ATR4252-RAQW [ATMEL]
All-in-One IC Solution for Active Antennas; 所有- in-One的IC解决方案的有源天线
| 型号： | ATR4252-RAQW |
| 厂家： | 
ATMEL |
| 描述： | All-in-One IC Solution for Active Antennas |
| 文件： | 总10页 (文件大小：352K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Features
• Highly Integrated - All-in-one Active Antenna IC
• Integrated AGC for AM and FM
• Integrated Driver for AM and FM PIN Diodes
• Integrated Power Supply Regulator
• Integrated Antenna Sensor
• Separated AM LNA, AM Buffer and FM Amplifier
• High Dynamic Range for AM and FM
• Excellent Noise Performance
All-in-One IC
Solution for
Active
• High Intercept Point 3rd Order for FM
• FM Amplifier Adjustable to Various Cable Impedances
• High Intercept Point 2nd and 3rd Order for AM
• Low Noise Output Voltage
• Low Power Consumption
• Low Output Impedance AM
Antennas
• Only Small Capacitor Values Necessary at AM AGC
• Large AM Frequency Range to Cover DRM Broadcast Signals
ATR4252
1. Description
The ATR4252 is a highly integrated high performance AM/FM antenna amplification
IC with several features. The device has built-in AGC's for both AM and FM, antenna
detection, a power supply regulator as well as additional pre-integrated peripherals.
Summary
Preliminary
The ATR4252 is based on BICMOS technology. The device is designed in particular
for car application and is suitable for active antennas located in several positions on
the car such as bumpers, windscreen, mirrors or windows.
Figure 1-1. Block Diagram
AM LNA
FM
BIAS
REF
21
AMPD GND2 BIAS
FMB
17
FME
16
FMPD
15
22
20
19
18
FM
Amplifier
AM
LNA
23
24
25
26
27
28
14
13
12
11
10
9
AM LNA IN
FMC
AM LNA
SOURCE
Voltage
Supply
AGC
(FM)
FMDET
FMTC
VS
CASCODE
FILTER
AM LNA OUT
AMBIAS
Antenna
Detect
Over
Voltage
AGC
(AM)
AMOUT
GND1
NOTE: This is a summary document.
The complete document is available
under NDA. For more information,
please contact your local Atmel sales
office.
AM
Buffer
AMBUF IN
1
2
3
4
5
6
7
8
ANTENNA
VS VSTART OVDET VREGO AMTC1 AMTC2 AMDET
SENSE FILTER
9154AS–AUDR–09/09
2. Pin Configuration
Figure 2-1. Pinning VQFN 4x5 / 28L
22 21 20 19 18 17 16 15
AM LNA IN 23
AM LNA SOURCE 24
CASCODE FILTER 25
AM LNA OUT 26
AMBIAS 27
14 FMC
13 FMDET
12 FMTC
11 VS
ATR4252
10 AMOUT
AMBUF IN 28
9
GND1
1
2
3
4
5
6
7
8
Table 2-1.
Pin Description
Pin
1
Symbol
ANTENNA SENSE
VS FILTER
VSTART
OVDET
VREGO
AMTC1
AMTC2
AMDET
GND1
Function
Antenna sense input
Supply voltage filter input
2
3
Comparator input of voltage detector
Overvoltage detection input
Output of voltage regulator
AM AGC time-constant capacitance 1
AM AGC time-constant capacitance 2
Level detector input of AM-AGC
Ground AM
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
AMOUT
VS
AM output, impedance matching
Supply voltage
FMTC
FM AGC time constant
FMDET
FMC
Level detector input of FM-AGC
Collector of FM amplifier (NPN)
FM AGC output for pin diode
FM amplifier emitter(NPN)
FM amplifier base (NPN)
Reference voltage 2.7V FM
Ground FM
FMPD
FME
FMB
FMBIAS
GND2
2
ATR4252 [Preliminary]
9154AS–AUDR–09/09
ATR4252 [Preliminary]
Table 2-1.
Pin Description (Continued)
Pin
20
Symbol
AMPD
Function
AM AGC output for pin diode
21
REF
Reference voltage 6V
22
AM LNA BIAS
AM LNA IN
AM LNA SOURCE
CASCODE FILTER
AM LNA OUT
AMBIAS
Reference voltage for AM LNA IN
AM LNA input terminal
23
24
AM LNA source terminal
25
AM Cascode filter terminal
AM LNA output terminal
26
27
Reference voltage for AMBUF IN
AM Buffer amplifier input, impedance matching
Ground paddle
28
AMBUF IN
GND
Paddle
3
9154AS–AUDR–09/09
3. Functional Description
The ATR4252 is a highly integrated AM/FM antenna IC with lots of features and functions. In fact
the most important feature is the impedance matching on both the antenna input and the cable.
The ATR4252 compensates cable losses between the antenna (for example, windscreen, roof
or bumper antennas) and the car radio, which is usually placed far away from the antenna.
AM means long wave (LW), medium wave (MW) and short wave (SW) frequency bands
(150 kHz to 30 MHz) that are usually used for AM as well as for DRM transmissions, and FM
means any of the world wide used frequency bands for FM radio broadcast (70 MHz to
110 MHz).
Two separate amplifier chains are used for AM and FM due to the different operation frequen-
cies and requirements in the AM and FM band. This allows the use of separate antennas (e.g.,
windscreen antennas) for AM and FM. Of course, both amplifier chain inputs can also be con-
nected to one antenna (e.g., roof antenna).
The AM amplifier chain is separated into two amplifiers. The first one is an LNA that is optimized
for low noise figure and low input capacitance. The second amplifier (AM buffer) is optimized to
drive a possibly long antenna cable with high parasitic capacitance. Both amplifiers have out-
standing large signal performance. All input and output terminals of these two amplifiers are
accessible from outside so they can be connected together according to the application needs.
Additionally, a filter can be inserted between LNA output and buffer amplifier input.
For AM and FM amplifier chain, two separate automatic gain control (AGC) circuits have been
integrated in order to avoid overdriving the amplifiers in large signal conditions. The two sepa-
rate AGC loops prevent strong AM signals from blocking FM stations and vice versa.
The integrated PIN diode drivers reduce the external component cost and board space.
A voltage regulation stage is integrated in order to further reduce the external component costs.
This stage provides overvoltage protection and current limitation. An external transistor is used
as power driver for this stage.
3.1
AM Amplifier
Due to the long wavelength in AM bands, the antennas used for AM reception in automotive
applications are short compared to the wavelength. Therefore, these antennas do not provide
50Ω output impedance, but have an output impedance of some pF. If these (passive) antennas
are connected to the car radio by a long cable, the capacitive load of this cable (some 100 pF)
dramatically reduces the signal level at the tuner input.
In order to overcome this problem, ATR4252 provides two AM amplifiers, one LNA and one AM
buffer amplifier. These two amplifiers can be used independently because all input/output termi-
nals and bias inputs are externally accessible for the application.
The AM LNA has low input capacitance (12 pF typically) to reduce the capacitive load at the
antenna and provides a voltage gain of typically 9 dB that can be varied from 0 to 15 dB depend-
ing on external application.
4
ATR4252 [Preliminary]
9154AS–AUDR–09/09
ATR4252 [Preliminary]
The AM buffer amplifier has a very low input capacitance of typically 2.45 pF and can also be
connected directly to the car antenna if no additional gain is required. Due to the low output
impedance of 8Ω, the buffer amplifier is perfectly suited to drive the capacitive load of long
antenna cables. The voltage gain of this amplifier is close to 1 (0 dB), but the insertion gain that
is achieved when the buffer amplifier is inserted between antenna output and antenna cable
may be much higher (up to 35 dB). The actual value, of course, depends on antenna and cable
capacitances.
The input of the buffer amplifier is connected by an external 4.7 MΩresistor to the bias voltage in
order to maintain high input impedance and low noise voltage.
AM tuners in car radios usually use PIN diode attenuators at their input. These PIN diode atten-
uators attenuate the signal by reducing the input impedance of the tuner. Therefore, a series
resistor is used at the AM amplifier output in the standard application. This series resistor guar-
antees well-defined source impedance for the radio tuner and protects the output of the AM
amplifier from short circuit by the PIN diode attenuator in the car radio.
3.2
AM AGC
The IC is equipped with an AM AGC capability to prevent overdriving of the amplifier in case the
amplifier operates near strong signal sources, e.g., transmitters.
The AM amplifier output AMOUT is applied to a resistive voltage divider. This divided signal
feeds the AGC level detector input pin AMDET. The rectified signal is compared against an inter-
nal reference. The threshold of the AGC can be adjusted by modification of the divider ratio of
the external voltage divider. If the threshold is reached ,the pin AMPD opens an internal transis-
tor, which controls the pin diode current and limits the antenna signal to prevent an overdriving
of the AM amplifier.
As the AM AGC has to react very slowly, large capacitors are usually needed for this time delay.
To reduce the cost of the external components, a current control for the time delay is integrated,
so that only small external capacitor values are needed.
The necessary driver for the external pin diode is already incorporated in the ATR4252 IC, which
reduces the BOM cost and the application size.
3.3
FM Amplifier
The FM amplifier is realized with a high performance single NPN transistor. This allows the use
of an amplifier configuration, which is optimized for the desired requirements. For low cost appli-
cation, the common emitter configuration provides good performance at reasonable BOM cost.
For high end application, common base configuration with lossless transformer feedback pro-
vides high IP3 and low noise figure at reasonable current consumption. In both configurations,
gain, input and output impedance can be adjusted by modification of external components.
The temperature compensated bias voltage (FMBIAS) for the base of the NPN transistor is
derived from an integrated voltage reference. The bias current of the FM amplifier is defined by
an external resistor.
5
9154AS–AUDR–09/09
3.4
FM AGC
The IC is equipped with an AGC capability to prevent overdriving of the amplifier in case the
amplifier is operated at strong antenna signals, e.g., near transmitters. It is possible to realize an
additional antenna amplifier path with integrated AGC and external RF transistor. The bandwidth
of the integrated AGC circuit is 900 MHz.
FM amplifier output FMC is connected to a capacitive voltage divider and the divided signal is
applied to the AGC level detector at pin FMDET. This level detector input is optimized for low
distortion. The rectified signal is compared against an internal reference. The threshold of the
AGC can be adjusted by tuning the divider ratio of the external voltage divider. If the threshold is
reached, pin FMPD opens an internal transistor, which controls the pin-diode current. By these
means, the amplifier input signal is limited and therefore the FM amplifier is prevented from sig-
nal overdrive.
The necessary driver for the external pin diode is already incorporated in the ATR4252 IC, which
reduces the BOM cost and the application size.
3.5
3.6
Supply Voltage Regulator
The driving voltage for an external power transistor is provided by an integrated regulator circuit.
An overvoltage protection circuit recognizes overvoltage condition and switches off the amplifier
and AGC circuits in order to reduce current consumption and avoid thermal overload.
Antenna Sensor
In addition, an antenna sensor has been integrated in order to recognize if the antenna is prop-
erly connected to the amplifier module. If no antenna is detected, the amplifier and AGC circuits
are switched off in order to signal this error via reduction of supply current consumption to the
unit that provides and monitors the supply current for the antenna amplifier (e.g., the car radio).
4. Absolute Maximum Ratings
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating
only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this
specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Reference point is ground.
Parameters
Pin
11
14
23
26
Symbol
Min.
–0.3
3
Max.
+12
16
Unit
V
Supply voltage
VS
FMC
Collector of FM amplifier
AM LNA input terminal
AM LNA output terminal
Power dissipation
Junction temperature
Ambient temperature
Storage temperature
ESD HBM
V
AM LNA IN
AM LNA OUT
Ptot
0
2
V
7
12
V
1200
150
+105
+150
+2
mW
°C
°C
°C
kV
Tj
Tamb
–40
–50
–2
Tstg
all
VHBM
6
ATR4252 [Preliminary]
9154AS–AUDR–09/09
ATR4252 [Preliminary]
5. Electrical Characteristics
Verified on test circuits (demo design made by Atmel), VS = 10 V, Tamb = 25°C, unless otherwise specified
No. Parameters
Test Conditions
Pin
Symbol
Min.
Typ.
Max.
Unit
VS, FMC,
AM LNA OUT
AGC OFF
Is
77
mA
VS, FMC,
AM LNA OUT
1.1 Supply current
FMAGC ON
Is
Is
85
95
99
mA
mA
Tamb = –40 to +105°C;
FMAGC ON
VS, FMC,
AM LNA OUT
2
AM LNA+ Buffer(2)
2.1 Input capacitance
2.4 Voltage gain
f = 1 MHz
f = 1 MHz
AM LNA IN
CAMLNAIN
12
9
pF
dB
AM/FM-OUT
Buffer OUT,
RBIAS = 4.7 MΩ, B = 9 kHz
f = 1 MHz
Antenna
Dummy Input
2.5 Input noise voltage
VN
–12
dBµV
MHz
Maximum operating
2.7
3 dB corner
AM/FM-OUT
30
frequency
AM/FM Out;
finp = 1 MHz + 1.1 MHz,
Vout = 110 dBµV,
1K II 500 pF load,
Vs = 10V
2.8 OIP3(1)
144
170
dBµV
dBµV
AM/FM Out;
finp = 1 MHz + 1.1 MHz,
Vout = 110 dBµV,
1K II 500 pF load,
Vs = 10V
2.9 OIP2(1)
4
AM AGC
4.1 Input resistance
4.2 Input capacitance
AM DET
AM DET
RAMDET
CAMDET
40
50
kΩ
f = 1 MHz
2.6
3.2
3.8
4
pF
AGC threshold increased by
3 dB
4.4 3 dB corner frequency
AM PD
30
MHz
4.5 Saturation voltage
4.6 Leakage current
10 mA
AM PD
AM PD
VS – 1.9
35
V
µA
Maximum PIN Diode
current
4.7
AGC active
AM PD
22
mA
5
FM Amplifier
5.3 Supply current
5.4 Supply current (3)
Common base
FMC
FMC
IFMC
IFMC
29
35
mA
mA
Common emitter
Maximum output
voltage
5.5
Vs = 10V
FMC
12
Vpp
Ω
5.6 Input resistance
f = 100 MHz
FM IN
RFMIN
50
50
Maximum operating
frequency
3 dB corner,
common emitter
5.7
FM OUT
FM OUT
450
MHz
Ω
5.8 Output resistance
f = 100 MHz
RFMOUT
Notes: 1. AGC Loop deactivated
2. Measured with antenna dummy.
7
9154AS–AUDR–09/09
5. Electrical Characteristics (Continued)
Verified on test circuits (demo design made by Atmel), VS = 10 V, Tamb = 25°C, unless otherwise specified
No. Parameters
Test Conditions
Pin
Symbol
Min.
Typ.
Max.
Unit
f = 100 MHz,
common base circuit
5.9 Power gain
G
5
8
dB
5.10 OIP3 at FMOUT
5.11 NF
Common base circuit
Common base circuit
FM OUT
145
1.9
dBµV
dB
f = 100 MHz,
common emitter circuit
5.12 Power gain
G
13.5
dB
5.13 OIP3 at FMOUT
5.14 NF
Common emitter circuit
Common emitter circuit
FM OUT
FM OUT
140
3.5
dBµV
dB
6
FM AGC
Maximum PIN Diode
current
6.4
AGC active
f = 100 MHz
FMPD
12
14
mA
6.5 Input resistance
6.6 Input capacitance
FM DET
FM DET
RFMDET
CFMDET
17
21
25
kΩ
1.5
1.75
2.0
pF
7
Voltage Regulator / Monitor
Output voltage of
regulator
Battery voltage
VB = 14V
7.1
VS
9.5
40
10
50
10.5
V
Ripple rejection of
regulator
7.2
100 Hz, VB > VS + 1V
VB, AM/FM-Out
dB
Notes: 1. AGC Loop deactivated
2. Measured with antenna dummy.
6. Ordering Information
Extended Type Number
Package
Remarks
ATR4252-RAPW
VQFN 4x5 / 28L
VQFN 4x5 / 28L
Taped on reel, 1.5k volume
Taped on reel, 6k volume
ATR4252-RAQW
8
ATR4252 [Preliminary]
9154AS–AUDR–09/09
ATR4252 [Preliminary]
7. Package Information
Top View
D
28
1
PIN 1 ID
technical drawings
according to DIN
specifications
8
Dimensions in mm
Side View
Bottom View
D2
9
14
15
22
8
COMMON DIMENSIONS
(Unit of Measure = mm)
Symbol MIN
NOM
0.9
MAX NOTE
A
A1
A3
D
0.8
0.0
1
0.02
0.2
0.05
0.25
4.1
1
0.15
3.9
28
23
Z
4
e
D2
E
2.45
4.9
2.6
2.75
5.1
5
E2
L
3.45
0.3
3.6
3.75
0.5
Z 10:1
0.4
b
0.16
0.23
0.5 BSC
0.3
e
b
06/18/08
DRAWING NO.
TITLE
REV.
Package Drawing Contact:
packagedrawings@atmel.com
Package: VQFN_4x5_28L
Exposed pad 2.6x3.6
6.543-5143.01-4
2
9
9154AS–AUDR–09/09
Headquarters
International
Atmel Corporation
2325 Orchard Parkway
San Jose, CA 95131
USA
Tel: 1(408) 441-0311
Fax: 1(408) 487-2600
Atmel Asia
Atmel Europe
Le Krebs
8, Rue Jean-Pierre Timbaud
BP 309
Atmel Japan
Unit 1-5 & 16, 19/F
BEA Tower, Millennium City 5
418 Kwun Tong Road
Kwun Tong, Kowloon
Hong Kong
9F, Tonetsu Shinkawa Bldg.
1-24-8 Shinkawa
Chuo-ku, Tokyo 104-0033
Japan
78054
Saint-Quentin-en-Yvelines Cedex Tel: (81) 3-3523-3551
Tel: (852) 2245-6100
Fax: (852) 2722-1369
France
Tel: (33) 1-30-60-70-00
Fax: (33) 1-30-60-71-11
Fax: (81) 3-3523-7581
Product Contact
Web Site
Technical Support
Sales Contact
www.atmel.com
broadcast@atmel.com
www.atmel.com/contacts
Literature Requests
www.atmel.com/literature
Disclaimer: The information in this document is provided in connection with Atmel products. No license, express or implied, by estoppel or otherwise, to any
intellectual property right is granted by this document or in connection with the sale of Atmel products. EXCEPT AS SET FORTH IN ATMEL’S TERMS AND CONDI-
TIONS OF SALE LOCATED ON ATMEL’S WEB SITE, ATMEL ASSUMES NO LIABILITY WHATSOEVER AND DISCLAIMS ANY EXPRESS, IMPLIED OR STATUTORY
WARRANTY RELATING TO ITS PRODUCTS INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE, OR NON-INFRINGEMENT. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE, SPECIAL OR INCIDEN-
TAL DAMAGES (INCLUDING, WITHOUT LIMITATION, DAMAGES FOR LOSS OF PROFITS, BUSINESS INTERRUPTION, OR LOSS OF INFORMATION) ARISING OUT OF
THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no
representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications
and product descriptions at any time without notice. Atmel does not make any commitment to update the information contained herein. Unless specifically provided
otherwise, Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel’s products are not intended, authorized, or warranted for use
as components in applications intended to support or sustain life.
© 2009 Atmel Corporation. All rights reserved. Atmel®, logo and combinations thereof, and others are registered trademarks or trademarks of
Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others.
9154AS–AUDR–09/09
相关型号：
©2020 ICPDF网 联系我们和版权申明