PXD10 Datasheet, PDF (62/130 Pages) Lumins Inc. – 4” Dia.X 6” extruded aluminum step poles

Electrical characteristics
3.4.2 Connecting power supply pins: What to do and what not to do
• Do:
— Have all power/ground supplies connected on the board from a strong supply source rather than
weak voltage divider sources unless there is “NO IO activity” in the section
— Meet the supply specifications for max / typical operating conditions to guarantee correct
operation
— Place the decoupling near the supply/ground pin pair for EMI emissions reduction
— Route high-noise supply/ground away from sensitive signals (for example, ADC channels must
be away from SMD supply/motor pads)
— Use star routing for the ballast supply from the VDDR supply to avoid ballast startup noise
injected to VDDR supply of the device
— Use LC inductive filtering for ADC, OSC, and PLL supplies if these are generated from
common board regulators
• Do not:
— Violate injection current limit per IO/All IO pins as per specifications
— Connect sensitive supplies/ground on noisy supplies/ground (that is, ADC, PLL, and OSC)
— Use SMD supply for generation of noise free supply as these are most noisy lines in the system
— Connect different VDD pins (connected together inside the device) to different potentials.
3.5 Thermal characteristics
Table 15. LQFP thermal characteristics
Symbol C
Parameter
Conditions
Value
Unit
144-pin 176-pin
R_JA CC D Thermal resistance, junction-to-ambient Single layer board—1s
natural convection¹
CC
Four layer board—2s2p
50
43 °C/W
41
35 °C/W
R_JMA CC D Thermal resistance, junction-to-moving-air @ 200 ft./min., single layer 41
ambient²
board—1s
35 °C/W
CC
@ 200 ft./min., four layer
35
30 °C/W
board—2s2p
R_JB CC D Thermal resistance, junction-to-board² —
29
24 °C/W
R_JCtop CC D Thermal resistance, junction-to-case
—
(top)³
10
9 °C/W
_JT CC D Junction-to-package top thermal
—
characterization parameter, natural
convection⁴
2
2 °C/W
NOTES:
1 _{Junction-to-ambient thermal resistance determined per JEDEC JESD51-3 and JESD51-6. Thermal test board}
meets JEDEC specification for this package.
2 _{Junction-to-board thermal resistance determined per JEDEC JESD51-8. Thermal test board meets JEDEC}
specification for the specified package.
PXD10 Microcontroller Data Sheet, Rev. 1
62
Freescale Semiconductor