參數(shù)資料
型號: TC911ACPA
廠商: Microchip Technology Inc.
英文描述: Monolithic Auto-Zeroed Operational Amplifers
中文描述: 單片自動清零操作Amplifers
文件頁數(shù): 4/5頁
文件大?。?/td> 69K
代理商: TC911ACPA
3-266
TELCOM SEMICONDUCTOR, INC.
AUTO-ZEROED MONOLITHIC
OPERATIONAL AMPLIFIERS
TC911A
TC911B
Pin Compatibility
The CMOS TC911 is pin compatible with the industry
standard ICL7650 chopper-stabilized amplifier. The ICL7650
must use external 0.1
μ
F capacitors connected at pins 1 and
8.
With the TC911, external offset voltage error cancel-
ing capacitors are not required.
On the TC911 pins 1, 8
and 5 are not connected internally. The ICL7650 uses pin 5
as an optional output clamp connection. External chopper
capacitors and clamp connections are not necessary with
the TC911. External circuits connected to pins 1, 8 and 5 will
have no effect. The TC911 can be quickly evaluated in
existing ICL7650 designs. Since external capacitors are not
required, system part count, assembly time, and total sys-
tem cost are reduced. Reliability is increased and PC board
layout eased by having the error storage capacitors inte-
grated on the TC911 chip.
The TC911 pinout matches many existing op amps:
741, LM101, LM108, OP05–OP08, OP-20, OP-21, ICL7650
and ICL7652. In many applications operating from +5V
supplies the TC911 offers superior electrical performance
and can be a functional pin-compatible replacement. Offset
voltage correction potentiometers, compensation capaci-
tors, and chopper-stabilization capacitors can be removed
when retrofitting existing equipment designs.
Thermocouple Errors
Heating one joint of a loop made from two different
metallic wires causes current flow. This is known as the
Seebeck effect. By breaking the loop, an open circuit voltage
(Seebeck voltage) can be measured. Junction temperature
and metal type determine the magnitude. Typical values are
0.1
μ
V/
°
C to 10
μ
V/
°
C. Thermal-induced voltages can be
many times larger than the TC911 offset voltage drift. Unless
unwanted thermocouple potentials can be controlled, sys-
tem performance will be less than optimum.
Unwanted thermocouple junctions are created when
leads are soldered or sockets/connectors are used. Low
thermo-electric coefficient solder can reduce errors. A 60%
Sn/36% Pb solder has 1/10 the thermal voltage of common
64% Sn/36% Pb solder at a copper junction.
The number and type of dissimilar metallic junctions in
the input circuit loop should be balanced. If the junctions are
kept at the same temperature, their summation will add to
zero-canceling errors (Figure 1).
Shielding precision analog circuits from air currents —
especially those caused by power dissipating components
and fans — will minimize temperature gradients and ther-
mocouple-induced errors.
Avoiding Latch-Up
Junction-isolated CMOS circuits inherently contain a
parasitic p-n-p-n transistor circuit. Voltages exceeding the
supplies by 0.3V should not be applied to the device pins.
Larger voltages can turn the p-n-p-n device on, causing
excessive device power supply current and excessive power
dissipation. TC911 power supplies should be established at
the same time or before input signals are applied. If this is not
possible input current should be limited to 0.1mA to avoid
triggering the p-n-p-n structure.
Overload Recovery
The TC911 recovers quickly from the output saturation.
Typical recovery time from positive output saturation is
20msec. Negative output saturation recovery time is typi-
cally 5msec.
Figure 1. Unwanted Thermocouple Errors Eliminated by
Reducing Thermal Gradients and Balancing Junctions
J3
J4
J5
J2
J1
J6
PACKAGE
PIN
3
2
1
4
5
6
NO TEMPERATURE DIFFERENTIAL
AND SAME METALLIC CONNECTION
+
+
+
+
+
+
V2
V1
V5
J5
V6
J6
V4
V3
J4
J3
J2
J1
VT
T
1
2
3
4
5
6
相關PDF資料
PDF描述
TC911B Monolithic Auto-Zeroed Operational Amplifers
TC911BCPA Monolithic Auto-Zeroed Operational Amplifers
TC911BCOA Monolithic Auto-Zeroed Operational Amplifers
TC911ACOA AUTO-ZEROED OPERATIONAL AMPLIFIERS
TC911A AUTO-ZEROED OPERATIONAL AMPLIFIERS
相關代理商/技術參數(shù)
參數(shù)描述
TC911B 制造商:TELCOM 制造商全稱:TelCom Semiconductor, Inc 功能描述:AUTO-ZEROED OPERATIONAL AMPLIFIERS
TC911BCOA 功能描述:運算放大器 - 運放 Mono Auto-Zero 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
TC911BCPA 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:Monolithic Auto-Zeroed Operational Amplifiers
TC912 SC 制造商:Thomas & Betts 功能描述:3/4" CONN,COMP.,90DEG,EMT,DC 制造商:Thomas & Betts 功能描述:Fittings Connector 0.75inch Zinc
TC9122P 制造商:未知廠家 制造商全稱:未知廠家 功能描述:HIGH-SPEED BCD PROGRAMMABLE COUNTER