- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383388 > MAX4122 (Maxim Integrated Products, Inc.) Single/Dual/Quad, Wide-Bandwidth, Low-Power, Single-Supply Rail-to-Rail I/O Op Amps PDF資料下載
參數(shù)資料
| 型號： | MAX4122 |
| 廠商： | Maxim Integrated Products, Inc. |
| 英文描述： | Single/Dual/Quad, Wide-Bandwidth, Low-Power, Single-Supply Rail-to-Rail I/O Op Amps |
| 中文描述： | 單/雙/四路、寬帶、低功耗、單電源、滿擺幅輸入/輸出運算放大器 |
| 文件頁數(shù)： | 11/16頁 |
| 文件大?。?/td> | 285K |
| 代理商： | MAX4122 |
Applic ations Information
Rail-to-Rail Input S tage
Devices in the MAX4122–MAX4129 family of high-
speed amplifiers have rail-to-rail input and output
stages designed for low-voltage single-supply opera-
tion. The input stage consists of separate NPN and
PNP differential stages, which combine to provide an
input common-mode range extending 0.2V beyond the
supply rails. The PNP stage is active for input voltages
close to the negative rail, and the NPN stage is active
for input voltages near the positive rail. The input offset
voltage is typically below 200μV. The switchover transi-
tion region, which occurs near V
CC
/2, has been
extended to minimize the slight degradation in CMRR
caused by the mismatch of the input pairs. Their low
offset voltage, high bandwidth, and rail-to-rail common-
mode range make these op amps excellent choices for
precision low-voltage data-acquisition systems.
Since the input stage switches between the NPN and
PNP pairs, the input bias current changes polarity as
the input voltage passes through the transition region.
To reduce the offset error caused by input bias cur-
rents flowing through external source impedances,
match the effective impedance seen by each input
(Figures 1a, 1b). High source impedances, together
with the input capacitance, can create a parasitic pole
that produces an underdamped signal response.
Reducing the input impedance or placing a small (2pF
to 10pF) capacitor across the feedback resistor
improves the response.
The MAX4122–MAX4129’s inputs are protected from
large differential input voltages by 1k
series resistors
and back-to-back triple diodes across the inputs
(Figure 2). For differential input voltages less than 1.8V
the input resistance is typically 500k
. For differential
input voltages greater than 1.8V the input resistance is
approximately 2k
, and the input bias current is
determined by the following equation:
= V
BIAS
Rail-to-Rail Output S tage
The minimum output voltage will be within millivolts of
ground for single-supply operation where the load is
referenced to ground (V
EE
). Figure 3 shows the input
voltage range and output voltage swing of a MAX4123
connected as a voltage follower. With a +3V supply
and the load tied to ground, the output swings from
0.00V to 2.90V. The maximum output voltage swing
depends on the load, but will be within 150mV of a +3V
supply, even with the maximum load (500
to ground).
Driving a capacitive load can cause instability in most
high-speed op amps, especially those with low quiescent
current. The MAX4122–MAX4129 have a high tolerance
for capacitive loads. They are stable with capacitive
loads up to 500pF. Figure 4 gives the stable operating
region for capacitive loads. Figures 5–8 show the
response with capacitive loads, and the results of adding
an isolation resistor in series with the output (Figure 9).
The resistor improves the circuit’s phase margin by iso-
lating the load capacitor from the op amp’s output.
I
- 1.8V
2k
DIFF
M
S ingle/Dual/Quad, Wide-Bandwidth, Low-Power,
S ingle-S upply Rail-to-Rail I/O Op Amps
______________________________________________________________________________________
11
IN
TIME (2
μ
s/div)
V
OUT
V
CC
= 3V
A
V
= +1
Figure 3. Rail-to-Rail Input /Output Voltage Range
10,000
100
100
1k
RESISTIVE LOAD (
)
100k
10k
C
1000
UNSTABLE
REGION
R
L
TOV
EE
V
OUT
= V
CC
/2
Figure 4. Capacitive-Load Stability
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MAX4123 | Single/Dual/Quad, Wide-Bandwidth, Low-Power, Single-Supply Rail-to-Rail I/O Op Amps |
| MAX4123ESA | Single/Dual/Quad, Wide-Bandwidth, Low-Power, Single-Supply Rail-to-Rail I/O Op Amps |
| MAX4124 | Single/Dual/Quad, Wide-Bandwidth, Low-Power, Single-Supply Rail-to-Rail I/O Op Amps |
| MAX4125 | Single/Dual/Quad, Wide-Bandwidth, Low-Power, Single-Supply Rail-to-Rail I/O Op Amps |
| MAX4126 | Single/Dual/Quad, Wide-Bandwidth, Low-Power, Single-Supply Rail-to-Rail I/O Op Amps |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MAX4122EUK | 制造商:Maxim Integrated Products 功能描述:SINGLE/DUAL/QUAD WIDE-BANDWIDTH LOW-POWER SINGLE-SUPPLY RAIL - Bulk |
| MAX4122EUK/GH9 | 制造商:Maxim Integrated Products 功能描述:SINGLE/DUAL/QUAD, WIDE-BANDWIDTH, LOW-POWER, SINGLE-SUPPLY R - Bulk |
| MAX4122EUK/GH9-T | 功能描述:運算放大器 - 運放 Single-Supply Rail-to-Rail I/O Op Amps 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(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel |
| MAX4122EUK+ | 制造商:Maxim Integrated Products 功能描述:OP AMP SGL GP R-R I/O 3.25V/6.5V 5PIN SOT-23 - Bulk |
| MAX4122EUK+T | 功能描述:運算放大器 - 運放 Single Wide-Bandwdth Single-Supply R-R 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(fēng)格:SMD/SMT 封裝 / 箱體:QFN-16 轉(zhuǎn)換速度:0.89 V/us 關(guān)閉:No 輸出電流:55 mA 最大工作溫度:+ 125 C 封裝:Reel |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。