Pin Functions
Pin No.
Function
1
FM IF input
Pin voltage
(V)
Vreg
LA1844MC
Equivalent circuit
Notes
Input impedance Ri = 330Ω
2
AM mixer output
VCC
Connect the mixer coil between this pin and VCC
3
REG
2.1
Vreg = 2.4V
4
AM IF input
Vreg
5
GND
6
Tu-LED
7
ST-LED / AM-IF
output
0
VCC
8
FM detector
9
VCC
10 AM / FM IF
counter output,
output control
switch,
mute switch
VCC
5.0
0
11
Phase comparator
VCC-1.0
low-pass filter
(AM/FM switching)
Input impedance Ri = 2kΩ
Active low
Open collector
The 600BEAS-10471 (Toko Mfg. Co., Ltd.) is
recommended for detector coil.
V10 ≤ 0.5V : Reception state (Normal)
1.4V ≤ V10 ≤ 2.2V : Muting on (Mute)
V10 ≥ 3.5V : IF counter output and muting on
(Seek)
The device operates in AM mode when a current
of over 200μA flows from pin 12.
Continued on next page.
No.A2057-6/11