency around 10kHz-1MHz [1,2].
As the dissipated power depends on the voltages and
currents driving the circuit, temperature is a signature of its
performance and state, being traditionally used to enhance
observability in digital circuits.
II.APLICATIONS TO TEST OF ANALOGUE CIRCUITS
The use of temperature to test analogue circuits is proposed
in [3,4]. From Fig. 1 we can see that the temperature is a down
converted physical magnitude that contains information of high
frequency electrical signals. In this figure, the Joule effect is
modeled as a frequency mixer: thanks to its quadratic nature,
the spectral components of the power dissipated by a device are
frequency shifted from the spectral components of the
electrical signals that drive it.
Figure 1. Down conversion from high frequency electrical signals to low
frequency temperature increase.
For instance,  shows how to stimuli a 2.4GHz narrow
band linear amplifier in order to achieve a power dissipation
whose spectral component at 1kHz is proportional to the high
frequency gain of the amplifier.
III.SENSING TEMPERATURE FOR TEST APPLICATIONS
Several techniques exist to sense this temperature increase,
which can be classified as off-chip or embedded . The use of
off-chip strategies allow to enhance the observability of blocks
in an analogue-RF system whose nodes are not accessible from
input/output pins in a debugging or failure analysis scenario
[4,5]. Embedded temperature sensors  allow to measure
temperature in field application, to either detect faults or to
activate self-healing strategies.
Fig. 2 compares the electrical signal measured at the output of
an LNA at 800MHz with the amplitude of the spectral
component of the temperature increase at 1kHz, when sensed
near this device with an embedded temperature sensor . As
it can be seen, it is possible to induce the 1dB compression
point of this amplifier from temperature measurements.
Figure 2. Measurement of the 1dB compression point from high frequency
electrical measurements (800MHz) or low frequency temperature measurements
 J. Altet et al. “Four different approaches for the measurement of IC
surface temperature: Application to thermal testing”. Microelectronics
journal, Sep. 2002, vol. 33, p. 689-696.
J. Altet et al. “Dynamic surface temperature measurements in IC's”.
Proceedings of the IEEE", August 2006, vol. 94, núm. 8, p. 1519-1533.
D. Mateo et al., "Frequency characterization of a 2.4 GHz CMOS LNA
by thermal measurements," in Proc. IEEE Radio Frequency Integrated
Circuits (RFIC) Symp., pp. 565-568, June 2006.
E. Aldrete-Vidrio et al. “Using Temperature as observable of the
frequency response of RF CMOS amplifiers,” in IEEE Eur. Test Symp.
2008. Pp. 47-52..
 J. Altet et al. “A heterodyne method for the thermal observation of the
electrical behavior of high-frequency integrated circuits,” Measurement
Science and Technology, vol. 19, no. 11, pp. 115704 (8pp) , Nov. 2008.
 E. Aldrete-Vidrio et al., "Differential temperature sensors fully
compatible with a 0.35-μm CMOS process," IEEE Trans. Components
and Packaging Technologies, vol. 30, no. 4, pp. 618-626, Dec. 2007.
E. Aldrete et al, “Strategies for Built-In Characterization Testingand
Performance Monitoring of Analog RF Circuits with Temperature
Measurements,” Measurement Science and Technology, In Pres.
Supported by: MODERN E-01076 and TERASYSTEMS TEC2008-
978-1-4244-7723-4/$26.00 c ?2010 IEEE