MAX2742ECM-C0A [MAXIM]
Switched Capacitor Filter, 1 Func, Bandpass, CMOS, 7 X 7 MM, 1 MM HEIGHT, MS-026ABC, TQFN-48;
| 型号： | MAX2742ECM-C0A |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Switched Capacitor Filter, 1 Func, Bandpass, CMOS, 7 X 7 MM, 1 MM HEIGHT, MS-026ABC, TQFN-48 LTE 有源滤波器 |
| 文件： | 总8页 (文件大小：157K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-3469; Rev 1; 3/06
Single-Chip Global Positioning System
Receiver Front-End
General Description
Features
♦ Complete Single-Chip GPS Front-End Receiver
♦ Single-Ended or Differential Outputs at 1.023MHz
♦ Low 4.5dB Typical Noise Figure
The MAX2742 complete single-chip global positioning
system (GPS) RF front-end utilizes many innovative and
leading-edge RF CMOS design techniques. This high-
performance, state-of-the-art device consumes extreme-
ly low power and eliminates the need for costly SAW
and bulky discrete IF filters. The MAX2742 incorporates
a fully integrated low-noise amplifier (LNA) and mixer, IF
section, digital sampler, and local oscillator synthesizer.
♦ No External IF SAW or Discrete Filters Required
♦ Very Low 32mW Power Consumption at +2.4V
The intended input signal for the MAX2742 is the L1
GPS signal 1.57542GHz. This device supports high-
accuracy output quantization, which delivers the best
performance obtainable for the GPS receiver. The
power consumption of the MAX2742 is as low as 32mW
at a +2.4V supply.
♦ Wide +2.4V to +3.6V Operational Supply Voltage
Range
♦ Extended -40°C to +85°C Temperature Range
The MAX2742 is available in a space-saving 48-pin
TQFP package and is specified for the extended (-40°C
to +85°C) temperature range.
Applications
Ordering Information
In-Vehicle Navigation Systems (IVNS)
PART
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
48 TQFP-EP*
48 TQFP-EP*
Location-Based Services (PDAs and
Accessories)
MAX2742ECM
MAX2742ECM+
Recreational Handheld/Walkie Talkies
Geographical Information Systems (GISs)
*EP = Exposed paddle.
+Denotes lead-free package.
Telematics (Vehicle, Asset Tracking, and
Inventory Management)
Block Diagram/
Pin Configuration
Emergency Roadside Assistance
Emergency Response Systems
Digital Cameras/Camcorders
Consumer Electronics
48
47
46
45
44
43
42
41
40
39
38
37
I.C.
I.C.
I.C.
I.C.
RBIAS
CBIAS
1
2
3
4
5
6
7
8
9
36
35
34
33
32
31
30
29
28
27
26
25
CONTROL
BLOCK
BIAS
CP
V
DD
TCXO
BUFFER
PFD
DIV
V
DD
V
GND
GND
RFIN
GND
GND
DD
MAX2742
DIN
LNA
GND
CLKOUT2
DOUT
I.C.
IFSEL 10
I.C. 11
VGA
COMP
AGC
20
CLKOUT1
V
V
DD
12
DD
13
14
15
16
17
18
19
21
22
23
24
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Single-Chip Global Positioning System
Receiver Front-End
ABSOLUTE MAXIMUM RATINGS
DD
All Other Pins to GND.................................-0.3V to (V
RF LNA Input Power.......................................................+10dBm
V
to GND...........................................................-0.3V to +3.7V
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Soldering Temperature (10s)...........................................+300°C
+ 0.3V)
DD
Continuous Power Dissipation (T = +70°C)
A
48-Pin TQFP-EP (derate 12.5mW/°C above +70°C)....100mW
CAUTION! ESD SENSITIVE DEVICE
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
DC ELECTRICAL CHARACTERISTICS
(MAX2742 EV kit, V
= +2.4V to +3.6V, SHDN = V , T = -40°C to +85°C. Typical values are at V
= +3V and T = +25°C,
DD A
DD
DD
A
unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Voltage
2.4
3.6
V
V
= +3.0V, T = +25°C (Note 1)
14
10
20
mA
µA
V
DD
A
Supply Current
Shutdown mode
Logic-Input High Voltage
Logic-Input Low Voltage
Logic-Input Bias Current
V
- 0.5
DD
0.5
V
-40
+40
µA
AC ELECTRICAL CHARACTERISTICS
(MAX2742 EV kit, V
= +2.4V to +3.6V, SHDN = V , T = -40°C to +85°C. Typical values are at V
= +3V and T = +25°C,
DD A
DD
DD
A
unless otherwise noted.)
PARAMETER
GENERAL PERFORMANCE
Maximum Conversion Gain
Input Frequency
CONDITIONS
MIN
TYP
MAX
UNITS
(Notes 2, 3)
102
1575.42
4.5
117
dB
MHz
dB
Noise Figure
Measured at quantizer input
f = 1.5MHz and f = 2.0MHz above carrier frequency
Return Loss (S11)
-15
dB
LNA/Mixer Input IP3
Output IF Frequency
OUTPUT STAGE
-32
dBm
MHz
1
2
1.023
Differential (VOUT+, VOUT-), C < 20pF
25
5
L
Output Rise/Fall Time
ns
V
Single ended (DOUT), C < 20pF
L
Differential
V
- 0.9
DD
Output-Voltage-Level Low
Output-Voltage-Level High
Single ended
Differential
0
V
V
DD
Single ended
2
_______________________________________________________________________________________
Single-Chip Global Positioning System
Receiver Front-End
AC ELECTRICAL CHARACTERISTICS (continued)
(MAX2742 EV kit, V
= +2.4V to +3.6V, SHDN = V , T = -40°C to +85°C. Typical values are at V
= +3V and T = +25°C,
DD A
DD
DD
A
unless otherwise noted.)
PARAMETER
SYNTHESIZER
CONDITIONS
MIN
TYP
MAX
UNITS
TCXO Input Frequency
Charge-Pump Current
Fundamental frequency crystal
18.414
0.4
MHz
mA
f
f
= 10kHz offset, BW
= 70kHz
= 70kHz
-71
OFFSET
LOOP
Phase Noise
dBc/Hz
= 1MHz offset, BW
= 70kHz
-106
-66
OFFSET
LOOP
Comparison Frequency Spur
VCO Turning Range
VCO Tuning Gain
BW
dBc
MHz
LOOP
(Notes 2, 3)
(Notes 2, 3)
148
139
210
200
277
305
MHz/V
IF STAGE
IF Stage Gain
VGA set at maximum gain
77
50
dB
dB
Dynamic Range IF Stage Gain
Low-frequency corner
High-frequency corner
0.1
3.2
Bandpass Filter 1dB Corner
Frequency
MHz
MHz
Bandpass Filter 60dB High-Side
Rejection
5.0
Image Rejection
In-Band Ripple
18
1
dB
dB
ms
AGC Loop Lock Time
1
Note 1: At T = +25°C, min/max limits are guaranteed by production test.
A
Note 2: At T = -40°C, min/max limits are guaranteed by design and characterization.
A
Note 3: At T = +25°C and +85°C, min/max limits are guaranteed by production test.
A
_______________________________________________________________________________________
3
Single-Chip Global Positioning System
Receiver Front-End
Typical Operating Characteristics
(MAX2742 EV kit, V
= +3V, and T = +25°C, unless otherwise noted.)
A
DD
LNA/MIXER GAIN
vs. TEMPERATURE
SUPPLY CURRENT
vs. TEMPERATURE
30
16
15
29
V
= +2.4V
CC
28
27
26
25
24
23
22
21
20
V
= +3.0V
CC
14
13
12
V
= +2.7V
CC
V
= +2.4V
CC
V
= +3.0V
CC
V
= +2.7V
CC
11
10
-40
-20
0
20
40
60
80
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
TEMPERATURE (°C)
MAXIMUM IF STAGE GAIN
vs. TEMPERATURE
TOTAL CONVERSION GAIN
vs. TEMPERATURE
80
79
78
77
76
105
104
103
V
= +3.0V
CC
V
= +3.0V
CC
V
= +2.7V
CC
102
101
100
V
= +2.7V
CC
V
= +2.4V
CC
V
= +2.4V
0
CC
75
-40
-20
0
20
40
60
80
-40
-20
20
40
60
80
TEMPERATURE (°C)
TEMPERATURE (°C)
4
_______________________________________________________________________________________
Single-Chip Global Positioning System
Receiver Front-End
Pin Description
PIN
1
NAME
RBIAS
CBIAS
FUNCTION
External Bias Resistor. Connect a 100kΩ 1% resistor in parallel with a 0.1µF capacitor in
series with a 71kΩ resistor to GND.
2
External Bias Capacitor. Connect a 0.1µF capacitor to GND.
3, 4, 12, 17, 23,
25, 32, 39, 44, 46
V
Supply Voltage. Bypass to GND with a capacitor as close to the pin as possible.
DD
5, 6, 8, 9, 13, 24,
30, 38, 42, 45
GND
RFIN
IFSEL
Ground. Connect to PC board ground plane.
LNA Input. Requires external matching network.
7
IF Output Select. Selects output type. Drive high for single-ended output, drive low for
differential output.
10
11, 21, 22,
27, 33–36, 40
I.C.
Internally Connected. Leave unconnected.
14
15
DCLK
Digital Control Clock
CLKENB2
CLKENB1
AGCFLT
Clock Output Enable 2. Drive high to enable limited-swing clock output.
Clock Output Enable 1. Drive high to enable full-swing clock output.
AGC External Filter
16
18
19, 20
26
OUT-, OUT+ Differential Comparator Outputs
CLKOUT1
DOUT
Full-Swing Clock Output
Digital Output
28
29
CLKOUT2
DIN
Limited-Swing Clock Output
Digital-Control Data Input
31
Shutdown. Drive SHDN high to disable all device functions. Drive SHDN low for normal
operation.
37
SHDN
41
43
VTUNE
CPOUT
VCO Tuning Input
Charge-Pump Output. Connect directly to loop filter.
XTALIN1,
XTALIN2
Connect XTALIN1 and XTALIN2 together and to the TCXO output through a coupling
capacitor.
47, 48
EP
GND
Exposed Paddle. Connect to PC board ground plane for optimal performance.
_______________________________________________________________________________________
5
Single-Chip Global Positioning System
Receiver Front-End
VCO, TCXO buffer, main frequency divider, phase-fre-
Detailed Description
quency detector, and charge pump. It uses an off-chip
PLL loop filter and TCXO. Connect the output of the
TCXO to XTALIN1 and XTALIN2 through a coupling
capacitor.
LNA/Mixer
The RF input from the GPS antenna is fed through an
LNA with a 24dB gain. The amplified signal is then fed
to a mixer that downconverts the signal (1575.42MHz)
to a quadrature differential IF of 1.023MHz.
The main division ratio for the synthesizer is 684. With this
division ratio, a low-side injection LO can be synthesized
with an 18.414MHz TXCO.
IF Stage
The quadrature IF signals pass through the IF filter,
which rejects the out-of-band spurs by more than 60dB
and the image noise by 18dB (typ). After the image
reject filter, the signal is converted from quadrature to
differential. The filtered IF signal is then amplified by the
AGC block, which sets the VGA output signal level to a
predetermined value through the application using 50dB
of dynamic range. The internal offset-cancellation mech-
anism generates a highpass characteristic for the IF
section with a 1dB corner frequency of about 100kHz.
Applications Information
Layout Issues
A properly designed PC board is an essential part of any
RF/microwave circuit. On all high-frequency inputs and
outputs, use controlled impedance lines and keep them
as short as possible to minimize losses and radiation.
Keeping the traces short also reduces parasitic induc-
tance. To further reduce the parasitic inductance, use
wider traces and a solid ground or power plane below
the signal traces. Also, place decoupling capacitors as
close to the supply pins as possible. For proper power
dissipation and operation, connect the metal exposed
paddle solidly to the ground plane of the PC board.
IF Output Selection
The sampled outputs of the GPS signal are available in
a single-ended or differential format. The IFSEL pin
controls the output format.
Synthesizer
An on-chip VCO provides quadrature differential LO
signals to the downconverting mixer and controls the
frequency. An on-board TCXO generates the reference
frequency. The integrated synthesizer includes the
6
_______________________________________________________________________________________
Single-Chip Global Positioning System
Receiver Front-End
Typical Application Circuit
TCXO
48
47
46
45
44
43
42
41
40
39
38
37
RBIAS
CBIAS
I.C.
I.C.
I.C.
I.C.
1
2
36
35
34
33
32
31
30
29
28
27
26
25
CONTROL
BLOCK
BIAS
CP
V
DD
3
TCXO
BUFFER
V
DD
PFD
DIV
4
V
GND
DD
5
MAX2742
GND
RFIN
GND
DIN
6
GND
LNA
7
CLKOUT2
DOUT
8
GND
9
IFSEL
I.C.
10
11
12
VGA
COMP
CLKOUT1
I.C.
AGC
20
V
V
DD
DD
13
14
15
16
17
18
19
21
22
23
24
Chip Information
PROCESS: CMOS
TRANSISTOR COUNT: 18443
_______________________________________________________________________________________
7
Single-Chip Global Positioning System
Receiver Front-End
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)
PACKAGE OUTLINE,
48L TQFP, 7x7x1.0mm EP OPTION
1
21-0065
G
2
PACKAGE OUTLINE,
48L TQFP, 7x7x1.0mm EP OPTION
2
21-0065
G
2
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2006 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products, Inc.
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