Zakładka z wyszukiwarką danych komponentów |
|
AD1583A Arkusz danych(PDF) 9 Page - Analog Devices |
|
AD1583A Arkusz danych(HTML) 9 Page - Analog Devices |
9 / 12 page AD1582/AD1583/AD1584/AD1585 –9– REV. D THEORY OF OPERATION The AD1582/AD1583/AD1584/AD1585 family uses the band gap concept to produce stable, low temperature coefficient voltage references suitable for high accuracy data acquisition components and systems. This family of precision references uses the underlying temperature characteristics of a silicon transistor’s base emitter voltage in the forward-biased operating region. Under this condition, all such transistors have a –2 mV/ °C temperature coefficient (TC) and a VBE that, when extrapolated to absolute zero, 0 °K (with collector current proportional to absolute temperature), approximates the silicon band gap voltage. By summing a voltage that has an equal and opposite temperature coefficient of 2 mV/ °C with the V BE of a forward-biased transistor, an almost zero TC reference can be developed. In the AD1582/ AD1583/AD1584/AD1585 simplified circuit diagram shown in Figure 2, such a compensating voltage, V1, is derived by driving two transistors at different current densities and amplifying the resultant VBE difference ( ∆V BE, which has a positive TC). The sum of VBE and V1(VBG) is then buffered and ampli- fied to produce stable reference voltage outputs of 2.5 V, 3 V, 4.096 V, and 5 V. R3 R4 VBE R2 R6 R5 VOUT VIN VBG GND V1 + – R1 + – Figure 2. Simplified Schematic APPLYING THE AD1582/AD1583/AD1584/AD1585 The AD1582/AD1583/AD1584/AD1585 is a family of series references that can be used for many applications. To achieve optimum performance with these references, only two external components are required. Figure 3 shows the AD1582 configured for operation under all loading conditions. With a simple 4.7 µF capacitor attached to the input and a 1 µF capacitor applied to the output, the devices can achieve specified performance for all input voltage and output current requirements. For best transient response, add a 0.1 µF capacitor in parallel with the 4.7 µF capacitor. While a 1 µF output capacitor can provide stable performance for all loading conditions, the AD1582 can operate under low (–100 µA < I OUT < +100 µA) current conditions with just a 0.2 µF output capacitor. The 4.7 µF capacitor on the input can be reduced to 1 µF in this condition. Unlike conventional shunt reference designs, the AD1582/ AD1583/AD1584/AD1585 family provides stable output voltages at constant operating current levels. When properly decoupled, as shown in Figure 3, these devices can be applied to any circuit and provide superior low power solutions. + – VOUT 1 F 1 2 VIN 4.7 F 3 AD1582/ AD1583/ AD1584/ AD1585 Figure 3. Typical Connection Diagram TEMPERATURE PERFORMANCE The AD1582/AD1583/AD1584/AD1585 family of references is designed for applications where temperature performance is important. Extensive temperature testing and characterization ensures that the device’s performance is maintained over the specified temperature range. The error band guaranteed with the AD1582/AD1583/AD1584/ AD1585 family is the maximum deviation from the initial value at 25 °C. Thus, for a given grade of the AD1582/AD1583/AD1584/ AD1585, the designer can easily determine the maximum total error by summing initial accuracy and temperature variation, e.g., for the AD1582BRT, the initial tolerance is ±2 mV, the temperature error band is ±8 mV, thus the reference is guaranteed to be 2.5 V ± 10 mV from –40°C to +125°C. Figure 4 shows the typical output voltage drift for the AD1582 and illustrates the methodology. The box in Figure 4 is bounded on the x-axis by operating temperature extremes. It is bounded on the y-axis by the maximum and minimum output voltages observed over the operating temperature range. The slope of the diagonal drawn from the initial output value at 25 °C to the output values at +125 °C and –40°C determines the performance grade of the device. Duplication of these results requires a test system that is highly accurate with stable temperature control. Evaluation of the AD1582 produces curves similar to those in TPC 3 and Figure 4, but output readings may vary depending upon the test methods and test equipment used. TEMPERATURE ( C) –40 –20 0 20 40 60 80 100 120 2.504 2.502 2.496 2.494 2.492 2.500 2.498 Figure 4. Output Voltage vs. Temperature |
Podobny numer części - AD1583A |
|
Podobny opis - AD1583A |
|
|
Link URL |
Polityka prywatności |
ALLDATASHEET.PL |
Czy Alldatasheet okazała się pomocna? [ DONATE ] |
O Alldatasheet | Reklama | Kontakt | Polityka prywatności | Linki | Lista producentów All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |