NSC LMX2502LQX1635, LMX2502LQ1635 Datasheet
LMX2502/LMX2512
LMX2502/LMX2512 Frequency Synthesizer System with Integrated VCO
June 2003
PLLatinum
™
Frequency Synthesizer System with
Integrated VCO
General Description
LMX2502 and LMX2512 are highly integrated, high performance, low power frequency synthesizer systems optimized
for Korean PCS and Korean Cellular CDMA (1xRTT, IS-95)
mobile handsets. Using a proprietary digital phase locked
loop technique, LMX2502 and LMX2512 generate very
stable, low noise local oscillator signals for up and down
conversion in wireless communications devices.
LMX2502 and LMX2512 include a voltage controlled oscillator (VCO), a loop filter, and a fractional-N RF PLL based on
a delta sigma modulator. In concert these blocks form a
closed loop RF synthesizer system. LMX2502 supports the
Korean PCS band and LMX2512 supports the Korean Cellular band.
LMX2502 and LMX2512 include an Integer-N IF PLL also.
For more flexible loop filter designs, the IF PLL includes a
4-level programmable charge pump. Together with an external VCO and loop filter, LMX2502 and LMX2512 make a
complete closed loop IF synthesizer system.
Serial data is transferred to the device via a three-wire
MICROWIRE interface (DATA, LE, CLK).
Operating supply voltage ranges from 2.7 V to 3.3 V.
LMX2502 and LMX2512 feature low current consumption:
17 mA at 2.8 V.
LMX2502 and LMX2512 are available in a 28-pin leadless
leadframe package (LLP).
Features
n Small Size
5.0 mm X 5.0 mm X 0.75 mm 28-Pin LLP Package
n RF Synthesizer System
Integrated RF VCO
Integrated Loop Filter
Low Spurious, Low Phase Noise Fractional-N RF PLL
Based on 11-Bit Delta Sigma Modulator
10 kHz Frequency Resolution
n IF Synthesizer System
Integer-N IF PLL
Programmable Charge Pump Current Levels
Programmable Frequency
n Supports Various Reference Frequencies
19.20/19.68 MHz
n Fast Lock Time: 500 µs
n Low Current Consumption
17 mA at 2.8 V
n 2.7 V to 3.3 V Operation
n Digital Filtered Lock Detect Output
n Hardware and Software Power Down Control
Applications
n Korean PCS CDMA Systems
n Korean Cellular CDMA Systems
Functional Block Diagram
20068001
PLLatinum™is a trademark of National Semiconductor Corporation.
© 2003 National Semiconductor Corporation DS200680 www.national.com
Connection Diagram
LMX2502/LMX2512
28-Pin LLP (LQ) Package
NOTE: Analog ground connected through exposed die attached pad.
Pin Descriptions
Pin Number Name I/O Description
1 CPout O IF PLL charge pump output
2 NC – Do not connect to any node on the printed circuit board.
3 NC – Do not connect to any node on the printed circuit board.
4V
5 LE I MICROWIRE Latch Enable
6 CLK I MICROWIRE Clock
7 DATA I MICROWIRE Data
8V
9 NC – Do not connect to any node on the printed circuit board.
10 NC – Do not connect to any node on the printed circuit board.
11 NC – Do not connect to any node on the printed circuit board.
12 NC – Do not connect to any node on the printed circuit board.
13 V
14 V
15 RFout O Buffered VCO output
16 V
17 V
18 V
19 LD O Lock Detect
20 CE I Chip Enable control pin
21 GND – Ground for digital circuitry
22 OSCin I Reference frequency input
23 V
24 GND – Ground for digital circuitry
25 V
26 Fin I IF buffer/prescaler input
27 V
28 NC – Do not connect to any node on the printed circuit board.
DD
DD
DD
DD
CC
CC
CC
CC
CC
CC
20068002
– Supply voltage for IF analog circuitry
– Supply voltage for VCO
– Supply voltage for VCO
– Supply voltage for VCO output buffer
– Supply voltage for RF prescaler
– Supply voltage for charge pump
– Supply voltage for RF digital circuitry
– Supply voltage for reference input buffer
– Supply voltage for IF digital circuitry
– Supply voltage for IF buffer/prescaler
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Ordering Information
LMX2502/LMX2512
Part Number RF Min.
(MHz)
LMX2502LQX1635 1619.62 1649.62
LMX2502LQ1635 1619.62 1649.62
LMX2512LQX0967 954.42 979.35
LMX2512LQ0967 954.42 979.35
LMX2512LQX1065 1052.64 1077.57
LMX2512LQ1065 1052.64 1077.57
Part Number Description
RF Max.
(MHz)
RF Center
(MHz)
~
1635 440.76 25021635 4500 units on
~
1635 440.76 25021635 1000 units on
~
967 170.76 25120967 4500 units on
~
967 170.76 25120967 1000 units on
~
1065 367.20 25121065 4500 units on
~
1065 367.20 25121065 1000 units on
IF
(MHz)
Package
Marking
Supplied As
tape and reel
tape and reel
tape and reel
tape and reel
tape and reel
tape and reel
20068003
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Absolute Maximum Ratings (Notes 1,
2, 3)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Parameter Symbol Ratings Units
LMX2502/LMX2512
Supply Voltage V
Voltage on any pin
to GND
Storage Temperature
Range
CC,VDD
V
I
T
STG
-0.3 to 3.6 V
-0.3toVCC+0.3 V
-0.3toV
DD
-65 to 150 ˚C
+0.3 V
Recommended Operating Conditions
Parameter Symbol Min Typ Max Units
Ambient Temperature T
Supply Voltage (to GND) V
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, refer to the Electrical Characteristics section. The guaranteed specifications apply only for the conditions listed.
Note 2: This device is a high performance RF integrated circuit with an ESD
<
rating
2 kV and is ESD sensitive. Handling and assembly of this device
should be done at ESD protected work stations.
Note 3: GND=0V.
A
CC,VDD
-30 25 85 ˚C
2.7 3.3 V
Electrical Characteristics (V
CC=VDD
= 2.8 V, TA= 25 ˚C; unless otherwise noted)
Symbol Parameter Condition Min Typ Max Units
I
PARAMETERS
CC
I
CC+IDD
(I
+
CC
I
DD)RF
I
PD
Total Supply Current OB_CRL [1:0] = 00 17 19 mA
RF PLL Total Supply Current OB_CRL [1:0] = 00 16 18 mA
Power Down Current (Note 4) CE = LOW or
20 µA
RF_EN = 0
IF_EN = 0
REFERENCE OSCILLATOR PARAMETERS
f
OSCin
V
OSCin
Reference Oscillator Input Frequency
(Note 5)
Reference Oscillator Input Sensitivity 0.2 V
19.20 MHz and 19.68
MHz are supported
19.20 19.68 MHz
CC
Vp-p
RF VCO
f
RFout
Frequency Range
(Note 6)
LMX2502LQ1635 RF VCO 1619.62 1649.62 MHz
LMX2512LQ0967 954.42 979.35 MHz
LMX2512LQ1065 1052.64 1077.57 MHz
P
RFout
RF Output Power OB_CRL [1:0] = 11 -2 1 4 dBm
OB_CRL [1:0] = 10 -5 -2 1 dBm
OB_CRL [1:0] = 01 -7 -4 -1 dBm
OB_CRL [1:0] = 00 -9 -6 -3 dBm
Lock Time
(Note 7)
LMX2502LQ1635 30 MHz Band for RF
PLL
LMX2512LQ0967 25 MHz Band for RF
500 800 µs
500 800 µs
PLL
LMX2512LQ1065 25 MHz Band for RF
500 800 µs
PLL
Reference Spurs -75 dBc
RMS Phase Error RF PLL in all band 1.3 degrees
L(f)
RFout
Phase Noise LMX2502LQ1635
LMX2512LQ0967
LMX2512LQ1065
@
100 kHz offset -113 -112 dBc/Hz
@
1.25 MHz offset -138 -136 dBc/Hz
@
100 kHz offset -117 -115 dBc/Hz
@
900 kHz offset -139 -138 dBc/Hz
@
100 kHz offset -117 -115 dBc/Hz
@
900 kHz offset -139 -138 dBc/Hz
2nd Harmonic Suppression -25 dBc
3rd Harmonic Suppression -20 dBc
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LMX2502/LMX2512
Electrical Characteristics (V
CC=VDD
= 2.8 V, TA= 25 ˚C; unless otherwise noted) (Continued)
Symbol Parameter Condition Min Typ Max Units
IF PLL
f
Fin
Operating Frequency
(Note 8)
LMX2502LQ1635 IF_FREQ [1:0] = 10,
Default Value
LMX2512LQ0967 IF_FREQ [1:0] = 00,
440.76 MHz
170.76 MHz
Default Value
LMX2512LQ1065 IF_FREQ [1:0] = 01,
367.20 MHz
Default Value
P
f
ΦIF
I
CPout
Fin
IF Input Sensitivity -10 0 dBm
Phase Detector Frequency 120 kHz
Charge Pump Current IF_CUR [1:0] = 00 100 µA
IF_CUR [1:0] = 01 200 µA
IF_CUR [1:0] = 10 300 µA
IF_CUR [1:0] = 11 800 µA
DIGITAL INTERFACE (DATA, CLK, LE, LD, CE)
V
IH
V
IL
I
IH
I
IL
High-Level Input Voltage 0.8 V
0.8 V
DD
CC
Low-Level Input Voltage 0 0.2 V
0 0.2 V
V
DD
V
CC
DD
CC
High-Level Input Current -10 10 µA
Low-Level Input Current -10 10 µA
V
V
V
V
Input Capacitance 3 pF
V
OH
V
OL
High-Level Output Voltage 0.9 V
0.9 V
DD
CC
Low-Level Output Voltage 0.1 V
0.1 V
V
V
DD
CC
V
V
Output Capacitance 5pF
MICROWIRE INTERFACE TIMING
t
CS
t
CH
t
CWH
t
CWL
t
ES
t
EW
Note 4: In power down mode, set DATA, CLK, and LE pins to 0 V (GND).
Note 5: The reference frequency must also be programmed using the OSC_FREQ control bit. For other reference frequencies, please contact National
Semiconductor.
Note 6: For other frequency ranges, please contact National Semiconductor.
Note 7: Lock time is defined as the time difference between the beginning of the frequency transition and the point at which the frequency remains within +/- 1 kHz
of the final frequency.
Note 8: Frequencies other that the default value can be programmed using Words R4 and R5. See Programming Description for details.
Data to Clock Set Up Time 50 - - ns
Data to Clock Hold Time 10 - - ns
Clock Pulse Width HIGH 50 - - ns
Clock Pulse Width LOW 50 - - ns
Clock to Latch Enable Set Up Time 50 - - ns
Latch Enable Pulse Width 50 - - ns
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Microwire Interface Timing Diagram
LMX2502/LMX2512
20068004
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