- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄377720 > LT1970 (Linear Technology Corporation) 500mA Power Op Amp with Adjustable Precision Current Limit PDF資料下載
參數(shù)資料
| 型號(hào)： | LT1970 |
| 廠商： | Linear Technology Corporation |
| 英文描述： | 500mA Power Op Amp with Adjustable Precision Current Limit |
| 中文描述： | 500mA的電源運(yùn)算放大器精密可調(diào)電流限制 |
| 文件頁數(shù)： | 11/12頁 |
| 文件大小： | 233K |
| 代理商： | LT1970 |
11
LT1970
1970f
but these supply pins do not carry high currents, and the
power saving is much less. V
CC
and V
EE
must be greater
than the maximum output swing by 2V or more.
When V
–
and V
+
are provided separately from V
CC
and V
EE
,
care must be taken to insure that V
–
and V
+
are always less
than or equal to the main supplies in magnitude. Protec-
tion Schottky diodes may be required to insure this in all
cases, including power on/off transients.
Operation with reduced V
+
and V
–
supplies does not affect
any performance parameters except maximum output
swing. All DC accuracy and AC performance specifications
guaranteed with V
CC
= V
+
and V
EE
= V
–
are still valid within
the reduced signal swing range.
Heat Sinking
The power dissipated in the LT1970 die must have a path
to the environment. With 100
°
C/W thermal resistance in
free air with no heat sink, the package power dissipation is
limited to only 1W. The 20-pin TSSOP package with
exposed copper underside is an efficient heat conductor if
it is effectively mounted on a PC board. Thermal resis-
tances as low as 40
°
C/W can be obtained by soldering the
bottom of the package to a large copper pattern on the PC
board. For operation at 85
°
C, this allows up to 1.625W of
power to be dissipated on the LT1970. At 25
°
C operation,
up to 3.125W of power dissipation can be achieved. The
PC board heat spreading copper area must be connected
to V
EE
.
DRIVING REACTIVE LOADS
Capacitive Loads
The LT1970 is much more tolerant of capacitive loading
than most operational amplifiers. In a worst-case configu-
ration as a voltage follower, the circuit is stable for capaci-
tive loads less than 2.5nF. Higher gain configurations
improve the C
LOAD
handling. If very large capacitive loads
are to be driven, a resistive decoupling of the amplifier
from the capacitive load is effective in maintaining stability
and reducing peaking. The current sense resistor, usually
connected between the output pin and the load can serve
as a part of the decoupling resistance.
Very large capacitive loads above 1
μ
F can also cause
transient overshoots when the current limiting circuits
activate. The FILTER pin is provided to assist in controlling
this problem. Should load capacitance cause transient
overshoot, a 1nF to 100nF capacitor between the FILTER
and SENSE
–
pins will minimize the overshoot. The best
value of capacitor to use in this situation will likely require
some empirical evaluation, as the optimum is a complex
function of output current, load resistance, sense resistor
and load capacitance.
Inductive Loads
Load inductance is usually not a problem at the outputs of
operational amplifiers, but the LT1970 can be used as a
high output impedance current source. This condition
may be the main operating mode, or when the circuit
enters a protective current limit mode. Just as load capaci-
tance degrades the phase margin of normal op amps, load
inductance causes a peaking in the loop response of the
feedback controlled current source. The inductive load
may be caused by long lead lengths at the amplifier output.
If the amplifier will be driving inductive loads or long lead
lengths (greater than 4 inches) a 500pF capacitor from the
SENSE
–
pin to the ground plane will cancel the inductive
load and insure stability.
Supply Bypassing
The LT1970 can supply large currents from the power
supplies to a load at frequencies up to 4MHz. Power supply
impedance must be kept low enough to deliver these
currents without causing supply rails to droop. Low ESR
capacitors, such as 0.1
μ
F or 1
μ
F ceramics, located close
to the pins are essential in all applications. When large,
high speed transient currents are present additional ca-
pacitance may be needed near the chip. Check supply rails
with a scope and if signal related ripple is seen on the
supply rail, increase the decoupling capacitor as needed.
APPLICATIOU
W
U
U
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LT1970CFE | 500mA Power Op Amp with Adjustable Precision Current Limit |
| LT1977 | High Voltage 1.5A, 500kHz Step-Down Switching Regulator with 100uA Quiescent Current |
| LT1977EFE | High Voltage 1.5A, 500kHz Step-Down Switching Regulator with 100uA Quiescent Current |
| LT1977IFE | High Voltage 1.5A, 500kHz Step-Down Switching Regulator with 100uA Quiescent Current |
| LT1990 | 250V Input Range G = 1, 10, Micropower, Difference Amplifier |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LT1970_1 | 制造商:LINER 制造商全稱:Linear Technology 功能描述:500mA Power Op Amp with Adjustable Precision Current Limit |
| LT1970A | 制造商:LINER 制造商全稱:Linear Technology 功能描述:500mA Power Op Amp with Adjustable Precision Current Limit |
| LT1970ACFE#PBF | 功能描述:IC OP AMP 500MA ADJ CURR 20TSSOP RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:50 系列:- 放大器類型:J-FET 電路數(shù):2 輸出類型:- 轉(zhuǎn)換速率:3.5 V/µs 增益帶寬積:1MHz -3db帶寬:- 電流 - 輸入偏壓:30pA 電壓 - 輸入偏移:2000µV 電流 - 電源:200µA 電流 - 輸出 / 通道:- 電壓 - 電源，單路/雙路(±):7 V ~ 36 V，±3.5 V ~ 18 V 工作溫度:0°C ~ 70°C 安裝類型:通孔 封裝/外殼:8-DIP（0.300"，7.62mm） 供應(yīng)商設(shè)備封裝:8-PDIP 包裝:管件 |
| LT1970ACFE#TRPBF | 功能描述:IC OP AMP 500MA ADJ CURR 20TSSOP RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:50 系列:- 放大器類型:J-FET 電路數(shù):2 輸出類型:- 轉(zhuǎn)換速率:3.5 V/µs 增益帶寬積:1MHz -3db帶寬:- 電流 - 輸入偏壓:30pA 電壓 - 輸入偏移:2000µV 電流 - 電源:200µA 電流 - 輸出 / 通道:- 電壓 - 電源，單路/雙路(±):7 V ~ 36 V，±3.5 V ~ 18 V 工作溫度:0°C ~ 70°C 安裝類型:通孔 封裝/外殼:8-DIP（0.300"，7.62mm） 供應(yīng)商設(shè)備封裝:8-PDIP 包裝:管件 |
| LT1970AIFE#PBF | 功能描述:IC OP AMP 500MA ADJ CURR 20TSSOP RoHS:是 類別:集成電路 (IC) >> Linear - Amplifiers - Instrumentation 系列:- 標(biāo)準(zhǔn)包裝:50 系列:- 放大器類型:J-FET 電路數(shù):2 輸出類型:- 轉(zhuǎn)換速率:3.5 V/µs 增益帶寬積:1MHz -3db帶寬:- 電流 - 輸入偏壓:30pA 電壓 - 輸入偏移:2000µV 電流 - 電源:200µA 電流 - 輸出 / 通道:- 電壓 - 電源，單路/雙路(±):7 V ~ 36 V，±3.5 V ~ 18 V 工作溫度:0°C ~ 70°C 安裝類型:通孔 封裝/外殼:8-DIP（0.300"，7.62mm） 供應(yīng)商設(shè)備封裝:8-PDIP 包裝:管件 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。