DA9078.003
28 January 2004
TYPICAL APPLICATION
Note 1
X1
AON (=AGC on)
QO
QI
Ferrite-
Receiver
output
Antenna
RFI
Demodulator
OUT
AGC Amplifier
&
Comparator
VDD
Power Supply/Biasing
PDN
1.4 V
VSS
AGC
DEC
Note 2
Note 3
CDEM
47 nF
CAGC
Power Down /
Fast Startup
Control
10 uF
Note 1: Crystal
The crystal as well as ferrite antenna frequencies are chosen according to the time-signal system (Table 1). The
crystal shunt capacitance C0 should be matched as well as possible with the internal shunt capacitance
compensation capacitance CC. MAS9078 has five compensation capacitance options. Capacitance values and
suitable crystals are described in Table 2. See also Ordering Information (p.10).
Time-Signal System
Location
Antenna Frequency Recommended Crystal Frequency
DCF77
Germany
United Kingdom
USA
77.5 kHz
77.503 kHz
MSF
60 kHz
60.003 kHz
WWVB
JJY
Table 1
60 kHz
60.003 kHz
Japan
40 kHz and 60 kHz
40.003 kHz and 60.003 kHz
Time-Signal System Frequencies
Device
CC
Crystal Description
MAS9078B1
MAS9078B2
MAS9078B3
MAS9078B4
MAS9078B5
Table 2
0.75 pF
1.25 pF
1.625 pF
2.5 pF
For single low C0 crystal (Nominal value)
For single high C0 crystal
For two parallel low C0 crystals (dual band receiver)
For two parallel high C0 crystals (dual band receiver)
Any crystal with parallel external compensation capacitor
3.875 pF
Compensation Capacitance Options
Note 2: AGC Capacitor
The AGC and DEC capacitors must have low leakage currents due to very small 40 nA signal currents through
the capacitors. The insulation resistance of these capacitors should be higher than 70 MΩ. Also probes with at
least 100 MΩ impedance should be used for voltage probing of AGC and DEC pins.
Note 3: Power Down / Fast Startup Control
Both power down and fast startup are controlled using the PDN pin. The device is in power down (turned off) if
PDN = VDD and in power up (turned on) if PDN = VSS. Fast startup is triggered by the falling edge of PDN
signal, i.e., controlling device from power down to power up. The startup time without using the fast startup
control can be several minutes but with fast startup it is shortened typically to 12 s.
4 (10)
MAS [ MICRO ANALOG SYSTEMS ]
