52
Communication ICs
FM IF detector for cordless phones
BA4116FV
The BA4116FV is an IC with mixing circuit, IF circuit, FM detector circuit, RSSI circuit, and noise detector circuit. As it
can operate at low voltages, it is ideal for use in cordless phones.
F
Applications
Cordless phones, amateur short wave radios, and other portable wireless equipment
F
Features
1) Input frequencies of 10MHz to 150MHz can be ac-
commodated.
2) Low-voltage operation. (1.8 to 5.5V)
3) Excellent temperature characteristic.
4) High sensitivity; 12dB SINAD sensitivity = 8dB
VEMF
(50
)
5) High intercept point. (11dBm)
6) Small package used. (0.65mm pitch)
F
Absolute maximum ratings (Ta = 25
_
C)
F
Recommended operating conditions (Ta = 25
_
C)
57
Communication ICs
BA4116FV
F
Electrical characteristics (unless otherwise noted, Ta = 25
_
C, V
CC
= 2.0V, f
IN
(Mix)
= 21.7MHz, f
IN
(IF)
= 450kHz,
f =
1.5kHzdev, fm = 1kHz, all AC levels open (EMF) display)
60
Communication ICs
BA4116FV
F
Attached components
F
Determining the filter amplifier constant (multi-layer recovery band pass filter)
f
0
: Center frequency
Q: Center frequency f
0
/ band width BW
A
0
: I / O gain
The reference resistance R
0
is determined as C
1
= C
2
=
C
0
.
R
0
= 1 / 2
f
0
S
C
0
R
1
= R
0
S
Q / A
0
R
2
= R
0
/ [2Q - (A
0
/ Q)]
R
3
= 2R
0
S
Q
The Filter gain can be adjusted by varying R
1
, but with the
A
0
> 1 design, please be aware that influence from the
open loop characteristic of the amplifier causes offset in
the center frequency f
0
.
F
Electrical characteristic curves