Datasheet LM334S (Analog Devices) - 7
| Hersteller | Analog Devices |
| Beschreibung | Constant Current Source and Temperature Sensor |
| Seiten / Seite | 12 / 7 — APPLICATIO S I FOR ATIO. Figure 3. Centigrade Temperature Sensor. Figure … |
| Dateiformat / Größe | PDF / 165 Kb |
| Dokumentensprache | Englisch |
APPLICATIO S I FOR ATIO. Figure 3. Centigrade Temperature Sensor. Figure 4. Centigrade Temperature Sensor with 2 Point Trim
Modelllinie für dieses Datenblatt
Textversion des Dokuments
LM134 Series
U U W U APPLICATIO S I FOR ATIO
The two trims shown in Figure 3 are still intended to be a If higher accuracy is required, a two point calibration “one point” temperature calibration, where the zero and technique can be used. In Figure 4, separate zero and slope the slope are trimmed at a single temperature. The LT1009 trims are provided. Residual nonlinearity is now the limi- reference is adjusted to give 2.700V at node “a” at TSENSOR tation on accuracy. Nonlinearity of the LM134 in a 100°C = 25°C. The 1k trimmer then adjusts the output for 0.25V, span is typically less than 0.5°C. This particular method of completing the calibration. If the calibration is to be done trimming has the advantage that the slope trim does not at a temperature other than 25°C , trim the LT1009 for interact with the zero trim. Trim procedure is to adjust for 2.7025—(1µA)[TSENSOR (°C)](100Ω) at node “a”, then zero output with TSENSOR = 0°C, then trim slope for proper adjust the 1k trimmer for proper output. output at some convenient second temperature. No fur- ther trimming is required. VS ≥ 4V V+ V+ ≥ 5V LM134-3 R V+ LM134-3 OUTPUT R R SET 10mV/°C V– 226Ω 9.53k OUTPUT 1% 226Ω* V– 10mV/°C 1k 332k 11k* 50k SLOPE 1% 1% ADJ SLOPE LT1009 *LOW TC, STABLE RESISTOR TRIM ZERO 100Ω 15k “a” 500k TRIM LT1009 10k 10k –15V 134 F03 10k 134 F04 –15V ZERO ADJ
Figure 3. Centigrade Temperature Sensor Figure 4. Centigrade Temperature Sensor with 2 Point Trim U TYPICAL APPLICATIO S Basic 2-Terminal Low Output Impedance Zero Temperature Current Source Thermometer (Kelvin Output) Coefficient Current Source
VIN V V IN ≥ 4.8V IN I+ V+ V+ V+ R3* R R 600Ω V I OUT = 10mV/°K R SET ZOUT ≤ 100Ω R1 RSET 230Ω LM334 V– LM334 V– LM334 V– 1% RSET R2 C1 D1 R1* 134 TA02 10k 0.1µF 1N457 ≈10 R –VIN 1% SET 134 TA03 –V 134 TA04 IN *SELECT RATIO OF R1 TO RSET TO *OUTPUT IMPEDANCE OF THE LM134 AT THE “R” PIN IS OBTAIN ZERO DRIFT. I+ ≈2 ISET. –RO APPROXIMATELY Ω, WHERE RO IS THE EQUIVALENT 16 EXTERNAL RESISTANCE CONNECTED TO THE V– PIN. THIS NEGATIVE RESISTANCE CAN BE REDUCED BY A FACTOR OF 5 OR MORE BY INSERTING AN EQUIVALENT RESISTOR IN SERIES WITH THE OUTPUT. 7
U U W U APPLICATIO S I FOR ATIO
The two trims shown in Figure 3 are still intended to be a If higher accuracy is required, a two point calibration “one point” temperature calibration, where the zero and technique can be used. In Figure 4, separate zero and slope the slope are trimmed at a single temperature. The LT1009 trims are provided. Residual nonlinearity is now the limi- reference is adjusted to give 2.700V at node “a” at TSENSOR tation on accuracy. Nonlinearity of the LM134 in a 100°C = 25°C. The 1k trimmer then adjusts the output for 0.25V, span is typically less than 0.5°C. This particular method of completing the calibration. If the calibration is to be done trimming has the advantage that the slope trim does not at a temperature other than 25°C , trim the LT1009 for interact with the zero trim. Trim procedure is to adjust for 2.7025—(1µA)[TSENSOR (°C)](100Ω) at node “a”, then zero output with TSENSOR = 0°C, then trim slope for proper adjust the 1k trimmer for proper output. output at some convenient second temperature. No fur- ther trimming is required. VS ≥ 4V V+ V+ ≥ 5V LM134-3 R V+ LM134-3 OUTPUT R R SET 10mV/°C V– 226Ω 9.53k OUTPUT 1% 226Ω* V– 10mV/°C 1k 332k 11k* 50k SLOPE 1% 1% ADJ SLOPE LT1009 *LOW TC, STABLE RESISTOR TRIM ZERO 100Ω 15k “a” 500k TRIM LT1009 10k 10k –15V 134 F03 10k 134 F04 –15V ZERO ADJ
Figure 3. Centigrade Temperature Sensor Figure 4. Centigrade Temperature Sensor with 2 Point Trim U TYPICAL APPLICATIO S Basic 2-Terminal Low Output Impedance Zero Temperature Current Source Thermometer (Kelvin Output) Coefficient Current Source
VIN V V IN ≥ 4.8V IN I+ V+ V+ V+ R3* R R 600Ω V I OUT = 10mV/°K R SET ZOUT ≤ 100Ω R1 RSET 230Ω LM334 V– LM334 V– LM334 V– 1% RSET R2 C1 D1 R1* 134 TA02 10k 0.1µF 1N457 ≈10 R –VIN 1% SET 134 TA03 –V 134 TA04 IN *SELECT RATIO OF R1 TO RSET TO *OUTPUT IMPEDANCE OF THE LM134 AT THE “R” PIN IS OBTAIN ZERO DRIFT. I+ ≈2 ISET. –RO APPROXIMATELY Ω, WHERE RO IS THE EQUIVALENT 16 EXTERNAL RESISTANCE CONNECTED TO THE V– PIN. THIS NEGATIVE RESISTANCE CAN BE REDUCED BY A FACTOR OF 5 OR MORE BY INSERTING AN EQUIVALENT RESISTOR IN SERIES WITH THE OUTPUT. 7