參數(shù)資料
型號: MAX9810
廠商: Maxim Integrated Products, Inc.
英文描述: Electret Condenser Microphone Cartridge Preamplifier
中文描述: 駐極體麥克風(fēng)前置放大器
文件頁數(shù): 12/17頁
文件大?。?/td> 325K
代理商: MAX9810
M
Ultra-Low-Power, Open-Drain,
Single/Dual-Supply Comparators
12
______________________________________________________________________________________
2) Select R1. The leakage current into INB- is normally
under 1nA, so the current through R1 should exceed
100nA for the thresholds to be accurate. R1 values
up to about 10M
can be used, but values in the
100k
to 1M
range are usually easier to deal with.
In this example, choose R1 = 294k
.
3) Calculate R2 + R3. The overvoltage threshold
should be 5.5V when V
IN
is rising. The design
equation is as follows:
V
V
REF
=
4) Calculate R2. The undervoltage threshold should be
4.5V when V
IN
is falling. The design equation is as
follows:
5) Calculate R3:
Choose R3 = 1M
(1% standard value)
6) Verify the resistor values. The equations are as
follows, evaluated for the above example:
Overvoltage Threshold:
Battery Switchover Circuit
The switchover from line-powered DC to a backup
battery is often accomplished with diodes. But this
simple method is sometimes unacceptable, due to the
voltage drop and associated power loss across the
diode in series with the battery. Figure 6
s circuit
replaces the diode with a P-channel MOSFET
controlled by one of the MAX9_3 comparator outputs.
When the DC wall adapter drops below 4V (determined
by R1 and R2), OUTA goes low, turning on Q1.
Comparator B is used to measure the battery voltage,
and gives a
low-battery
indication when the battery
drops below 3.6V.
Level-Shifter
Figure 7 shows a circuit to shift from bipolar ±5V inputs
to single-ended 5V outputs. The 10k
resistors protect
the comparator inputs, and do not materially affect the
circuit
s operation.
V
(V
V )
(R1
R2
R1
R3)
Undervoltage Threshold:
5.474V
V
(V
V )
(R1
R2
R3)
(R1 + R2)
4.484V
where the hysteresis voltage V
V
R5
R4
OTH
REF
UTH
REF
REF
=
+
×
+
+
=
=
×
+
+
=
=
×
.
R
R
R
R
M
k
M
3
2
3
2
1 068
61 9
1 006
(
+
)
.
=
=
=
R
R
R
R
V
V
V
1 182
R
k
M
k
k
Choose R
k
s
dard value
REF
H
UTH
2
1
2
3
1
294
(
0 005
4 5
.
294
.
62 2
2
61 9
1
(
+
+
)
(
)
+ 1 068
)
)
.
( %
).
=
×
=
×
=
=
tan
R
R
R
V
k
M
OTH
+
H
2
3
1
1
294
5 5
.
+
(1 182
0 005
1
1 068
)
+
=
×
=
×
MAX9_3
INB-
REF
HYST
INA+
3
5
6
4
1
8
V-
2
V+
7
1M
OUTA
OUTB
R5
10k
R1
294k
R2
62.2k
R3
1M
POWER GOOD
V
IN
V
OTH
= 5.5V
V
UTH
= 4.5V
R4
2.4M
5V
Figure 5. Window Detector
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參數(shù)描述
MAX9810AEBS 制造商:Maxim Integrated Products 功能描述:LECTRET CONDENSER MICROPHONE CARTR - Rail/Tube
MAX9810AEBS+T 功能描述:傳聲器前置放大器 RoHS:否 制造商:Texas Instruments 可用增益調(diào)整:Digital control, 65 dB to 0 dB 共模抑制比(最小值): 輸入補(bǔ)償電壓: 最大輸入電阻:9200 Ohms 最大工作溫度:+ 85 C 封裝 / 箱體:SSOP-28 封裝:Tube
MAX9810AEBS-T 功能描述:傳聲器前置放大器 RoHS:否 制造商:Texas Instruments 可用增益調(diào)整:Digital control, 65 dB to 0 dB 共模抑制比(最小值): 輸入補(bǔ)償電壓: 最大輸入電阻:9200 Ohms 最大工作溫度:+ 85 C 封裝 / 箱體:SSOP-28 封裝:Tube
MAX9810BEBS 制造商:Maxim Integrated Products 功能描述:LECTRET CONDENSER MICROPHONE CARTR - Rail/Tube
MAX9810BEBS+T 功能描述:傳聲器前置放大器 RoHS:否 制造商:Texas Instruments 可用增益調(diào)整:Digital control, 65 dB to 0 dB 共模抑制比(最小值): 輸入補(bǔ)償電壓: 最大輸入電阻:9200 Ohms 最大工作溫度:+ 85 C 封裝 / 箱體:SSOP-28 封裝:Tube