SPC560B50x datasheet(46/116 Pages) STMICROELECTRONICS

46 / 116 page

Package pinouts and signal descriptions

SPC560B40x/50x, SPC560C40x/50x

46/116

DocID14619 Rev 13

Most of the time for the applications, PI/O< PINT and may be neglected. On the other hand,

PI/O may be significant, if the device is configured to continuously drive external modules

and/or memories.

An approximate relationship between PD and TJ (if PI/O is neglected) is given by:

Equation 2 PD = K / (TJ + 273 °C)

Therefore, solving equations Equation 1 and Equation 2:

Equation 3 K = PD x (TA + 273 °C) + RJA x PD

Where:

K is a constant for the particular part, which may be determined from Equation 3

by measuring PD (at equilibrium) for a known TA. Using this value of K, the values

of PD and TJ may be obtained by solving equations Equation 1 and Equation 2

iteratively for any value of TA.

3.15

I/O pad electrical characteristics

3.15.1

I/O pad types

The device provides four main I/O pad types depending on the associated alternate

functions:



Slow pads—These pads are the most common pads, providing a good compromise

between transition time and low electromagnetic emission.



Medium pads—These pads provide transition fast enough for the serial communication

channels with controlled current to reduce electromagnetic emission.



Fast pads—These pads provide maximum speed. There are used for improved Nexus

debugging capability.



Input only pads—These pads are associated to ADC channels and the external 32 kHz

crystal oscillator (SXOSC) providing low input leakage.

Medium and Fast pads can use slow configuration to reduce electromagnetic emission, at

the cost of reducing AC performance.

3.15.2

I/O input DC characteristics

Table 16 provides input DC electrical characteristics as described in Figure 6.

SPC560B50x Datasheet(PDF) 46 Page - STMicroelectronics