DA9078.003

28 January 2004

4 (10)

TYPICAL APPLICATION

Note 1: Crystal

The crystal as well as ferrite antenna frequencies are chosen according to the time-signal system (Table 1). The

suitable crystals are described in Table 2. See also Ordering Information (p.10).

Time-Signal System

Location

Antenna Frequency

Recommended Crystal Frequency

DCF77

Germany

77.5 kHz

77.503 kHz

MSF

United Kingdom

60 kHz

60.003 kHz

WWVB

USA

60 kHz

60.003 kHz

JJY

Japan

40 kHz and 60 kHz

40.003 kHz and 60.003 kHz

Table 1

Time-Signal System Frequencies

Device

Crystal Description

MAS9078B1

0.75 pF

MAS9078B2

1.25 pF

MAS9078B3

1.625 pF

MAS9078B4

2.5 pF

MAS9078B5

3.875 pF

Any crystal with parallel external compensation capacitor

Table 2

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 M

Ω. Also probes with at

least 100 M

Ω 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.

AGC Amplifier

Demodulator

&

Comparator

Power Supply/Biasing

RFI

OUT

QI

QO

VSS

AGC

DEC

Receiver

output

Ferrite-

Antenna

Note 1

AON (=AGC on)

VDD

1.4 V

PDN

Note 2

X1

10 uF

47 nF

Note 3

Power Down /

Fast Startup

Control