DA9079.003
19 May, 2005
MAS9079
AM Receiver IC
•
Tri Band Receiver IC
•
High Sensitivity
•
Very Low Power Consumption
•
Wide Supply Voltage Range
•
Power Down Control
•
Control for AGC On
•
High Selectivity by Crystal Filter
•
Fast Startup Feature
DESCRIPTION
The MAS9079 AM-Receiver chip is a highly
sensitive, simple to use AM receiver specially
intended to receive time signals in the frequency
range from 40 kHz to 100 kHz. Only a few external
components are required for time signal receiving.
The circuit has preamplifier, wide range automatic
gain control, demodulator and output comparator
built in. The output signal can be processed directly
by an additional digital circuitry to extract the data
from the received signal. The control for AGC
(automatic gain control) can be used to switch AGC
on or off if necessary. MAS9079 supports tri band
operation by switching between three crystal filters
and two additional antenna tuning capacitors.
MAS9079 has asymmetric input and different internal
compensation capacitor options for compensating
shunt capacitances of different crystals (See ordering
information on page 9).
FEATURES
•
•
•
•
•
•
•
•
•
•
Tri Band Receiver IC
Highly Sensitive AM Receiver, 0.4
µV
RMS
typ.
Wide Supply Voltage Range from 1.1 V to 5 V
Very Low Power Consumption
Power Down Control
Fast Startup
Only a Few External Components Necessary
Control for AGC On
Wide Frequency Range from 40 kHz to 100 kHz
High Selectivity by Quartz Crystal Filter
APPLICATIONS
•
Multi Band Time Signal Receiver WWVB (USA),
JJY (Japan), DCF77 (Germany), MSF (UK), HGB
(Switzerland) and BPC (China)
BLOCK DIAGRAM
QO3
RFI1
RFI2
RFI3
AGC Amplifier
Demodulator
&
Comparator
OUT
QO2 QO1
QI
AON
Power Supply/Biasing
VDD
VSS PDN1 PDN2
AGC
DEC
1 (9)
DA9079.003
19 May, 2005
PAD LAYOUT
MAS9079Ax,
x=1..4
VDD
QO2
QO1
QO3
QI
AGC
PDN2
OUT
RFI1
RFI3
PDN1
AON
DEC
VSS
RFI2
1620 µm
DIE size = 1.62 x 1.89 mm; round PAD
∅
80
µm
Note:
Because the substrate of the die is internally connected to VDD, the die has to be connected to VDD or
left floating. Please make sure that VDD is the first pad to be bonded. Pick-and-place and all component
assembly are recommended to be performed in ESD protected area.
Note:
Coordinates are pad center points where origin has been located in bottom-left corner of the silicon die.
Pad Identification
Power Supply Voltage
Quartz Filter Output for Crystal 2
Quartz Filter Output for Crystal 1
Quartz Filter Output for Crystal 3
Quartz Filter Input for Crystals
AGC Capacitor
Power Down/Frequency Selection Input 2
Receiver Output
Demodulator Capacitor
AGC On Control
Power Down/Frequency Selection Input 1
Receiver Input 3 (for Antenna Capacitor 3)
Receiver Input
Receiver Input 2 (for Antenna Capacitor 2)
Power Supply Ground
Name
VDD
QO2
QO1
QO3
QI
AGC
PDN2
OUT
DEC
AON
PDN1
RFI3
RFI1
RFI2
VSS
X-coordinate
174
µm
174
µm
174
µm
174
µm
174
µm
174
µm
174
µm
175
µm
1442
µm
1442
µm
1442
µm
1442
µm
1442
µm
1442
µm
1442
µm
Y-coordinate
1657
µm
1452
µm
1248
µm
1043
µm
839
µm
634
µm
429
µm
225
µm
240
µm
444
µm
649
µm
853
µm
1058
µm
1467
µm
1671
µm
Note
1892 µm
3
1
2
3
Notes:
1) OUT = VSS when carrier amplitude at maximum; OUT = VDD when carrier amplitude is reduced
(modulated)
-
the output is a current source/sink with |I
OUT
| > 5
µA
-
at power down the output is pulled to VSS (pull down switch)
2) AON = VSS means AGC off (hold current gain level); AON = VDD means AGC on (working)
- Internal pull-up with current < 1
µA
which is switched off at power down
3) PDN1 = VDD and PDN2 = VDD means receiver off
-
Fast start-up is triggered when the receiver is after power down controlled to power up
2 (9)
DA9079.003
19 May, 2005
FREQUENCY SELECTION
The frequency selection and power down control is
accomplished via two digital control pins PDN1 and
PDN2. The control logic is presented in table 1.
Table 1
Frequency selection and power down control
PDN2
RFI2 Switch RFI3 Switch
PDN1
High
High
Low
Low
High
Low
High
Low
Open
Open
Closed
Closed
Open
Open
Open
Closed
Selected Crystal
Output
-
QO1
QO2
QO3
Description
Power down
Frequency 1
Frequency 2, RFI2 capacitor
connected in parallel with antenna
Frequency 3, RFI2 and RFI3
capacitors connected in parallel
with antenna
The internal antenna tuning capacitor switches
(RFI2, RFI3) and crystal filter output switches
(QO1, QO2, QO3) are controlled according table 1.
See switches in block diagram on page 1.
If frequency 1 is selected the RFI2 and RFI3
switches are open and only crystal output QO1 is
active. Antenna frequency is determined by
antenna inductor L
ANT
(see Typical Application on
page 5), antenna capacitor C
ANT1
and parasitic
capacitances related to antenna inputs RFI1, RFI2
and RFI3 (see Antenna Tuning Considerations
below). Frequency 1 is the highest frequency of the
three selected frequencies.
If frequency 2 is selected then RFI2 switch is closed
to connect C
ANT2
in parallel with ferrite antenna and
tune it to frequency 2. Then only crystal output QO2
is active. Frequency 2 is the medium frequency of
the three selected frequencies.
If frequency 3 is selected both RFI2 and RFI3
switches are closed to connect both C
ANT2
and
C
ANT3
capacitors in parallel with ferrite antenna and
tune it to frequency 3. Then only crystal QO3 is
active. Frequency 3 is the lowest frequency of the
three selected frequencies.
It is recommended to switch the device to power
down for 50ms before switching to another
frequency. This guarantees fast startup in switching
to another frequency. The 50ms power down period
is used to discharge AGC capacitor and to initialize
fast startup conditions.
3 (9)
DA9079.003
19 May, 2005
ANTENNA TUNING CONSIDERATIONS
The ferrite bar antenna having inductance L
ANT
and
parasitic coil capacitance C
COIL
is tuned to three
reception frequencies f
1
, f
2
and f
3
by parallel
capacitors C
ANT1
, C
ANT2
and C
ANT3
. The receiver
input stage and internal antenna capacitor switches
have capacitances C
RFI1
, C
OFF2
, C
OFF3
which affect
the resonance frequencies. C
OFF2
and C
OFF3
are
switch capacitances when switches are open.
When switches are closed these capacitances are
shorted by on resistance of the switches and they
are effectively eliminated. Following relationships
can be written into three tuning frequencies.
Frequency f
1
(highest frequency):
C
TOT1
=C
COIL
+C
ANT1
+C
RFI1
+C
OFF2
+C
OFF3
=C
COIL
+C
ANT1
+6.5pF+24pF+75pF
3
=C
COIL
+C
ANT1
+105.5pF,
1
f
1
=
2
π
L
ANT
⋅
C
TOT
1
Frequency f
2
(middle frequency):
C
TOT2
=C
COIL
+C
ANT1
+C
ANT2
+C
RFI1
+C
OFF3
=C
COIL
+C
ANT1
+C
ANT2
+ 6.5pF+75pF
3
=C
COIL
+C
ANT1
+C
ANT2
+ 81.5pF,
1
f
2
=
2
π
L
ANT
⋅
C
TOT
2
Frequency
f
3
(lowest frequency):
C
TOT3
=C
COIL
+C
ANT1
+ C
ANT2
+ C
ANT3
+C
RFI1
=C
COIL
+C
ANT1
+ C
ANT2
+ C
ANT3
+6.5pF,
1
f
3
=
2
π
L
ANT
⋅
C
TOT
3
4 (9)
DA9079.003
19 May, 2005
ABSOLUTE MAXIMUM RATINGS
Parameter
Supply Voltage
Input Voltage
Power Dissipation
Operating Temperature
Storage Temperature
Symbol
V
DD
-V
SS
V
IN
P
MAX
T
OP
T
ST
Conditions
Min
-0.3
V
SS
-0.3
-40
-55
Max
6
V
DD
+0.3
100
+85
+150
Unit
V
V
mW
o
C
o
C
ELECTRICAL CHARACTERISTICS
Operating Conditions: VDD = 1.4V, Temperature = 25°C
Parameter
Operating Voltage
Current Consumption
Symbol
V
DD
I
DD
Conditions
VDD=1.4 V, Vin=0.4
µVrms
VDD=1.4 V, Vin=20 mVrms
VDD=3.6 V, Vin=0.4
µVrms
VDD=3.6 V, Vin=20 mVrms
Min
1.10
Typ
64
37
67
40
Max
5
Unit
V
µA
31
27
40
Stand-By Current
Input Frequency Range
Minimum Input Voltage
Maximum Input Voltage
RFI1 Pin Input Resistance
RFI1 Pin Input Capacitance
RFI2 Switch On Resistance
RFI2 Switch Off Capacitance
RFI3 Switch On Resistance
RFI3 Switch Off Capacitance
Input Levels |l
IN
|<0.5
µA
Output Current
V
OL
<0.2 V
DD
;V
OH
>0.8 V
DD
Output Pulse
I
DDoff
f
IN
V
IN min
V
IN max
R
RFI1
C
RFI1
R
ON2
C
OFF2
R
ON3
C
OFF3
V
IL
V
IH
|I
OUT
|
T
100ms
T
200ms
T
500ms
T
800ms
0.4
20
f=40kHz..77.5 kHz
VDD=1.4 V
VDD=1.4 V
0.8 V
DD
5
1
µVrms ≤
V
IN
≤
20 mVrms
1
µVrms ≤
V
IN
≤
20 mVrms
1
µVrms ≤
V
IN
≤
20 mVrms
1
µVrms ≤
V
IN
≤
20 mVrms
Fast Start-up, Vin=0.4
µVrms
Fast Start-up, Vin=20 mVrms
50
150
400
700
500
800
1.3
3.5
50
630
6.5
3.8
24
2.4
75
85
65
0.1
100
1
µA
kHz
µVrms
mVrms
kΩ
pF
Ω
pF
Ω
pF
V
µA
0.2
V
DD
140
230
600
900
ms
ms
ms
ms
s
Startup Time
Output Delay Time
T
Start
T
Delay
100
ms
5 (9)
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