LT5568-2 - GSM/EDGE Optimized, High Linearity Direct Quadrature Modulator

LT5568-2
GSM/EDGE Optimized,
High Linearity Direct
Quadrature Modulator
DESCRIPTIO
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FEATURES
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The LT®5568-2 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
GSM, EDGE, CDMA, CDMA2000 and other systems that
operate in the 850MHz to 965MHz band. It may be configured 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 50Ω 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.
Optimized Image Rejection for 850MHz to 965MHz
High OIP3: +22.9dBm at 900MHz
Low Output Noise Floor at 5MHz Offset:
No RF: –159.4dBm/Hz
POUT = 4dBm: –153dBm/Hz
Integrated LO Buffer and LO Quadrature Phase
Generator
50Ω AC-Coupled Single-Ended LO and RF Ports
50Ω DC Interface to Baseband Inputs
Low Carrier Leakage: –43dBm at 900MHz
High Image Rejection: –52dBc at 900MHz
16-Lead 4mm × 4mm QFN Package
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APPLICATIO S
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Infrastructure Tx for GSM/Cellular Bands
Image Reject Up-Converters for Cellular Bands
Low-Noise Variable Phase-Shifter for 700MHz to
1050MHz Local Oscillator Signals
RFID Reader
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
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TYPICAL APPLICATIO
GSM EVM and Noise
vs RF Output Power at 900MHz
850MHz to 965MHz Direct Conversion Transmitter Application
LT5568-2
V-I
I-CHANNEL
PA
0°
EN
90°
Q-CHANNEL
Q-DAC
BALUN
5
–96
4
–98
3
–100
NOISE
2
V-I
–102
EVM
–104
1
BASEBAND
GENERATOR
55682 TA01
VCO/SYNTHESIZER
0
–10
NOISE FLOOR AT 6MHz
OFFSET (dBc/100kHz)
I-DAC
5V
100nF
x2
RF = 850MHz
TO 965MHz
EVM (%RMS)
VCC
4
–8 –6 –4 –2
0
2
GSM RF OUTPUT POWER (dBm)
6
–106
55682 TA02
55682f
1
LT5568-2
U
W W
W
ABSOLUTE
AXI U RATI GS
PIN CONFIGURATION
(Note 1)
VCC
BBPI
BBMI
GND
TOP VIEW
Supply Voltage .........................................................5.5V
Common Mode Level of BBPI, BBMI and
BBPQ, BBMQ .......................................................2.5V
Operating Ambient Temperature
(Note 2) ............................................... –40°C to 85°C
Storage Temperature Range................... –65°C to 125°C
Voltage on Any Pin
Not to Exceed...................... –500mV to VCC + 500mV
16 15 14 13
12 GND
EN 1
GND 2
11 RF
17
LO 3
10 GND
GND 4
GND
6
7
8
BBMQ
GND
BBPQ
VCC
9
5
UF PACKAGE
16-LEAD (4mm × 4mm) PLASTIC QFN
TJMAX = 125°C, θJA = 37°C/W
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
CAUTION: This part is sensitive to ESD. It is very
important that proper ESD precautions be observed
when handling the LT5568-2.
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LT5568-2EUF#PBF
LT5568-2EUF#TRPBF
55682
16-Lead (4mm × 4mm) Plastic QFN
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
ELECTRICAL CHARACTERISTICS
VCC = 5V, EN = High, TA = 25°C, fLO = 900MHz, fRF = 902MHz, PLO = 0dBm.
BBPI, BBMI, BBPQ, BBMQ inputs 0.54VDC, Baseband Input Frequency = 2MHz, I&Q 90° shifted (upper side-band selection).
PRF, OUT = –10dBm, unless otherwise noted. (Note 3)
SYMBOL
PARAMETER
CONDITIONS
fRF
RF Frequency Range
RF Frequency Range
–3dB Bandwidth
–1dB Bandwidth
S22, ON
RF Output Return Loss
S22, OFF
MIN
TYP
MAX
UNITS
RF Output (RF)
0.6 to 1.1
0.7 to 1
GHz
GHz
EN = High (Note 6)
–16
dB
RF Output Return Loss
EN = Low (Note 6)
–18
dB
NFloor
RF Output Noise Floor
No Input Signal (Note 8)
POUT = 4dBm (Note 9)
POUT = 4dBm (Note 10)
GP
Conversion Power Gain
POUT/PIN, I&Q
GV
Conversion Voltage Gain
20 • Log (VOUT, 50Ω/VIN, DIFF, I or Q)
–6.8
dB
POUT
Absolute Output Power
1VP-P DIFF CW Signal, I and Q
–2.8
dBm
G3LO vs LO
3 • LO Conversion Gain Difference
(Note 17)
–23
dB
OP1dB
Output 1dB Compression
(Note 7)
8.6
dBm
OIP2
Output 2nd Order Intercept
(Notes 13, 14)
59
dBm
OIP3
Output 3rd Order Intercept
(Notes 13, 15)
22.9
dBm
–159.4
–153
–152.6
–9
–6.8
dBm/Hz
dBm/Hz
dBm/Hz
–3
dB
55682f
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LT5568-2
ELECTRICAL CHARACTERISTICS
VCC = 5V, EN = High, TA = 25°C, fLO = 900MHz, fRF = 902MHz, PLO = 0dBm.
BBPI, BBMI, BBPQ, BBMQ inputs 0.54VDC, Baseband Input Frequency = 2MHz, I&Q 90° shifted (upper side-band selection).
PRF, OUT = –10dBm, unless otherwise noted. (Note 3)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
IR
Image Rejection
fBB = 100kHz (Note 16)
–52
dBc
LOFT
Carrier Leakage
(LO Feedthrough)
EN = High, PLO = 0dBm (Note 16)
EN = Low, PLO = 0dBm (Note 16)
–43
–65
dBm
dBm
0.6 to 1.1
GHz
LO Input (LO)
fLO
LO Frequency Range
PLO
LO Input Power
S11, ON
LO Input Return Loss
EN = High (Note 6)
–15
dB
S11, OFF
LO Input Return Loss
EN = Low (Note 6)
–2.5
dB
NFLO
LO Input Referred Noise Figure
(Note 5) at 900MHz
14.7
dB
GLO
LO to RF Small Signal Gain
(Note 5) at 900MHz
14.7
dB
IIP3LO
LO Input 3rd Order Intercept
(Note 5) at 900MHz
–3
dBm
MHz
–10
0
5
dBm
Baseband Inputs (BBPI, BBMI, BBPQ, BBMQ)
BWBB
Baseband Bandwidth
–3dB Bandwidth
380
VCMBB
DC Common Mode Voltage
(Note 4)
0.54
V
RIN, SE
Single-Ended Input Resistance
(Note 4)
47
Ω
PLO2BB
Carrier Feedthrough on BB
POUT = 0 (Note 4)
–38
dBm
IP1dB
Input 1dB Compression Point
Differential Peak-to-Peak (Notes 7, 18)
4.3
VP-P, DIFF
Power Supply (VCC)
VCC
Supply Voltage
ICC, ON
Supply Current
EN = High
4.5
5
5.25
V
80
110
145
mA
ICC, OFF
Supply Current, Sleep Mode
EN = 0V
100
µA
tON
Turn-On Time
EN = Low to High (Note 11)
0.3
µs
tOFF
Turn-Off Time
EN = High to Low (Note 12)
1.4
µs
245
V
µA
Enable (EN), Low = Off, High = On
Enable
Sleep
Input High Voltage
Input High Current
EN = High
EN = 5V
Input Low Voltage
Input Low Current
EN = Low
EN = 0V
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: Specifications over the –40°C to 85°C temperature range are assured
by design, characterization and correlation with statistical process controls.
Note 3: Tests are performed as shown in the configuration of Figure 7.
Note 4: On each of the four baseband inputs BBPI, BBMI, BBPQ and BBMQ.
Note 5: V(BBPI) – V(BBMI) = 1VDC, V(BBPQ) – V(BBMQ) = 1VDC.
Note 6: Maximum value within 850MHz to 965MHz.
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.
1.0
0.5
0.01
V
µA
Note 10: At 5MHz offset from the CW signal frequency.
Note 11: RF power is within 10% of final 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 = 900MHz.
Note 18: The input voltage corresponding to the output P1dB.
55682f
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LT5568-2
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TYPICAL PERFOR A CE CHARACTERISTICS
VCC = 5V, EN = High, TA = 25°C, fLO = 900MHz,
PLO = 0dBm. BBPI, BBMI, BBPQ, BBMQ inputs 0.54VDC, Baseband Input Frequency fBB = 2MHz, I&Q 90° shifted. fRF = fBB + fLO (upper
sideband selection). PRF, OUT = –10dBm (–10dBm/tone for 2-tone measurements), unless otherwise noted. (Note 3)
RF Output Power vs LO Frequency
at 1VP-P Differential Baseband Drive
Supply Current vs Supply Voltage
120
Voltage Gain vs LO Frequency
0
–4
–2
–6
–4
–8
25°C
110
–40°C
100
–6
–8
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
–10
–12
90
4.5
5
SUPPLY VOLTAGE (V)
–14
550
5.5
VOLTAGE GAIN (dB)
RF OUTPUT POWER (dBm)
SUPPLY CURRENT (mA)
85°C
650
–10
–12
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
–14
–16
–18
550
750 850 950 1050 1150 1250
LO FREQUENCY (MHz)
55682 G02
650
750 850 950 1050 1150 1250
LO FREQUENCY (MHz)
55682 G03
55682 G01
Output IP3 vs LO Frequency
26
70
fBB, 1 = 2MHz
fBB, 2 = 2.1MHz
24
Output 1dB Compression
vs LO Frequency
Output IP2 vs LO Frequency
10
fIM2 = fBB, 1 + fBB, 2 + fLO
fBB, 1 = 2MHz
fBB, 2 = 2.1MHz
65
8
20
18
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
16
14
12
550
650
OP1dB (dBm)
OIP2 (dBm)
OIP3 (dBm)
22
60
55
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
50
45
550
750 850 950 1050 1150 1250
LO FREQUENCY (MHz)
650
55682 G04
–45
–40
–50
–42
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
–44
–46
550
650
750 850 950 1050 1150 1250
LO FREQUENCY (MHz)
55682 G07
2
550
750 850 950 1050 1150 1250
LO FREQUENCY (MHz)
55682 G05
650
750 850 950 1050 1150 1250
LO FREQUENCY (MHz)
55682 G06
3 • LO Leakage to RF Output
vs 3 • LO Frequency
–45
–50
P(3 • LO) (dBm)
–38
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
4
2 • LO Leakage to RF Output
vs 2 • LO Frequency
P(2 • LO) (dBm)
LO FEEDTHROUGH (dBm)
LO Feedthrough to RF Output
vs LO Frequency
6
–55
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
–60
–65
1.1
1.3
1.5 1.7 1.9 2.1 2.3
2 • LO FREQUENCY (GHz)
–55
–60
–65
2.5
55682 G08
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
–70
1.65 1.95 2.25 2.55 2.85 3.15 3.45 3.75
3 • LO FREQUENCY (GHz)
55682 G09
55682f
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LT5568-2
U W
TYPICAL PERFOR A CE CHARACTERISTICS
VCC = 5V, EN = High, TA = 25°C, fLO = 900MHz,
PLO = 0dBm. BBPI, BBMI, BBPQ, BBMQ inputs 0.54VDC, Baseband Input Frequency fBB = 2MHz, I&Q 90° shifted. fRF = fBB + fLO (upper
sideband selection). PRF, OUT = –10dBm (–10dBm/tone for 2-tone measurements), unless otherwise noted. (Note 3)
Noise Floor vs RF Frequency
–30
–160
–161
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
–163
–163
550
650
–35
–45
–55
550
650
–40
550
750 850 950 1050 1150 1250
LO FREQUENCY (MHz)
55682 G11
PRF = –10dBm
fBB = 100kHz
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
– 48
–50
–20
–16
–12
–8
–4
0
4
LO INPUT POWER (dBm)
–16
55682 G13
–12 –8
–4
0
4
LO INPUT POWER (dBm)
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
–16
–20
55682 G14
10
10
–12
–8
–4
0
4
LO INPUT POWER (dBm)
8
55682 G16
HD2 (dBc), HD3 (dBc)
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
25°C
25°C
85°C
–40
85°C
–10
–20
25°C
HD3
–50
HD2
–40°C –30
–40
–60
85°C
–70
–80
0
1
2
3
4
5
I AND Q BASEBAND VOLTAGE (VP–P, DIFF)
HD2 = MAX POWER AT fLO + 2 • fBB OR fLO – 2 • fBB
HD3 = MAX POWER AT fLO + 3 • fBB OR fLO – 3 • fBB
0
–20
5V
–30
–40
–60
–80
5.5V
HD2
–30
4.5V –40
–50
–60
0
55682 G17
–20
5V
–60
–70
–10
HD3
–50
–50
4.5V
RF CW OUTPUT POWER (dBm)
19
8
55682 G15
–10
RF CW OUTPUT POWER (dBm)
0
–40°C
–12
–8
–4
0
4
LO INPUT POWER (dBm)
RF
–20
–30
–16
RF CW Output Power, HD2 and
HD3 vs CW Baseband Voltage
and Supply Voltage
RF
21
–16
–12
8
–40°C
15
–10
–14
–10
fBB, 1 = 2MHz
fBB, 2 = 2.1MHz
17
–8
RF CW Output Power, HD2 and
HD3 vs CW Baseband Voltage
and Temperature
23
13
–20
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
–50
Output IP3 vs LO Power
25
–6
–45
–55
–20
8
750 850 950 1050 1150 1250
RF FREQUENCY (MHz)
55682 G12
–40
VOLTAGE GAIN (dB)
IMAGE REJECTION (dBc)
–46
650
RF PORT, EN = HIGH, No LO
–4
–40
–44
RF PORT,
EN = HIGH,
PLO = 0dBm
Voltage Gain vs LO Power
–35
–42
RF PORT,
EN = LOW
LO PORT,
EN = HIGH,
PLO = 10dBm
Image Rejection vs LO Input Power
–38
LO FEEDTHROUGH (dBm)
–20
fBB = 100kHz
LO Feedthrough to RF Output
vs LO Input Power
LO PORT, EN = HIGH,
PLO = 0dBm
–30
–50
750 850 950 1050 1150 1250
RF FREQUENCY (MHz)
LO PORT, EN = LOW
–10
–40
55682 G10
0IP3 (dBm)
0
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
HD2 (dBc), HD3 (dBc)
NOISE FLOOR (dBm/Hz)
IMAGE REJECTION (dBc)
fLO = 900MHz
(FIXED)
NO RF
S11 (dB)
–158
–159
LO and RF Port Return Loss
vs RF Frequency
Image Rejection vs LO Frequency
5
1
2
3
4
I AND Q BASEBAND VOLTAGE (VP–P, DIFF)
HD2 = MAX POWER AT fLO + 2 • fBB OR fLO – 2 • fBB
HD3 = MAX POWER AT fLO + 3 • fBB OR fLO – 3 • fBB
55682 G18
55682f
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LT5568-2
U W
TYPICAL PERFOR A CE CHARACTERISTICS
VCC = 5V, EN = High, TA = 25°C, fLO = 900MHz,
PLO = 0dBm. BBPI, BBMI, BBPQ, BBMQ inputs 0.54VDC, Baseband Input Frequency fBB = 2MHz, I&Q 90° shifted. fRF = fBB + fLO (upper
sideband selection). PRF, OUT = –10dBm (–10dBm/tone for 2-tone measurements), unless otherwise noted. (Note 3)
RF Two-Tone Power (Each Tone),
IM2 and IM3 vs Baseband Voltage
LO Feedthrough to RF Output
Image Rejection
and Temperature
vs CW Baseband Voltage
vs CW Baseband Voltage
–42
–44
–50
fBB = 100kHz
–55
0
4.5V, 25°C
5.5V, 25°C
1
2
3
4
5
I AND Q BASEBAND VOLTAGE (VP-P,DIFF)
0
0.5
1
1.5
2
2.5
I AND Q BASEBAND VOLTAGE (VP-P,DIFF)
4.5V
5V, 5.5V
–30
–40
IM3
–50
IM2
–70
–80
5V
5.5V
4.5V
–60
1
10
0.1
I AND Q BASEBAND VOLTAGE (VP–P, DIFF, EACH TONE)
IM2 = POWER AT fLO + 4.1MHz
IM3 = MAX POWER AT fLO + 1.9MHz OR fLO + 2.2MHz
15
10
25°C
IM3
–50
–40°C
–60
IM2
–70
85°C
fBBI = 2MHz, 2.1MHz, 0°
fBBQ = 2MHz, 2.1MHz, 90°
–40°C
25°C
85°C
25
20
15
10
5
0
–9
–8.5
–8
–7.5 –7 –6.5
GAIN (dB)
–6
0
–160.4
–5.5
55682 G23
LO Leakage Distribution
35
85°C
5
fBBI = 2MHz, 2.1MHz, 0°
fBBQ = 2MHz, 2.1MHz, 90°
40
–30
–40
30
PERCENTAGE (%)
5V, 5.5V
25°C
Noise Floor Distribution
–40°C
25°C
85°C
20
PERCENTAGE (%)
–20
4.5V
–40°C
25°C
35
RF
55682 G22
PRF,TONE (dBm), IM2 (dBc), IM3 (dBc)
–10
–20
Gain Distribution
25
0
–10
10
1
0.1
I AND Q BASEBAND VOLTAGE (VP–P, DIFF, EACH TONE)
IM2 = POWER AT fLO + 4.1MHz
IM3 = MAX POWER AT fLO + 1.9MHz OR fLO + 2.2MHz
3
55682 G20
10
85°C
–40°C
–80
55682 G19
RF Two-Tone Power (Each Tone),
IM2 and IM3 vs Baseband Voltage
and Supply Voltage
RF
0
55682 G21
–40
5V, –40°C
5V, 25°C
5V, 85°C
PRF,TONE (dBm), IM2 (dBc), IM3 (dBc)
–38
10
–45
5V, –40°C
5V, 25°C
5V, 85°C
4.5V, 25°C
5.5V, 25°C
IMAGE REJECTION (dBc)
LO FEEDTHROUGH (dBm)
–36
–159.6
–159.2
–160
NOISE FLOOR (dBm/Hz)
–158.8
55682 G24
Image Rejection Distribution
25
–40°C
25°C
85°C
20
–40°C
25°C
85°C
PERCENTAGE (%)
PERCENTAGE (%)
30
25
20
15
10
15
10
5
5
0
< –54
–50
–46 –42 –38
LO LEAKAGE (dBm)
–34
–30
55682 G25
0
< –70
–66
–62 –58 –54 –50
IMAGE REJECTION (dBc)
–46
55682 G26
55682f
6
LT5568-2
U
U
U
PI FU CTIO S
EN (Pin 1): Enable Input. When the enable pin voltage is
higher than 1V, the IC is turned on. When the input voltage
is less than 0.5V, the IC is turned off.
BBPQ, BBMQ (Pins 7, 5): Baseband Inputs for the Q-channel, each 50Ω input impedance. Internally biased at about
0.54V. Applied voltage must stay below 2.5V.
GND (Pins 2, 4, 6, 9, 10, 12, 15): Ground. Pins 6, 9, 15
and 17 (exposed pad) are connected to each other internally. Pins 2 and 4 are connected to each other internally
and function as the ground return for the LO signal. Pins
10 and 12 are connected to each other internally and
function as the ground return for the on-chip RF balun.
For best RF performance, pins 2, 4, 6, 9, 10, 12, 15 and
the Exposed Pad 17 should be connected to the printed
circuit board ground plane.
VCC (Pins 8, 13): Power Supply. Pins 8 and 13 are connected to each other internally. It is recommended to use
0.1µF capacitors for decoupling to ground on each of
these pins.
LO (Pin 3): LO Input. The LO input is an AC-coupled singleended input with approximately 50Ω input impedance at
RF frequencies. Externally applied DC voltage should be
within the range –0.5V to VCC + 0.5V in order to avoid
turning on ESD protection diodes.
BBPI, BBMI (Pins 14, 16): Baseband Inputs for the
I-channel, each with 50Ω input impedance. Internally biased
at about 0.54V. Applied voltage must stay below 2.5V.
RF (Pin 11): RF Output. The RF output is an AC-coupled
single-ended output with approximately 50Ω output impedance at RF frequencies. Externally applied DC voltage
should be within the range –0.5V to VCC + 0.5V in order
to avoid turning on ESD protection diodes.
Exposed Pad (Pin 17): Ground. This pin must be soldered
to the printed circuit board ground plane.
55682f
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BLOCK DIAGRA
VCC
8
13
LT5568-2
BBPI 14
V-I
BBMI 16
11 RF
0°
90°
BALUN
BBPQ 7
1 EN
V-I
BBMQ 5
2
4
6
9
3
LO
GND
10
12
15
17
55682 BD
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The LT5568-2 consists of I and Q input differential voltage-to-current converters, I and Q up-conversion mixers,
an RF output balun, an LO quadrature phase generator
and LO buffers.
LT5568-2
RF
C
VCC = 5V
BALUN
FROM
Q
LOMI
R1A
25Ω
LOPI
R2B
23Ω
R1B
23Ω
BBPI
R2A
25Ω
CM
12pF
R3
R4
12pF
Baseband Interface
VREF = 540mV
BBMI
55682 F01
GND
Figure 1. Simplified Circuit Schematic of the LT5568-2
(Only I-Half is Drawn)
External I and Q baseband signals are applied to the differential baseband input pins, BBPI, BBMI, and BBPQ,
BBMQ. These voltage signals are converted to currents and
translated to RF frequency by means of double-balanced
up-converting mixers. The mixer outputs are combined
in an RF output balun, which also transforms the output
impedance to 50Ω. The center frequency of the resulting
RF signal is equal to the LO signal frequency. The LO input
drives a phase shifter which splits the LO signal into inphase and quadrature LO signals. These LO signals are then
applied to on-chip buffers which drive the up-conversion
mixers. Both the LO input and RF output are single-ended,
50Ω-matched and AC coupled.
The baseband inputs (BBPI, BBMI), (BBPQ, BBMQ) present
a differential input impedance of about 100Ω. At each of the
four baseband inputs, a first-order lowpass filter using 25Ω
55682f
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APPLICATIO S I FOR ATIO
and 12pF to ground is incorporated (see Figure 1), which
limits the baseband bandwidth to approximately 330MHz
(–1dB point). The common mode voltage is about 0.54V
and is approximately constant over temperature.
It is important that the applied common mode voltage level
of the I and Q inputs is about 0.54V in order to properly
bias the LT5568-2. Some I/Q test generators allow setting
the common mode voltage independently. In this case, the
common mode voltage of those generators must be set
to 0.27V to match the LT5568-2 internal bias, because for
DC signals, there is no –6dB source-load voltage division
(see Figure 2).
50Ω
+
–
50Ω
0.27VDC
0.54VDC
50Ω
GENERATOR
48Ω
0.54VDC
+
–
0.54VDC
0.54VDC
GENERATOR
+
–
LT5568-2
55682 F02
Figure 2. DC Voltage Levels for a Generator Programmed at
0.27VDC for a 50Ω Load and the LT5568-2 as a Load
The baseband inputs should be driven differentially; otherwise, the even-order distortion products will degrade the
overall linearity severely. Typically, a DAC will be the signal
source for the LT5568-2. Reconstruction filters should
be placed between the DAC output and the LT5568-2’s
baseband inputs. In Figure 3, a typical baseband interface
schematic for GSM is drawn. It shows a ground referenced
DAC output interface followed by a 3rd order active OpAmp
RC lowpass filter with a 400kHz cutoff frequency (–3dB).
The DAC in this example sources a current from 0mA to
20mA, with a voltage compliance range of at least 0V to
1V. This interface is DC coupled, which allows adjustment of the DAC’s differential output current to minimize
the LO feedthrough. The voltage swing at the LT5568-2
baseband inputs is about 2VP-P,DIFF, which results in a
1.2dBm GSM RF output power at 900MHz with noise floor
of –154.3dBm/Hz at 6MHz offset (= –104.3dBm/100kHz).
The RMS EVM is about 0.6%. The LT1819, which houses
two LT1818s, can be used instead of U2 and U3. The total
current in the positive supply is about 157mA and the
current in the negative supply is about 40mA.
C3
1nF
VCC = 4.5 TO 5.25V
R7
200Ω
R9
249Ω
3
C1
1.2nF
0mA to 20mA
+
U2
LT1818
–
2
R5
53.6Ω
R14
50Ω 0.54V
7 VCC
0.54V
6
R11
249Ω
4 V
SS
0.54V
R13
499Ω
GND
DAC
0mA to 20mA
R6
53.6Ω
R8
200Ω
2
R10
249Ω
C2
1.2nF
–
7 VCC
U3
LT1818
+
4 V
SS
R12
249Ω
6
0.54V
R15
50Ω
LT5568-2
BALUN
FROM
Q
C
C5
10nF
LOPI
LOMI
GND
BBPI
C4 3
1nF
VSS = –2V to –5.25V
RF =
1.2dBm,
GSM
C6
10nF
R1
45Ω
R2
45Ω
CM
R3
33Ω
VREF = 540mV
R4
33Ω
16mA
BBMI
U1
0.54V
55682 F03
GND
Figure 3. LT5568-2 GSM Baseband Interface with 3rd Order Lowpass Filter and Ground Referenced DAC (Only I-Channel is Shown)
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LO Section
The internal LO input amplifier performs single-ended to
differential conversion of the LO input signal. Figure 4
shows the equivalent circuit schematic of the LO input.
VCC
20pF
LO
INPUT
51Ω
5568 F04
Figure 4. Equivalent Circuit Schematic of the LO Input
The internal, differential LO signal is then split into in-phase
and quadrature (90° phase shifted) signals that drive LO
buffer sections. These buffers drive the double balanced I
and Q mixers. The phase relationship between the LO input
and the internal in-phase LO and quadrature LO signals
is fixed, and is independent of start-up conditions. The
internal phase shifters are designed to deliver accurate
quadrature signals. For LO frequencies significantly below 650MHz or above 1.25GHz, however, the quadrature
accuracy will diminish, causing the image rejection to
degrade. The LO pin input impedance is about 50Ω, and
the recommended LO input power is 0dBm. For lower
LO input power, the gain, OIP2, OIP3 and noise floor at
PRF = 4dBm will degrade, especially for PLO below –2dBm
and at TA = 85°C. For high LO input power (e.g., +5dBm),
the image rejection will degrade with no improvement in
linearity or gain. Harmonics present on the LO signal can
degrade the image rejection because they can introduce a
small excess phase shift in the internal phase splitter. For
the second (at 1.8GHz) and third harmonics (at 2.7GHz) at
–20dBc, the resulting signal at the image frequency is about
–61dBc or lower, corresponding to an excess phase shift
of much less than 1 degree. For the second and third LO
harmonics at –10dBc, the introduced signal at the image
frequency is about –51dBc. Higher harmonics than the third
will have less impact. The LO return loss typically will be
better than 11dB over the 700MHz to 1.05GHz range. Table
1 shows the LO port input impedance vs frequency.
Table 1. LO Port Input Impedance vs Frequency for EN = High
and PLO = 0dBm
Frequency
MHz
Input Impedance
Ω
Mag
S11
Angle
500
600
700
800
900
1000
1100
1200
47.5 + j12.1
59.4 + j8.4
66.2 – j1.14
67.2 – j13.4
61.1 – j23.9
53.3 – j26.8
48.2 – j26.1
42.0 – j27.4
0.126
0.115
0.140
0.185
0.232
0.252
0.258
0.297
95.0
37.8
–3.41
–31.7
–53.2
–68.7
–79.4
–90.0
If the part is in shutdown mode, the input impedance of
the LO port will be different. The LO input impedance for
EN = Low is given in Table 2.
Table 2. LO Port Input Impedance vs Frequency for EN = Low and
PLO = 0dBm
Frequency
MHz
Input Impedance
Ω
Mag
S11
Angle
500
600
700
800
900
1000
1100
1200
33.6 + j41.3
59.8 + j69.1
140 + j89.8
225 – j62.6
92.9 – j128
39.8 – j95.9
22.8 – j72.7
16.0 – j57.3
0.477
0.539
0.606
0.659
0.704
0.735
0.755
0.763
85.4
49.8
19.6
–6.8
–29.6
–45.5
–65.6
–79.7
RF Section
After up-conversion, the RF outputs of the I and Q mixers are
combined. An on-chip balun performs internal differential
to single-ended output conversion, while transforming the
output signal impedance to 50Ω. Table 3 shows the RF
port output impedance vs frequency.
Table 3. RF Port Output Impedance vs Frequency for EN = High
and PLO = 0dBm
Frequency
MHz
Input Impedance
Ω
Mag
S22
Angle
500
600
700
800
900
1000
1100
1200
22.0 + j5.7
28.2 + j12.5
38.8 + j14.8
49.4 + j7.2
49.3 – j5.1
42.5 – j11.1
36.7 – j11.7
33.0 – j10.3
0.395
0.317
0.206
0.072
0.051
0.143
0.202
0.238
164.2
141.3
117.5
90.6
–94.7
–117.0
–130.7
–141.6
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The RF output S22 with no LO power applied is given in
Table 4.
Table 4. RF Port Output Impedance vs Frequency for EN = High
and No LO Power Applied
Frequency
MHz
Input Impedance
Ω
Mag
S22
Angle
500
22.7 + j5.6
0.381
164.0
600
29.7 + j11.6
0.290
142.0
700
40.5 + j11.6
0.164
121.9
800
47.3 + j2.2
0.037
139.6
900
44.1 – j6.7
0.094
–126.9
1000
38.2 – j9.8
0.171
–133.9
1100
34.0 – j9.4
0.218
–143.1
1200
31.5 – j7.8
0.245
–151.6
For EN = Low the S22 is given in Table 5.
Table 5. RF Port Output Impedance vs Frequency for EN = Low
Frequency
MHz
Input Impedance
Ω
Mag
S22
Angle
500
21.2 + j5.4
0.409
164.9
600
26.6 + j12.5
0.340
142.5
700
36.6 + j16.6
0.241
118.1
800
49.2 + j11.6
0.116
87.4
900
52.9 – j2.0
0.034
–33.1
1000
46.4 – j11.2
0.121
–101.1
1100
39.3 – j13.2
0.188
–120.6
1200
34.4 – j12.1
0.231
–133.8
VCC
Note that an ESD diode is connected internally from the
RF output to ground (see Figure 5). For strong output
RF signal levels (higher than 3dBm), this ESD diode can
degrade the linearity performance if the 50Ω termination
impedance is connected directly to ground. To prevent this,
a coupling capacitor can be inserted in the RF output line.
This is strongly recommended during a 1dB compression
measurement.
Enable Interface
Figure 6 shows a simplified schematic of the EN pin
interface. The voltage necessary to turn on the LT5568-2
is 1V. To disable (shut down) the chip, the enable voltage
must be below 0.5V. If the EN pin is not connected, the
chip is disabled. This EN = Low condition is assured by
the 75k on-chip pull-down resistor. It is important that
the voltage at the EN pin does not exceed VCC by more
than 0.5V. If this should occur, the supply current could
be sourced through the EN pin ESD protection diodes,
which are not designed to carry the full supply current,
and damage may result.
VCC
EN
75k
25k
21pF
RF
OUTPUT
7nH
1pF
51Ω
55682 F06
55682 F05
Figure 5. Equivalent Circuit Schematic of the RF Output
Figure 6. EN Pin Interface
55682f
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Evaluation Board
Figure 7 shows the evaluation board schematic. A good
ground connection is required for the exposed pad. If this
is not done properly, the RF performance will degrade. Additionally, the exposed pad provides heat sinking for the part
and minimizes the possibility of the chip overheating.
J1
R1 (optional) limits the EN pin current in the event that
the EN pin is pulled high while the VCC inputs are low. In
Figures 8 and 9 the silk screens and the PCB board layout
are shown.
J2
BBMI
BBPI
VCC
16
R1
100Ω 1
VCC EN
2
J4
LO
IN
3
4
15
14
C2
100nF
13
BBMI GND BBPI VCC
EN
GND
GND
RF
LT5568-2
LO
GND
GND
GND
GND
BBMQ GND BBPQ VCC
5
6
7
12
BBMQ
RF
OUT
10
9
17
8
C1
100nF
J5
J3
11
J6
GND
BBPQ
BOARD NUMBER: DC1178A
Figure 7. Evaluation Circuit Schematic
55682 F07
Figure 8. Component Side of Evaluation Board
55682 F09
Figure 9. Bottom Side of Evaluation Board
55682f
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Application Measurements
The LT5568-2 is recommended for base-station applications using various modulation formats. Figure 10 shows a
typical application. Figure 11 shows the ACPR performance
for CDMA2000 using 1- and 3-carrier modulation. Figures
12 and 13 illustrate the 1- and 3-carrier CDMA2000 RF
spectrum. To calculate ACPR, a correction is made for the
spectrum analyzer noise floor. If the output power is high,
the ACPR will be limited by the linearity performance of the
part. If the output power is low, the ACPR will be limited
by the noise performance of the part. In the middle, an
optimum ACPR is observed.
V-I
I-CHANNEL
0°
1
EN
11
90°
7
Q-DAC
5
Q-CHANNEL
BALUN
V-I
PA
–60
–135
3-CH. ACPR
–70
–145
3-CH. AltCPR
1-CH. AltCPR
–80
BASEBAND
GENERATOR
2, 4, 6, 9, 10, 12, 15, 17
3
VCO/SYNTHESIZER
–125
DOWNLINK TEST MODEL 64 DPCH 1-CH.
ACPR
–155
NOISE FLOOR AT 30MHz
OFFSET (dBm/Hz)
16
–50
ACPR, AltCPR (dBc)
LT5568-2
14
The ACPR performance is sensitive to the amplitude match
of the BBPI and BBMI (or BBPQ and BBMQ) inputs. This
is because a difference in AC current amplitude will give
rise to a difference in amplitude between the even-order
harmonic products generated in the internal V-I converter.
As a result, they will not cancel out entirely. Therefore, it
is important to keep the currents in those pins exactly
5V
100nF
x2
RF = 850MHz
TO 965MHz
VCC 8, 13
I-DAC
Because of the LT5568-2’s very high dynamic range, the
test equipment can limit the accuracy of the ACPR measurement. See Application Note 99. Consult the factory
for advice on the ACPR measurement, if needed.
3-CH. NOISE
55682 F10
1-CH. NOISE
–90
–30
–165
–25
–15
–10
–5
–20
RF OUTPUT POWER PER CARRIER (dBm)
55682 F11
Figure 11. ACPR, AltCPR and Noise
CDMA2000 Modulation
Figure 10. 850MHz to 965MHz Direct
Conversion Transmitter Application
POWER IN 30kHz BW (dBm)
–40
–50
–60
–70
–80
–90
UNCORRECTED
SPECTRUM
–100
–30
DOWNLINK TEST
MODEL 64 DPCH
CORRECTED
SPECTRUM
–110
DOWNLINK
TEST
MODEL 64
DPCH
–40
POWER IN 30kHz BW (dBm)
–30
–50
–60
–70
–80
–90
UNCORRECTED
SPECTRUM
–100
–110
–120
–120
SPECTRUM ANALYSER NOISE FLOOR
–130
896.25 897.75 899.25 900.75 902.25 903.75
RF FREQUENCY (MHz)
–130
894
55682 F12
Figure 12. 1-Carrier CDMA2000 Spectrum
CORRECTED
SPECTRUM
896
SPECTRUM ANALYSER
NOISE FLOOR
900
902
904
898
RF FREQUENCY (MHz)
906
55682 F13
Figure 13. 3-Carrier CDMA2000 Spectrum
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the same (but of opposite sign). The current will enter
the LT5568-2’s common-base stage, and will flow to the
mixer upper switches. This can be seen in Figure 1 where
the internal circuit of the LT5568-2 is drawn.
After calibration when the temperature changes, the LO
feedthrough and the image rejection performance will
10
CALIBRATED WITH PRF = –10dBm
–70
IMAGE REJECTION
LO FEEDTHROUGH
–80 EN = High
fLO = 900MHz
VCC = 5V
fRF = fBB + fLO
fBBI = 2MHz, 0°
PLO = 0dBm
fBBQ = 2MHz, 90°
–90
40
20
0
80
60
–40 –20
TEMPERATURE (°C)
55682 F14
–10
85°C
25°C
–20
–30
–40
85°C
LOFT
–40°C IR
–50
85°C
–60
25°C
25°C
–70
–40°C
–80
–90
55682 F15
–60
–40°C
PRF
0
PRF (dBm), LOFT (dBm), IR (dBc)
LO FEEDTHROUGH (dBm), IR (dBc)
–50
change. This is illustrated in Figure 14. The LO feedthrough
and image rejection can also change as a function of the
baseband drive level, as is depicted in Figure 15. In Figure
16 the GSM EVM and noise performance vs RF output
power is drawn.
0
1
3
4
5
2
I AND Q BASEBAND VOLTAGE (VP-P, DIFF)
fBBI = 2MHz, 0°
fBBQ = 2MHz, 90°
VCC = 5V
EN = High
Figure 14. LO Feedthrough and Image Rejection
vs Temperature after Calibration at 25°C
fLO = 900MHz
fRF = fBB + fLO
PLO = 0dBm
5
–96
4
–98
3
–100
NOISE
2
–102
EVM
–104
1
0
–10
NOISE FLOOR AT 6MHz
OFFSET (dBc/100kHz)
EVM (%RMS)
Figure 15. LO Feedthrough and Image Rejection
vs Baseband Drive Voltage after Calibration at 25°C
4
–8 –6 –4 –2
0
2
GSM RF OUTPUT POWER (dBm)
6
–106
55682 F16
Figure 16. GSM EVM and Noise vs RF Output Power at 900MHz
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LT5568-2
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PACKAGE DESCRIPTIO
UF Package
16-Lead Plastic QFN (4mm × 4mm)
(Reference LTC DWG # 05-08-1692)
0.72 ±0.05
4.35 ± 0.05
2.15 ± 0.05
2.90 ± 0.05 (4 SIDES)
PACKAGE OUTLINE
0.30 ±0.05
0.65 BSC
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
BOTTOM VIEW—EXPOSED PAD
4.00 ± 0.10
(4 SIDES)
0.75 ± 0.05
R = 0.115
TYP
15
PIN 1 NOTCH R = 0.20 TYP
OR 0.35 × 45° CHAMFER
16
0.55 ± 0.20
PIN 1
TOP MARK
(NOTE 6)
1
2.15 ± 0.10
(4-SIDES)
2
(UF16) QFN 10-04
0.200 REF
0.00 – 0.05
0.30 ± 0.05
0.65 BSC
NOTE:
1. DRAWING CONFORMS TO JEDEC PACKAGE OUTLINE MO-220 VARIATION (WGGC)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON THE TOP AND BOTTOM OF PACKAGE
55682f
Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However,
no responsibility is assumed for its use. Linear Technology Corporation makes no representation that
the interconnection of its circuits as described herein will not infringe on existing patent rights.
15
LT5568-2
RELATED PARTS
PART NUMBER DESCRIPTION
COMMENTS
Infrastructure
LT5514
Ultralow Distortion, IF Amplifier/ADC Driver with
Digitally Controlled Gain
850MHz Bandwidth, 47dBm OIP3 at 100MHz, 10.5dB to 33dB Gain Control Range
LT5515
1.5GHz to 2.5GHz Direct Conversion Quadrature
Demodulator
20dBm IIP3, Integrated LO Quadrature Generator
LT5516
0.8GHz to 1.5GHz Direct Conversion Quadrature
Demodulator
21.5dBm IIP3, Integrated LO Quadrature Generator
LT5517
40MHz to 900MHz Quadrature Demodulator
21dBm IIP3, Integrated LO Quadrature Generator
LT5518
1.5GHz to 2.4GHz High Linearity Direct
Quadrature Modulator
22.8dBm OIP3 at 2GHz, –158.2dBm/Hz Noise Floor, 50Ω Single-Ended LO and RF
Ports, 4-Ch W-CDMA ACPR = –64dBc at 2.14GHz
LT5519
0.7GHz to 1.4GHz High Linearity Upconverting
Mixer
17.1dBm IIP3 at 1GHz, Integrated RF Output Transformer with 50Ω Matching,
Single-Ended LO and RF Ports Operation
LT5520
1.3GHz to 2.3GHz High Linearity Upconverting
Mixer
15.9dBm IIP3 at 1.9GHz, Integrated RF Output Transformer with 50Ω Matching,
Single-Ended LO and RF Ports Operation
LT5521
10MHz to 3700MHz High Linearity Upconverting
Mixer
24.2dBm IIP3 at 1.95GHz, NF = 12.5dB, 3.15V to 5.25V Supply, Single-Ended LO
Port Operation
LT5522
600MHz to 2.7GHz High Signal Level
Downconverting Mixer
4.5V to 5.25V Supply, 25dBm IIP3 at 900MHz, NF = 12.5dB, 50Ω Single-Ended RF
and LO Ports
LT5525
High Linearity, Low Power Downconverting Mixer Single-Ended 50Ω RF and LO Ports, 17.6dBm IIP3 at 1900MHz, ICC = 28mA
LT5526
High Linearity, Low Power Downconverting Mixer 3V to 5.3V Supply, 16.5dBm IIP3, 100kHz to 2GHz RF, NF = 11dB, ICC = 28mA,
–65dBm LO-RF Leakage
LT5527
400MHz to 3.7GHz High Signal Level
Downconverting Mixer
IIP3 = 23.5dBm and NF = 12.5dB at 1900MHz, 4.5V to 5.25V Supply, ICC = 78mA
LT5528
1.5GHz to 2.4GHz High Linearity Direct
Quadrature Modulator
21.8dBm OIP3 at 2GHz, –159.3dBm/Hz Noise Floor, 50Ω, 0.5VDC Baseband Interface,
4-Ch W-CDMA ACPR = –66dBc at 2.14GHz
LT5557
400MHz to 3.8GHz, 3.3V, Very High Linearity
Downconverting Mixer
IIP3 = 24.7dBm at 1.9GHz, 23.5dBm at 3.5GHz, Conversion Gain = 2.9dB at 1.9GHz,
3.3V at 82mA, –3dB LO Drive
LT5558
600MHz to 1100MHz High Linearity Direct
Quadrature Modulator
22.4dBm OIP3 at 900MHz, –158dBm/Hz Noise Floor, 3kΩ, 2.1VDC Baseband
Interface, 3-Ch CDMA2000 ACPR = –70.4dBc at 900MHz
LT5560
Ultra-Low Power Active Mixer
10mA Supply Current, 10dBm IIP3, 10dB NF, Usable as Up- or Down-Converter
LT5568
700MHz to 1050MHz High Linearity Direct
Quadrature Modulator
22.9dBm OIP3 at 850MHz, –160.3dBm/Hz Noise Floor, 50Ω, 0.5VDC Baseband
Interface, 3-Ch CDMA2000 ACPR = –71.4dBc at 850MHz
LT5572
1.5GHz to 2.5GHz High Linearity Direct
Quadrature Modulator
21.6dBm OIP3 at 2GHz, –158.6dBm/Hz Noise Floor, High-Ohmic 0.5VDC Baseband
Interface, 4-Ch W-CDMA ACPR = –67.7dBc at 2.14GHz
LT5575
800MHz to 2.7GHz High Linearity Direct
Conversion Quadrature Demodulator
28dBm IIP3 and 13.2dBm P1dB at 900MHz, 60dBm IIP2 and 12.7dB NF
at 1900MHz
RF Power Detectors
LTC®5505
RF Power Detectors with >40dB Dynamic Range
300MHz to 3GHz, Temperature Compensated, 2.7V to 6V Supply
LTC5507
100kHz to 1000MHz RF Power Detector
100kHz to 1GHz, Temperature Compensated, 2.7V to 6V Supply
LTC5508
300MHz to 7GHz RF Power Detector
44dB Dynamic Range, Temperature Compensated, SC70 Package
LTC5509
300MHz to 3GHz RF Power Detector
36dB Dynamic Range, Low Power Consumption, SC70 Package
LTC5530
300MHz to 7GHz Precision RF Power Detector
Precision VOUT Offset Control, Shutdown, Adjustable Gain
LTC5531
300MHz to 7GHz Precision RF Power Detector
Precision VOUT Offset Control, Shutdown, Adjustable Offset
LTC5532
300MHz to 7GHz Precision RF Power Detector
Precision VOUT Offset Control, Adjustable Gain and Offset
LT5534
50MHz to 3GHz Log RF Power Detector with
60dB Dynamic Range
±1dB Output Variation over Temperature, 38ns Response Time
LTC5536
Precision 600MHz to 7GHz RF Detector with Fast 25ns Response Time, Comparator Reference Input, Latch Enable Input, –26dBm to
Comparator
+12dBm Input Range
LT5537
Wide Dynamic Range Log RF/IF Detector
Low Frequency to 800MHz, 83dB Dynamic Range, 2.7V to 5.25V Supply
55682f
16 Linear Technology Corporation
LT 0307 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2007