Nov-07-2002
1
BB844
Silicon Variable Capacitance Diode
For FM radio tuner with extended frequency band
77MHz to 108MHz
Designed for application requiring back-to-back
diode configuration for optimum signal distortion
and detuning
High tuning ratio at low supply voltage (car radio)
Monolitic chip (common cathode) for perfect
dual diode tracking
Good C- V linearity
High figure of merit
BB844
3
1
D 2
2
D 1
Type
Package
Configuration
L
S
(nH) Marking
BB844
SOT23
common cathode
1.8
SNs
Maximum Ratings at T
A
= 25C, unless otherwise specified
Parameter
Symbol
Value
Unit
Diode reverse voltage
V
R
18
V
Peak reverse voltage
V
RM
20
Forward current
I
F
50
mA
Operating temperature range
T
op
-55 ... 150
C
Storage temperature
T
stg
-55 ... 150
Nov-07-2002
2
BB844
Electrical Characteristics at T
A
= 25C, unless otherwise specified
Parameter
Symbol
Values
Unit
min.
typ.
max.
DC Characteristics
Reverse current
V
R
= 16 V
V
R
= 16 V, T
A
= 85 C
I
R
-
-
-
-
20
200
nA
AC Characteristics
Diode capacitance
V
R
= 2 V, f = 1 MHz
V
R
= 4 V, f = 1 MHz
V
R
= 8 V, f = 1 MHz
C
T
42.5
25
10
43.75
27
11.5
45
29
13
pF
Capacitance ratio
V
R
= 2 V, V
R
= 8 V, f = 1 MHz
C
T2
/C
T8
3.2
3.8
-
Capacitance matching
1)
V
R
= 2V to 8V , f = 1 MHz
C
T
/C
T
-
-
1.5
%
Series resistance
V
R
= 2 V, f = 100 MHz
r
S
-
0.28
-
1
For details please refer to Application Note 047.
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