Peripheral operating requirements and behaviors
5.4.2 Thermal attributes
Board type Symbol
Description
64 LQFP 48 LQFP
44
32 QFN Unit Notes
Laminate
QFN
Single-layer RθJA
(1s)
Thermal resistance, junction to
ambient (natural convection)
73
54
61
48
37
79
55
66
48
34
108
98
33
81
28
13
°C/W
°C/W
°C/W
°C/W
°C/W
1
1
1
1
2
Four-layer
(2s2p)
RθJA
Thermal resistance, junction to
ambient (natural convection)
69
Single-layer RθJMA
(1s)
Thermal resistance, junction to
ambient (200 ft./min. air speed)
91
Four-layer
(2s2p)
RθJMA
Thermal resistance, junction to
ambient (200 ft./min. air speed)
63
—
RθJB
Thermal resistance, junction to
board
44
—
—
RθJC
Thermal resistance, junction to case 20
20
31
2.2
6.0
°C/W
°C/W
3
4
ΨJT
Thermal characterization
5.0
4.0
6.0
parameter, junction to package top
outside center (natural convection)
1. Determined according to JEDEC Standard JESD51-2, Integrated Circuits Thermal Test Method Environmental Conditions
—Natural Convection (Still Air), or EIA/JEDEC Standard JESD51-6, Integrated Circuit Thermal Test Method
Environmental Conditions—Forced Convection (Moving Air).
2. Determined according to JEDEC Standard JESD51-8, Integrated Circuit Thermal Test Method Environmental Conditions
—Junction-to-Board.
3. Determined according to Method 1012.1 of MIL-STD 883, Test Method Standard, Microcircuits, with the cold plate
temperature used for the case temperature. The value includes the thermal resistance of the interface material between
the top of the package and the cold plate.
4. Determined according to JEDEC Standard JESD51-2, Integrated Circuits Thermal Test Method Environmental Conditions
—Natural Convection (Still Air).
6 Peripheral operating requirements and behaviors
6.1 Core modules
6.1.1 Debug specifications
Table 12. Background debug mode (BDM) timing
Number
Symbol
tMSSU
Description
Min.
500
Max.
Unit
1
2
BKGD/MS setup time after issuing background
debug force reset to enter user mode or BDM
—
—
ns
µs
tMSH
BKGD/MS hold time after issuing background
debug force reset to enter user mode or BDM1
100
MCF51JU128 Data Sheet, Rev. 4, 01/2012.
Freescale Semiconductor, Inc.
21
FREESCALE [ Freescale ]
