BCR400 Datasheet, PDF (1/3 Pages) Infineon Technologies AG – Application Considerations for the Integrated Bias Control Circuits

Silicon Discrete Components
Application Considerations
for the Integrated Bias Control Circuits
BCR400R and BCR400W
Application Note No. 014
Figure 1 RF Transistor Controlled by BCR400
Operating Point
• BCR400 stabilizes the operating current (i.e. I_C or I_D), the collector (or drain) voltage
depends on the supply voltage: V_CE = V_S - 0.65 V
• The voltage drop of approximately 0.65 V on R_ext (i.e. between pins 3 and 4 of
BCR400) is almost constant (R_ext = 0.65 V x I_C)
• In case a lower V_CE is really required (e.g. to prevent exceeding of maximum V_CE or
V_DS ratings), an additional resistor R = (V_S - V_CE - 0.65 V) / I_C can be inserted either
between pin 4 and collector (or drain) or in series to the supply voltage V_S, thus
providing an additional voltage drop.
Application Note
1
2000-07-27