2.5GHz low voltage fractional-N
dual frequency synthesizer
Product specification
Supersedes data of 1999 Apr 16
1999 Nov 04
Page 2
Philips SemiconductorsProduct specification
TYPE NUMBER
2.5GHz low voltage fractional-N dual frequency
synthesizer
GENERAL DESCRIPTION
The SA8026 BICMOS device integrates programmable dividers,
charge pumps and a phase comparator to implement a
phase-locked loop. The device is designed to operate from 3 NiCd
cells, in pocket phones, with low current and nominal 3 V supplies.
The synthesizer operates at VCO input frequencies up to 2.5 GHz.
The synthesizer has fully programmable main, auxiliary and
reference dividers. All divider ratios are supplied via a 3-wire serial
programming bus.
Separate power and ground pins are provided to the analog and
digital circuits. The ground leads should be externally short-circuited
to prevent large currents flowing across the die and thus causing
damage. V
The charge pump current (gain) is set by an external resistance at
R
pin. Passive loop filters could be used; the charge pump
SET
operates within a wide voltage compliance range to provide a wider
tuning range.
FEA TURES
•Low phase noise
•Low power
•Fully programmable main and auxiliary dividers
•Normal & Integral charge pumps outputs
•Fast Locking Adaptive mode design
•Internal fractional spurious compensation
•Hardware and software power down
•Split supply for V
must be greater than or equal toV
DDCP
and V
DD
DDCP
DD
.
APPLICATIONS
•350 to 2500 MHz wireless equipment
•Cellular phones (all standards)
•WLAN
•Portable battery-powered radio equipment.
LOCK
TEST
RFin+
RFin–
GND
GND
V
GND
PHP
PHI
1
2
3
DD
4
5
6
7
CP
8
9
10
CP
20
19
18
17
16
15
14
13
12
11
PON
STROBE
DATA
CLOCK
REFin+
REFin–
R
V
AUXin
PHA
Figure 1. Pin Configuration
SA8026
SET
DDCP
SR01649
QUICK REFERENCE DATA
ORDERING INFORMATION
SYMBOLPARAMETERCONDITIONSMIN.TYP.MAX.UNIT
V
DD
V
DDCP
I
DDCP+IDD
I
DDCP+IDD
f
VCO
f
AUX
f
REF
f
PC
T
amb
Supply voltage2.7–5.5V
Analog supply voltageV
DDCP
w
V
DD
2.7–5.5V
Total supply currentMain and Aux. on–1012mA
Total supply current in power-down mode–1–µA
Input frequency350–2500MHz
Input frequency20–550MHz
Crystal reference input frequency5–40MHz
Maximum phase comparator frequency–4MHz
Operating ambient temperature–40–+85°C
PACKAGE
NAMEDESCRIPTIONVERSION
SA8026DHTSSOP20Plastic thin shrink small outline package; 20 leads; body width 4.4 mmSOT360–1
1999 Nov 04853–2141 22633
2
Page 3
Philips SemiconductorsProduct specification
2.5GHz low voltage fractional-N dual frequency
synthesizer
CLOCK
DATA
STROBE
RFin+
RFin–
REFin+
REFin–
17
18
19
5
6
AMP
16
15
2–BIT SHIFT
REGISTER
ADDRESS DECODER
LOAD SIGNALS
LATCH
REFERENCE
DIVIDER
22–BIT SHIFT
REGISTER
LATCH
MAIN DIVIDER
CONTROL
LATCH
SM
2222
SA
V
DD
3
PUMP
CURRENT
SETTING
PUMP
BIAS
COMP
PHASE
DETECTOR
V
DDCP
13
SA8026
14
R
SET
8
PHP
9
PHI
1
LOCK
TEST
12
AMP
2
AUX DIVIDER
AUXin
PINNING
SYMBOLPINDESCRIPTION
LOCK1Lock detect output
TEST2Test (should be either grounded or
V
DD
GND4Digital ground
RFin+5RF input to main divider
RFin–6RF input to main divider
GND
CP
PHP8Main normal charge pump
PHI9Main integral charge pump
GND
CP
connected to VDD)
3Digital supply
7Charge pump ground
10Charge pump ground
LATCH
4
GND
Figure 2. Block Diagram
SYMBOLPINDESCRIPTION
PHA11Auxiliary charge pump output
AUXin12Input to auxiliary divider
V
DDCP
R
SET
REFin–15Reference input
REFin+16Reference input
CLOCK17Programming bus clock input
DATA18Programming bus data input
STROBE19Programming bus enable input
PON20Power down control
PHASE
DETECTOR
7, 10
GND
CP
11
20
PHA
PON
SR01496
13Charge pump supply voltage
14External resistor from this pin to ground
sets the charge pump current
1999 Nov 04
3
Page 4
Philips SemiconductorsProduct specification
2.5GHz low voltage fractional-N dual frequency
SA8026
synthesizer
Limiting values
SYMBOLPARAMETERMIN.MAX.UNIT
V
DD
V
DDCP
∆V
DDCP–VDD
V
n
V
n
∆V
GND
T
stg
T
amb
T
j
Handling
Inputs and outputs are protected against electrostatic discharge in normal handling. However, to be totally safe, it is desirable to take normal
precautions appropriate to handling MOS devices.
Digital supply voltage–0.3+5.5V
Analog supply voltage–0.3+5.5V
Difference in voltage between V
Voltage at pins 1, 2, 5, 6, 12, 15 to 20–0.3V
Voltage at pin 8, 9, 11–0.3V
Difference in voltage between GNDCP and GND (these pins should be
connected together)
Storage temperature–55+125
Operating ambient temperature–40+85
Maximum junction temperature150
DDCP and
VDD (V
≥ VDD)–0.3+2.8V
DDCP
+ 0.3V
DD
DDCP
–0.3+0.3V
+ 0.3V
_C
_C
_C
Thermal characteristics
SYMBOLPARAMETERVALUEUNIT
R
th j–a
Thermal resistance from junction to ambient in free air135K/W
1999 Nov 04
4
Page 5
Philips SemiconductorsProduct specification
S
V
AC-coupled input signal level
in
()
S
2.5GHz low voltage fractional-N dual frequency
synthesizer
CHARACTERISTICS
V
DDCP
SYMBOL
= V
= +3.0V,T
DD
PARAMETERCONDITIONSMIN.TYP.MAX.UNIT
Supply; pins 3, 13
V
DD
V
DDCP
I
DDTotal
I
Standby
Digital supply voltage2.7–5.5V
Analog supply voltageV
Synthesizer operational total supply currentV
Total supply current in power-down modelogic levels 0 or VDD–1–µΑ
Charge pump current ratio to I
Sink-to-source current matchingVPH = 1/2 V
Output current variation versus V
Charge pump off leakage currentVPH = 1/2 V
Charge pump voltage compliance0.7–V
= +25°C;unless otherwise specified.
amb
p
p
1
SET
PH
V
w
DDCP
DD
(with main and aux on)
DD
= +3.0V
single-ended drive;
max. limit is indicative
@ 500 to 2500 MHz
= 2.4 GHz–300–Ω
VCO
= 2.4 GHz–1–pF
VCO
Rin (external) = R
max. limit is indicative
= 500 MHz–3.9–kΩ
VCO
= 500 MHz–0.5–pF
VCO
max. limit is indicative
= 20 MHz–10–kΩ
REF
= 20 MHz–1–pF
REF
= 7.5 kΩ–1.25–V
SET
Current gain = IPH/I
DDCP
2
V
in compliance range–10+10%
PH
DDCP
= 50Ω;
= 7.5 kΩ, FC = 80
SET
SET
SA8026
2.7–5.5V
–1012mA
–18–0dBm
–18–0dBm
80–632mV
360–1300mV
–15+15%
–10+10%
–10+10nA
–0.8V
DDCP
PP
PP
1999 Nov 04
5
Page 6
Philips SemiconductorsProduct specification
f
REF
13MHz, TCXO
L
f
REF
44MHz, TCXO
2.5GHz low voltage fractional-N dual frequency
SA8026
synthesizer
CHARACTERISTICS (continued)
SYMBOLPARAMETERCONDITIONSMIN.TYP.MAX.UNIT
Phase noise (condition R
Synthesizer’s contribution to close-in phase noise
of 900 MHz RF signal at 1 kHz offset.
Synthesizer’s contribution to close-in phase noise
of 1800 MHz RF signal at 1 kHz offset.
(f)
Synthesizer’s contribution to close-in phase noise
of 800 MHz RF signal at 1 kHz offset.
Synthesizer’s contribution to close-in phase noise
of 2100 MHz RF signal at 1 kHz offset.
HIGH level input voltage0.7*V
LOW level input voltage–0.3–0.3*V
Input leakage currentlogic 1 or logic 0–0.5–+0.5µA
Lock detect output signal (in push/pull mode); pin 1
V
OL
V
OH
LOW level output voltageI
HIGH level output voltageI
NOTES:
V
SET
1. I
SET =
bias current for charge pumps.
R
SET
2. The relative output current variation is defined as:
= 7.5 kΩ, CP = 00)
SET
––90–dBc/Hz
––83–dBc/Hz
f
COMP
=
=
= 1MHz
GSM
,
indicative, not tested
––85–dBc/Hz
––77–dBc/Hz
f
COMP
=
= 19.
= 240kHz
TDMA
,
indicative, not tested
DD
= 2mA––0.4V
sink
= –2mAVDD–0.4––V
source
–VDD+0.3V
DD
V
DI
OUT
I
OUT
+ 2
.
I(I
(I2–I1)
) I1)I
2
I
ZOUT
; with V1+ 0.7V, V2+ V
CURRENT
I
2
I
1
I
2
I
1
–0.8V (See Figure 3.)
DDCP
V
1
V
V
2
PH
SR00602
Figure 3. Relative Output Current Variation
1999 Nov 04
6
Page 7
Philips SemiconductorsProduct specification
2.5GHz low voltage fractional-N dual frequency
synthesizer
FUNCTIONAL DESCRIPTION
Main Fractional-N divider
The RFin inputs drive a pre-amplifier to provide the clock to the first
divider stage. For single ended operation, the signal should be fed to
one of the inputs while the other one is AC grounded. The
pre-amplifier has a high input impedance, dominated by pin and pad
capacitance. The circuit operates with signal levels from –18 dBm to
0 dBm, and at frequencies as high as 2.5 GHz. The divider consists
of a fully programmable bipolar prescaler followed by a CMOS
counter. Total divide ratios range from 512 to 65536.
At the completion of a main divider cycle, a main divider output
pulse is generated which will drive the main phase comparator. Also,
the fractional accumulator is incremented by the value of NF. The
accumulator works with modulo Q set by FMOD. When the
accumulator overflows, the overall division ratio N will be increased
by 1 to N + 1, the average division ratio over Q main divider cycles
(either 5 or 8) will be
Nfrac + N )
The output of the main divider will be modulated with a fractional
phase ripple. The phase ripple is proportional to the contents of the
fractional accumulator and is nulled by the fractional compensation
charge pump.
The reloading of a new main divider ratio is synchronized to the
state of the main divider to avoid introducing a phase disturbance.
NF
Q
Auxiliary divider
The AUXin input drives a pre-amplifier to provide the clock to the
first divider stage. The pre-amplifier has a high input impedance,
dominated by pin and pad capacitance. The circuit operates with
signal levels from –18dBm to 0 dBm (80 to 636 mVpp), and at
frequencies as high as 550 MHz. The divider consists of a fully
programmable bipolar prescaler followed by a CMOS counter. Total
divide ratios ranges from 128 to 16383.
Reference divider
The reference divider consists of a divider with programmable
values between 4 and 1023 followed by a three bit binary counter.
The 3 bit SM (SA) register (see figure 4) determines which of the 5
output pulses are selected as the main (auxiliary) phase detector
input.
Phase detector (see Figure 5)
The reference and main (aux) divider outputs are connected to a
phase/frequency detector that controls the charge pump. The pump
current is set by an external resistor in conjunction with control bits
CP0 and CP1 in the C-word (see Charge Pump table). The dead
zone (caused by finite time taken to switch the current sources on or
off) is cancelled by forcing the pumps ON for a minimum time at
every cycle (backlash time) providing improved linearity.
SA8026
REFERENCE
INPUT
DIVIDE BY R/2/2/2/2
Figure 4. Reference Divider
SM=”000”
SM=”001”
SM=”010”
SM=”011”
SM=”100”
SA=”100”
SA=”011”
SA=”010”
SA=”001”
SA=”000”
TO
MAIN
PHASE
DETECTOR
TO
AUXILIARY
PHASE
DETECTOR
SR01415
1999 Nov 04
7
Page 8
Philips SemiconductorsProduct specification
2.5GHz low voltage fractional-N dual frequency
synthesizer
f
REF
REF DIVIDER
AUX/MAIN
DIVIDER
“1”
“1”
X
D
R
Q
CLK
R
τ
R
D
CLK
Q
SA8026
V
CC
P
N
GND
P–TYPE
CHARGE PUMP
I
PH
N–TYPE
CHARGE PUMP
f
REF
R
N
I
PH
X
τ
P
τ
SR01451
Figure 5. Phase Detector Structure with Timing
1999 Nov 04
8
Page 9
Philips SemiconductorsProduct specification
2.5GHz low voltage fractional-N dual frequency
synthesizer
Main Output Charge Pumps and Fractional
Compensation Currents (see Figure 6)
The main charge pumps on pins PHP and PHI are driven by the
main phase detector and the charge pump current values are
determined by the current at pin R
in conjunction with bits CP0,
SET
CP1 in the C-word (see table of charge pump ratios). The fractional
compensation is derived from the current at R
, the contents of
SET
the fractional accumulator FRD and by the program value of the
FDAC. The timing for the fractional compensation is derived from
the main divider. The main charge pumps will enter speed up mode
after the A-word is set and strobe goes High. When strobe goes
Low, charge pump will exit speed up mode.
Principle of Fractional Compensation
The fractional compensation is designed into the circuit as a means
of reducing or eliminating fractional spurs that are caused by the
fractional phase ripple of the main divider. If I
compensation current and I
is the pump current, then for each
PUMP
charge pump:
I
PUMP_TOTAL
= I
PUMP
+ I
COMP
COMP
is the
.
The compensation is done by sourcing a small current, I
Figure 7, that is proportional to the fractional error phase. For proper
fractional compensation, the area of the fractional compensation
current pulse must be equal to the area of the fractional charge
pump ripple. The width of the fractional compensation pulse is fixed
to 128 VCO cycles, the amplitude is proportional to the fractional
accumulator value and is adjusted by FDAC values (bits FC7–0 in
the B-word). The fractional compensation current is derived from the
main charge pump in that it follows all the current scaling through
external resistor setting, R
For a given charge pump,
FRD is the fractional accumulator value.
The target values for FDAC are: 128 for FMOD = 1 (modulo 5) and
80 for FMOD = 0 (modulo 8).
I
COMP
SA8026
, programming or speed-up operation.
SET
= ( I
/ 128 ) * ( FDAC / 5*128) * FRD
PUMP
COMP
, see
REFERENCE R
MAIN M
DIVIDE RATIO
DETECTOR
OUTPUT
ACCUMULATOR
FRACTIONAL
COMPENSATION
CURRENT
OUTPUT ON
PUMP
NOTE: For a proper fractional compensation, the area of the fractional compensation current pulse must be equal to the area of the charge pump ripple output.
The auxiliary charge pump on pin PHA are driven by the auxiliary phase detector and PHP, PHI are driven by the main phase detector. The
current value is determined by the external resistor attached to pin R
Main and auxiliary charge pump currents
CP1
001.5xl
010.5xl
101.5xl
110.5xl
CP0I
PHA
SET
SET
SET
SET
NOTES
= V
1. I
SET
2. CP1 is used to disable the PHI pump, I
SET/RSET
: bias current for charge pumps.
is the total current at pin PHP during speed up condition.
PHP–SU
Lock Detect
The output LOCK maintains a logic ‘1’ when the auxiliary phase
detector ANDed with the main phase detector indicates a lock
condition. The lock condition for the main and auxiliary synthesizers
is defined as a phase difference of less than "1 period of the
frequency at the input REF
condition when the other counter is powered down. Out of lock (logic
’0’) is indicated when both counters are powered down.
. One counter can fulfill the lock
in+, –
.
SET
3xI
1xl
3xl
1xl
I
PHP
SET
SET
SET
SET
I
PHP–SU
15xl
SET
5xl
SET
15xl
SET
5xl
SET
36xl
12xl
Power-down mode
The power-down signal can be either hardware (PON) or software
(PD). The PON signal is exclusively ORed with the PD bits in
B-word. If PON = 0, then the part is powered up when PD = 1. PON
can be used to invert the polarity of the software bit PD. When the
synthesizer is reactivated after power-down, the main and reference
dividers are synchronized to avoid possibility of random phase
errors on power-up.
I
PHI
SET
SET
0
0
1999 Nov 04
10
Page 11
Philips SemiconductorsProduct specification
2.5GHz low voltage fractional-N dual frequency
synthesizer
Serial programming bus
The serial input is a 3-wire input (CLOCK, STROBE, DATA) to
program all counter divide ratios, fractional compensation DAC,
selection and enable bits. The programming data is structured into
24 bit words; each word includes 2 or 3 address bits. Figure 8
shows the timing diagram of the serial input. When the STROBE
goes active HIGH, the clock is disabled and the data in the shift
register remains unchanged. Depending on the address bits, the
Serial bus timing characteristics. See Figure 8.
V
= V
DD
Serial programming clock; CLK
t
r
t
f
T
cy
Enable programming; STROBE
t
START
t
W
t
SU;E
Register serial input data; DATA
t
SU;DAT
t
HD;DAT
DDCP
SYMBOL
=+3.0V; T
= +25°C unless otherwise specified.
amb
PARAMETERMIN.TYP .MAX.UNIT
Input rise time–1040ns
Input fall time–1040ns
Clock period100––ns
Delay to rising clock edge40––ns
Minimum inactive pulse width1/f
Enable set-up time to next clock edge20––ns
Input data to clock set-up time20––ns
Input data to clock hold time20––ns
data is latched into different working registers or temporary
registers. In order to fully program the synthesizer, 3 words must be
sent: C, B, and A. Table 1 shows the format and the contents of
each word. The D word is normally used for testing purposes. When
sending the B-word, data bits FC7–0 for the fractional compensation
DAC are not loaded immediately. Instead they are stored in
temporary registers. Only when the A-word is loaded, these
temporary registers are loaded together with the main divider ratio.
Default
A word selectFixed to 00.
Fractional Modulus selectFM 0 = modulo 8, 1 = modulo 5.
Fractional-N IncrementNF2..0 Fractional N Increment values 000 to 111.
N-DividerN0..N15, Main divider values 512 to 65535 allowed for divider ratio.
Default
B word selectFixed to 01
R-DividerR0..R9, Reference divider values 4 to 1023 allowed for divider ration.
Lock detect outputL1 L0
Power downMain = 1: power to N-divider, reference divider, main charge pumps, Main = 0 to power down.
Fractional CompensationFC7..0 Fractional Compensation charge pump current DAC, values 0 to 255.
0010001000100011000000
0001010001001101010000
0 0 Combined main, aux. lock detect signal present at the LOCK pin (push/pull).
0 1 Combined main, aux, lock detect signal present at the LOCK pin (open drain).
1 0 Main lock detect signal present at the LOCK pin (push/pull).
1 1 Auxiliary loop lock detect signal present at the LOCK pin (push/pull).
When auxiliary loop and main loop are in power down mode, the lock indicator is low.
Aux = 1: power to Aux divider, reference divider, aux charge pump, Aux = 0 to power down.
Default
C word selectFixed to 10
A-DividerA0..A13, Auxiliary divider values 128 to 16383 allowed for divider ratio.
Charge pump current RatioCP1, CP0: Charge pump current ratio, see table of charge pump currents.
Main comparison selectSM comparison divider select for main phase detector.
Aux comparison selectSA Comparison divider select for auxiliary phase detector.
0000011100101011000000
Table 5. D word, length 24 bits
AddressSynthesizer Test BitsSynthesizer Test Bits
110–––––Tspu–––––––––––––––
Default
Tspu: Speed up = 1Forces the main charge pumps in speed-up mode all the time.
1999 Nov 04
000000000000000000000
NOTE: All test bits must be set to 0 for normal operation.
12
Page 13
Philips SemiconductorsProduct specification
2.5GHz low voltage fractional-N dual frequency
synthesizer
Figure 28. Auxiliary Divider Input Sensitivity vs.
Frequency and Temperature
(Supply = 3.00 V)
SA8026
+85_C
–40_C
+25_C
SR01881
0.00
MINIMUM SIGNAL POWER LEVEL (dBm)
–5
–10
–15
–20
–25
–30
–35
–40
–45
–50
–55
0
5 10152025303540455055606570
FREQUENCY (MHz)
VDD = 5.00 V
VDD = 3.75 V
VDD = 3.00 V
VDD = 2.70 V
Figure 29. Reference Divider Input Sensitivity vs.
Frequency and Supply Voltage
(Temp = 25_C)
13
12
11
I TOTAL (mA)
10
9
22.533.544.555.56
SUPPLY VOLTAGE (V)
Figure 31. Current Supply Over V
DD
SR01890
+85_C
+25_C
–40_C
SR01854
0
MINIMUM SIGNAL POWER LEVEL (dBm)
–5
–10
–15
–20
–25
–30
–35
–40
–45
–50
–55
0
5 10152025303540455055606570
Temp = –40_C
Temp = +85_C
Temp = +25_C
FREQUENCY (MHz)
Figure 30. Reference Divider Input Sensitivity vs.
Frequency and Temperature
= 3.00 V)
(V
DD
SR01891
1999 Nov 04
16
Page 17
Philips SemiconductorsProduct specification
2.5GHz low voltage fractional–N dual frequency
synthesizer
TSSOP20: plastic thin shrink small outline package; 20 leads; body width 4.4 mmSOT360-1
SA8026
1999 Nov 04
17
Page 18
Philips SemiconductorsProduct specification
2.5GHz low voltage fractional–N dual frequency
synthesizer
Data sheet status
Data sheet
status
Objective
specification
Preliminary
specification
Product
specification
Product
status
Development
Qualification
Production
Definition
This data sheet contains the design target or goal specifications for product development.
Specification may change in any manner without notice.
This data sheet contains preliminary data, and supplementary data will be published at a later date.
Philips Semiconductors reserves the right to make chages at any time without notice in order to
improve design and supply the best possible product.
This data sheet contains final specifications. Philips Semiconductors reserves the right to make
changes at any time without notice in order to improve design and supply the best possible product.
[1]
SA8026
[1] Please consult the most recently issued datasheet before initiating or completing a design.
Definitions
Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For
detailed information see the relevant data sheet or data handbook.
Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one
or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or
at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended
periods may affect device reliability.
Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips
Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or
modification.
Disclaimers
Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can
reasonably be expected to result in personal injury . Philips Semiconductors customers using or selling these products for use in such applications
do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application.
Right to make changes — Philips Semiconductors reserves the right to make changes, without notice, in the products, including circuits, standard
cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no
responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these
products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless
otherwise specified.
Philips Semiconductors
811 East Arques Avenue
P.O. Box 3409
Sunnyvale, California 94088–3409
Telephone 800-234-7381
Copyright Philips Electronics North America Corporation 1999
All rights reserved. Printed in U.S.A.
Date of release: 11-99
Document order number:9397 750 06567
1999 Nov 04
18
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