LMX2335/LMX2336/LMX2337
PLLatinum
TM
Dual Frequency Synthesizer for RF
Personal Communications
LMX2335
1.1 GHz/1.1 GHz
LMX2336
2.0 GHz/1.1 GHz
LMX2337
550 MHz/550 MHz
General Description
The LMX2335, LMX2336 and LMX2337 are monolithic, inte-
grated dual frequency synthesizers, including two high fre-
quency prescalers, and are designed for applications requir-
ing two RF phase-lock loops. They are fabricated using
National's ABiC IV silicon BiCMOS process.
The LMX2335/36/37 contains two dual modulus prescalers.
A 64/65 or a 128/129 prescaler can be selected for each RF
synthesizer. A second reference divider chain is included in
the IC for improved system noise. LMX2335/36/37, which
employ a digital phase locked loop technique, combined with
a high quality reference oscillator and loop filters, provide the
tuning voltages for voltage controlled oscillators to generate
very stable low noise RF local oscillator signals.
Serial data is transferred into the LMX2335/36/37 via a three
wire interface (Data, Enable, Clock). Supply voltage can
range from 2.7V to 5.5V. The LMX2335/36/37 feature very
low current consumption; LMX2335/37 -10 mA at 3V,
LMX2336 -13 mA at 3V. The LMX2335/37 are available in
both a JEDEC SO and TSSOP 16-pin surface mount plastic
package. The LMX2336 is available in a TSSOP 20-pin sur-
face mount plastic package.
Features
n
2.7V to 5.5V operation
n
Low current consumption
n
Selectable powerdown mode:
I
CC
= 1 A (typ)
n
Dual modulus prescaler: 64/65 or 128/129
n
Selectable charge pump TRI-STATE
mode
n
Selectable charge pump current levels
n
Selectable FastLock
TM
mode
Applications
n
Cellular telephone systems (AMPS, ETACS, RCR-27)
n
Cordless telephone systems (DECT, ISM, PHS, CT-1+)
n
Personal Communication Systems
(DCS-1800, PCN-1900)
n
Dual Mode PCS phones
n
CATV
n
Other wireless communication systems
Functional Block Diagram
TRI-STATE
is a registered trademark of National Semiconductor Corporation.
Fastlock
TM
, MICROWIRE
TM
and PLLatinum
TM
are trademarks of National Semiconductor Corporation.
DS012332-1
September 1996
LMX2335/LMX2336/LMX2337
PLLatinum
Dual
Frequency
Synthesizer
for
RF
Personal
Communications
1999 National Semiconductor Corporation
DS012332
www.national.com
Connection Diagrams
Pin Descriptions
Pin No.
2335/37
Pin No.
2336
Pin
Name
I/O
Description
1
1
V
CC
1
Power supply voltage input for RF1 analog and RF1 digital circuits. Input may range
from 2.7V to 5.5V. V
CC
1 must equal V
CC
2. Bypass capacitors should be placed as
close as possible to this pin and be connected directly to the ground plane.
2
2
V
p
1
Power supply for RF1 charge pump. Must be
V
CC
.
3
3
D
o
1
O
RF1 charge pump output. For connection to a loop filter for driving the input of an
external VCO.
4
4
GND
LMX2335/37: Ground for RF1 analog and RF1 digital circuits. LMX2336: Ground for RF
digital circuitry.
5
5
f
IN
1
I
First RF prescaler input. Small signal input from the VCO.
X
6
f
IN
1
I
RF1 prescaler complementary input. A bypass capacitor should be placed as close as
possible to this pin and be connected directly to the ground plane. Capacitor is optional
with loss of some sensitivity.
X
7
GND
Ground for RF1 analog circuitry.
6
8
OSC
in
I
Oscillator input. The input has a V
CC
/2 input threshold and can be driven from an
external CMOS or TTL logic gate.
7
9
OSC
out
O
Oscillator output.
8
10
F
o
LD
O
Multiplexed output of the programmable or reference dividers, lock detect signals and
Fastlock mode. CMOS output
(see Programmable Modes).
9
11
Clock
I
High impedance CMOS Clock input. Data for the various latches is clocked in on the
rising edge, into the 20-bit shift register.
10
12
Data
I
Binary serial data input. Data entered MSB first. The last two bits are the control bits.
High impedance CMOS input.
11
13
LE
I
Load enable high impedance CMOS input. When LE goes HIGH, data stored in the
shift registers is loaded into one of the 4 appropriate latches (control bit dependent).
X
14
GND
Ground for RF2 analog circuitry.
X
15
f
IN
2
I
RF2 prescaler complementary input. A bypass capacitor should be placed as close as
possible to this pin and be connected directly to the ground plane. Capacitor is optional
with loss of some sensitivity.
12
16
f
IN
2
I
RF2 prescaler input. Small signal input from the VCO.
13
17
GND
LMX2335/37: Ground for RF2 analog, RF2 digital, MICROWIRE
TM
, F
o
LD and Oscillator
circuits. LMX2336: Ground for RF2 digital, MICROWIRE, F
o
LD and Oscillator circuits.
14
18
D
o
2
O
RF2 charge pump output. For connection to a loop filter for driving the input of an
external VCO.
15
19
V
p
2
Power supply for RF2 charge pump. Must be
V
CC
.
LMX2335/LMX2337
DS012332-2
Order Number LMX2335M/LMX2335TM or
LMX2337M/LMX2337TM
NS Package Number M16A and MTC16
LMX2336
DS012332-16
Order Number LMX2336TM
NS Package Number MTC20
www.national.com
2
Pin Descriptions
(Continued)
Pin No.
2335/37
Pin No.
2336
Pin
Name
I/O
Description
16
20
V
CC
2
Power supply voltage input for RF2 analog. RF2 digital, MICROWIRE, F
o
LD and
Oscillator circuits. Input may range from 2.7V to 5.5V. V
CC
2 must equal V
CC
1. Bypass
capacitors should be placed as close as possible to this pin and be connected directly
to the ground plane.
Block Diagram
DS012332-17
Note: V
CC
1 supplies power to the RF1 prescaler, N-counter, R-counter, and phase detector. V
CC
2 supplies power to the RF2 prescaler, N-counter, phase
detector, R-counter along with the OSC
in
buffer, MICROWIRE, and F
o
LD. V
CC
1 and V
CC
2 are clamped to each other by diodes and must be run at the same
voltage level.
V
P
1 and V
P
2 can be run separately as long as V
P
V
CC
.
LMX2335/37 Pin #
8/10
LMX2336 Pin #
Pin Name
F
o
LD
X signifies a function not available
www.national.com
3
Absolute Maximum Ratings
(Notes 1, 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Power Supply Voltage
V
CC
-0.3V to +6.5V
V
P
-0.3V to +6.5V
Voltage on Any Pin
with GND = 0V (V
I
)
-0.3V to V
CC
+0.3V
Storage Temperature Range (T
S
)
-65C to +150C
Lead Temperature (solder 4 sec.) (T
L
)
+260C
Recommended Operating
Conditions
Power Supply Voltage
V
CC
2.7V to 5.5V
V
P
V
CC
to +5.5V
Operating Temperature (T
A
)
-40C to +85C
Electrical Characteristics
V
CC
= 5.0V, V
p
= 5.0V; T
A
= 25C, except as specified
Symbol
Parameter
Conditions
Value
Units
Min
Typ
Max
I
CC
Power Supply
Current
LMX2335/37
RF1 and RF2
V
CC
= 2.7V to 5.5V
10
15
mA
I
CC
LMX2335/37 RF1
only
6
8
mA
I
CC
LMX2336
RF1 and RF2
13
18
mA
LMX2336 RF1 only
7
11
mA
f
IN
1
Operating
Frequency
LMX2335
0.100
1.1
GHz
f
IN
2
0.050
1.1
GHz
f
IN
1
LMX2336
0.200
2.0
GHz
f
IN
2
0.050
1.1
GHz
f
IN
1
LMX2337
100
550
MHz
f
IN
2
50
550
MHz
I
CC-PWDN
Powerdown Current
LMX2335/2336
V
CC
= 5.5V
1
25
A
LMX2337
100
f
OSC
Oscillator Frequency
With resonator load on OSC
out
5
20
MHz
f
OSC
No load on OSC
OUT
5
40
MHz
f
Phase Detector Frequency
10
MHz
Pf
IN
1
and Pf
in
2
RF Input Sensitivity
V
CC
= 3.0V, f
>
100 MHz
-15
+4
dBm
V
CC
= 5.0V, f
>
100 MHz
-10
+4
V
CC
= 2.7 to 5.5V,
f
>
100 MHz
-10
0
V
OSC
Oscillator Sensitivity
OSC
IN
0.5
V
PP
V
IH
High-Level Input Voltage
(Note 4)
0.8
V
CC
V
V
IL
Low-Level Input Voltage
(Note 4)
0.2
V
CC
V
I
IH
High-Level Input Current
V
IH
= V
CC
= 5.5V (Note 4)
-1.0
1.0
A
I
IL
Low-Level Input Current
V
IL
= 0V, V
CC
= 5.5V (Note 4)
-1.0
1.0
A
I
IH
Oscillator Input Current
V
IH
= V
CC
= 5.5V
100
A
I
IL
Oscillator Input Current
V
IL
= 0V, V
CC
= 5.5V
-100
A
I
Do-SOURCE
Charge Pump Output Current
V
Do
= V
p
/2, I
CPo
= LOW
(Note 3)
-1.25
mA
I
Do-SINK
V
Do
= V
p
/2, I
CPo
= LOW
(Note 3)
1.25
mA
I
Do-SOURCE
V
Do
= V
p
/2, I
CPo
= HIGH
(Note 3)
-5.0
mA
I
Do-SINK
V
Do
= V
p
/2, I
CPo
= HIGH
(Note 3)
5.0
mA
www.national.com
4
Electrical Characteristics
(Continued)
V
CC
= 5.0V, V
p
= 5.0V; T
A
= 25C, except as specified
Symbol
Parameter
Conditions
Value
Units
Min
Typ
Max
I
Do-TRI
Charge Pump
TRI-STATE
CURRENT
LMX2335
LMX2336
0.5V
V
Do
V
p
- 0.5V
T = 25C
-5.0
5.0
nA
I
Do-TRI
Charge Pump
TRI-STATE
CURRENT
LMX2337
0.5V
V
Do
V
p
- 0.5V
T = 25C
5
nA
V
OH
High-Level Output Voltage
I
OH
= -500 A
V
CC
-
0.4
V
V
OL
Low-Level Output Voltage
I
OL
= 500 A
0.4
V
t
CS
Data to Clock Setup Time
See Data Input Timing
50
ns
I
CH
Data to Clock Hold Time
See Data Input Timing
10
ns
t
CWH
Clock Pulse Width High
See Data Input Timing
50
ns
t
CWL
Clock Pulse Width Low
See Data Input Timing
50
ns
t
ES
Clock to Load Enable Set Up Time
See Data Input Timing
50
ns
t
EW
Load Enable Pulse Width
See Data Input Timing
50
ns
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 performanced limits. For guaranteed specifications and test conditions, see the Electrical Char-
acteristics. The guaranteed specifications apply only for the test conditions listed.
Note 2: This device is a high performance RF integrated circuit with an ESD rating
<
2 keV and is ESD sensitive. Handling and assembly of this device should only
be done at ESD protected workstations.
Note 3: See PROGRAMMABLE MODES for I
CPo
description.
Note 4: Clock, Data and LE does not include f
IN
1, f
IN
2 and OSC
in
.
Typical Performance Characteristics
ICC vs V
CC
LMX2335/37
DS012332-19
I
CC
vs V
CC
LMX2336
DS012332-20
www.national.com
5
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