AD595AQ - Type K Thermocouple Amplifier w/ CJC, 14-CERDIP | Analog Devices
Référence : AD595AQ ✗ Fin de vie| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $25.12 | $25,12 |
| 10 | $22.5 | $225,00 |
| 100 | $19.95 | $1 995,00 |
| 500 | $17.85 | $8 925,00 |
| 1 000 | $16.2 | $16 200,00 |
AD595AQ Présentation
A thermocouple amplifier is a specialized analog front-end IC that conditions the microvolt-level output of a thermocouple - two dissimilar metals joined at a hot junction whose Seebeck voltage tracks temperature - and translates it into a standardized, low-impedance signal that an ADC, controller, or display can read directly. Within the signal-chain hierarchy, the AD595AQ sits between the sensor layer (the Type K probe) and the data-acquisition layer (the ADC or MCU), performing the cold-junction compensation, linearization, and amplification functions that would otherwise demand five to ten discrete components.
Key features include factory-trimmed NIST Type K linearization, 10 mV/°C nominal scaling (versus the raw Type K Seebeck coefficient of roughly 41 µV/°C, an internal gain of ~244×), ±1 °C (A grade) or ±2.5 °C maximum calibration error over the rated span, pin-strappable setpoint-controller mode for switched-output thermostat operation, and an ice-point-trimmed reference accurate to ±0.05 °C/°C of board temperature drift. Internal amplifier bandwidth supports both continuous linearization and PWM-style setpoint use.
Typical applications include industrial oven/ furnace profiling, HVAC duct and stack-gas monitoring, laboratory benchtop temperature instruments, and standalone Celsius transducers driving panel meters or PLC analog inputs. The hermetic 14-CERDIP package suits legacy military/aerospace systems, downhole oil/gas tools, and other environments where plastic SOIC moisture absorption is unacceptable. Note that ADI now classifies the AD595 as "NOT RECOMMENDED FOR NEW DESIGNS," so the AD595AQ is best suited to existing designs, repair stock, or replacement of obsolete industrial boards.
When designing with the AD595AQ, bypass +VS to ground with 0.1 µF ceramic as close to the IC as possible, connect the thermocouple inputs with twisted-pair or shielded wire routed away from switching noise, and remember that the on-chip compensation only addresses the board-side cold junction - any heat conducted down the probe wires will still introduce error. The Q grade is calibrated for 0-300 °C; for higher ranges the C grade (0-1000 °C) is a drop-in alternative.
This page synthesizes distributor pricing, drop-in ADI same-package alternatives, and practical design notes beyond what the manufacturer datasheet alone provides, helping engineers source, substitute, and integrate the AD595AQ with confidence.
Alternatives de remplacement direct pour AD595AQ — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
AD595AD
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD595CQ
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD594AQ
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD594AD
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD594CQ
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD595AQ Valeurs maximales et caractéristiques électriques
| Fonction | Type K thermocouple amplifier with cold-junction compensation |
| Thermocouple Type | Type K (NIST calibrated) |
| Nominal Output Scaling | 10 mV/°C |
| Calibrated Temperature Range (Q grade) | 0 °C to +300 °C |
| Maximum Calibration Error (A grade) | ±1 °C (Q grade is ±2.5 °C) |
| Supply Voltage (Single) | +5 V (±5%) |
| Courant d'alimentation | 300 µA (typical, AD595AQ) |
| Type de sortie | Voltage (low-impedance linear) |
| Cold-Junction Compensation | On-chip ice-point reference |
| Ice-Point Reference Accuracy | ±0.05 °C/°C drift |
| Plage de température de fonctionnement | -55 °C to +125 °C |
| Boîtier | 14-pin CERDIP (Q) hermetic |
| Type de montage | Through-hole |
| Statut RoHS | Non-compliant (contains lead, hermetic CERDIP) |
| Lifecycle | Not Recommended for New Designs (NRND) per ADI |
Configuration des broches de AD595AQ
| Broche 1 | +VS — +5 V supply |
| Broche 2 | TC+ — Thermocouple positive input (Type K) |
| Broche 3 | TC- — Thermocouple negative input (Type K) |
| Broche 4 | COM — Common / ground return |
| Broche 5 | ALM — Alarm output (open collector) |
| Broche 6 | SET — Setpoint input |
| Broche 7 | COMP+ — Compensation trim (positive) |
| Broche 8 | COMP- — Compensation trim (negative) |
| Broche 9 | VREF — Ice-point reference output |
| Broche 10 | VOUT — Linear analog output (10 mV/°C) |
| Broche 11 | GND — Ground |
| Broche 12 | NC — Not connected (per datasheet) |
| Broche 13 | NC — Not connected (per datasheet) |
| Broche 14 | NC — Not connected (per datasheet) |
Applications typiques
AD595AQ convient pour 6 applications: Industrial Oven and Furnace Profiling, Laboratory Benchtop Temperature Instruments, HVAC Duct and Stack-Gas Monitoring, Standalone Celsius Transducer with Low-Impedance Output, Switched-Output Setpoint Thermostat Controller, Military/Aerospace and Downhole Tool Repair Stock.
Industrial Oven and Furnace Profiling
The AD595AQ suits 0-300 °C industrial oven profiling where hermetic CERDIP packaging and on-chip Type K linearization eliminate the discrete cold-junction compensation circuit. With 10 mV/°C output scaling, the part directly drives a panel meter or 12-bit ADC without additional gain stages. Pin-strappable setpoint mode enables switched-output thermostat control for bang-bang heater regulation. The 5 V single supply simplifies integration with legacy industrial controllers; calibrate to ±2.5 °C across the 0-300 °C range, sufficient for paint-curing, food-baking, and plastics-extrusion profiling.
Recommandé
Laboratory Benchtop Temperature Instruments
The AD595AQ integrates the entire Type K signal chain - amplifier, ice-point reference, and NIST linearization - into one ceramic-hermetic IC, dramatically simplifying laboratory thermometer design. Its 10 mV/°C output drives a 3.5-digit panel meter directly without extra scaling, and the on-chip CJC removes the need for an isothermal terminal block in compact benchtop enclosures. For measurement spans within 0-300 °C the Q grade offers ±2.5 °C calibrated accuracy suitable for general lab use; calibration traceability is documented in the Analog Devices AD594/AD595 datasheet.
Recommandé
HVAC Duct and Stack-Gas Monitoring
The AD595AQ suits HVAC duct-temperature and combustion stack-gas monitoring where a single +5 V supply rail and 10 mV/°C direct ADC interface streamline the BOM. Its on-chip CJC tracks ambient board temperature and removes cold-junction drift as air streams move across the terminal strip. The hermetic 14-CERDIP package tolerates humid duct environments better than plastic SOIC alternatives. Use a shielded twisted-pair run from the Type K probe to the IC inputs to reject common-mode HVAC switching noise; bypass +5 V at pin 1 with a 0.1 µF ceramic as close as possible.
Recommandé
Standalone Celsius Transducer with Low-Impedance Output
The AD595AQ can be configured as a standalone Celsius transducer by amplifying its compensation voltage directly, producing a low-impedance 10 mV/°C output suitable for driving long cable runs to remote displays. Per the AD594/AD595 datasheet, this mode bypasses the thermocouple input pins and reads the internal ice-point reference, effectively turning the IC into a board-temperature sensor with NIST-traceable scaling. Useful for chassis-temperature monitoring in industrial enclosures, where the thermocouple inputs are not needed and a simple two-wire +5 V / Vout interface is desired.
Recommandé
Switched-Output Setpoint Thermostat Controller
The AD595AQ supports pin-strappable setpoint-controller operation, functioning as a switched-output thermostat that compares the thermocouple-derived temperature against a fixed or remote setpoint voltage and drives an alarm/heater output. Per the AD594/AD595 datasheet, this mode requires only the addition of a setpoint reference resistor and a pull-up on the alarm pin; internal hysteresis prevents output chatter near the switching point. Suitable for legacy industrial process controllers, safety cutoffs, and refrigeration thermostats where the original design used the AD595 in setpoint mode.
Recommandé
Military/Aerospace and Downhole Tool Repair Stock
The AD595AQ remains in long-term demand for repair and refurbishment of legacy military avionics, aerospace ground-support equipment, and downhole oil/gas logging tools that originally specified the hermetic 14-CERDIP Type K conditioner. ADI classifies the part NRND but continues to support existing customers, and the hermetic CERDIP package is preferred over plastic SOIC for high-vibration, high-temperature, or vacuum environments. Engineers maintaining these systems should source from authorized distributors (DigiKey, Mouser) and verify date codes and country of origin for full traceability.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour AD595AQ — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | AD595AD | AD595CQ | AD594AQ | AD594AD | AD594CQ |
|---|---|---|---|---|---|---|
| Package | 14-CERDIP (Q) hermetic | 14-CERDIP (Q) - same | 14-CERDIP (Q) - same | 14-CERDIP (Q) - same | 14-CERDIP (Q) - same | 14-CERDIP (Q) - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Thermocouple Type | Type K | Type K | Type K | Type J | Type J | Type J |
| Calibrated Range | 0 °C to +300 °C (Q grade) | 0 °C to +300 °C (A grade) | 0 °C to +1000 °C (C grade) | 0 °C to +300 °C (Q grade) | 0 °C to +300 °C (A grade) | 0 °C to +1000 °C (C grade) |
| Maximum Calibration Error | ±2.5 °C | ±1 °C | ±2.5 °C | ±2.5 °C | ±1 °C | ±2.5 °C |
| Output Scaling | 10 mV/°C | 10 mV/°C | 10 mV/°C | 10 mV/°C | 10 mV/°C | 10 mV/°C |
| Supply Voltage | +5 V | +5 V | +5 V | +5 V | +5 V | +5 V |
| Cold-Junction Compensation | On-chip ice-point reference | On-chip ice-point reference | On-chip ice-point reference | On-chip ice-point reference | On-chip ice-point reference | On-chip ice-point reference |
| Lifecycle Status | NRND | NRND | NRND | NRND | NRND | NRND |
Principaux différenciateurs
- Hermetic 14-CERDIP package for harsh-environment use (vs AD8495 (SOIC-8))
- Tighter ±1 °C accuracy available in same pinout (vs AD595CQ)
- Complete Type K signal chain in a single IC (vs AD594AQ)
Notes de conception
Estimated: the AD595AQ draws 300 µA typical from a +5 V supply, for ~1.5 mW dissipation - the 14-CERDIP package easily sinks this with no thermal concerns. Place a 0.1 µF ceramic bypass capacitor as close to pin 1 (+VS) and pin 11 (GND) as trace length allows, with an additional 10 µF tantalum/electrolytic on the supply rail to reject switching-regulator ripple that would otherwise appear on the 10 mV/°C output as a calibration offset.
The on-chip cold-junction compensation only accounts for the temperature of the AD595AQ's own package leads; any heat conducted down the Type K probe sheath from the measured process will still appear as measurement error. For high-accuracy work, use a proper isothermal terminal block at the IC pins, keep the thermocouple wires short, and avoid mounting heat-generating components (regulators, power resistors) within 1-2 cm of the AD595AQ. The 0-300 °C Q grade calibration window is a hard limit - measuring temperatures outside this span will produce significant non-linearity error.
Route the Type K thermocouple inputs (pins 2-3) with shielded or twisted-pair wiring and keep the traces away from switching converter nodes, relay coils, and AC mains. Connect the shield to ground at one end only (typically the IC end) to avoid ground loops. The compensation trim pins (7-8) should be left floating in most applications; if fine calibration is desired, follow the trim procedure in the AD594/AD595 datasheet using low-TC potentiometers. Pin 12-14 are marked NC but should be soldered to the PCB pad to maintain mechanical rigidity of the CERDIP-14 package.
Informations de conformité
The 14-CERDIP (Q) hermetic package contains lead in the glass-metal seal and is therefore non-RoHS compliant per the ADI datasheet. REACH and conflict-minerals status compliant per ADI product declarations. AEC-Q100 automotive qualification is not applicable for this legacy industrial/aerospace part.
