BCR400W
Aug-07-20011
Active Bias Controller
Characteristics
Supplies stable bias current even at low battery
voltage and extreme ambient temperature variation
Low voltage drop of 0.7V
Application notes
Stabilizing bias current of NPN transistors
and FET's from less than 0.2mA up to
more than 200mA
Ideal supplement for Sieget and other transistors
also usable as current source up to 5mA
VPS05605
4
2
1
3
EHA07188
4 3
21
Type Marking Pin Configuration Package
BCR400W W4s 1=GND/ENPN 2=Contr/BNPN 3VS4=Rext/CNPN SOT343
(ENPN, BNPN, CNPN are electrodes of a stabilized NPN transistor)
Maximum Ratings
Parameter Symbol Value Unit
Source voltage VS18 V
Control current IContr. 10 mA
Control voltage VContr. 16 V
Reverse voltage between all terminals VR0.5
Total power dissipation, TS = 117 °C Ptot 330 mW
Junction temperature Tj150 °C
Storage temperature Tstg -65 ... 150
Thermal Resistance
Junction - soldering point1) RthJS
100 K/W
1For calculation of RthJA please refer to Application Note Thermal Resistance
BCR400W
Aug-07-20012
Electrical Characteristics at TA=25°C, unless otherwise specified
Parameter Symbol Values Unit
min. typ. max.
DC Characteristics
Additional current consumption
VS = 3 V I0- 20 40 µA
Lowest stabilizing current
VS = 3 V Imin - 0.1 - mA
DC Characteristics with stabilized NPN-Transistors
Lowest sufficient battery voltage
IB (NPN) < 0.5mA VSmin - 1.6 - V
Voltage drop (VS - VCE)
IC = 25 mA Vdrop - 0.65 -
Change of IC versus hFE
hFE = 50
IC/IC- 0.08 -
hFE /
hFE
Change of IC versus VS
VS = 3 V
IC/IC- 0.15 -
VS/VS
Change of IC versus TA
IC/IC- 0.2 - %/K
BCR400W
Aug-07-20013
Collector current IC = f (hFE)
IC and hFE refer to stabilized NPN Transisto
r
Parameter Rext. (
)
0 50 100 150 200 250 -350
hFE
-1
10
0
10
1
10
2
10
3
10
mA
I
C
760
5.9
67
Collector Current IC = f (VS)
of stabilized NPN Transistor
Parameter Rext. (
)
0 2 4 6 8 V11
VS
-1
10
0
10
1
10
2
10
3
10
mA
I
C
2.1
5.9
12.4
67
760
4.3k
Voltage drop Vdrop = f (IC)
10 -2 10 -1 10 0 10 1 10 2 10 3
mA
IC
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
V2
V
drop
Collector current IC = f (Rext.)
of stabilized NPN Transistor
10 0 10 1 10 2 10 3 10 4
Ohm
Rext.
-1
10
0
10
1
10
2
10
3
10
mA
I
C
BCR400W
Aug-07-20014
Control current I = f (Rext.)
in current source application
10 -1 10 0 10 1 10 2 10 3
KOhm
Rext.
-1
10
0
10
1
10
mA
I
Contr.
Collector current TA = f (IC)
of stabilized NPN Transistor
Parameter: Rext.(
)
-40 -20 0 20 40 60 80 100 120 °C 160
TA
-1
10
0
10
1
10
2
10
3
10
mA
I
C
2.2
6
26
65
290
760
4.3k
Control current I = f (VS)
in current source application
0 2 4 6 8 V11
VS
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
mA
2.2
I
Contr.
Control current I = f (TA)
in current source application
-20 0 20 40 60 80 °C 110
TA
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
mA
1.5
I
Contr.
BCR400W
Aug-07-20015
Total power dissipation Ptot = f (TS)
0 20 40 60 80 100 120 °C 150
TS
0
50
100
150
200
250
300
mW
400
P
tot
Note that up to TS=115°C
it is not possible to exceed Ptot
respecting the maximum
ratings of VS and IContr.
The collector or drain
current (respectively) of
the stabilized RF transistor
does not affect BCR 400
directly, as it provides just the
base current.
Typical application for GaAs FET
with active bias controller
EHA07190
400BCR
4
3
1
2
+S
V
Rext
100 pF
VG
-
Ωk100
100 kΩ
1 nF
RF IN RF OUT
BCR400W
Aug-07-20016
RF transistor controlled by BCR400
EHA07217
VS
+
3
4
BCR 400
12
RF-Transistor
ext.
R
Ι
contr.
C
Ι
drop
V
C21
C
RF IN
RF OUT
Be aware that BCR400 stabilized
bias current of transistors in an active
control loop
In order to avoid loop ascillation
(hunting),
time constants must be chosen
adequately, i.e. C1 >= 10 x C2
RX/TX antenna switch, compatible to control logic
and working at wide battery voltage range
EHA07218
BCR 400
4
3
1
2+S
V
Rext
4λ/
TX RX
TX
RX
> 2.7 V
= 100 -220 ΩΩ
Antenna
BCR400W
Aug-07-20017
Low voltage reference
EHA07219
BCR 400
4
3
1
2+S
V
VREF
Red
LED
Precision timer with BCR400
providing constant charge current
EHA07191
3
41
2
7
6
215
S
V+
84
3
Timer IC
(555)
R
ext
BCR 400
