TS68302 Datasheet, PDF (8/47 Pages) ATMEL Corporation – Integrated Multiprotocol Processor IMP

This device contains protective circuitry to protect the inputs against damage due to high
static voltages or electrical fields; however, it is advised that normal precautions be
taken to avoid application of any voltages higher than maximum-rated voltages to this
high-impedance circuit. Reliability of operation is enhanced if unused inputs are tied to
an appropriate logic voltage level (e.g., either GND or V_DD).
Figure 5. Clock Input Timing Diagram
tcyc
2.0V
0.8V
tr (C)
tf (C)
Note:
Timing measurements are referenced to and from a low voltage of 0.8V and a voltage of 2.0V, unless otherwise noted. The volt-
age swing through this range should start outside, and pass through, the range such that the rise or fall will be linear between
0.8V and 2.0V.
Table 4. Thermal Characteristics at 25°C
Package
Symbol Parameter
PGA 132
CERQUAD 132
θ_JA
Thermal Resistance - Ceramic Junction To Ambient
θ_JC
Thermal Resistance - Ceramic Junction To Case
θ_JA
Thermal Resistance - Ceramic Junction To Ambient
θ_JC
Thermal Resistance - Ceramic Junction To Case
Value
33
5
46
2
Unit
°C/W
°C/W
°C/W
°C/W
Power Considerations
The average chip-junction temperature, T_J, in °C can be obtained from:
T_J = T_A + (P_D ⋅ θ_JA)
(1)
T_A = Ambient Temperature, °C
θ_JA = Package Thermal Resistance, Junction-to-Ambient, °C/W
P_D = P_INT + P_I/O
P_INT = I_CC ⋅ V_CC, Watts - Chip Internal Power
P_I/O = Power Dissipation on Input and Output pins - user determined
Note: For T_A = 70°C and P_D = 0.5 W at 12.5 MHz T_j = 88°C.
For most applications P_I/O < 0,30 P_INT and can be neglected.
An approximate relationship between P_D and T_J (if P_I/O is neglected) is:
P_D = K ÷ (T_J + 273)
(2)
Solving equations (1) and (2) for K gives:
K = P_D ⋅ (T_A + 273) + θ_JA ⋅ P_D2
(3)
where K is a constant pertaining to the particular part. K can be determined from equa-
tion (3) by measuring P_D (at equilibrium) for a known T_A. Using this value of K, the
values of P_D and T_J can be obtained by solving equations (1) and (2) iteratively for any
value of T_A.
8 TS68302
2117A–HIREL–11/02