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參數(shù)資料
| 型號： | CA3240E1 |
| 元件分類： | 通用總線功能 |
| 英文描述： | 12 STAGE RIPPLE-CARRY BINARY COUNTER/DIVIDERS |
| 中文描述： | 集成電路雙運算放大器 |
| 文件頁數(shù)： | 6/14頁 |
| 文件大?。?/td> | 342K |
| 代理商： | CA3240E1 |
3-120
Application Information
Circuit Description
The schematic diagram details one amplifier section of the
CA3240. It consists of a differential amplifier stage using PMOS
transistors (Q
9
and Q
10
) with gate-to-source protection against
static discharge damage provided by zener diodes D
3
, D
4
, and
D
5
. Constant current bias is applied to the differential amplifier
from transistors Q
2
and Q
5
connected as a constant current
source. This assures a high common-mode rejection ratio. The
output of the differential amplifier is coupled to the base of gain
stage transistor Q
13
by means of an NPN current mirror that
supplies the required differential-to-single-ended conversion.
Provision for offset null for types in the 14 lead plastic package
(E1 suffix) is provided through the use of this current mirror.
The gain stage transistor Q
13
has a high impedance active load
(Q
3
and Q
4
) to provide maximum open-loop gain. The collector
of Q
13
directly drives the base of the compound emitter-follower
output stage. Pulldown for the output stage is provided by two
independent circuits: (1) constant-current-connected transistors
Q
14
and Q
15
and (2) dynamic current-sink transistor Q
16
and
its associated circuitry.The level of pulldown current is constant
at about 1mA for Q
15
and varies from 0 to 18mA for Q
16
depending on the magnitude of the voltage between the output
terminal and V+.The dynamic current sink becomes active
whenever the output terminal is more negative than V+ by
about 15V. When this condition exists, transistors Q
21
and Q
16
are turned on causing Q
16
to sink current from the output termi-
nal to V-. This current always flows when the output is in the lin-
ear region, either from the load resistor or from the emitter of
Q
18
if no load resistor is present. The purpose of this dynamic
sink is to permit the output to go within 0.2V (V
CE
(sat)) of V-
with a 2k
load to ground. When the load is returned to V+, it
may be necessary to supplement the 1mA of current from Q
15
in order to turn on the dynamic current sink (Q
16
).This may be
accomplished by placing a resistor (Approx. 2k
) between the
output and V-.
Output Circuit Considerations
Figure 24 shows output current-sinking capabilities of the
CA3240 at various supply voltages. Output voltage swing to
the negative supply rail permits this device to operate both
power transistors and thyristors directly without the need for
level-shifting circuitry usually associated with the 741 series
of operational amplifiers.
Figure 3 shows some typical configurations. Note that a series
resistor, RL, is used in both cases to limit the drive available to
the driven device. Moreover, it is recommended that a series
diode and shunt diode be used at the thyristor input to prevent
large negative transient surges that can appear at the gate of
thyristors, from damaging the integrated circuit.
Input Circuit Considerations
As indicated by the typical VICR, this device will accept
inputs as low as 0.5V below V-. However, a series current-
limiting resistor is recommended to limit the maximum input
terminal current to less than 1mA to prevent damage to the
input protection circuitry.
Moreover, some current-limiting resistance should be pro-
vided between the inverting input and the output when the
CA3240 is used as a unity-gain voltage follower. This resis-
tance prevents the possibility of extremely large input-signal
transients from forcing a signal through the input-protection
network and directly driving the internal constant-current
source which could result in positive feedback via the output
terminal. A 3.9kW resistor is sufficient.
The typical input current is on the order of 10pA when the
inputs are centered at nominal device dissipation. As the
output supplies load current, device dissipation will increase,
rasing the chip temperature and resulting in increased input
current. Figure 4 shows typical input-terminal current versus
ambient temperature for the CA3240.
It is well known that MOSFET devices can exhibit slight
changes in characteristics (for example, small changes in
input offset voltage) due to the application of large differen-
tial input voltages that are sustained over long periods at
elevated temperatures.
CA3240
R
S
R
L
MT
1
MT
2
120V
AC
LOAD
30V NO LOAD
CA3240
LOAD
R
L
V+
+HV
FIGURE 3. METHODS OF UTILIZING THE V
CE (SAT)
SINKING
CURRENT CAPABILITY OF THE CA3240 SERIES
V
S
=
±
15V
TEMPERATURE (
o
C)
-60
-40
-20
0
20
40
60
80
100
120 140
100
10
I
1K
10K
FIGURE 4. INPUT CURRENT vs TEMPERATURE
CA3240, CA3240A
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相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| CA3240EX | 制造商:Rochester Electronics LLC 功能描述:BIMOS DUAL OP AMP MOSFET IN BIP OUT BURN-IN 8 PDIP COM - Bulk |
| CA3240EZ | 功能描述:運算放大器 - 運放 OPAMP 2X 4.5MHZ LWBI AS 0.05NA 8PDIP RoHS:否 制造商:STMicroelectronics 通道數(shù)量:4 共模抑制比（最小值）:63 dB 輸入補償電壓:1 mV 輸入偏流（最大值）:10 pA 工作電源電壓:2.7 V to 5.5 V 安裝風格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel |
| CA3240R2188 | 制造商:Harris Corporation 功能描述: |
| CA3240T | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC |
| CA3241E | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Consumer IC |
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