5568.indd
LT5568
1
5568f
RF OUTPUT POWER PER CARRIER (dBm)
30
ACPR, AltCPR (dBc)
NOISE FLOOR AT 30MHz
OFFSET (dBm/Hz)
70
60
10
5568 TA02
80
90
25
20
15
5
50
145
135
155
165
125
DOWNLINK TEST MODEL 64 DPCH
1-CH. NOISE
3-CH. NOISE
1-CH. AltCPR
1-CH.
ACPR
3-CH. ACPR
3-CH. AltCPR
700MHz 1050MHz High
Linearity Direct Quadrature
Modulator
The LT
5568 is a direct I/Q modulator designed for high
performance wireless applications, including wireless
infrastructure. It allows direct modulation of an RF signal
using differential baseband I and Q signals. It supports
PHS, GSM, EDGE, TD-SCDMA, CDMA, CDMA2000, W-
CDMA, and other systems. It may also be confi gured
as an image reject upconverting mixer, by applying
90 phase-shifted signals to the I and Q inputs. The I/Q
baseband inputs consist of voltage-to-current converters
that in turn drive double-balanced mixers. The outputs of
these mixers are summed and applied to an on-chip RF
transformer, which converts the differential mixer signals
to a 50 single-ended output. The four balanced I and Q
baseband input ports are intended for DC coupling from a
source with a common mode voltage level of about 0.5V.
The LO path consists of an LO buffer with single-ended
input, and precision quadrature generators that produce
the LO drive for the mixers. The supply voltage range is
4.5V to 5.25V.
Infrastructure Tx for Cellular Bands
Image Reject Up-Converters for Cellular Bands
Low-Noise Variable Phase-Shifter for 700MHz to
1050MHz Local Oscillator Signals
RFID Reader
Frequency Range: 700MHz to 1050MHz
High OIP3: +22.9dBm at 850MHz
Low Output Noise Floor at 5MHz Offset:
No RF: 160.3dBm/Hz
P
OUT
= 4dBm: 154dBm/Hz
3-Ch CDMA2000 ACPR: 71.4dBc at 850MHz
Integrated LO Buffer and LO Quadrature Phase
Generator
50 AC-Coupled Single-Ended LO and RF Ports
50 DC Interface to Baseband Inputs
Low Carrier Leakage: 43dBm at 850MHz
High Image Rejection: 46dBc at 850MHz
16-Lead 4mm 4mm QFN Package
700MHz to 1050MHz Direct Conversion Transmitter Application
APPLICATIO S
U
FEATURES
DESCRIPTIO
U
TYPICAL APPLICATIO
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
CDMA2000 ACPR, AltCPR and Noise vs RF
Output Power at 850MHz for 1 and 3 Carriers
90
0
LT5568
BASEBAND
GENERATOR
PA
VCO/SYNTHESIZER
RF = 700MHz
TO 1050MHz
100nF
x2
EN
5V
V-I
V-I
I-CHANNEL
Q-CHANNEL
BALUN
V
CC
5568 TA01a
I-DAC
Q-DAC
LT5568
2
5568f
Supply Voltage .........................................................5.5V
Common Mode Level of BBPI, BBMI and
BBPQ, BBMQ .......................................................2.5V
Operating Ambient Temperature
(Note 2) ............................................... 40C to 85C
Storage Temperature Range ................... 65C to 125C
Voltage on any Pin
Not to Exceed ...................... 500mV to V
CC
+ 500mV
(Note 1)
ABSOLUTE AXI U
RATI GS
W
W
W
U
PACKAGE/ORDER I FOR ATIO
U
U
W
16 15 14 13
5
6
7
8
TOP VIEW
9
10
11
12
4
3
2
1
EN
GND
LO
GND
GND
RF
GND
GND
BBMI
GND
BBPI
V
CC
BBMQ
GND
BBPQ
V
CC
17
UF PACKAGE
16-LEAD (4mm
4mm) PLASTIC QFN
T
JMAX
= 125C,
JA
= 37C/W
EXPOSED PAD (PIN 17) IS GROUND, MUST BE SOLDERED TO PCB
ORDER PART NUMBER
UF PART MARKING
LT5568EUF
5568
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking:
http://www.linear.com/leadfree/
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges.
V
CC
= 5V, EN = High, T
A
= 25C, f
LO
= 850MHz, f
RF
= 852MHz, P
LO
= 0dBm.
BBPI, BBMI, BBPQ, BBMQ inputs 0.54V
DC
, Baseband Input Frequency = 2MHz, I&Q 90 shifted (upper side-band selection).
P
RF, OUT
= 10dBm, unless otherwise noted. (Note 3)
ELECTRICAL CHARACTERISTICS
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
RF Output (RF)
f
RF
RF Frequency Range
RF Frequency Range
3dB Bandwidth
1dB Bandwidth
0.6 to 1.2
0.7 to 1.05
GHz
GHz
S
22, ON
RF Output Return Loss
EN = High (Note 6)
14
dB
S
22, OFF
RF Output Return Loss
EN = Low (Note 6)
12
dB
NFloor
RF Output Noise Floor
No Input Signal (Note 8)
P
OUT
= 4dBm (Note 9)
P
OUT
= 4dBm (Note 10)
160.3
154
154
dBm/Hz
dBm/Hz
dBm/Hz
G
P
Conversion Power Gain
P
OUT
/P
IN, I&Q
9
6.8
3
dB
G
V
Conversion Voltage Gain
20 Log (V
OUT, 50
/V
IN, DIFF, I or Q
)
6.8
dB
P
OUT
Absolute Output Power
1V
P-P DIFF
CW Signal, I and Q
2.8
dBm
G
3LO vs LO
3 LO Conversion Gain Difference
(Note 17)
23
dB
OP1dB
Output 1dB Compression
(Note 7)
8.3
dBm
OIP2
Output 2nd Order Intercept
(Notes 13, 14)
63
dBm
OIP3
Output 3rd Order Intercept
(Notes 13, 15)
22.9
dBm
IR
Image Rejection
(Note 16)
46
dBc
LOFT
Carrier Leakage
(LO Feedthrough)
EN = High, P
LO
= 0dBm (Note 16)
EN = Low, P
LO
= 0dBm (Note 16)
43
65
dBm
dBm
LT5568
3
5568f
V
CC
= 5V, EN = High, T
A
= 25C, f
LO
= 850MHz, f
RF
= 852MHz, P
LO
= 0dBm.
BBPI, BBMI, BBPQ, BBMQ inputs 0.54V
DC
, Baseband Input Frequency = 2MHz, I&Q 90 shifted (upper side-band selection).
P
RF, OUT
= 10dBm, unless otherwise noted. (Note 3)
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: Specifi cations over the 40C to 85C temperature range are
assured by design, characterization and correlation with statistical process
controls.
Note 3: Tests are performed as shown in the confi guration of Figure 7.
Note 4: On each of the four baseband inputs BBPI, BBMI, BBPQ and
BBMQ.
Note 5: V(BBPI) V(BBMI) = 1V
DC
, V(BBPQ) V(BBMQ) = 1V
DC
.
Note 6: Maximum value within 1dB bandwidth.
Note 7: An external coupling capacitor is used in the RF output line.
Note 8: At 20MHz offset from the LO signal frequency.
Note 9: At 20MHz offset from the CW signal frequency.
Note 10: At 5MHz offset from the CW signal frequency.
Note 11: RF power is within 10% of fi nal value.
Note 12: RF power is at least 30dB lower than in the ON state.
Note 13: Baseband is driven by 2MHz and 2.1MHz tones. Drive level is set
in such a way that the two resulting RF tones are 10dBm each.
Note 14: IM2 measured at LO frequency + 4.1MHz.
Note 15: IM3 measured at LO frequency + 1.9MHz and LO frequency +
2.2MHz.
Note 16: Amplitude average of the characterization data set without image
or LO feedthrough nulling (unadjusted).
Note 17: The difference in conversion gain between the spurious signal at
f = 3 LO BB versus the conversion gain at the desired signal at f = LO +
BB for BB = 2MHz and LO = 850MHz.
Note 18: The input voltage corresponding to the output P1dB.
ELECTRICAL CHARACTERISTICS
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
LO Input (LO)
f
LO
LO Frequency Range
0.6 to 1.2
GHz
P
LO
LO Input Power
10
0
5
dBm
S
11, ON
LO Input Return Loss
EN = High (Note 6)
11.4
dB
S
11, OFF
LO Input Return Loss
EN = Low (Note 6)
2.7
dB
NF
LO
LO Input Referred Noise Figure
(Note 5) at 850MHz
12.7
dB
G
LO
LO to RF Small Signal Gain
(Note 5) at 850MHz
23.8
dB
IIP3
LO
LO Input 3rd Order Intercept
(Note 5) at 850MHz
11.5
dBm
Baseband Inputs (BBPI, BBMI, BBPQ, BBMQ)
BW
BB
Baseband Bandwidth
3dB Bandwidth
380
MHz
V
CMBB
DC Common Mode Voltage
(Note 4)
0.54
V
R
IN, SE
Single-Ended Input Resistance
(Note 4)
48
P
LO2BB
Carrier Feedthrough on BB
P
OUT
= 0 (Note 4)
38
dBm
IP1dB
Input 1dB Compression Point
Differential Peak-to-Peak (Notes 7, 18)
4.3
V
P-P, DIFF
G
I/Q
I/Q Absolute Gain Imbalance
0.07
dB
I/Q
I/Q Absolute Phase Imbalance
0.45
Deg
Power Supply (V
CC
)
V
CC
Supply Voltage
4.5
5
5.25
V
I
CC, ON
Supply Current
EN = High
80
117
165
mA
I
CC, OFF
Supply Current, Sleep Mode
EN = 0V
50
A
t
ON
Turn-On Time
EN = Low to High (Note 11)
0.3
s
t
OFF
Turn-Off Time
EN = High to Low (Note 12)
1.4
s
Enable (EN), Low = Off, High = On
Enable
Input High Voltage
Input High Current
EN = High
EN = 5V
1.0
230
V
A
Sleep
Input Low Voltage
Input Low Current
EN = Low
EN = 0V
0
0.5
V
A
LT5568
4
5568f
SUPPLY VOLTAGE (V)
4.5
SUPPL
Y CURRENT (mA)
140
130
120
110
100
5568 G01
5
5.5
85
C
25
C
40
C
LO FREQUENCY (MHz)
10
RF OUTPUT POWER (dBm)
6
8
4
2
0
5568 G02
5.5V, 25
C
4.5V, 25
C
5V, 85
C
5V, 25
C
5V, 40
C
550
650
750
850
950 1050 1150 1250
LO FREQUENCY (MHz)
14
VOLTAGE GAIN (dB)
10
12
8
6
4
5568 G03
5.5V, 25
C
4.5V, 25
C
5V, 85
C
5V, 25
C
5V, 40
C
550
650
750
850
950 1050 1150 1250
LO FREQUENCY (MHz)
16
OIP3 (dBm)
20
18
22
24
26
5568 G04
5.5V, 25
C
4.5V, 25
C
5V, 85
C
5V, 25
C
5V, 40
C
550
650
750
850
950 1050 1150 1250
f
BB, 1
= 2MHz
f
BB, 2
= 2.1MHz
LO FREQUENCY (MHz)
550
50
OIP2 (dBm)
60
55
65
70
650
750
850
950
5568 G05
1050 1150 1250
5.5V, 25
C
4.5V, 25
C
5V, 85
C
5V, 25
C
5V, 40
C
f
IM2
= f
BB, 1
+ f
BB, 2
+ f
LO
f
BB, 1
= 2MHz
f
BB, 2
= 2.1MHz
LO FREQUENCY (MHz)
550
2
OP1dB (dBm)
6
4
8
10
650
750
850
950
5568 G06
1050 1150 1250
5.5V, 25
C
4.5V, 25
C
5V, 85
C
5V, 25
C
5V, 40
C
LO FREQUENCY (MHz)
550
48
LOFT (dBm)
44
46
42
40
650
750
850
950
5568 G07
1050 1150 1250
5.5V, 25
C
4.5V, 25
C
5V, 85
C
5V, 25
C
5V, 40
C
2 LO FREQUENCY (GHz)
1.1
60
P(2 LO) (dBm)
50
55
45
40
1.3
1.5
1.7
1.9
5568 G08
2.1
2.3
2.5
5.5V, 25
C
4.5V, 25
C
5V, 85
C
5V, 25
C
5V, 40
C
3 LO FREQUENCY (GHz)
1.65
65
60
P(3 LO) (dBm)
50
55
45
40
1.95 2.25 2.55 2.85
5568 G09
3.15 3.45 3.75
5.5V, 25
C
4.5V, 25
C
5V, 85
C
5V, 25
C
5V, 40
C
V
CC
= 5V, EN = High, T
A
= 25C, f
LO
= 850MHz,
P
LO
= 0dBm. BBPI, BBMI, BBPQ, BBMQ inputs 0.54V
DC
, Baseband Input Frequency f
BB
= 2MHz, I&Q 90 shifted. f
RF
= f
BB
+ f
LO
(upper
sideband selection). P
RF, OUT
= 10dBm (10dBm/tone for 2-tone measurements), unless otherwise noted. (Note 3)
Supply Current vs Supply Voltage
RF Output Power vs LO Frequency
at 1V
P-P
Differential Baseband Drive
Voltage Gain vs LO Frequency
Output IP3 vs LO Frequency
Output IP2 vs LO Frequency
Output 1dB Compression
vs LO Frequency
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
LO Feedthrough to RF Output
vs LO Frequency
2 LO Leakage to RF Output
vs 2 LO Frequency
3 LO Leakage to RF Output
vs 3 LO Frequency
LT5568
5
5568f
RF FREQUENCY (MHz)
550
164
NOISE FLOOR (dBm/Hz)
162
163
161
160
650
750
850
950
5568 G10
1050 1150 1250
5.5V, 25
C
4.5V, 25
C
5V, 85
C
5V, 25
C
5V, 40
C
f
LO
= 850MHz
(FIXED)
LO FREQUENCY (MHz)
550
50
IMAGE REJECTION (dBc)
40
45
35
30
650
750
850
950
5568 G11
1050 1150 1250
5.5V, 25
C
4.5V, 25
C
5V, 85
C
5V, 25
C
5V, 40
C
RF FREQUENCY (MHz)
550
40
S
11
(dB)
20
30
10
0
650
750
850
950
5568 G12
1050 1150 1250
LO PORT, EN = LOW
LO PORT, EN = HIGH,
P
LO
= 0dBm
RF PORT,
EN = LOW
RF PORT, EN = HIGH, P
LO
= 0dBm
RF PORT, EN = HIGH, No LO
LO PORT,
EN = HIGH,
P
LO
= 10dBm
LO FREQUENCY (MHz)
550
0
ABSOLUTE I/Q GAIN IMBALANCE (dB)
0.1
0.2
650
750
850
950
5568 G13
1050 1150 1250
5.5V, 25
C
4.5V, 25
C
5V, 85
C
5V, 25
C
5V, 40
C
LO FREQUENCY (MHz)
550
0
ABSOLUTE I/Q PHASE IMBALANCE (DEG)
2
1
3
4
650
750
850
950
5568 G14
1050 1150 1250
5.5V, 25
C
4.5V, 25
C
5V, 85
C
5V, 25
C
5V, 40
C
LO INPUT POWER (dBm)
16
14
VOLTAGE GAIN (dB)
10
12
8
6
4
5568 G15
5.5V, 25
C
4.5V, 25
C
5V, 85
C
5V, 25
C
5V, 40
C
20
16
12
8
4
0
4
8
LO INPUT POWER (dBm)
13
15
0IP3 (dBm)
19
17
21
23
25
5568 G16
5.5V, 25
C
4.5V, 25
C
5V, 85
C
5V, 25
C
5V, 40
C
20
16
12
8
4
0
4
8
f
BB, 1
= 2MHz
f
BB, 2
= 2.1MHz
I AND Q BASEBAND VOLTAGE (V
PP, DIFF
)
0
80
HD2, HD3 (dBc)
RF CW OUTPUT POWER (dBm)
40
60
20
10
1
2
3
4
5568 G17
50
70
30
60
20
40
0
10
30
50
10
5
HD2 = MAX POWER AT f
LO
+ 2 f
BB
OR f
LO
2 f
BB
HD3 = MAX POWER AT f
LO
+ 3 f
BB
OR f
LO
3 f
BB
40
C
25
C
HD3
85
C
RF
40
C
85
C
HD2
25
C
40
C
25
C
85
C
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
V
CC
= 5V, EN = High, T
A
= 25C, f
LO
= 850MHz,
P
LO
= 0dBm. BBPI, BBMI, BBPQ, BBMQ inputs 0.54V
DC
, Baseband Input Frequency f
BB
= 2MHz, I&Q 90 shifted. f
RF
= f
BB
+ f
LO
(upper
sideband selection). P
RF, OUT
= 10dBm (10dBm/tone for 2-tone measurements), unless otherwise noted. (Note 3)
Noise Floor vs RF Frequency
Image Rejection vs LO Frequency
LO and RF Port Return Loss
vs RF Frequency
Absolute I/Q Gain Imbalance
vs LO Frequency
Absolute I/Q Phase Imbalance
vs LO Frequency
Voltage Gain vs LO Power
Output IP3 vs LO Power
RF CW Output Power, HD2 and HD3 vs
CW Baseband Voltage and Temperature
PDF 
ZIP