MC68HC908QC16_07 Datasheet, PDF (237/274 Pages) Freescale Semiconductor, Inc – Microcontrollers

5-V DC Electrical Characteristics
The average chip-junction temperature (T_J) in °C can be obtained from:
T_J = T_A + (P_D × θ_JA)
Eqn. 19-1
where:
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_DD × V_DD, Watts — chip internal power
P_I/O = Power dissipation on input and output pins — user determined
For most applications, P_I/O << 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°C)
Eqn. 19-2
Solving Equation 19-1 and Equation 19-2 for K gives:
K = P_D × (T_A + 273°C) + θ_JA × (P_D)²
Eqn. 19-3
where K is a constant pertaining to the particular part. K can be determined from equation 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 Equation 19-1 and Equation 19-2 iteratively for any value of T_A.
19.5 5-V DC Electrical Characteristics
Characteristic⁽¹⁾
Output high voltage
I_Load = –2.0 mA, all I/O pins
I_Load = –10.0 mA, all I/O pins
I_Load = –15.0 mA, PTA0, PTA1, PTA3–PTA5 only
Maximum combined I_OH (all I/O pins)
Output low voltage
I_Load = 1.6 mA, all I/O pins
I_Load = 10.0 mA, all I/O pins
I_Load = 15.0 mA, PTA0, PTA1, PTA3–PTA5 only
Maximum combined I_OL (all I/O pins)
Input high voltage
PTA0–PTA5, PTB0–PTB7, PTC3–PTC0, PTD7–PTD0
Input low voltage
PTA0–PTA5, PTB0–PTB7, PTC3–PTC0, PTD7–PTD0
Input hysteresis
Symbol
V_OH
I_OHT
V_OL
I_OHL
V_IH
V_IL
V_HYS
Min
Typ⁽²⁾
Max
Unit
V_DD – 0.4
—
V_DD – 1.5
—
V_DD – 0.8
—
—
—
—
—
V
—
50
mA
—
—
—
—
—
—
—
—
0.7 x V_DD
—
0.4
1.5
V
0.8
50
mA
V_DD
V
V_SS
—
0.3 x V_DD
V
0.06 x V_DD
—
—
V
— Continued on next page
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 3
Freescale Semiconductor
237