LT1008CH - Picoamp Precision Operational Amplifier | Analog Devices
MPN: LT1008CH ✓ نشطLT1008CH نظرة عامة
An operational amplifier is a high-gain differential amplifier whose output responds to the voltage difference between its non-inverting and inverting inputs. Negative feedback causes the amplifier to amplify only the signal presented within its linear operating range while rejecting common-mode voltage and supply-noise variations. Within the broader hierarchy, the LT1008CH is an instrumentation amplifier, an operational amplifier, an analog amplifier, a semiconductor, and ultimately a linear integrated circuit.
The LT1008 family's defining characteristic is input bias current maintained in the picoampere range over the full -55°C to 125°C temperature range. This behavior makes the device useful with high-impedance sources, charge-sensitive transducers, leakage-sensitive sensors, and precision bridges where conventional CMOS or bipolar amplifiers may introduce unacceptable input-current error. The microvolt offset specification and low drift support stable DC measurements, while low voltage noise and current noise improve the useful resolution of small-signal chains.
Extremely high common-mode rejection ratio and power-supply rejection ratio allow the LT1008 to reject interference coupled from the input source or from imperfect power-supply rails. These characteristics matter in systems where the signal of interest is small but supply noise and ground offsets are much larger. The manufacturer describes the device as a universal precision operational amplifier suitable for practically all precision applications.
Typical uses include precision strain-gauge and bridge amplifiers, low-current pH and ion-selective measurement front ends, photodiode and charge-sensitive preamplifiers, laboratory references, low-leakage buffer stages, and precision current-to-voltage converters. The 8-lead TO-5 construction is mechanically robust and suited to laboratory, industrial, and instrumentation systems where through-hole mounting and hermetic construction are preferred.
When designing around the LT1008CH, account for input-bias-current error in the feedback network, provide adequate supply bypassing at the pins, and use guarding to minimize leakage on high-impedance nodes. Because the device can operate from ±18 V, verify the complete circuit's absolute maximum voltages and ensure input common-mode limits are respected during startup and fault conditions. This page consolidates manufacturer specifications, sourcing information, application guidance, and design notes that are not consolidated in a single distributor listing.
بدائل مباشرة لـ LT1008CH — نفس الحزمة، متوافق دبوس بدبوس. تُستثنى القطع ذات الحزم المختلفة التي تتطلب تعديل PCB.
LT1008MH
✅ بديل مباشر📋 بديل مرجعي (غير موجود في الكتالوج)
LT1008CH الحدود القصوى والخصائص الكهربائية
| Amplifier Type | 1 Circuit |
| Product Category | Standard (General Purpose) Amplifier |
| Architecture | Single operational amplifier |
| Input Bias Current | Picoampere range |
| Input Offset Voltage | Microvolt range |
| Voltage Noise | Low noise |
| Current Noise | Low noise |
| Common-Mode Rejection Ratio | Extremely high |
| Power Supply Rejection Ratio | Extremely high |
| Output Current | 5 mA load current |
| Maximum Supply Current | 0.8 mA |
| جهد التغذية | ±18 V |
| نطاق درجة حرارة التشغيل | -55°C to 125°C |
| Bias Current Temperature Stability | Picoampere bias current maintained over -55°C to 125°C |
| Package Type | TO-5, round, 8 leads, wire form |
| Number of Terminals | 8 |
| نوع التركيب | Through-hole |
دليل تكوين أطراف LT1008CH to-5, round, 8 leads, wire form
تكوين الأطراف لـ LT1008CH (حزمة to-5, round, 8 leads, wire form). يتميز هذا المكوّن التناظري بأطراف الإدخال والإخراج وإمداد الطاقة. راجع ورقة بيانات الشركة المصنعة لتكوينات طرف إلغاء الإزاحة والتعويض والتمكين. مثالي لدوائر تكييف الإشارة والمضخمات.
لا تتوفر بيانات مفصلة لمخطط التوصيلات لـ LT1008CH.
راجع ورقة البيانات للحصول على تكوين الأطراف الكامل.
التطبيقات النموذجية
LT1008CH مناسب لـ 6 التطبيقs: Precision Bridge and Strain-Gauge Amplification, Low-Current Sensor and pH Front End, Photodiode and Charge-Sensitive Preamplification, Precision Current-to-Voltage Conversion, Laboratory Reference and Buffer Stage, Industrial Process Instrumentation.
Precision Bridge and Strain-Gauge Amplification
The LT1008CH suits strain-gauge and resistive-bridge front ends because its picoampere input bias current produces minimal error in the high-value bridge and feedback networks. The microvolt-level offset and low drift also help preserve the small full-scale signal generated by mechanical strain. Place the amplifier in the bridge leg nearest the sensor, use matched high-precision resistors, and guard the input node against surface leakage. Compared with a general-purpose amplifier such as the LM324D, the LT1008CH better preserves DC accuracy when source impedance and bridge resistance are high. Its 5 mA output capability provides adequate drive for subsequent ADC front ends while keeping the overall system insensitive to supply and common-mode disturbances.
موصى به
Low-Current Sensor and pH Front End
The LT1008CH is well matched to pH electrodes, ion-selective electrodes, and other sensors whose useful output is measured in picoamperes or microvolts. Picoampere input bias current prevents the amplifier itself from generating an error comparable to the sensor current, while low voltage noise helps resolve small potential changes. Use guarding, clean connectors, and moisture control around high-impedance input nodes to avoid board leakage that can overwhelm the measurement. The LT1008CH's extremely high common-mode rejection is valuable when the sensor output is referenced to a noisy analog ground. Compared with the MC1458D, the LT1008CH is the better primary choice when picoampere bias-current stability is the dominant error term.
موصى به
Photodiode and Charge-Sensitive Preamplification
The LT1008CH can serve as the first amplifier stage for photodiode, ion detector, or other charge-sensitive sensing because picoampere bias current minimizes disturbance of the sensing node. Low current noise and low voltage noise preserve resolution when the useful signal is smaller than the sensor leakage floor. Place the amplifier close to the detector, shield sensitive inputs, and maintain a guarded, low-leakage layout around the feedback components. The device's 5 mA output-current capability is adequate for driving a following filter stage over reasonable cable distances. Compared with the LM324D, whose bias current is substantially higher, the LT1008CH offers a clear advantage whenever input-current error defines the measurement limit.
موصى به
Precision Current-to-Voltage Conversion
The LT1008CH is suitable for converting small currents into measurable voltages when bias-current and offset errors would otherwise obscure the result. Picoampere input bias current is especially valuable with currents in the picoampere-to-nanoampere range, while microvolt-level offset and low drift stabilize the zero point. Choose feedback resistors with tight tolerance and low voltage coefficients, and verify the amplifier's input-voltage and input-current limits against the expected operating range. Its extremely high power-supply rejection helps isolate the conversion stage from supply ripple. The MC1458D is a practical general-purpose alternative for less demanding conversions, but the LT1008CH is preferable when the input source approaches the picoampere range.
موصى به
Laboratory Reference and Buffer Stage
The LT1008CH can buffer stable references, divider outputs, and laboratory sources where added noise, offset drift, or loading error would affect the measurement. Its low noise and high voltage gain allow it to maintain signal integrity behind higher-impedance downstream loads, while the 8-lead TO-5 package provides a mechanically robust through-hole solution for laboratory and industrial equipment. The 5 mA output capability is suitable for moderate loads, but the design should account for output-current limits and stability at the selected gain. Compared with the LM324D, the LT1008CH contributes less input bias current, offset voltage, and drift. The NE5534DR is a reasonable low-noise alternative when picoampere bias current is unnecessary and lower-noise audio-style performance is more important.
موصى به
Industrial Process Instrumentation
The LT1008CH fits industrial process-measurement modules that combine a slow sensor signal with a relatively noisy 4-20 mA process environment. Picoampere input bias current reduces error at high-impedance sensor connections, and the extremely high common-mode rejection helps suppress ground-potential differences and coupling from adjacent machinery. Its TO-5 hermetic package and -55°C to 125°C bias-current stability are useful for rugged equipment. The 5 mA output rating supports moderate downstream loads, while ±18 V capability allows dual-rail implementation. The LM224DR can handle less sensitive auxiliary channels, but the LT1008CH should be selected for the input directly connected to the precision sensor. Grounding and guarding remain essential because the amplifier cannot compensate for contaminated or poorly insulated sensor wiring.
موصى به
ملخص المنتجات الموصى بها
بيانات مرجعية هندسية لـ LT1008CH — المقارنة وإرشادات التصميم ومعلومات الامتثال.
دليل الاختيار
المقارنة مع البدائل
| المعامل | هذا المنتج | LT1008MH |
|---|---|---|
| Brand | Analog Devices | Analog Devices |
| Package | TO-5, round, 8 leads | TO-5, round, 8 leads |
| Amplifier Type | 1 Circuit | 1 Circuit |
| Product Category | Standard (General Purpose) Amplifier | Standard precision operational amplifier |
| Input Bias Current | Picoampere range | Picoampere range |
| Input Offset Voltage | Microvolt range | Microvolt range |
| Common-Mode Rejection Ratio | Extremely high | Extremely high |
| Power Supply Rejection Ratio | Extremely high | Extremely high |
| Output Current Capability | 5 mA | 5 mA |
| Supply Voltage | ±18 V | ±18 V |
| Temperature Range | -55°C to 125°C | Military-grade suffix configuration; confirm exact rating |
أبرز الفروقات
- Picoampere-class input bias current supports very high source impedances (مقابلLM324D)
- Microvolt-level offset supports precision DC measurement (مقابلMC1458D)
- Hermetic 8-lead TO-5 construction for precision instrumentation (مقابلTLV1504ID)
ملاحظات التصميم
The most common error is selecting a general-purpose amplifier for a high-impedance source. The LT1008CH is justified when input bias current is comparable to the signal current; use it for picoampere-level sources, not merely to obtain a conventional low-noise amplifier. Keep high-value feedback resistors away from contaminated board surfaces, use guarding around sensitive inputs, and verify that connector leakage, solder-flux residue, and humidity do not exceed the available measurement current.
Although the LT1008CH is a through-lead TO-5 device, layout quality still affects precision performance. Place input and feedback components close to pins 1-8 as identified in the official datasheet, keep input traces short, and provide a quiet analog ground path. Avoid routing high-current or switching-node copper beneath the input and feedback network. Use a grounded guard trace around the most sensitive input node to suppress surface leakage.
Bypass the power-supply pins with short, low-inductance ceramic capacitors placed adjacent to the device, and avoid long traces between the amplifier and bypass components. The verified records identify ±18 V operation and 5 mA output-load capability, but designers must check the official absolute-maximum table before applying rail transients. Provide controlled power sequencing so that input and output voltages do not exceed the specified common-mode and supply limits during startup.
معلومات الامتثال
The supplied verified records identify the LT1008CH as a general-purpose precision amplifier in an 8-lead TO-5 package but do not state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. No compliance declaration was inferred.
