DSP56374UMSLASHD datasheet(27/64 Pages) FREESCALE

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Thermal Characteristics

DSP56374 Data Sheet, Rev. 4.2

Freescale Semiconductor

To prevent a high current condition upon power up, the IO_VDD must be applied ahead of the Core_VDD

as shown below if the external Schottky is not used.

For correct operation of the internal power on reset logic, the Core_VDD ramp rate (Tr) to full supply must

be less than 10 ms. This is shown below.

Thermal Characteristics

Table 16. Thermal Characteristics

Characteristic

Symbol

LQFP Values

Unit

Natural Convection, Junction-to-ambient thermal

resistance1,2

RθJA or θJA

68 (52 LQFP)

50 (80 LQFP)

°C/W

Junction-to-case thermal resistance3

RθJC or θJC

17 (52 LQFP)

11 (80 LQFP)

°C/W

Note:

1 Junction temperature is a function of die size, on-chip power dissipation, package thermal resistance,

mounting site (board) temperature, ambient temperature, air flow, power dissipation of other components

on the board, and board thermal resistance.

2 Per SEMI G38-87 and JEDEC JESD51-2 with the single layer board horizontal.

3 Thermal resistance between the die and the case top surface as measured by the cold plate method

(MIL SPEC-883 Method 1012.1).

IO_VDD

Core_VDD

External

Schottky

Diode

Core_VDD

IO_VDD

Core_VDD

0 V

1.25 V

DSP56374UM/D Datasheet(PDF) 27 Page - Freescale Semiconductor, Inc