National Semiconductor LMX2487 Technical data

查询LMX2487SQX供应商
LMX2487
3.0 GHz - 6.0 GHz High Performance Delta-Sigma Low
LMX2487 High Performance Delta-Sigma Low Power Dual PLLatinum Frequency Synthesizer
February 2006
Power Dual PLLatinum
Frequency Synthesizers with
3.0 GHz Integer PLL
General Description
The LMX2487 is a low power, high performance delta-sigma fractional-N PLL with an auxiliary integer-N PLL. It is fabri­cated using National Semiconductor’s advanced process.
With delta-sigma architecture, fractional spurs at lower offset frequencies are pushed to higher frequencies outside the loop bandwidth. The ability to push close in spur and phase noise energy to higher frequencies is a direct function of the modulator order. Unlike analog compensation, the digital feedback technique used in the LMX2487 is highly resistant to changes in temperature and variations in wafer process­ing. The LMX2487 delta-sigma modulator is programmable up to fourth order, which allows the designer to select the optimum modulator order to fit the phase noise, spur, and lock time requirements of the system.
Serial data for programming the LMX2487 is transferred via a three line high speed (20 MHz) MICROWIRE interface. The LMX2487 offers fine frequency resolution, low spurs, fast programming speed, and a single word write to change the frequency. This makes it ideal for direct digital modula­tion applications, where the N counter is directly modulated with information. The LMX2487 is available in a 24 lead
4.0 X 4.0 X 0.8 mm LLP package.
Applications
n Cellular phones and base stations
n Direct digital modulation applications n Satellite and cable TV tuners n WLAN Standards
Features
Quadruple Modulus Prescalers for Lower Divide Ratios
n RF PLL: 16/17/20/21 or 32/33/36/37 n IF PLL: 8/9 or 16/17
Advanced Delta Sigma Fractional Compensation
n 12 bit or 22 bit selectable fractional modulus n Up to 4th order programmable delta-sigma modulator
Features for Improved Lock Times and Programming
n Fastlock / Cycle slip reduction n Integrated time-out counter n Single word write to change frequencies with Fastlock
Wide Operating Range
n LMX2487 RF PLL: 3.0 GHz to 6.0 GHz
Useful Features
n Digital lock detect output n Hardware and software power-down control n On-chip crystal reference frequency doubler. n RF phase comparison frequency up to 50 MHz n 2.5 to 3.6 volt operation with I
= 8.5 mA at 3.0 V
CC
Functional Block Diagram
20154701
PLLatinum™is a trademark of National Semiconductor Corporation.
© 2006 National Semiconductor Corporation DS201547 www.national.com
Connection Diagram
LMX2487
Pin Descriptions
Pin # Pin
0 GND - Ground Substrate. This is on the bottom of the package and must be grounded.
1 CPoutRF O RF PLL charge pump output.
2 GND - RF PLL analog ground.
3 VddRF1 - RF PLL analog power supply.
4 FinRF I RF PLL high frequency input pin.
5 FinRF* I RF PLL complementary high frequency input pin. Shunt to ground with a 100 pF
6 LE I MICROWIRE Load Enable. High impedance CMOS input. Data stored in the shift
7 DATA I MICROWIRE Data. High impedance binary serial data input.
8 CLK I MICROWIRE Clock. High impedance CMOS Clock input. Data for the various counters is
9 VddRF2 - Power supply for RF PLL digital circuitry.
10 CE I Chip Enable control pin. Must be pulled high for normal operation.
11 VddRF5 I Power supply for RF PLL digital circuitry.
12 Ftest/LD O Test frequency output / Lock Detect.
13 FinIF I IF PLL high frequency input pin.
14 VddIF1 - IF PLL analog power supply.
15 GND - IF PLL digital ground.
16 CPoutIF O IF PLL charge pump output
17 VddIF2 - IF PLL power supply.
18 OSCout O Buffered output of the OSCin signal.
19 ENOSC I Oscillator enable. When this is set to high, the OSCout pin is enabled regardless of the
20 OSCin I Reference Input.
21 NC I This pin must be left open.
22 VddRF3 - Power supply for RF PLL digital circuitry.
23 FLoutRF O RF PLL Fastlock Output. Also functions as Programmable TRI-STATE CMOS output.
24 VddRF4 - RF PLL analog power supply.
Name
Top View
24-Pin LLP (SQ)
20154722
I/O Pin Description
capacitor.
registers is loaded into the internal latches when LE goes HIGH
clocked into the 24 bit shift register on the rising edge
state of other pins or register bits.
www.national.com 2
Absolute Maximum Ratings (Notes 1, 2)
LMX2487
Parameter Symbol
Power Supply Voltage V
Voltage on any pin with GND = 0V V
Storage Temperature Range T
Lead Temperature (Solder 4 sec.) T
Min Typ Max
CC
i
s
L
-0.3 4.25 V
-0.3 VCC+0.3 V
-65 +150 ˚C
Value
Units
+260 ˚C
Recommended Operating Conditions
Parameter Symbol
Power Supply Voltage (Note 1) V
Operating Temperature T
Note 1: “Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur. "Recommended Operating Conditions" indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. The voltage at all the power supply pins of VddRF1, VddRF2, VddRF3, VddRF4, VddRF5, VddIF1 and VddIF2 must be the same. V through all these power pins.
Note 2: This Device is a high performance RF integrated circuit with an ESD rating be done at ESD-free workstations.
Electrical Characteristics (V
CC
A
will be used to refer to the voltage at these pins and ICCwill be used to refer to the sum of all currents
CC
= 3.0V; -40˚C TA≤ +85˚C unless otherwise specified)
CC
Min Typ Max
2.5 3.0 3.6 V
-40 25 +85 ˚C
<
2 kV and is ESD sensitive. Handling and assembly of this device should only
Symbol Parameter Conditions
Icc PARAMETERS
I
RF
CC
IF
I
CC
TOTAL
I
CC
PD Power Down Current
I
CC
Power Supply Current, RF Synthesizer
Power Supply Current, IF Synthesizer
Power Supply Current, Entire Synthesizer
IF PLL OFF RF PLL ON Charge Pump TRI-STATE
IF PLL ON RF PLL OFF Charge Pump TRI-STATE
IF PLL ON RF PLL ON Charge Pump TRI-STATE
CE = ENOSC = 0V CLK, DATA, LE = 0V
RF SYNTHESIZER PARAMETERS
f
FinRF
p
FinRF
Operating Frequency
LMX2487
Input Sensitivity 3000 - 6000 MHz -10 0 dBm
RF_P = 16 3000 4000
RF_P = 32 3000 6000
Phase Detector
f
COMP
Frequency (Note 3)
RF_CPG = 0
CPoutRF
CPoutRF
=VCC/2
=VCC/2
I
CPoutRF
SRCE
RF Charge Pump Source Current (Note 4)
V
RF_CPG = 1 V
... ... µA
RF_CPG = 15 V
CPoutRF
=VCC/2
Value
Value
Min Typ Max
5.7 mA
2.5 mA
8.5 mA
<
A
95 µA
190 µA
1520 µA
Units
50 MHz
Units
MHz
www.national.com3
Electrical Characteristics (V
= 3.0V; -40˚C TA≤ +85˚C unless otherwise specified) (Continued)
CC
LMX2487
Symbol Parameter Conditions
RF SYNTHESIZER PARAMETERS
RF Charge Pump Sink
I
CPoutRF
SINK
Current (Note 4)
RF Charge Pump
I
CPoutRF
TRI
TRI-STATE Current Magnitude
Magnitude of RF CP
|I
CPoutRF
%MIS |
Sink vs. CP Source Mismatch
|I
|I
CPoutRF
CPoutRF
%V |
%T |
Magnitude of RF CP Current vs. CP Voltage
Magnitude of RF CP Current vs. Temperature
IF SYNTHESIZER PARAMETERS
f
FinIF
p
FinIF
f
COMP
I
CPoutIF
I
CPoutIF
SRCE
SINK
Operating Frequency
IF Input Sensitivity -10 +5 dBm
Phase Detector Frequency
IF Charge Pump Source Current
IF Charge Pump Sink Current
IF Charge Pump
I
CPoutIF
TRI
TRI-STATE Current Magnitude
|I
|I
|I
CPoutIF
CPoutIF
CPoutIF
%MIS |
%V |
%TEMP
Magnitude of IF CP Sink vs. CP Source Mismatch
Magnitude of IF CP Current vs. CP Voltage
Magnitude of IF CP Current vs. Temperature
OSCILLATOR PARAMETERS
f
OSCin
v
OSCin
I
OSCin
Oscillator Operating Frequency
Oscillator Input Sensitivity
Oscillator Input Current -100 100 µA
SPURS
Spurs in band(Note 5) -55 dBc
RF_CPG = 0
CPoutRF
=VCC/2
V
RF_CPG = 1 V
CPoutRF
=VCC/2
Value
Min Typ Max
-95 µA
-190 µA
Units
... ... µA
RF_CPG = 15 V
0.5 V
V V T
A
0.5 V T
A
V
=VCC/2
CPoutRF
VCC-0.5 2 10 nA
=
RF_CPG
>
2 3 10 %
RF_CPG 2 3 13 %
VCC-0.5
CPoutRF
/2
CC
= 25˚C
CPoutRF
CPoutRF
= 25˚C
=VCC/2 4 %
CPoutRF
IF_P = 8 250 2000
IF_P = 16 250 3000
-1520 µA
28 %
MHz
10 MHz
V
CPoutIF=VCC
V
CPoutIF=VCC
0.5 V
V
CPoutIF=VCC
= 25˚C
T
A
0.5 V = 25˚C
T
A
V
CPoutIF=VCC
/2 3.5 mA
/2 -3.5 mA
VCCRF -0.5 2 10 nA
CPoutIF
CPoutIF
/2
VCC-0.5
18 %
410 %
/2 4 %
OSC2X = 0 5 110 MHz
OSC2X = 1 5 20 MHz
0.5 V
CC
V
P-P
www.national.com 4
LMX2487
Electrical Characteristics (V
Symbol Parameter Conditions
= 3.0V; -40˚C TA≤ +85˚C unless otherwise specified) (Continued)
CC
Value
Min Typ Max
PHASE NOISE
RF_CPG = 0 -202
RF Synthesizer
L
F1Hz
RF
Normalized Phase Noise Contribution(Note 6)
RF_CPG = 1 -204
RF_CPG = 3 -206
RF_CPG = 7 -210
RF_CPG = 15 -210
IF Synthesizer
IF
L
F1Hz
Normalized Phase Noise
-209 dBc/Hz
Contribution
DIGITAL INTERFACE (DATA, CLK, LE, ENOSC, CE, Ftest/LD, FLoutRF)
V
IH
V
IL
I
IH
I
IL
V
OH
V
OL
High-Level Input Voltage 1.6 V
CC
Low-Level Input Voltage 0.4 V
High-Level Input Current VIH=V
CC
-1.0 1.0 µA
Low-Level Input Current VIL= 0 V -1.0 1.0 µA
High-Level Output Voltage
Low-Level Output Voltage
= -500 µA VCC-0.4 V
I
OH
= 500 µA 0.4 V
I
OL
MICROWIRE INTERFACE TIMING
t
CS
t
CH
t
CWH
t
CWL
t
ES
t
EW
Note 3: For Phase Detector Frequencies above 20 MHz, Cycle Slip Reduction (CSR) may be required. Legal divide ratios are also required.
Note 4: Refer to table in Section 2.4.2 RF_CPG -- RF PLL Charge Pump Gain for complete listing of charge pump currents.
Note 5: In order to measure the in-band spur, the fractional word is chosen such that when reduced to lowest terms, the fractional numerator is one. The spur offset
frequency is chosen to be the comparison frequency divided by the reduced fractional denominator. The loop bandwidth must be sufficiently wide to negate the impact of the loop filter. Measurement conditions are: Spur Offset Frequency = 10 kHz, Loop Bandwidth = 100 kHz, Fraction = 1/2000, Comparison Frequency = 20 MHz, RF_CPG = 7, DITH = 0, VCO Frequency = 3 GHz, and a 4th Order Modulator (FM = 0). These are relatively consistent over tuning range.
Note 6: Normalized Phase Noise Contribution is defined as: L measured at an offset frequency, f, ina1HzBandwidth. The offset frequency, f, must be chosen sufficiently smaller than the PLL loop bandwidth, yet large enough to avoid substantial phase noise contribution from the reference source. Measurement conditions are: Offset Frequency = 11 kHz, Loop Bandwidth = 100 kHz for RF_CPG = 7, Fraction = 1/2000, Comparison Frequency = 20 MHz, FM = 0, DITH = 0, VCO Frequency = 3 GHz.
Data to Clock Set Up Time
See MICROWIRE Input Timing 25 ns
Data to Clock Hold Time See MICROWIRE Input Timing 8 ns
Clock Pulse Width High See MICROWIRE Input Timing 25 ns
Clock Pulse Width Low See MICROWIRE Input Timing 25 ns
Clock to Load Enable Set Up Time
Load Enable Pulse Width
See MICROWIRE Input Timing 25 ns
See MICROWIRE Input Timing 25 ns
(f) = L(f) – 20log(N) – 10log(f
N
) where L(f) is defined as the single side band phase noise
COMP
Units
dBc/Hz
V
MICROWIRE INPUT TIMING DIAGRAM
20154775
www.national.com5
Typical Performance Characteristics : Sensitivity (Note 7)
LMX2487
RF PLL Fin Sensitivity
= 25˚C, RF_P = 32
T
A
20154745
RF PLL Fin Sensitivity
= 3.0 V, RF_P = 32
V
CC
20154746
www.national.com 6
Typical Performance Characteristics : Sensitivity (Note 7) (Continued)
IF PLL Fin Sensitivity
T
= 25˚C, IF_P = 16
A
LMX2487
IF PLL Fin Sensitivity
= 3.0 V, IF_P = 16
V
CC
20154747
20154748
www.national.com7
Typical Performance Characteristics : Sensitivity (Note 7) (Continued)
LMX2487
OSCin Sensitivity
T
= 25˚C, OSC_2X = 0
A
20154749
OSCin Sensitivity
= 3.0 V, OSC_2X = 0
V
CC
20154756
www.national.com 8
Typical Performance Characteristics : Sensitivity (Note 7) (Continued)
OSCin Sensitivity
T
= 25˚C, OSC_2X =1
A
LMX2487
OSCin Sensitivity
= 3.0 V, OSC_2X = 1
V
CC
20154773
20154774
www.national.com9
Typical Performance Characteristic : FinRF Input Impedance (Note 7)
LMX2487
20154768
FinRF Input Impedance
Frequency (MHz) Real (Ohms) Imaginary (Ohms)
3000 39 -94
3200 37 -86
3400 33 -78
3600 30 -72
3800 28 -69
4000 26 -66
4250 24 -63
4500 23 -60
4750 22 -57
5000 20 -54
5250 19 -50
5500 18 -49
5750 17 -47
6000 17 -45
6250 16 -44
6500 16 -42
6750 16 -40
7000 16 -39
www.national.com 10
Typical Performance Characteristic : FinIF Input Impedance (Note 7)
20154754
FinIF Input Impedance
Frequency (MHz) Real (Ohms) Imaginary (Ohms)
100 508 -233
150 456 -215
200 420 -206
250 403 -205
300 370 -207
400 344 -215
500 207 -223
600 274 -225
700 242 -225
800 242 -225
900 214 -222
1000 171 -208
1200 137 -191
1400 112 -176
1600 91 -158
1800 76 -139
2000 62 -122
2200 51 -105
2300 46 -96
2400 42 -88
2600 37 -74
2800 29 -63
3000 25 -54
LMX2487
www.national.com11
Typical Performance Characteristic : OSCin Input Impedance (Note 7)
LMX2487
Frequency (MHz) Powered Up Powered Down
Real Imaginary Magnitude Real Imaginary Magnitude
5 1730 -3779 4157 392 -8137 8146
10 846 -2236 2391 155 -4487 4490
20 466 -1196 1284 107 -2215 2217
30 351 -863 932 166 -1495 -1504
40 316 -672 742 182 -1144 1158
50 278 -566 631 155 -912 925
60 261 -481 547 153 -758 774
70 252 -425 494 154 -652 669
80 239 -388 456 147 -576 595
90 234 -358 428 145 -518 538
100 230 -337 407 140 -471 492
110 225 -321 392 138 -436 458
120 219 -309 379 133 -402 123
130 214 -295 364 133 -374 397
140 208 -285 353 132 -349 373
150 207 -279 348 133 -329 355
20154755
www.national.com 12
Loading...
+ 25 hidden pages