- 您现在的位置：买卖IC网 > PDF目录382335 > MM74C918N (NATIONAL SEMICONDUCTOR CORP) Dual CMOS 30V Relay Driver PDF资料下载
参数资料
| 型号： | MM74C918N |
| 厂商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分类： | 外设及接口 |
| 英文描述： | Dual CMOS 30V Relay Driver |
| 中文描述： | 0.5 A 2 CHANNEL, NAND GATE BASED PRPHL DRVR, PDIP14 |
| 封装： | PLASTIC, DIP-14 |
| 文件页数： | 4/6页 |
| 文件大小： | 153K |
| 代理商： | MM74C918N |
Power Considerations
Calculating Output ‘‘ON’’ Resistance (R
L
l
18
X
)
The output ‘‘ON’’ resistance, R
ON
, is a function of the junc-
tion temperature, T
J
, and is given by:
R
ON
e
9 (T
J
b
25) (0.008)
a
9
and T
J
is given by:
T
J
e
T
A
a
P
DAV
i
JA
,
where T
A
e
ambient temperature,
i
JA
e
thermal resist-
ance, and P
DAV
is the average power dissipated within the
device. P
DAV
consists of normal CMOS power terms (due to
leakage currents, internal capacitance, switching, etc.)
which are insignificant when compared to the power dissi-
pated in the outputs. Thus, the output power term defines
the allowable limits of operation and includes both outputs,
A and B. P
D
is given by:
P
D
e
I
OA2
R
ON
a
I
OB2
R
ON
,
where I
O
is the output current, given by:
I
O
e
V
CC
b
V
L
R
ON
a
R
L
V
L
is the load voltage.
The average power dissipation, P
DAV
, is a function of the
duty cycle:
P
DAV
e
I
OA2
R
ON
(Duty Cycle
A
)
a
I
OB2
R
ON
(Duty Cycle
B
)
where the duty cycle is the % time in the current source
state. Substituting equations (1) and (5) into (2) yields:
T
J
e
T
A
a
i
JA
[
9 (T
J
b
25) (0.008)
a
9
]
[
I
OA2
(Duty Cycle
A
)
a
I
OB2
(Duty Cycle
B
)
]
simplifying:
T
J
e
T
A
a
7.2
i
JA
[
I
OA2
(Duty Cycle
A
)
a
I
OB2
(Duty Cycle
B
)
]
1
b
0.072
i
JA
[
I
OA2
(Duty Cycle
A
)
a
I
OB2
(Duty Cycle
B
)
]
Equations (1), (4), and (6b) can be used in an iterative meth-
od to determine the output current, output resistance and
junction temperature.
(1)
(2)
(3)
(4)
(5)
(6a)
TL/F/5912–6
For example, let V
CC
e
15V, R
LA
e
100
X
, R
LB
e
100
X
,
V
L
e
0V, T
A
e
25
§
C,
i
JA
e
110
§
C/W, Duty Cycle
A
e
50%, Duty Cycle
B
e
75%.
Assuming R
ON
e
11
X
, then:
V
CC
b
V
L
R
ON
a
R
LA
11
a
100
V
CC
b
V
L
R
ON
a
R
LB
and
T
J
e
T
A
a
7.2
i
JA
[
I
OA2
(Duty Cycle
A
)
a
I
OB2
(Duty Cycle
B
)
]
1
b
0.072
i
JA
[
I
OA2
(Duty Cycle
A
)
a
I
OB2
(Duty Cycle
B
)
]
I
OA
e
e
15
e
135.1 mA,
I
OB
e
e
135.1 mA
T
J
e
25
a
(7.2) (110)
[
(0.1351)
2
(0.5)
a
(0.1351)
2
(0.75)
]
1
b
(0.072) (110)
[
(0.1351)
2
(0.5)
a
(0.1351)
2
(0.75)
]
T
J
e
52.6
§
C
and R
ON
e
9 (T
J
b
25) (0.008)
a
9
e
9(52.6
b
25) (0.008)
a
9
e
11
X
Applications
(See AN-177 for applications)
4
相关PDF资料 |
PDF描述 |
|---|---|
| MM74C928 | 4-Digit Counters with Multiplexed 7-Segment Output Drivers |
| MM74C95 | 4-Bit Right-Shift Left-Shift Register |
| MM74C95J | 4-Bit Right-Shift Left-Shift Register |
| MM74C95N | 4-Bit Right-Shift Left-Shift Register |
| MM54C95 | 4-Bit Right-Shift Left-Shift Register |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MM74C922 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:16, 20-Key Encoder |
| MM74C922N | 功能描述:编码器、解码器、复用器和解复用器 16-Key Encoder RoHS:否 制造商:Micrel 产品:Multiplexers 逻辑系列:CMOS 位数: 线路数量（输入/输出）:2 / 12 传播延迟时间:350 ps, 400 ps 电源电压-最大:2.625 V, 3.6 V 电源电压-最小:2.375 V, 3 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Tray |
| MM74C922N | 制造商:Fairchild Semiconductor Corporation 功能描述:IC 74C CMOS 74C922 DIP18 |
| MM74C922N_Q | 功能描述:编码器、解码器、复用器和解复用器 16-Key Encoder RoHS:否 制造商:Micrel 产品:Multiplexers 逻辑系列:CMOS 位数: 线路数量（输入/输出）:2 / 12 传播延迟时间:350 ps, 400 ps 电源电压-最大:2.625 V, 3.6 V 电源电压-最小:2.375 V, 3 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Tray |
| MM74C922N-G | 制造商:Rochester Electronics LLC 功能描述: |
发布紧急采购，3分钟左右您将得到回复。