參數(shù)資料
型號: OP295GSZ-REEL7
廠商: ANALOG DEVICES INC
元件分類: 運算放大器
英文描述: Dual Rail-to-Rail Operational Amplifiers; Package: SOIC; No of Pins: 8; Temperature Range: Industrial
中文描述: DUAL OP-AMP, 800 uV OFFSET-MAX, 0.085 MHz BAND WIDTH, PDSO8
封裝: ROHS COMPLIANT, MS-012AA, SOIC-8
文件頁數(shù): 5/16頁
文件大小: 384K
代理商: OP295GSZ-REEL7
OP295/OP495
Rev. F | Page 13 of 16
V+
100k
58.7k
R
FREQ OUT
4
1
8
3
2
C
1
RC
FOSC =
< 350Hz @ V+ = 5V
1/2
OP295/
OP495
+
+
00
33
1-
0
30
Amplifier A1 provides error amplification for the normal
voltage regulation loop. As long as the output current is less
than 1 A, the output of Amplifier A2 swings to ground, reverse-
biasing the diode and effectively taking itself out of the circuit.
However, as the output current exceeds 1 A, the voltage that
develops across the 0.1 Ω sense resistor forces the output of
Amplifier A2 to go high, forward-biasing the diode, which in
turn closes the current-limit loop. At this point, the A2’s lower
output resistance dominates the drive to the power MOSFET
transistor, thereby effectively removing the A1 voltage regula-
tion loop from the circuit.
Figure 31. Square Wave Oscillator Has Stable Frequency Regardless of
Supply Changes
If the output current greater than 1 A persists, the current limit
loop forces a reduction of current to the load, which causes a
corresponding drop in output voltage. As the output voltage
drops, the current-limit threshold also drops fractionally,
resulting in a decreasing output current as the output voltage
decreases, to the limit of less than 0.2 A at 1 V output. This fold-
back effect reduces the power dissipation considerably during a
short circuit condition, thus making the power supply far more
forgiving in terms of the thermal design requirements. Small
heat sinking on the power MOSFET can be tolerated.
10k
90.9k
V+
100k
10k
20k
V+
SPEAKER
+
1/4
OP295/
OP495
1/4
OP295/
OP495
1/4
OP295/
OP495
VIN
2.2F
+
+
+
00
33
1-
0
31
The rail-to-rail swing of the OP295 exacts higher gate drive to
the power MOSFET, providing a fuller enhancement to the tran-
sistor. The regulator exhibits 0.2 V dropout at 500 mA of load
current. At 1 A output, the dropout voltage is typically 5.6 V.
Figure 32. Single-Supply Differential Speaker Driver
HIGH ACCURACY, SINGLE-SUPPLY, LOW POWER
COMPARATOR
SQUARE WAVE OSCILLATOR
The OP295/OP495 make accurate open-loop comparators.
With a single 5 V supply, the offset error is less than 300 μV.
Figure 33 shows the response time of the OP295/OP495 when
operating open-loop with 4 mV overdrive. They exhibit a 4 ms
response time at the rising edge and a 1.5 ms response time at
the falling edge.
The circuit in Figure 31 is a square wave oscillator (note the
positive feedback). The rail-to-rail swing of the OP295/OP495
helps maintain a constant oscillation frequency even if the supply
voltage varies considerably. Consider a battery-powered system
where the voltages are not regulated and drop over time. The
rail-to-rail swing ensures that the noninverting input sees the
full V+/2, rather than only a fraction of it.
10
100
0%
90
5ms
2V
1V
OUTPUT
INPUT
(5mV OVERDRIVE
@ OP295 INPUT)
00331-
032
The constant frequency comes from the fact that the 58.7 kΩ
feedback sets up Schmitt trigger threshold levels that are directly
proportional to the supply voltage, as are the RC charge voltage
levels. As a result, the RC charge time, and therefore, the frequency,
remain constant, independent of supply voltage. The slew rate
of the amplifier limits oscillation frequency to a maximum of about
800 Hz at a 5 V supply.
SINGLE-SUPPLY DIFFERENTIAL SPEAKER DRIVER
Connected as a differential speaker driver, the OP295/OP495
can deliver a minimum of 10 mA to the load. With a 600 Ω load,
the OP295/OP495 can swing close to 5 V p-p across the load.
Figure 33. Open-Loop Comparator Response Time with 5 mV Overdrive
相關PDF資料
PDF描述
OP296GS-REEL Micropower, Rail-to-Rail Input and Output Operational Amplifiers; Package: SOIC; No of Pins: 8; Temperature Range: Industrial
OP296HRU-REEL Micropower, Rail-to-Rail Input and Output Operational Amplifiers; Package: TSSOP; No of Pins: 8; Temperature Range: Industrial
OP296GSZ Micropower, Rail-to-Rail Input and Output Operational Amplifiers; Package: SOIC; No of Pins: 8; Temperature Range: Industrial
OP296GSZ-REEL Micropower, Rail-to-Rail Input and Output Operational Amplifiers; Package: SOIC; No of Pins: 8; Temperature Range: Industrial
OP296GSZ-REEL7 Micropower, Rail-to-Rail Input and Output Operational Amplifiers; Package: SOIC; No of Pins: 8; Temperature Range: Industrial
相關代理商/技術參數(shù)
參數(shù)描述
OP296 制造商:AD 制造商全稱:Analog Devices 功能描述:Micropower, Rail-to-Rail Input and Output Operational Amplifiers
OP296A 功能描述:紅外發(fā)射源 Infrared 890nm RoHS:否 制造商:Fairchild Semiconductor 波長:880 nm 射束角:+/- 25 輻射強度: 最大工作溫度:+ 100 C 最小工作溫度:- 40 C 封裝 / 箱體:Side Looker 封裝:Bulk
OP296B 功能描述:紅外發(fā)射源 Infrared 890nm RoHS:否 制造商:Fairchild Semiconductor 波長:880 nm 射束角:+/- 25 輻射強度: 最大工作溫度:+ 100 C 最小工作溫度:- 40 C 封裝 / 箱體:Side Looker 封裝:Bulk
OP296C 功能描述:紅外發(fā)射源 Infrared 890nm RoHS:否 制造商:Fairchild Semiconductor 波長:880 nm 射束角:+/- 25 輻射強度: 最大工作溫度:+ 100 C 最小工作溫度:- 40 C 封裝 / 箱體:Side Looker 封裝:Bulk
OP296GP 制造商:Analog Devices 功能描述:OP AMP DUAL CMOS UPOWER DIP8 296