- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383606 > MIC2753 (Micrel Semiconductor,Inc.) Power Supply Supervisors(電源監(jiān)控器（帶低壓和過壓檢測）) PDF資料下載
參數(shù)資料
| 型號： | MIC2753 |
| 廠商： | Micrel Semiconductor,Inc. |
| 英文描述： | Power Supply Supervisors(電源監(jiān)控器（帶低壓和過壓檢測）) |
| 中文描述： | 電源監(jiān)控器（電源監(jiān)控器（帶低壓和過壓檢測）） |
| 文件頁數(shù)： | 9/12頁 |
| 文件大?。?/td> | 124K |
| 代理商： | MIC2753 |
June 1999
9
MIC2753/2754
MIC2753/2754
Application Information
Supply Transients
The MIC2753/4 are inherently immune to very short “glitches”
on V
IN
. In the case of very brieftransients, V
IN
may drop
below the reset threshold or exceed the overvoltage thresh-
old without activating the RST, /RST or /HV output. As shown
in the graphs of Figure 1, the narrower the transient, the
deeper the threshold overdrive that will be ignored by the
MIC2753/4. The lines on the graph represent the typical
allowable transient duration for a given amount of threshold
overdrive that will not generate a reset or overvoltage indica-
tion. The data from which Figure 1 is derived was taken by
adding negative-going square-wave pulses to a dc V
IN
set at
0.5V above or below the actual measured threshold for the
part being characterized.
In the case of the MIC2754L/M for example (refer to Figure 1),
a transient on V
IN
which goes below the reset threshold by
100mV and lasts no more than 8.4
μ
s will typically not cause
a reset to occur. Bypass capacitance placed as close as
physically possible to the device’s VIN and GND pins will
increase the transient immunity (0.1
μ
F, for example).
Ensuring Proper Operation at Low Supply
At levels of V
IN
below 1.5V, the MIC2754’s /RST output driver
cannot turn on sufficiently to sink current and produce a valid
logic-low on the /RST output. In this situation, other CMOS
circuits driven by /RST could be allowed to float, causing
Micrel
undesired operation. (In most cases, however, it is expected
that the circuits driven by the MIC2754 will be similarly
inoperative at V
CC
≤
1.5V.)
If a given application requires that /RST be valid below V
IN
=
1.5V, this can be accomplished by adding a pull-down resis-
tor to the /RST output. A value of 100k
is recommended as
this is usually an acceptable compromise of leakage current
and pull-down current. The resistor’s value is not critical,
however.
The statements above also apply to the MIC2753’s RST
output. That is, to ensure valid RST signal levels at V
IN
< 1.5V,
a pull-up resistor (as opposed to a pull-down) should be
added to the RST output. A value of 100k
is typical for this
application as well. See Figure 2.
Interfacing to Processors with Bidirectional Reset Pins
Some microcontrollers and microprocessors utilize reset
signal pins that are bidirectional in nature, rather than simply
being input only. The Motorola 68HC11 family is one ex-
ample. To use the MIC2753/4 with these processors, it is
necessary to insert a resistor into the signal path between the
MIC2753/4’s reset output and the microprocessor’s reset
input. This prevents excessive current from flowing due to
contention between the two drivers. The signal present at the
processor’s reset pin will now be of limited drive capability, so
it is necessary to buffer it in order to drive other circuits. This
technique is shown in Figure 3.
0
10
20
30
40
1
10
100
1000
D
μ
s
OVERDRIVE (mV)
Reset Comparator Overdrive
vs. Duration
T
A
= 25
°
C
A. Reset
0
1
2
3
4
5
6
7
8
1
10
100
1000
D
μ
s
OVERDRIVE (mV)
Overvoltage Comparator
Overdrive vs. Duration
T
A
= 25
°
C
B. Overvoltage
Figure 1. MIC2753/2754 Transient Immunity Behavior
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MIC2754 | Power Supply Supervisors(電源監(jiān)控器（帶低壓和過壓檢測）) |
| MIC2753-LBM5 | Power Supply Supervisors Preliminary Information |
| MIC2753-MBM5 | Power Supply Supervisors Preliminary Information |
| MIC2754-MBM5 | Power Supply Supervisors Preliminary Information |
| MIC2754-SBM5 | Power Supply Supervisors Preliminary Information |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MIC2753-LBM5 | 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:RF Micro Devices Inc 功能描述: 制造商:Micrel Inc 功能描述: |
| MIC2753-MBM5 | 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:RF Micro Devices Inc 功能描述: 制造商:Micrel Inc 功能描述: |
| MIC2753-SBM5 | 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:RF Micro Devices Inc 功能描述: 制造商:Micrel Inc 功能描述: |
| MIC2754-LBM5 | 制造商:RF Micro Devices Inc 功能描述: |
| MIC2754-RBM5 | 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:RF Micro Devices Inc 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。