參數(shù)資料
型號(hào): μPD72045F
廠商: NEC Corp.
元件分類: 8位微控制器
英文描述: 8 Bit Single Chip Microcontrollers
中文描述: 8位單片機(jī)微控制器
文件頁數(shù): 36/72頁
文件大?。?/td> 547K
代理商: ΜPD72045F
36
m
PD78042F, 78043F, 78044F, 78045F
The following total power consumption calculation example assumes the case where the characters shown in the
figure on the next page are displayed.
Example:
The operating conditions are as follows:
V
DD
= 5 V ±10 %, operating at 5.0 MHz
Supply current (I
DD
) = 21.6 mA
Display outputs: 11 grids
10 segments (cut width is 1/16)
It is assumed that up to 15 mA flows to each grid pin, and that up to 3 mA flows to each segment pin.
It is also assumed that all display outputs are turned off at key scan timings.
Display output voltage: grid
V
O3
= V
DD
– 2 V (Voltage drop of 2 V is assumed.)
segment
V
O3
= V
DD
– 0.4 V (Voltage drop of 0.4 V is assumed.)
Voltage applied to fluorescent indication panel (V
LOAD
) = –30 V
Mask-option pull-down resistor = 25 ky
The total power loss is calculated by determining power consumption
1
to
3
under the above
conditions.
1
Power consumption of CPU: 5.5 V
21.6 mA = 118.8 mW
2
Power consumption at output pins:
total current for all grids
Grid:
(V
DD
– V
O3
)
digit width (1 – cut width) =
number of grids + 1
15 mA
11 grids
2 V
(1 – 1/16) = 25.8 mW
11 grids + 1
total segment current for all dots to be lit
Segment: (V
DD
– V
O3
)
=
number of grids + 1
3 mA
31 dots
11 grids + 1
0.4 V
= 3.1 mW
3
Power consumption at pull-down resistors:
Grid:
(V
O3
– V
LOAD
)
2
digit width =
pull-down resistance
number of grids + 1
(5.5 V – 2 V – (–30 V))
2
11 grids
(1 – 1/16) = 38.6 mW
25 ky
11 grids + 1
(V
O3
– V
LOAD
)
2
number of dots to be lit
=
pull-down resistance
number of grids + 1
(5.5 V – 0.4 V – (–30 V))
2
31 dots
= 127.3 mW
25 ky
11 grids + 1
number of grids
Segment:
Total power consumption =
1
+
2
+
3
= 118.8 + 25.8 + 3.1 + 38.6 + 127.3 = 313.6 mW
In this example, the total power consumption does not exceed the rated value for the permissible total power loss
shown in the graph on the previous page. Therefore, the calculation result in this example (313.6 mW) satisfies the
requirement. If the total power consumption exceed the rated value for the permissible total power loss, the power
consumption must be reduced, by reducing the number of built-in pull-down resistors.
相關(guān)PDF資料
PDF描述
μPD750004 4 Bit Single Chip Microcontrollers(4位單片微控制器)
μPD750004(A) 4 Bit Single Chip Microcontrollers(4位單片微控制器)
μPD750006 4 Bit Single Chip Microcontrollers(4位單片微控制器)
μPD750006(A) 4 Bit Single Chip Microcontrollers(4位單片微控制器)
μPD750008 4 Bit Single Chip Microcontrollers(4位單片微控制器)
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PD7-20-70A 制造商:MERRIMAC 制造商全稱:MERRIMAC 功能描述:0 , 75 ohm POWER DIVIDERS / COMBINERS
PD721MCS10A/1-001 制造商:HOTWATT 功能描述:AMMETER 0/10A DC
PD721MCS1A/2-003 制造商:HOTWATT 功能描述:AMMETER 0/1A DC
PD721MCS30V/2-001 制造商:HOTWATT 功能描述:VOLTMETER 0/30V DC
PD721MCS50A/1-001 制造商:HOTWATT 功能描述:AMMETER 0/50A DC