Datasheet MAT04 (Analog Devices) - 6
| Hersteller | Analog Devices |
| Beschreibung | Matched Monolithic Quad Transistor |
| Seiten / Seite | 12 / 6 — MAT04. APPLICATION NOTES. APPLICATIONS CURRENT SOURCES |
| Dateiformat / Größe | PDF / 874 Kb |
| Dokumentensprache | Englisch |
MAT04. APPLICATION NOTES. APPLICATIONS CURRENT SOURCES
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Textversion des Dokuments
MAT04
TPC 10. Total Noise vs. TPC 11. Collector-to-Base TPC 12. Collector-to-Substrate Collector Current Capacitance vs. Collector-to- Capacitance vs. Collector-to- Base Voltage Substrate Voltage
APPLICATION NOTES
It is recommended that one of the substrate pins (Pins 4 and 11) be tied to the most negative circuit potential to minimize cou- pling between devices. Pins 4 and 11 are internally connected.
APPLICATIONS CURRENT SOURCES
The MAT04 can be used to implement a variety of high imped- ance current mirrors as shown in Figures 1, 2, and 3. These current mirrors can be used as biasing elements and load de- vices for amplifier stages. Figure 2. Current Mirror, IOUT = 2(lREF) Figure 1. Unity Gain Current Mirror, I Figure 3. Current Mirror, I OUT = IREF OUT = 1/2(IREF) The unity-gain current mirror of Figure 1 has an accuracy of Figure 4 is a temperature independent current sink that has an better than 1% and an output impedance of over 100 MΩ at accuracy of better than 1% at an output current of 100 µA to 1 100 µA. Figures 2 and 3 show modified current mirrors de- mA. The Schottky diode acts as a clamp to ensure correct cir- signed for a current gain of two, and one-half respectively. The cuit start-up at power on. The resistors used in this circuit accuracy of these mirrors is reduced from that of the unity-gain should be 1% metal-film type. source due to base current errors but is still better than 2%. –6– REV. D
TPC 10. Total Noise vs. TPC 11. Collector-to-Base TPC 12. Collector-to-Substrate Collector Current Capacitance vs. Collector-to- Capacitance vs. Collector-to- Base Voltage Substrate Voltage
APPLICATION NOTES
It is recommended that one of the substrate pins (Pins 4 and 11) be tied to the most negative circuit potential to minimize cou- pling between devices. Pins 4 and 11 are internally connected.
APPLICATIONS CURRENT SOURCES
The MAT04 can be used to implement a variety of high imped- ance current mirrors as shown in Figures 1, 2, and 3. These current mirrors can be used as biasing elements and load de- vices for amplifier stages. Figure 2. Current Mirror, IOUT = 2(lREF) Figure 1. Unity Gain Current Mirror, I Figure 3. Current Mirror, I OUT = IREF OUT = 1/2(IREF) The unity-gain current mirror of Figure 1 has an accuracy of Figure 4 is a temperature independent current sink that has an better than 1% and an output impedance of over 100 MΩ at accuracy of better than 1% at an output current of 100 µA to 1 100 µA. Figures 2 and 3 show modified current mirrors de- mA. The Schottky diode acts as a clamp to ensure correct cir- signed for a current gain of two, and one-half respectively. The cuit start-up at power on. The resistors used in this circuit accuracy of these mirrors is reduced from that of the unity-gain should be 1% metal-film type. source due to base current errors but is still better than 2%. –6– REV. D