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參數(shù)資料
| 型號： | LM359M |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | 運動控制電子 |
| 英文描述： | Dual, High Speed, Programmable, Current Mode Norton Amplifiers |
| 中文描述： | DUAL OP-AMP, 30 MHz BAND WIDTH, PDSO14 |
| 封裝： | PLASTIC, SOP-14 |
| 文件頁數(shù)： | 9/24頁 |
| 文件大?。?/td> | 742K |
| 代理商： | LM359M |
Application Hints
(Continued)
these parameters are significant in wide band amplifier de-
sign. The input stage current is approximately 3 times
I
and by using this relationship the following first order
approximations for these AC parameters are:
where C
is the total capacitance from the compensation
pin (pin 3 or pin 13) to ground, A
is the low frequency
open loop voltage gain in V/V and an ambient temperature of
25C is assumed (KT/q = 26 mV and
β
= 150). I
also controls the DC input bias current by the expression:
which is important for DC biasing considerations.
The total device supply current (for both amplifiers) is also a
direct function of the set currents and can be approximated
by:
I
supply
27 x I
SET(OUT)
+ 11 x I
SET(IN)
with each set current programmed by individual resistors.
PROGRAMMING WITH A SINGLE RESISTOR
Operating current programming may also be accomplished
using only one resistor by letting I
equal I
SET(OUT)
. The
programming current is now referred to as I
ated by connecting a resistor from pin 1 to pin 8 (Figure 8).
This configuration does not affect any of the internal set cur-
rent dependent parameters differently than previously dis-
cussed except the total supply current which is now equal to:
I
supply
37 x I
SET
Care must be taken when using resistors to program the set
current to prevent significantly increasing the supply voltage
above the value used to determine the set current. This
would cause an increase in total supply current due to the re-
sulting increase in set current and the maximum device
power dissipation could be exceeded. The set resistor val-
ue(s) should be adjusted for the new supply voltage.
One method to avoid this is to use an adjustable current
source which has voltage compliance to generate the set
current as shown in Figure 9
This circuit allows I
to remain constant over the entire
supply voltage range of the LM359 which also improves
power supply ripple rejection as illustrated in the Typical Per-
formance Characteristics. It should be noted, however, that
the current through the LM334 as shown will change linearly
with temperature but this can be compensated for (see
LM334 data sheet).
Pin 1 must never be shorted to ground or pin 8 never shorted
to V
+
without limiting the current to 2 mA or less to prevent
catastrophic device failure.
CONSIDERATIONS FOR HIGH FREQUENCY
OPERATION
The LM359 is intended for use in relatively high frequency
applications and many factors external to the amplifier itself
must be considered. Minimization of stray capacitances and
their effect on circuit operation are the primary requirements.
The following list contains some general guidelines to help
accomplish this end:
1.
Keep the leads of all external components as short as
possible.
2.
Place components conducting signal current from the
output of an amplifier away from that amplifier’s
non-inverting input.
3.
Use reasonably low value resistances for gain setting
and biasing.
4.
Use of a ground plane is helpful in providing a shielding
effect between the inputs and from input to output. Avoid
using vector boards.
5.
Use a single-point ground and single-point supply distri-
bution to minimize crosstalk. Always connect the two
grounds (one from each amplifier) together.
6.
Avoid use of long wires (
>
2") but if necessary, use
shielded wire.
7.
Bypass the supply close to the device with a low induc-
tance, low value capacitor (typically a 0.01 μF ceramic)
to create a good high frequency ground. If long supply
leads are unavoidable, a small resistor (
z
10
) in series
with the bypass capacitor may be needed and using
shielded wire for the supply leads is also recommended.
COMPENSATION
The LM359 is internally compensated for stability with closed
loop inverting gains of 10 or more. For an inverting gain of
less than 10 and all non-inverting amplifiers (the amplifier al-
ways has 100% negative current feedback regardless of the
DS007788-13
I
SET(IN)
= I
SET(OUT)
= I
SET
FIGURE 8. Single Resistor Programming of I
SET
DS007788-14
FIGURE 9. Current Source Programming of I
SET
www.national.com
9
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM359M/NOPB | 功能描述:特殊用途放大器 RoHS:否 制造商:Texas Instruments 通道數(shù)量:Single 共模抑制比（最小值）: 輸入補(bǔ)償電壓: 工作電源電壓:3 V to 5.5 V 電源電流:5 mA 最大功率耗散: 最大工作溫度:+ 70 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-20 封裝:Reel |
| LM359MX | 功能描述:特殊用途放大器 RoHS:否 制造商:Texas Instruments 通道數(shù)量:Single 共模抑制比（最小值）: 輸入補(bǔ)償電壓: 工作電源電壓:3 V to 5.5 V 電源電流:5 mA 最大功率耗散: 最大工作溫度:+ 70 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-20 封裝:Reel |
| LM359MX/NOPB | 功能描述:特殊用途放大器 RoHS:否 制造商:Texas Instruments 通道數(shù)量:Single 共模抑制比（最小值）: 輸入補(bǔ)償電壓: 工作電源電壓:3 V to 5.5 V 電源電流:5 mA 最大功率耗散: 最大工作溫度:+ 70 C 最小工作溫度:- 40 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:QFN-20 封裝:Reel |
| LM359N | 制造商:Panasonic Industrial Company 功能描述:IC 制造商:OC White Company 功能描述:SP Amp DIFF AMP Dual 22V 14-Pin PDIP Rail |
| LM359N | 制造商:Texas Instruments 功能描述:IC AMP DUAL NORTON DIP14 359 |
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