BCR400 Datasheet, PDF (2/3 Pages) Infineon Technologies AG – Application Considerations for the Integrated Bias Control Circuits

Application Considerations for the Integrated
Bias Control Circuits BCR400R and BCR400W
Stability
BCR400 stabilizes bias current of transistors in an active control loop. In order to avoid
loop oscillation (hunting), time constants must be chosen adequately, i.e. C₁ >= 10 x C₂.
It is strongly recommended that the entire DC circuit is analyzed and optimized for
stability with one of the commercially available SPICE simulators.
Thermal considerations
The collector or drain current of a stabilized RF transistor does not directly affect
BCR400, as it must only provide the base current (or gate bias current). Even as a stand-
alone current source it is not possible to exceed P_tot (up to T_s = 115°C), if the maximum
ratings of V_s and I_contr are adhered to (see data sheet).
Preliminary SPICE Parameters
*****************************************************************
.MODEL DI400 D(
+
IS= 6.00E-15
N= 1.20E+00 RS= 5.0E+01
+
IBV= 1.00E-04 BV= 7.50E+01
+
M= 1.00E-01 CJO= 6.87E-13 EG= 1.11E+00
+
TT= 8.66E-09 VJ= 2.00E+00 XTI= 5.00E+00)
* one internal Diode of BCR400
*****************************************************************
.MODEL TR400 PNP(
+
BF= 3.00E+02 BR= 3.38E+00 CJC= 2.00E-12
+
CJE= 1.56E-11 CJS= 0.00E+00 EG= 1.11E+00 FC= 8.28E-01
+
IKF= 1.00E-02 IKR= 0.40E-02 IRB= 0.30E-06 IS= 0.30E-14
+
ISC= 2.00E-14 ISE= 0.50E-13 ITF= 0.50E-01
+
MJC= 3.49E-01 MJE= 4.18E-01 MJS= 3.30E-01 NC= 1.19E+00
+
NE= 1.83E+00 NF= 1.00E+00 NR= 1.00E+00 PTF= 0.00E+00
+
RB= 1.00E+02 RBM= 1.00E+01 RC= 5.00E+00 RE= 2.00E-01
+
TF= 6.05E-10 TR= 0.00E+00 VAF= 5.90E+01 VAR= 1.74E+01
+
VJC= 3.00E-01 VJE= 8.00E-01 VJS= 7.50E-01 VTF= 4.39E+00
+
XCJC= 1.00E+00 XTB= 0.00E+00 XTF= 5.81E+00 XTI= 1.50E+00)
*****************************************************************
* internal parallel resistance Rint= 6.5 kOhm
* Rb= 75 kOhm
*****************************************************************
Application Note
2
2000-07-27