U4222B Datasheet, PDF (2/9 Pages) TEMIC Semiconductors – Radio Controlled Clock Receiver

U4222B
Pin Description
Pin Symbol
Function
1
IN2 Amplifier 1 – Input 2
2
IN1 Amplifier 1 – Input 1
3
GND Analog ground
4
CAGC Time constant of AGC
5 CDEM Low pass filter
6
INA2 Amplifier 2 input
7
GND Digital ground
8 OUTA1 Amplifier 1 output
9
V_CCD Supply voltage (digital)
10
NC Not connected
11
NC Not connected
12
NC Not connected
13
TCO Time code output
14
PON Power ON/OFF control
15
GND Ground (substrate)
16
V_CCA Supply voltage (analog)
TELEFUNKEN Semiconductors
IN2 1
IN1 2
16 ^VCCA
15 ^GND
GND ³
14 PON
CAGC ⁴
CDEM 5
U4222B
13 TCO
12 NC
INA2 6
11 NC
GND 7
10 NC
OUTA1 8
94 8031 e
9 ^VCCD
IN1, IN2
IN2 is connected to pin 16 (V_CCA). A ferrite antenna is
connected between IN1 and IN2. Q of antenna circuit
should be as high as possible, but the temperature
W W ^{influence must be compensated. The resonant resistance}
should be 200 k to 300 k for optimal sensitivity.
OUTA1, INA2
To achieve a high selectivity, a quartz resonator is
connected between the pins OUTA1 and INA2. It is used
with the serial resonance frequency of the time code
transmitter (e.g. 40 kHz JG2AS). The parasitic parallel
capacitance C₀ of the quartz resonator should be 0.5 pF
to 1 pF.
CAGC
A control voltage derived from the field strength is
generated to control the amplifiers. The time constant of
this automatic gain control (AGC) is influenced by the
capacitor CAGC.
CDEM
After demodulation the signal is low pass filtered by the
capacitor CDEM.
PON
If PON is connected to V_CCD, the U4222B receiver IC
will be activated. The set-up time is typical 2.5 s after
applying V_CCD at this pin. If PON is connected to GND,
the receiver will go into stop mode.
2 (9)
Preliminary Information
Rev. A1: 07.08.1995