LINER LTC2240-10 10-bit, 170msps adc Datasheet

LTC2240-10
10-Bit, 170Msps ADC
FEATURES
DESCRIPTION
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The LTC®2240-10 is a 170Msps, sampling 10-bit A/D converter designed for digitizing high frequency, wide dynamic
range signals. The LTC2240-10 is perfect for demanding
communications applications with AC performance that
includes 60.6dB SNR and 80dB SFDR. Ultralow jitter of
95fsRMS allows IF undersampling with excellent noise
performance.
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Sample Rate: 170Msps
60.6dB SNR
80dB SFDR
1.2GHz Full Power Bandwidth S/H
Single 2.5V Supply
Low Power Dissipation: 445mW
LVDS, CMOS, or Demultiplexed CMOS Outputs
Selectable Input Ranges: ±0.5V or ±1V
No Missing Codes
Optional Clock Duty Cycle Stabilizer
Shutdown and Nap Modes
Data Ready Output Clock
Pin Compatible Family
250Msps: LTC2242-12 (12-Bit), LTC2242-10 (10-Bit)
210Msps: LTC2241-12 (12-Bit), LTC2241-10 (10-Bit)
170Msps: LTC2240-12 (12-Bit), LTC2240-10 (10-Bit)
185Msps: LTC2220-1 (12-Bit)*
170Msps: LTC2220 (12-Bit), LTC2230 (10-Bit)*
135Msps: LTC2221 (12-Bit), LTC2231 (10-Bit)*
64-Pin 9mm × 9mm QFN Package
APPLICATIONS
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DC specs include ±0.3LSB INL (typ), ±0.1LSB DNL (typ)
and no missing codes over temperature.
The digital outputs can be either differential LVDS, or
single-ended CMOS. There are three format options for
the CMOS outputs: a single bus running at the full data
rate or two demultiplexed buses running at half data rate
with either interleaved or simultaneous update. A separate
output power supply allows the CMOS output swing to
range from 0.5V to 2.625V.
The ENC+ and ENC – inputs may be driven differentially or
single ended with a sine wave, PECL, LVDS, TTL, or CMOS
inputs. An optional clock duty cycle stabilizer allows high
performance over a wide range of clock duty cycles.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
*LTC2220-1, LTC2220, LTC2221, LTC2230, LTC2231 are 3.3V parts.
Wireless and Wired Broadband Communication
Cable Head-End Systems
Power Amplifier Linearization
Communications Test Equipment
TYPICAL APPLICATION
SNR vs Input Frequency
2.5V
VDD
REFH
REFL
62
0.5V
TO 2.625V
FLEXIBLE
REFERENCE
61
OVDD
2V RANGE
+
ANALOG
INPUT
INPUT
S/H
–
10-BIT
PIPELINED
ADC CORE
CORRECTION
LOGIC
D9
•
•
•
D0
OUTPUT
DRIVERS
CMOS
OR
LVDS
SNR (dBFS)
60
59
58
1V RANGE
57
OGND
CLOCK/DUTY
CYCLE
CONTROL
56
55
0 100 200 300 400 500 600 700 800 900 1000
INPUT FREQUENCY (MHz)
224010 TA01
224010 G10
ENCODE
INPUT
224010fb
1
LTC2240-10
ABSOLUTE MAXIMUM RATINGS
OVDD = VDD (Notes 1, 2)
Supply Voltage (VDD) ...............................................2.8V
Digital Output Ground Voltage (OGND) ........ –0.3V to 1V
Analog Input Voltage (Note 3) .......–0.3V to (VDD + 0.3V)
Digital Input Voltage......................–0.3V to (VDD + 0.3V)
Digital Output Voltage ................ –0.3V to (OVDD + 0.3V)
Power Dissipation .............................................1500mW
Operating Temperature Range
LTC2240C-10 ........................................... 0°C to 70°C
LTC2240I-10 ........................................–40°C to 85°C
Storage Temperature Range................... –65°C to 150°C
PIN CONFIGURATION
64 GND
63 VDD
62 VDD
61 GND
60 VCM
59 SENSE
58 MODE
57 LVDS
56 OF+/OFA
55 OF–/DA9
54 D9+/DA8
53 D9–/DA7
52 D8+/DA6
51 D8–/DA5
50 OGND
49 OVDD
TOP VIEW
AIN+ 1
AIN+ 2
AIN– 3
AIN– 4
REFHA 5
REFHA 6
REFLB 7
REFLB 8
REFHB 9
REFHB 10
REFLA 11
REFLA 12
VDD 13
VDD 14
VDD 15
GND 16
48 D7+/DA4
47 D7–/DA3
46 D6+/DA2
45 D6–/DA1
44 D5+/DA0
43 D5–/DNC
42 OVDD
41 OGND
40 D4+/DNC
39 D4–/CLKOUTA
38 D3+/CLKOUTB
37 D3–/OFB
36 CLKOUT+/DB9
35 CLKOUT–/DB8
34 OVDD
33 OGND
ENC+ 17
ENC– 18
SHDN 19
OE 20
DNC 21
DNC 22
DNC/DB0 23
DNC/DB1 24
OGND 25
OVDD 26
D0–/DB2 27
D0+/DB3 28
D1–/DB4 29
D1+/DB5 30
D2–/DB6 31
D2+/DB7 32
65
UP PACKAGE
64-LEAD (9mm × 9mm) PLASTIC QFN
EXPOSED PAD (PIN 65) IS GND, MUST BE SOLDERED TO PCB
TJMAX = 150°C, θJA = 20°C/W
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC2240CUP-10#PBF
LTC2240CUP-10#TRPBF
LTC2240UP-10
64-Lead (9mm × 9mm) Plastic QFN
0°C to 70°C
LTC2240IUP-10#PBF
LTC2240IUP-10#TRPBF
LTC2240UP-10
64-Lead (9mm × 9mm) Plastic QFN
–40°C to 85°C
LEAD BASED FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC2240CUP-10
LTC2240CUP-10#TR
LTC2240UP-10
64-Lead (9mm × 9mm) Plastic QFN
0°C to 70°C
LTC2240IUP-10
LTC2240IUP-10#TR
LTC2240UP-10
64-Lead (9mm × 9mm) Plastic QFN
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *Temperature grades are identified by a label on the shipping container.
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/
224010fb
2
LTC2240-10
CONVERTER CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. (Note 4)
PARAMETER
CONDITIONS
Resolution (No Missing Codes)
MIN
l
10
TYP
MAX
UNITS
Bits
Integral Linearity Error
Differential Analog Input (Note 5)
l
–0.8
±0.3
0.8
LSB
Differential Linearity Error
Differential Analog Input
l
–0.6
±0.1
0.6
LSB
Offset Error
(Note 6)
l
–15
±5
15
mV
Gain Error
External Reference
l
–3.8
±0.7
3.8
%FS
Offset Drift
±10
μV/C
Full-Scale Drift
Internal Reference
External Reference
±60
±45
ppm/C
ppm/C
Transition Noise
SENSE = 1V
0.18
LSBRMS
ANALOG INPUT The l denotes the specifications which apply over the full operating temperature range, otherwise
specifications are at TA = 25°C. (Note 4)
SYMBOL
PARAMETER
CONDITIONS
VIN
Analog Input Range (AIN+ – AIN–)
2.375V < VDD < 2.625V (Note 7)
l
VIN, CM
Analog Input Common Mode (AIN+ + AIN–)/2
Differential Input (Note 7)
l
1.2
IIN
Analog Input Leakage Current
0 < AIN+, AIN– < VDD
l
ISENSE
SENSE Input Leakage
0V < SENSE < 1V
l
IMODE
MODE Pin Pull-Down Current to GND
7
μA
ILVDS
LVDS Pin Pull-Down Current to GND
7
μA
tAP
Sample and Hold Acquisition Delay Time
0.4
ns
tJITTER
Sample and Hold Acquisition Delay Time Jitter
95
fsRMS
1200
MHz
Full Power Bandwidth
MIN
TYP
MAX
UNITS
±0.5 to ±1
1.3
V
–1
1
μA
–1
1
μA
Figure 8 Test Circuit
1.25
V
DYNAMIC ACCURACY
The l denotes the specifications which apply over the full operating temperature range,
otherwise specifications are at TA = 25°C. AIN = –1dBFS. (Note 4)
SYMBOL
PARAMETER
SNR
Signal-to-Noise Ratio (Note 10)
CONDITIONS
MIN
TYP
60.6
dB
59.7
60.6
dB
140MHz Input
60.5
dB
240MHz Input
60.5
dB
10MHz Input
80
dB
10MHz Input
70MHz Input
SFDR
Spurious Free Dynamic Range
2nd or 3rd Harmonic
(Note 11)
Spurious Free Dynamic Range
4th Harmonic or Higher
(Note 11)
l
l
UNITS
75
dB
140MHz Input
74
dB
240MHz Input
72
dB
70MHz Input
65
MAX
10MHz Input
85
dB
85
dB
140MHz Input
85
dB
240MHz Input
85
dB
70MHz Input
l
74
224010fb
3
LTC2240-10
DYNAMIC ACCURACY
The l denotes the specifications which apply over the full operating temperature range,
otherwise specifications are at TA = 25°C. AIN = –1dBFS. (Note 4)
SYMBOL
PARAMETER
CONDITIONS
S/(N+D)
Signal-to-Noise Plus
Distortion Ratio
(Note 12)
10MHz Input
IMD
Intermodulation Distortion
MIN
l
MAX
UNITS
dB
60.5
dB
140MHz Input
60.4
dB
240MHz Input
60.1
dB
81
dBc
70MHz Input
59.1
TYP
60.5
fIN1 = 135MHz, fIN2 = 140MHz
INTERNAL REFERENCE CHARACTERISTICS (Note 4)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
VCM Output Voltage
IOUT = 0
1.225
1.25
1.275
V
VCM Output Tempco
±35
ppm/°C
VCM Line Regulation
2.375V < VDD < 2.625V
3
mV/V
VCM Output Resistance
–1mA < IOUT < 1mA
2
Ω
DIGITAL INPUTS AND DIGITAL OUTPUTS
The l denotes the specifications which apply over the
full operating temperature range, otherwise specifications are at TA = 25°C. (Note 4)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
ENCODE INPUTS (ENC +, ENC –)
VID
Differential Input Voltage
(Note 7)
l
VICM
Common Mode Input Voltage
Internally Set
Externally Set (Note 7)
l
RIN
Input Resistance
CIN
Input Capacitance
0.2
1.2
(Note 7)
V
1.5
1.5
2.0
V
V
4.8
kΩ
2
pF
LOGIC INPUTS (OE, SHDN)
VIH
High Level Input Voltage
VDD = 2.5V
l
VIL
Low Level Input Voltage
VDD = 2.5V
l
l
1.7
V
–10
0.7
V
10
μA
IIN
Input Current
VIN = 0V to VDD
CIN
Input Capacitance
(Note 7)
3
pF
LOGIC OUTPUTS (CMOS MODE)
OVDD = 2.5V
COZ
Hi-Z Output Capacitance
OE = High (Note 7)
3
pF
ISOURCE
Output Source Current
VOUT = 0V
37
mA
ISINK
Output Sink Current
VOUT = 2.5V
23
mA
VOH
High Level Output Voltage
IO = –10μA
IO = –500μA
2.495
2.45
V
V
VOL
Low Level Output Voltage
0.005
0.07
V
V
OVDD = 1.8V
VOH
High Level Output Voltage
IO = –500μA
1.75
V
VOL
Low Level Output Voltage
IO = 500μA
0.07
V
224010fb
4
LTC2240-10
DIGITAL INPUTS AND DIGITAL OUTPUTS
The l denotes the specifications which apply over the
full operating temperature range, otherwise specifications are at TA = 25°C. (Note 4)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
mV
LOGIC OUTPUTS (LVDS MODE)
VOD
Differential Output Voltage
100Ω Differential Load
l
247
350
454
VOS
Output Common Mode Voltage
100Ω Differential Load
l
1.125
1.250
1.375
V
POWER REQUIREMENTS
The l denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at TA = 25°C. (Note 9)
SYMBOL
PARAMETER
CONDITIONS
VDD
Analog Supply Voltage
(Note 8)
PSLEEP
Sleep Mode Power
SHDN = High, OE = High, No CLK
1
mW
PNAP
Nap Mode Power
SHDN = High, OE = Low, No CLK
28
mW
(Note 8)
l
MIN
TYP
MAX
UNITS
2.375
2.5
2.625
V
LVDS OUTPUT MOD
l
OVDD
Output Supply Voltag
2.5
2.625
IVDD
Analog Supply Current
l
2.375
170
185
mA
V
IOVDD
Output Supply Current
l
58
70
mA
PDISS
Power Dissipation
l
570
638
mW
2.5
2.625
170
185
CMOS OUTPUT MODE
OVDD
Output Supply Voltage
(Note 8)
l
IVDD
Analog Supply Current
(Note 7)
l
PDISS
Power Dissipation
0.5
445
V
mA
mW
TIMING CHARACTERISTICS
The l denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at TA = 25°C. (Note 4)
SYMBOL
PARAMETER
CONDITIONS
fS
Sampling Frequency
(Note 8)
l
MIN
1
tL
ENC Low Time (Note 7)
Duty Cycle Stabilizer Off
Duty Cycle Stabilizer On
l
l
2.79
1.5
tH
ENC High Time (Note 7)
Duty Cycle Stabilizer Off
Duty Cycle Stabilizer On
l
l
2.79
1.5
tAP
Sample-and-Hold Aperture Delay
tOE
Output Enable Delay
(Note 7)
l
ENC to DATA Delay
(Note 7)
l
ENC to CLKOUT Delay
(Note 7)
l
DATA to CLKOUT Skew
(tC – tD) (Note 7)
l
TYP
MAX
UNITS
170
MHz
2.94
2.94
500
500
ns
ns
2.94
2.94
500
500
ns
ns
0.4
ns
5
10
ns
1
1.7
2.8
ns
1
1.7
2.8
ns
–0.6
0
0.6
ns
LVDS OUTPUT MODE
tD
tC
Rise Time
0.5
ns
Fall Time
0.5
ns
Pipeline Latency
5
Cycles
CMOS OUTPUT MODE
tD
ENC to DATA Delay
(Note 7)
l
1
1.7
2.8
ns
tC
ENC to CLKOUT Delay
(Note 7)
l
1
1.7
2.8
ns
224010fb
5
LTC2240-10
TIMING CHARACTERISTICS
The l denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at TA = 25°C. (Note 4)
SYMBOL
Pipeline Latency
PARAMETER
CONDITIONS
DATA to CLKOUT Skew
(tC – tD) (Note 7)
l
MIN
TYP
MAX
–0.6
0
0.6
UNITS
ns
Full Rate CMOS
5
Cycles
Demuxed Interleaved
5
Cycles
5 and 6
Cycles
Demuxed Simultaneous
ELECTRICAL CHARACTERISTICS
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: All voltage values are with respect to ground with GND and OGND
wired together (unless otherwise noted).
Note 3: When these pin voltages are taken below GND or above VDD, they
will be clamped by internal diodes. This product can handle input currents
of greater than 100mA below GND or above VDD without latchup.
Note 4: VDD = 2.5V, fSAMPLE = 170MHz, LVDS outputs, differential
ENC+/ENC– = 2VP-P sine wave, input range = 2VP-P with differential
drive, unless otherwise noted.
Note 5: Integral nonlinearity is defined as the deviation of a code from
a “best straight line” fit to the transfer curve. The deviation is measured
from the center of the quantization band.
Note 6: Offset error is the offset voltage measured from –0.5 LSB when
the output code flickers between 00 0000 0000 and 11 1111 1111 in 2’s
complement output mode.
Note 7: Guaranteed by design, not subject to test.
Note 8: Recommended operating conditions.
Note 9: VDD = 2.5V, fSAMPLE = 170MHz, differential ENC+/ENC– = 2VP-P
sine wave, input range = 1VP-P with differential drive, output CLOAD = 5pF.
Note 10: SNR minimum and typical values are for LVDS mode. Typical
values for CMOS mode are typically 0.2dB lower.
Note 11: SFDR minimum values are for LVDS mode. Typical values are for
both LVDS and CMOS modes.
Note 12: SINAD minimum and typical values are for LVDS mode. Typical
values for CMOS mode are typically 0.2dB lower.
TYPICAL PERFORMANCE CHARACTERISTICS
8192 Point FFT, fIN = 5MHz,
–1dB, 2V Range, LVDS Mode
Differential Nonlinearity
Integral Nonlinearity
1.0
0
0.8
0.8
–10
0.6
0.6
–20
0.4
0.4
0.2
0.2
0
–0.2
–30
AMPLITUDE (dB)
DNL (LSB)
1.0
INL (LSB)
(TA = 25°C unless otherwise noted, Note 4)
0
–0.2
–40
–50
–60
–70
–0.4
–0.4
–0.6
–0.6
–90
–0.8
–0.8
–100
–1.0
0
256
512
OUTPUT CODE
768
1024
224010 G01
–80
–110
–1.0
0
256
512
OUTPUT CODE
768
1024
224010 G02
0
10
20
30 40 50 60
FREQUENCY (MHz)
70
80
224010 G03
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6
LTC2240-10
TYPICAL PERFORMANCE CHARACTERISTICS
8192 Point FFT, fIN = 140MHz,
–1dB, 2V Range, LVDS Mode
8192 Point FFT, fIN = 240MHz,
–1dB, 2V Range, LVDS Mode
0
0
–10
–10
–20
–20
–20
–30
–30
–30
–40
–50
–60
–70
AMPLITUDE (dB)
0
–10
AMPLITUDE (dB)
AMPLITUDE (dB)
8192 Point FFT, fIN = 70MHz,
–1dB, 2V Range, LVDS Mode
(TA = 25°C unless otherwise noted, Note 4)
–40
–50
–60
–70
–40
–50
–60
–70
–80
–80
–90
–90
–80
–90
–100
–100
–100
–110
–110
0
10
20
30 40 50 60
FREQUENCY (MHz)
70
–110
0
80
10
20
30 40 50 60
FREQUENCY (MHz)
70
0
8192 Point FFT, fIN = 500MHz,
–1dB, 1V Range, LVDS Mode
0
–10
–20
–20
–20
–30
–30
–30
–70
AMPLITUDE (dB)
0
–10
AMPLITUDE (dB)
0
–60
–40
–50
–60
–70
–50
–70
–90
–90
–90
–100
–100
–100
–80
–110
10
20
30 40 50 60
FREQUENCY (MHz)
70
80
–110
0
10
20
30 40 50 60
FREQUENCY (MHz)
70
224010 G07
80
2V RANGE
85
70
65
1V RANGE
60
2V RANGE
55
57
70
90
SFDR (dBFS)
SFDR (dBFS)
SNR (dBFS)
1V RANGE
30 40 50 60
FREQUENCY (MHz)
95
75
59
20
SFDR (HD4+) vs Input Frequency,
–1dB, LVDS Mode
80
2V RANGE
10
224010 G09
85
60
58
0
SFDR (HD2 and HD3) vs Input
Frequency, –1dB, LVDS Mode
62
61
80
224010 G08
SNR vs Input Frequency, –1dB,
LVDS Mode
80
–60
–80
0
70
–40
–80
–110
30 40 50 60
FREQUENCY (MHz)
224010 G06
–10
–50
20
8192 Point 2-Tone FFT,
fIN = 135MHz and 140MHz,
–1dB, 2V Range, LVDS Mode
8192 Point FFT, fIN = 1GHz,
–1dB, 1V Range, LVDS Mode
–40
10
224010 G05
224010 G04
AMPLITUDE (dB)
80
1V RANGE
80
75
70
50
56
65
45
55
40
0 100 200 300 400 500 600 700 800 900 1000
INPUT FREQUENCY (MHz)
224010 G10
0 100 200 300 400 500 600 700 800 900 1000
INPUT FREQUENCY (MHz)
224012 G11
60
0 100 200 300 400 500 600 700 800 9001000
INPUT FREQUENCY (MHz)
224010 G12
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7
LTC2240-10
TYPICAL PERFORMANCE CHARACTERISTICS
SFDR and SNR vs Sample Rate,
2V Range, fIN = 30MHz, –1dB,
LVDS Mode
SFDR vs Input Level, fIN = 70MHz,
2V Range
90
SNR vs SENSE, fIN = 5MHz, –1dB
100
61.0
dBFS
90
85
SFDR
60.5
80
80
75
70
65
SNR
60.0
70
SNR (dBFS)
SFDR (dBc AND dFBS)
SFDR AND SNR (dBFS)
(TA = 25°C unless otherwise noted, Note 4)
60
dBc
50
40
30
58.5
58.0
10
0
59.0
20
60
55
59.5
0
–50
20 40 60 80 100 120 140 160 180 200
SAMPLE RATE (Msps)
–40
0
–20
–30
–10
INPUT LEVEL (dBFS)
224010 G13
57.5
0.5
0.6
0.7
0.9
1
224010 G15
224212 G14
IVDD vs Sample Rate, 5MHz Sine
Wave Input, –1dB
0.8
SENSE PIN (V)
IOVDD vs Sample Rate, 5MHz Sine
Wave Input, –1dB
190
60
180
LVDS OUTPUTS
OVDD = 2.5V
50
170
40
IOVDD (mA)
IVDD (mA)
2V RANGE
160
1V RANGE
150
20
140
CMOS OUTPUTS
OVDD = 1.8V
10
130
220
30
0
40
80
160
120
SAMPLE RATE (Msps)
200
224010 G16
0
0
40
80
120
160
SAMPLE RATE (Msps)
200
224010 G17
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8
LTC2240-10
PIN FUNCTIONS
(CMOS Mode)
AIN+ (Pins 1, 2): Positive Differential Analog Input.
AIN – (Pins 3, 4): Negative Differential Analog Input.
REFHA (Pins 5, 6): ADC High Reference. Bypass to
Pins 7, 8 with 0.1μF ceramic chip capacitor, to Pins 11,
12 with a 2.2μF ceramic capacitor and to ground with 1μF
ceramic capacitor.
REFLB (Pins 7, 8): ADC Low Reference. Bypass to Pins
5, 6 with 0.1μF ceramic chip capacitor. Do not connect to
Pins 11, 12.
REFHB (Pins 9, 10): ADC High Reference. Bypass to
Pins 11, 12 with 0.1μF ceramic chip capacitor. Do not
connect to Pins 5, 6.
REFLA (Pins 11, 12): ADC Low Reference. Bypass to
Pins 9, 10 with 0.1μF ceramic chip capacitor, to Pins 5,
6 with a 2.2μF ceramic capacitor and to ground with 1μF
ceramic capacitor.
VDD (Pins 13, 14, 15, 62, 63): 2.5V Supply. Bypass to
GND with 0.1μF ceramic chip capacitors.
GND (Pins 16, 61, 64): ADC Power Ground.
ENC+ (Pin 17): Encode Input. Conversion starts on the
positive edge.
ENC – (Pin 18): Encode Complement Input. Conversion
starts on the negative edge. Bypass to ground with 0.1μF
ceramic for single-ended encode signal.
SHDN (Pin 19): Shutdown Mode Selection Pin. Connecting
SHDN to GND and OE to GND results in normal operation
with the outputs enabled. Connecting SHDN to GND and
OE to VDD results in normal operation with the outputs at
high impedance. Connecting SHDN to VDD and OE to GND
results in nap mode with the outputs at high impedance.
Connecting SHDN to VDD and OE to VDD results in sleep
mode with the outputs at high impedance.
OE (Pin 20): Output Enable Pin. Refer to SHDN pin function.
DNC (Pins 21, 22, 40, 43): Do not connect these pins.
DB0-DB9 (Pins 23, 24, 27, 28, 29, 30, 31, 32, 35, 36):
Digital Outputs, B Bus. DB9 is the MSB. At high impedance
in full rate CMOS mode.
OGND (Pins 25, 33, 41, 50): Output Driver Ground.
OVDD (Pins 26, 34, 42, 49): Positive Supply for the
Output Drivers. Bypass to ground with 0.1μF ceramic chip
capacitor.
OFB (Pin 37): Over/Under Flow Output for B Bus. High
when an over or under flow has occurred. At high impedance in full rate CMOS mode.
CLKOUTB (Pin 38): Data Valid Output for B Bus. In demux
mode with interleaved update, latch B bus data on the falling edge of CLKOUTB. In demux mode with simultaneous
update, latch B bus data on the rising edge of CLKOUTB.
This pin does not become high impedance in full rate
CMOS mode.
CLKOUTA (Pin 39): Data Valid Output for A Bus. Latch A
bus data on the falling edge of CLKOUTA.
DA0-DA9 (Pins 44, 45, 46, 47, 48, 51, 52, 53, 54, 55):
Digital Outputs, A Bus. DA9 is the MSB.
OFA (Pin 56): Over/Under Flow Output for A Bus. High
when an over or under flow has occurred.
LVDS (Pin 57): Output Mode Selection Pin. Connecting
LVDS to 0V selects full rate CMOS mode. Connecting LVDS
to 1/3VDD selects demux CMOS mode with simultaneous
update. Connecting LVDS to 2/3VDD selects demux CMOS
mode with interleaved update. Connecting LVDS to VDD
selects LVDS mode.
MODE (Pin 58): Output Format and Clock Duty Cycle
Stabilizer Selection Pin. Connecting MODE to 0V selects
offset binary output format and turns the clock duty cycle
stabilizer off. Connecting MODE to 1/3VDD selects offset
binary output format and turns the clock duty cycle stabilizer
on. Connecting MODE to 2/3VDD selects 2’s complement
output format and turns the clock duty cycle stabilizer on.
Connecting MODE to VDD selects 2’s complement output
format and turns the clock duty cycle stabilizer off.
SENSE (Pin 59): Reference Programming Pin. Connecting
SENSE to VCM selects the internal reference and a ±0.5V
input range. Connecting SENSE to VDD selects the internal
reference and a ±1V input range. An external reference
greater than 0.5V and less than 1V applied to SENSE
selects an input range of ±VSENSE. ±1V is the largest valid
input range.
VCM (Pin 60): 1.25V Output and Input Common Mode Bias.
Bypass to ground with 2.2μF ceramic chip capacitor.
GND (Exposed Pad) (Pin 65): ADC Power Ground. The
exposed pad on the bottom of the package needs to be
soldered to ground.
224010fb
9
LTC2240-10
PIN FUNCTIONS
(LVDS Mode)
AIN+ (Pins 1, 2): Positive Differential Analog Input.
AIN– (Pins 3, 4): Negative Differential Analog Input.
REFHA (Pins 5, 6): ADC High Reference. Bypass to
Pins 7, 8 with 0.1μF ceramic chip capacitor, to Pins 11,
12 with a 2.2μF ceramic capacitor and to ground with 1μF
ceramic capacitor.
REFLB (Pins 7, 8): ADC Low Reference. Bypass to Pins
5, 6 with 0.1μF ceramic chip capacitor. Do not connect to
Pins 11, 12.
REFHB (Pins 9, 10): ADC High Reference. Bypass to
Pins 11, 12 with 0.1μF ceramic chip capacitor. Do not
connect to Pins 5, 6.
REFLA (Pins 11, 12): ADC Low Reference. Bypass to
Pins 9, 10 with 0.1μF ceramic chip capacitor, to Pins 5,
6 with a 2.2μF ceramic capacitor and to ground with 1μF
ceramic capacitor.
VDD (Pins 13, 14, 15, 62, 63): 2.5V Supply. Bypass to
GND with 0.1μF ceramic chip capacitors.
GND (Pins 16, 61, 64): ADC Power Ground.
ENC+ (Pin 17): Encode Input. Conversion starts on the
positive edge.
ENC– (Pin 18): Encode Complement Input. Conversion
starts on the negative edge. Bypass to ground with 0.1μF
ceramic for single-ended encode signal.
SHDN (Pin 19): Shutdown Mode Selection Pin. Connecting
SHDN to GND and OE to GND results in normal operation
with the outputs enabled. Connecting SHDN to GND and
OE to VDD results in normal operation with the outputs at
high impedance. Connecting SHDN to VDD and OE to GND
results in nap mode with the outputs at high impedance.
Connecting SHDN to VDD and OE to VDD results in sleep
mode with the outputs at high impedance.
OE (Pin 20): Output Enable Pin. Refer to SHDN pin function.
DNC (Pins 21, 22, 23, 24): Do not connect these pins.
D0–/D0+ to D9–/D9+ (Pins 27, 28, 29, 30, 31, 32, 37,
38, 39, 40, 43, 44, 45, 46, 47, 48, 51, 52, 53, 54):
LVDS Digital Outputs. All LVDS outputs require differential
100Ω termination resistors at the LVDS receiver. D9–/D9+
is the MSB.
OGND (Pins 25, 33, 41, 50): Output Driver Ground.
OVDD (Pins 26, 34, 42, 49): Positive Supply for the Output Drivers. Bypass to ground with 0.1μF ceramic chip
capacitor.
CLKOUT–/CLKOUT+ (Pins 35 to 36): LVDS Data Valid
Output. Latch data on rising edge of CLKOUT–, falling
edge of CLKOUT+.
OF–/OF+ (Pins 55 to 56): LVDS Over/Under Flow Output.
High when an over or under flow has occurred.
LVDS (Pin 57): Output Mode Selection Pin. Connecting
LVDS to 0V selects full rate CMOS mode. Connecting LVDS
to 1/3VDD selects demux CMOS mode with simultaneous
update. Connecting LVDS to 2/3VDD selects demux CMOS
mode with interleaved update. Connecting LVDS to VDD
selects LVDS mode.
MODE (Pin 58): Output Format and Clock Duty Cycle
Stabilizer Selection Pin. Connecting MODE to 0V selects
offset binary output format and turns the clock duty cycle
stabilizer off. Connecting MODE to 1/3VDD selects offset
binary output format and turns the clock duty cycle stabilizer
on. Connecting MODE to 2/3VDD selects 2’s complement
output format and turns the clock duty cycle stabilizer on.
Connecting MODE to VDD selects 2’s complement output
format and turns the clock duty cycle stabilizer off.
SENSE (Pin 59): Reference Programming Pin. Connecting
SENSE to VCM selects the internal reference and a ±0.5V
input range. Connecting SENSE to VDD selects the internal
reference and a ±1V input range. An external reference
greater than 0.5V and less than 1V applied to SENSE
selects an input range of ±VSENSE. ±1V is the largest valid
input range.
VCM (Pin 60): 1.25V Output and Input Common Mode Bias.
Bypass to ground with 2.2μF ceramic chip capacitor.
GND (Exposed Pad) (Pin 65): ADC Power Ground. The
exposed pad on the bottom of the package needs to be
soldered to ground.
224010fb
10
LTC2240-10
FUNCTIONAL BLOCK DIAGRAM
AIN+
AIN–
VCM
VDD
INPUT
S/H
FIRST PIPELINED
ADC STAGE
SECOND PIPELINED
ADC STAGE
THIRD PIPELINED
ADC STAGE
FOURTH PIPELINED
ADC STAGE
FIFTH PIPELINED
ADC STAGE
GND
1.25V
REFERENCE
2.2μF
SHIFT REGISTER
AND CORRECTION
RANGE
SELECT
SENSE
REFH
REF
BUF
REFL
INTERNAL CLOCK SIGNALS
OVDD
DIFFERENTIAL
INPUT
LOW JITTER
CLOCK
DRIVER
DIFF
REF
AMP
REFLB REFHA
2.2μF
0.1μF
1μF
CONTROL
LOGIC
+
–+
–
D0
CLKOUT
224010 F01
REFLA REFHB
0.1μF
•
•
•
OUTPUT
DRIVERS
+ OF
–+
– D9
OGND
ENC
+
ENC–
M0DE LVDS SHDN
OE
1μF
Figure 1. Functional Block Diagram
224010fb
11
LTC2240-10
TIMING DIAGRAMS
LVDS Output Mode Timing
All Outputs Are Differential and Have LVDS Levels
tAP
ANALOG
INPUT
N+4
N+2
N
N+3
tH
N+1
tL
ENC–
ENC+
tD
N–5
D0-D9, OF
N–4
N–3
N–2
N–1
tC
CLKOUT–
CLKOUT+
224010 TD01
Full-Rate CMOS Output Mode Timing
All Outputs Are Single-Ended and Have CMOS Levels
tAP
ANALOG
INPUT
N+4
N+2
N
N+3
tH
N+1
tL
ENC–
ENC+
tD
N–5
DA0-DA9, OFA
N–4
N–3
N–2
N–1
tC
CLKOUTB
CLKOUTA
DB0-DB9, OFB
HIGH IMPEDANCE
224010 TD02
224010fb
12
LTC2240-10
TIMING DIAGRAMS
Demultiplexed CMOS Outputs with Interleaved Update
All Outputs Are Single-Ended and Have CMOS Levels
tAP
ANALOG
INPUT
N+4
N+2
N
N+3
tH
N+1
tL
ENC–
ENC+
tD
N–5
DA0-DA9, OFA
N–3
N–1
tD
N–6
DB0-DB9, OFB
N–4
tC
N–2
tC
CLKOUTB
CLKOUTA
224010 TD03
Demultiplexed CMOS Outputs with Simultaneous Update
All Outputs Are Single-Ended and Have CMOS Levels
tAP
ANALOG
INPUT
N+4
N+2
N
N+3
tH
N+1
tL
ENC–
ENC+
tD
DA0-DA9, OFA
N–6
N–4
N–2
N–5
N–3
N–1
tD
DB0-DB9, OFB
tC
CLKOUTB
CLKOUTA
224010 TD04
224010fb
13
LTC2240-10
APPLICATIONS INFORMATION
DYNAMIC PERFORMANCE
Signal-to-Noise Plus Distortion Ratio
The signal-to-noise plus distortion ratio [S/(N + D)] is
the ratio between the RMS amplitude of the fundamental input frequency and the RMS amplitude of all other
frequency components at the ADC output. The output is
band limited to frequencies above DC to below half the
sampling frequency.
2fa + fb, 2fb + fa, 2fa – fb and 2fb – fa. The intermodulation distortion is defined as the ratio of the RMS value of
either input tone to the RMS value of the largest 3rd order
intermodulation product.
Spurious Free Dynamic Range (SFDR)
Spurious free dynamic range is the peak harmonic or spurious noise that is the largest spectral component excluding
the input signal and DC. This value is expressed in decibels
relative to the RMS value of a full scale input signal.
Signal-to-Noise Ratio
The signal-to-noise ratio (SNR) is the ratio between the
RMS amplitude of the fundamental input frequency and
the RMS amplitude of all other frequency components
except the first five harmonics and DC.
Full Power Bandwidth
Total Harmonic Distortion
Aperture Delay Time
Total harmonic distortion is the ratio of the RMS sum
of all harmonics of the input signal to the fundamental
itself. The out-of-band harmonics alias into the frequency
band between DC and half the sampling frequency. THD
is expressed as:
The time from when a rising ENC+ equals the ENC– voltage
to the instant that the input signal is held by the sample
and hold circuit.
⎛
THD = 20Log ⎜
⎝
( V2 + V3 + V4 + ...Vn )/ V1⎞⎟⎠
2
2
2
2
where V1 is the RMS amplitude of the fundamental frequency and V2 through Vn are the amplitudes of the second
through nth harmonics. The THD calculated in this data
sheet uses all the harmonics up to the fifth.
Intermodulation Distortion
If the ADC input signal consists of more than one spectral
component, the ADC transfer function nonlinearity can
produce intermodulation distortion (IMD) in addition to
THD. IMD is the change in one sinusoidal input caused
by the presence of another sinusoidal input at a different
frequency.
If two pure sine waves of frequencies fa and fb are applied to the ADC input, nonlinearities in the ADC transfer
function can create distortion products at the sum and
difference frequencies of mfa ± nfb, where m and n = 0,
1, 2, 3, etc. The 3rd order intermodulation products are
The full power bandwidth is that input frequency at which
the amplitude of the reconstructed fundamental is reduced
by 3dB for a full scale input signal.
Aperture Delay Jitter
The variation in the aperture delay time from conversion
to conversion. This random variation will result in noise
when sampling an AC input. The signal to noise ratio due
to the jitter alone will be:
SNRJITTER = –20log (2π • fIN • tJITTER)
CONVERTER OPERATION
As shown in Figure 1, the LTC2240-10 is a CMOS pipelined
multi-step converter. The converter has five pipelined ADC
stages; a sampled analog input will result in a digitized
value five cycles later (see the Timing Diagram section). For
optimal performance the analog inputs should be driven
differentially. The encode input is differential for improved
common mode noise immunity. The LTC2240-10 has two
phases of operation, determined by the state of the differential ENC+/ENC– input pins. For brevity, the text will
refer to ENC+ greater than ENC– as ENC high and ENC+
less than ENC– as ENC low.
224010fb
14
LTC2240-10
APPLICATIONS INFORMATION
Each pipelined stage shown in Figure 1 contains an ADC,
a reconstruction DAC and an interstage residue amplifier.
In operation, the ADC quantizes the input to the stage and
the quantized value is subtracted from the input by the
DAC to produce a residue. The residue is amplified and
output by the residue amplifier. Successive stages operate
out of phase so that when the odd stages are outputting
their residue, the even stages are acquiring that residue
and vice versa.
When ENC is low, the analog input is sampled differentially
directly onto the input sample-and-hold capacitors, inside
the “Input S/H” shown in the block diagram. At the instant
that ENC transitions from low to high, the sampled input is
held. While ENC is high, the held input voltage is buffered
by the S/H amplifier which drives the first pipelined ADC
stage. The first stage acquires the output of the S/H during this high phase of ENC. When ENC goes back low, the
first stage produces its residue which is acquired by the
second stage. At the same time, the input S/H goes back
to acquiring the analog input. When ENC goes back high,
the second stage produces its residue which is acquired
by the third stage. An identical process is repeated for the
third and fourth stages, resulting in a fourth stage residue
that is sent to the fifth stage ADC for final evaluation.
Each ADC stage following the first has additional range to
accommodate flash and amplifier offset errors. Results
from all of the ADC stages are digitally synchronized such
that the results can be properly combined in the correction
logic before being sent to the output buffer.
SAMPLE/HOLD OPERATION AND INPUT DRIVE
Sample/Hold Operation
Figure 2 shows an equivalent circuit for the LTC2240-10
CMOS differential sample-and-hold. The analog inputs are
connected to the sampling capacitors (CSAMPLE) through
NMOS transistors. The capacitors shown attached to
each input (CPARASITIC) are the summation of all other
capacitance associated with each input.
During the sample phase when ENC is low, the transistors
connect the analog inputs to the sampling capacitors and
they charge to, and track the differential input voltage.
When ENC transitions from low to high, the sampled input
LTC2240-10
VDD
AIN+
RON
14Ω
10Ω
CPARASITIC
1.8pF
VDD
AIN–
CSAMPLE
2pF
RON
14Ω
10Ω
CSAMPLE
2pF
CPARASITIC
1.8pF
VDD
1.5V
6k
ENC+
ENC–
6k
1.5V
224010 F02
Figure 2. Equivalent Input Circuit
voltage is held on the sampling capacitors. During the
hold phase when ENC is high, the sampling capacitors are
disconnected from the input and the held voltage is passed
to the ADC core for processing. As ENC transitions from
high to low, the inputs are reconnected to the sampling
capacitors to acquire a new sample. Since the sampling
capacitors still hold the previous sample, a charging glitch
proportional to the change in voltage between samples will
be seen at this time. If the change between the last sample
and the new sample is small, the charging glitch seen at
the input will be small. If the input change is large, such
as the change seen with input frequencies near Nyquist,
then a larger charging glitch will be seen.
Common Mode Bias
For optimal performance the analog inputs should be driven
differentially. Each input should swing ±0.5V for the 2V
range or ±0.25V for the 1V range, around a common mode
voltage of 1.25V. The VCM output pin (Pin 60) may be used
to provide the common mode bias level. VCM can be tied
directly to the center tap of a transformer to set the DC
input level or as a reference level to an op amp differential
driver circuit. The VCM pin must be bypassed to ground
close to the ADC with a 2.2μF or greater capacitor.
224010fb
15
LTC2240-10
APPLICATIONS INFORMATION
Input Drive Impedance
As with all high performance, high speed ADCs, the dynamic performance of the LTC2240-10 can be influenced
by the input drive circuitry, particularly the second and
third harmonics. Source impedance and input reactance
can influence SFDR. At the falling edge of ENC, the
sample-and-hold circuit will connect the 2pF sampling
capacitor to the input pin and start the sampling period.
The sampling period ends when ENC rises, holding the
sampled input on the sampling capacitor. Ideally the
input circuitry should be fast enough to fully charge the
sampling capacitor during the sampling period 1/(2fS);
however, this is not always possible and the incomplete
settling may degrade the SFDR. The sampling glitch has
been designed to be as linear as possible to minimize the
effects of incomplete settling.
Figure 5 shows a capacitively-coupled input circuit. The impedance seen by the analog inputs should be matched.
The 25Ω resistors and 12pF capacitor on the analog inputs
serve two purposes: isolating the drive circuitry from
10Ω
2.2μF
0.1μF
ANALOG
INPUT
Figure 3 shows the LTC2240-10 being driven by an RF
transformer with a center tapped secondary. The secondary
center tap is DC biased with VCM, setting the ADC input
signal at its optimum DC level. Terminating on the transformer secondary is desirable, as this provides a common
mode path for charging glitches caused by the sample and
hold. Figure 3 shows a 1:1 turns ratio transformer. Other
turns ratios can be used if the source impedance seen
by the ADC does not exceed 100Ω for each ADC input.
A disadvantage of using a transformer is the loss of low
frequency response. Most small RF transformers have
poor performance at frequencies below 1MHz.
Figure 4 demonstrates the use of a differential amplifier to
convert a single ended input signal into a differential input
signal. The advantage of this method is that it provides
low frequency input response; however, the limited gain
bandwidth of most op amps will limit the SFDR at high
input frequencies.
T1
1:1
25Ω
25Ω
AIN+
0.1μF
AIN+
LTC2240-10
12pF
25Ω
AIN–
25Ω
AIN–
T1 = MA/COM ETC1-1T
RESISTORS, CAPACITORS
ARE 0402 PACKAGE SIZE
224010 F03
Figure 3. Single-Ended to Differential
Conversion Using a Transformer
For the best performance, it is recommended to have a
source impedance of 100Ω or less for each input. The
source impedance should be matched for the differential
inputs. Poor matching will result in higher even order
harmonics, especially the second.
Input Drive Circuits
VCM
50Ω
HIGH SPEED
DIFFERENTIAL
AMPLIFIER
ANALOG
INPUT
+
0.1μF
–
+
VCM
2.2μF
25Ω
AIN+
3pF
AIN+
LTC2240-10
12pF
CM
–
AIN–
25Ω
AIN–
3pF
224010 F04
Figure 4. Differential Drive with an Amplifier
VCM
100Ω
0.1μF
100Ω
2.2μF
25Ω
AIN+
AIN+
ANALOG
INPUT
12pF
0.1μF
25Ω
LTC2240-10
AIN–
AIN–
224010 F05
Figure 5. Capacitively-Coupled Drive
224010fb
16
LTC2240-10
APPLICATIONS INFORMATION
the sample-and-hold charging glitches and limiting the
wideband noise at the converter input. For input frequencies higher than 100MHz, the capacitor may need to be
decreased to prevent excessive signal loss.
10Ω
2.2μF
0.1μF
ANALOG
INPUT
25Ω
The AIN+ and AIN– inputs each have two pins to reduce
package inductance. The two AIN+ and the two AIN– pins
should be shorted together.
For input frequencies above 100MHz the input circuits of
Figure 6, 7 and 8 are recommended. The balun transformer
gives better high frequency response than a flux coupled
center tapped transformer. The coupling capacitors allow
the analog inputs to be DC biased at 1.25V. In Figure 8 the
series inductors are impedance matching elements that
maximize the ADC bandwidth.
VCM
12Ω
AIN+
0.1μF
AIN+
T1
0.1μF
LTC2240-10
8pF
25Ω
12Ω
AIN–
AIN–
T1 = MA/COM ETC1-1-13
RESISTORS, CAPACITORS
ARE 0402 PACKAGE SIZE
224010 F06
Figure 6. Recommended Front End Circuit for
Input Frequencies Between 100MHz and 250MHz
10Ω
Reference Operation
VCM
2.2μF
Figure 9 shows the LTC2240-10 reference circuitry consisting of a 1.25V bandgap reference, a difference amplifier
and switching and control circuit. The internal voltage
reference can be configured for two pin selectable input
ranges of 2V (±1V differential) or 1V (±0.5V differential).
Tying the SENSE pin to VDD selects the 2V range; typing
the SENSE pin to VCM selects the 1V range.
The 1.25V bandgap reference serves two functions: its
output provides a DC bias point for setting the common
mode voltage of any external input circuitry; additionally,
the reference is used with a difference amplifier to generate the differential reference levels needed by the internal
ADC circuitry. An external bypass capacitor is required
for the 1.25V reference output, VCM. This provides a high
frequency low impedance path to ground for internal and
external circuitry.
The difference amplifier generates the high and low
reference for the ADC. High speed switching circuits are
connected to these outputs and they must be externally
bypassed. Each output has four pins: two each of REFHA
and REFHB for the high reference and two each of REFLA
and REFLB for the low reference. The multiple output pins
are needed to reduce package inductance. Bypass capacitors must be connected as shown in Figure 9.
0.1μF
AIN+
ANALOG
INPUT
25Ω
0.1μF
AIN+
LTC2240-10
T1
0.1μF
AIN–
25Ω
AIN–
T1 = MA/COM ETC1-1-13
RESISTORS, CAPACITORS
ARE 0402 PACKAGE SIZE
224010 F07
Figure 7. Recommended Front End Circuit for
Input Frequencies Between 250MHz and 500MHz
10Ω
VCM
2.2μF
0.1μF
2.7nH
ANALOG
INPUT
25Ω
0.1μF
AIN+
AIN+
LTC2240-10
T1
0.1μF
25Ω
2.7nH
AIN–
AIN–
T1 = MA/COM ETC1-1-13
RESISTORS, CAPACITORS
ARE 0402 PACKAGE SIZE
224010 F08
Figure 8. Recommended Front End Circuit for
Input Frequencies Above 500MHz
224010fb
17
LTC2240-10
APPLICATIONS INFORMATION
Input Range
LTC2240-10
VCM
1.25V
2Ω
The input range can be set based on the application.
The 2V input range will provide the best signal-to-noise
performance while maintaining excellent SFDR. The 1V
input range will have better SFDR performance, but the
SNR will degrade by 1.7dB. See the Typical Performance
Characteristics section.
1.25V BANDGAP
REFERENCE
2.2μF
1V
RANGE
DETECT
AND
CONTROL
TIE TO VDD FOR 2V RANGE;
TIE TO VCM FOR 1V RANGE;
RANGE = 2 • VSENSE FOR
0.5V < VSENSE < 1V
1μF
0.5V
SENSE
REFLB
BUFFER
Driving the Encode Inputs
INTERNAL ADC
HIGH REFERENCE
0.1μF
REFHA
2.2μF
DIFF AMP
1μF
REFLA
0.1μF
INTERNAL ADC
LOW REFERENCE
REFHB
224010 F09
Figure 9. Equivalent Reference Circuit
1.25V
8k
Any noise present on the encode signal will result in additional aperture jitter that will be RMS summed with the
inherent ADC aperture jitter.
VCM
2.2μF
0.75V
SENSE
12k
1μF
The noise performance of the LTC2240-10 can depend
on the encode signal quality as much as on the analog
input. The ENC+/ENC– inputs are intended to be driven
differentially, primarily for noise immunity from common mode noise sources. Each input is biased through
a 4.8k resistor to a 1.5V bias. The bias resistors set the
DC operating point for transformer coupled drive circuits
and can set the logic threshold for single-ended drive
circuits.
LTC2240-10
In applications where jitter is critical (high input frequencies) take the following into consideration:
1. Differential drive should be used.
224010 F10
Figure 10. 1.5V Range ADC
Other voltage ranges in between the pin selectable ranges
can be programmed with two external resistors as shown
in Figure 10. An external reference can be used by applying its output directly or through a resistor divider to
SENSE. It is not recommended to drive the SENSE pin
with a logic device. The SENSE pin should be tied to the
appropriate level as close to the converter as possible. If
the SENSE pin is driven externally, it should be bypassed
to ground as close to the device as possible with a 1μF
ceramic capacitor.
2. Use as large an amplitude as possible; if transformer
coupled use a higher turns ratio to increase the amplitude.
3. If the ADC is clocked with a sinusoidal signal, filter the
encode signal to reduce wideband noise.
4. Balance the capacitance and series resistance at both
encode inputs so that any coupled noise will appear at both
inputs as common mode noise. The encode inputs have a
common mode range of 1.2V to 2.0V. Each input may be
driven from ground to VDD for single-ended drive.
224010fb
18
LTC2240-10
APPLICATIONS INFORMATION
VDD
LTC2240-10
TO INTERNAL
ADC CIRCUITS
CLOCK
INPUT
VDD
T1
MA/COM
0.1μF ETC1-1-13
•
1.5V BIAS
4.8k
ENC+
•
50Ω
8.2pF
100Ω
50Ω
0.1μF
ENC–
VDD
1.5V BIAS
4.8k
0.1μF
224010 F11
Figure 11. Transformer Driven ENC+/ENC–
0.1μF
ENC+
VTHRESHOLD = 1.5V
1.5V ENC– LTC2240-10
LVDS
CLOCK
100Ω 0.1μF
ENC+
ENC–
LTC2240-10
0.1μF
224010 F12a
Figure 12a. Single-Ended ENC Drive,
Not Recommended for Low Jitter
Maximum and Minimum Encode Rates
The maximum encode rate for the LTC2240-10 is 170Msps.
For the ADC to operate properly, the encode signal should
have a 50% (±5%) duty cycle. Each half cycle must have at
least 2.79ns for the ADC internal circuitry to have enough
settling time for proper operation. Achieving a precise 50%
duty cycle is easy with differential sinusoidal drive using
a transformer or using symmetric differential logic such
as PECL or LVDS.
An optional clock duty cycle stabilizer circuit can be used if
the input clock has a non 50% duty cycle. This circuit uses
the rising edge of the ENC+ pin to sample the analog input.
The falling edge of ENC+ is ignored and the internal falling
edge is generated by a phase-locked loop. The input clock
duty cycle can vary from 40% to 60% and the clock duty
cycle stabilizer will maintain a constant 50% internal duty
224010 F12b
Figure 12b. ENC Drive Using LVDS
cycle. If the clock is turned off for a long period of time,
the duty cycle stabilizer circuit will require one hundred
clock cycles for the PLL to lock onto the input clock. To
use the clock duty cycle stabilizer, the MODE pin should be
connected to 1/3VDD or 2/3VDD using external resistors.
The lower limit of the LTC2240-10 sample rate is determined
by droop of the sample-and-hold circuits. The pipelined
architecture of this ADC relies on storing analog signals on
small valued capacitors. Junction leakage will discharge
the capacitors. The specified minimum operating frequency
for the LTC2240-10 is 1Msps.
DIGITAL OUTPUTS
Table 1 shows the relationship between the analog input
voltage, the digital data bits, and the overflow bit.
224010fb
19
LTC2240-10
APPLICATIONS INFORMATION
Digital Output Buffers (CMOS Modes)
Table 1. Output Codes vs Input Voltage
AIN+ – AIN–
(2V Range)
OF
D9 – D0
(Offset Binary)
D9 – D0
(2’s Complement)
>+1.000000V
+0.998047V
+0.996094V
1
0
0
11 1111 1111
11 1111 1111
11 1111 1110
01 1111 1111
01 1111 1111
01 1111 1110
+0.001953V
0.000000V
–0.001953V
–0.003906V
0
0
0
0
10 0000 0001
10 0000 0000
01 1111 1111
01 1111 1110
00 0000 0001
00 0000 0000
11 1111 1111
11 1111 1110
–0.998047V
–1.000000V
<–1.000000V
0
0
1
00 0000 0001
00 0000 0000
00 0000 0000
10 0000 0001
10 0000 0000
10 0000 0000
Digital Output Modes
The LTC2240-10 can operate in several digital output
modes: LVDS, CMOS running at full speed, and CMOS
demultiplexed onto two buses, each of which runs at half
speed. In the demultiplexed CMOS modes the two buses
(referred to as bus A and bus B) can either be updated on
alternate clock cycles (interleaved mode) or simultaneously
(simultaneous mode). For details on the clock timing, refer
to the timing diagrams.
The LVDS pin selects which digital output mode the part
uses. This pin has a four-level logic input which should
be connected to GND, 1/3VDD, 2/3VDD or VDD. An external
resistor divider can be used to set the 1/3VDD or 2/3VDD
logic values. Table 2 shows the logic states for the LVDS
pin.
Table 2. LVDS Pin Function
LVDS
DIGITAL OUTPUT MODE
GND
Full-Rate CMOS
1/3VDD
Demultiplexed CMOS, Simultaneous Update
2/3VDD
Demultiplexed CMOS, Interleaved Update
VDD
LVDS
Figure 13a shows an equivalent circuit for a single
output buffer in the CMOS output mode. Each buffer is
powered by OVDD and OGND, which are isolated from the
ADC power and ground. The additional N-channel transistor
in the output driver allows operation down to voltages as
low as 0.5V. The internal resistor in series with the output
makes the output appear as 50Ω to external circuitry and
may eliminate the need for external damping resistors.
As with all high speed/high resolution converters, the
digital output loading can affect the performance. The
digital outputs of the LTC2240-10 should drive a minimal
capacitive load to avoid possible interaction between the
digital outputs and sensitive input circuitry. The output
should be buffered with a device such as an 74VCX245
CMOS latch. For full speed operation the capacitive load
should be kept under 10pF.
Lower OVDD voltages will also help reduce interference
from the digital outputs.
Digital Output Buffers (LVDS Mode)
Figure 13b shows an equivalent circuit for a differential
output pair in the LVDS output mode. A 3.5mA current is
steered from OUT+ to OUT– or vice versa which creates a
±350mV differential voltage across the 100Ω termination
resistor at the LVDS receiver. A feedback loop regulates
the common mode output voltage to 1.25V. For proper
operation each LVDS output pair needs an external 100Ω
termination resistor, even if the signal is not used (such
as OF+/OF– or CLKOUT+/CLKOUT–). To minimize noise
the PC board traces for each LVDS output pair should be
routed close together. To minimize clock skew all LVDS PC
board traces should have about the same length.
224010fb
20
LTC2240-10
APPLICATIONS INFORMATION
LTC2240-10
LTC2240-10
OVDD
VDD
OVDD
2.5V
0.5V
TO 2.625V
VDD
0.1μF
0.1μF
OUT+
–
DATA
FROM
LATCH
PREDRIVER
LOGIC
D
D
OVDD
43Ω
TYPICAL
DATA
OUTPUT
10k
+
10k
OUT–
LVDS
RECEIVER
D
D
OE
100Ω
1.25V
OGND
3.5mA
OGND
224010 F13a
Figure 13a. Digital Output Buffer in CMOS Mode
224010 F13b
Figure 13b. Digital Output in LVDS Mode
Data Format
Output Clock
The LTC2240-10 parallel digital output can be selected
for offset binary or 2’s complement format. The format
is selected with the MODE pin. Connecting MODE to GND
or 1/3VDD selects offset binary output format. Connecting
MODE to 2/3VDD or VDD selects 2’s complement output
format. An external resistor divider can be used to set the
1/3VDD or 2/3VDD logic values. Table 3 shows the logic
states for the MODE pin.
The ADC has a delayed version of the ENC+ input available
as a digital output, CLKOUT. The CLKOUT pin can be used
to synchronize the converter data to the digital system.
This is necessary when using a sinusoidal encode. In
all CMOS modes, A bus data will be updated just after
CLKOUTA rises and can be latched on the falling edge of
CLKOUTA. In demux CMOS mode with interleaved update,
B bus data will be updated just after CLKOUTB rises and
can be latched on the falling edge of CLKOUTB. In demux
CMOS mode with simultaneous update, B bus data will be
updated just after CLKOUTB falls and can be latched on
the rising edge of CLKOUTB. In LVDS mode, data will be
updated just after CLKOUT+/CLKOUT– rises and can be
latched on the falling edge of CLKOUT+/CLKOUT–.
Table 3. MODE Pin Function
MODE PIN
GND
OUTPUT FORMAT
CLOCK DUTY
CYCLE STABILIZER
Offset Binary
Off
1/3VDD
Offset Binary
On
2/3VDD
2’s Complement
On
VDD
2’s Complement
Off
Overflow Bit
An overflow output bit indicates when the converter is
overranged or underranged. In CMOS mode, a logic high
on the OFA pin indicates an overflow or underflow on the
A data bus, while a logic high on the OFB pin indicates an
overflow or underflow on the B data bus. In LVDS mode,
a differential logic high on the OF+/OF– pins indicates an
overflow or underflow.
Output Driver Power
Separate output power and ground pins allow the output
drivers to be isolated from the analog circuitry. The power
supply for the digital output buffers, OVDD, should be tied
to the same power supply as for the logic being driven.
For example if the converter is driving a DSP powered
by a 1.8V supply then OVDD should be tied to that same
1.8V supply.
224010fb
21
LTC2240-10
APPLICATIONS INFORMATION
In the CMOS output mode, OVDD can be powered with
any voltage up to 2.625V. OGND can be powered with any
voltage from GND up to 1V and must be less than OVDD.
The logic outputs will swing between OGND and OVDD.
printed circuit board should ensure that digital and analog
signal lines are separated as much as possible. In particular,
care should be taken not to run any digital signal alongside
an analog signal or underneath the ADC.
In the LVDS output mode, OVDD should be connected to a
2.5V supply and OGND should be connected to GND.
High quality ceramic bypass capacitors should be used at
the VDD, OVDD, VCM, REFHA, REFHB, REFLA and REFLB
pins. Bypass capacitors must be located as close to the
pins as possible. Of particular importance are the capacitors between REFHA and REFLB and between REFHB and
REFLA. These capacitors should be as close to the device
as possible (1.5mm or less). Size 0402 ceramic capacitors
are recommended. The 2.2μF capacitor between REFHA
and REFLA can be somewhat further away. The traces
connecting the pins and bypass capacitors must be kept
short and should be made as wide as possible.
Output Enable
The outputs may be disabled with the output enable pin,
OE. In CMOS or LVDS output modes OE high disables all
data outputs including OF and CLKOUT. The data access
and bus relinquish times are too slow to allow the outputs
to be enabled and disabled during full speed operation.
The output Hi-Z state is intended for use during long
periods of inactivity.
The Hi-Z state is not a truly open circuit; the output pins
that make an LVDS output pair have a 20k resistance between them. Therefore in the CMOS output mode, adjacent
data bits will have 20k resistance in between them, even
in the Hi-Z state.
The LTC2240-10 differential inputs should run parallel and
close to each other. The input traces should be as short as
possible to minimize capacitance and to minimize noise
pickup.
Sleep and Nap Modes
Most of the heat generated by the LTC2240-10 is transferred from the die through the bottom-side exposed
pad and package leads onto the printed circuit board. For
good electrical and thermal performance, the exposed
pad should be soldered to a large grounded pad on the
PC board. It is critical that all ground pins are connected
to a ground plane of sufficient area.
The converter may be placed in shutdown or nap modes
to conserve power. Connecting SHDN to GND results in
normal operation. Connecting SHDN to VDD and OE to VDD
results in sleep mode, which powers down all circuitry
including the reference and typically dissipates 1mW. When
exiting sleep mode it will take milliseconds for the output
data to become valid because the reference capacitors
have to recharge and stabilize. Connecting SHDN to VDD
and OE to GND results in nap mode, which typically dissipates 28mW. In nap mode, the on-chip reference circuit
is kept on, so that recovery from nap mode is faster than
that from sleep mode, typically taking 100 clock cycles. In
both sleep and nap mode all digital outputs are disabled
and enter the Hi-Z state.
GROUNDING AND BYPASSING
The LTC2240-10 requires a printed circuit board with a
clean unbroken ground plane. A multilayer board with an
internal ground plane is recommended. Layout for the
HEAT TRANSFER
Clock Sources for Undersampling
Undersampling is especially demanding on the clock source
and the higher the input frequency, the greater the sensitivity
to clock jitter or phase noise. A clock source that degrades
SNR of a full-scale signal by 1dB at 70MHz will degrade
SNR by 3dB at 140MHz, and 4.5dB at 190MHz.
In cases where absolute clock frequency accuracy is
relatively unimportant and only a single ADC is required, a
canned oscillator from vendors such as Saronix or Vectron
can be placed close to the ADC and simply connected
directly to the ADC. If there is any distance to the ADC,
224010fb
22
LTC2240-10
APPLICATIONS INFORMATION
some source termination to reduce ringing that may occur
even over a fraction of an inch is advisable. You must not
allow the clock to overshoot the supplies or performance
will suffer. Do not filter the clock signal with a narrow band
filter unless you have a sinusoidal clock source, as the
rise and fall time artifacts present in typical digital clock
signals will be translated into phase noise.
The lowest phase noise oscillators have single-ended
sinusoidal outputs, and for these devices the use of a
filter close to the ADC may be beneficial. This filter should
be close to the ADC to both reduce roundtrip reflection
times, as well as reduce the susceptibility of the traces
between the filter and the ADC. If the circuit is sensitive
to close-in phase noise, the power supply for oscillators
and any buffers must be very stable, or propagation delay variation with supply will translate into phase noise.
Even though these clock sources may be regarded as
digital devices, do not operate them on a digital supply.
If your clock is also used to drive digital devices such as
an FPGA, you should locate the oscillator, and any clock
fan-out devices close to the ADC, and give the routing
to the ADC precedence. The clock signals to the FPGA
should have series termination at the driver to prevent
high frequency noise from the FPGA disturbing the substrate of the clock fan-out device. If you use an FPGA as a
programmable divider, you must re-time the signal using
the original oscillator, and the re-timing flip-flop as well
as the oscillator should be close to the ADC, and powered
with a very quiet supply.
For cases where there are multiple ADCs, or where the
clock source originates some distance away, differential
clock distribution is advisable. This is advisable both from
the perspective of EMI, but also to avoid receiving noise
from digital sources both radiated, as well as propagated in
the waveguides that exist between the layers of multilayer
PCBs. The differential pairs must be close together and
distanced from other signals. The differential pair should
be guarded on both sides with copper distanced at least
3x the distance between the traces, and grounded with
vias no more than 1/4 inch apart.
224010fb
23
SMA
VERSION
DC997B-A
DC997B-B
DC997B-C
DC997B-D
DC997B-E
DC997B-F
3.3V TP5
GND TP4
2.5V TP3
(NO TURRET)
C11
0.1μF
C1
0.1μF
J7
ENCODE C2
CLK 0.1μF
AIN
C12
0.1μF
2.5V 1
VCM 3
EXT REF 5
R5
4.99Ω
R41
100Ω
C4
1.8pF
DEVICE
BITS SAMPLE RATE
LTC2242-12 12
250Msps
LTC2241-12 12
210Msps
LTC2240-12 12
170Msps
LTC2242-10 10
250Msps
LTC2241-10 10
210Msps
LTC2240-10 10
170Msps
J6
AUX PWR
CONNECTOR
1
2
3
2.5V
C36
4.7μF
TP2
GND
TP1
EXT REF
TP6
VCM
C3
0.1μF
R2
49.9Ω
R1
49.9Ω
R4
4.99Ω
C10
0.1μF
T1
MABA-007159-000000
T2
MABA-007159-000000
C7
0.1μF
C6
0.1μF
C17
2.2μF
1
C16
1μF
C15
1μF
R8 1k
J2
MODE
R6 1k
2
SHDN 3
VDD 1
GND 5
SJ
R13
4.99Ω
11
10
R25
1k
8
2
4 2/3
6 1/3
AIN
AIN+
AIN–
AIN–
REFHA
REFHA
REFLB
REFLB
+
19
20
59
58
57
60
17
18
SHDN
OE
SENSE
MODE
LVDS
VCM
ENC+
ENC–
10
REFHB
9
REFHB
12
REFLA
11
REFLA
2
1
4
3
6
5
8
7
U5
GND GP
7
GP
SHDN
IN
IN
VO
BYP
SEN
6
5
3
2
C38
0.01μF
3.3V
R37
BLM18BB470SN1D
C22 0.1μF
C20 0.1μF
C23 0.1μF
VO
OF+/OFA
OF–/DA9
D9+/DA8
D9–/DA7
D8+/DA6
D8–/DA5
D7+/DA4
D7–/DA3
D6+/DA2
D6–/DA1
D5+/DA0
D5–/DNC
D4+/DNC
D4–/CLKOUTA
D3+/CLKOUTB
D3–/OFB
CLKOUT+/DB9
CLKOUT–/DB8
D2+/DB7
D2–/DB6
D1+/DB5
D1–/DB4
D0+/DB3
D0–/DB2
DNC/DB1
DNC/DB0
DNC
DNC
LTC2240-10
C21 0.1μF
LT1763CDE-2.5
R7
1k
4 OE
2 VDD
6 GND
C14
0.1μF
C13
0.1μF
R14
4.99Ω
C9
1.8pF
R24
1k
C34
0.1μF
1
VDD 3
GND 5
2.5V
R15
49.9Ω
2.5V
2
4
6
C19
0.1μF
J4
SENSE
C18
2.2μF
R23
100Ω
R10
12.4Ω
R27
49.9Ω
R12
49.9Ω
R11
49.9Ω
R9
12.4Ω
25
OGND
33
OGND
41
OGND
50
OGND
J5
SMA
C25 0.1μF
C26 0.1μF
65
64
61
16
63
62
15
14
13
GND
GND
GND
GND
VDD
VDD
VDD
VDD
VDD
26
OVDD
34
OVDD
42
OVDD
49
OVDD
C24
10μF
+2.5V
+3.3V
56
55
54
53
52
51
48
47
46
45
44
43
40
39
38
37
36
35
32
31
30
29
28
27
24
23
22
21
2.5V
C28
0.1μF
R43
100Ω
R17
100Ω
R3
100Ω
C29
0.1μF
R42
100Ω
R18
100Ω
C31
0.1μF
C32
0.1μF
R39
100Ω
R20
100Ω
LVDS BUFFER BYPASS
C30
0.1μF
R40
100Ω
R19
100Ω
C33
0.1μF
R38
100Ω
R21
100Ω
C5
0.1μF
C8
0.1μF
R30 100Ω
R28 100Ω
R22
100Ω
24
20
21
18
19
16
17
14
15
10
11
8
9
6
7
4
5
3
22
27
46
13
3.3V
24
20
21
18
19
16
17
14
15
10
11
8
9
6
7
4
5
3
22
27
46
13
3.3V
12
25
26
47
48
VBB
I8N
I8P
I7N
I7P
I6N
I6P
I5N
I5P
I4N
I4P
I3N
I3P
I2N
I2P
I1N
I1P
U3 FINII08
EN12
EN34
EN56
EN78
EN
O8N
O8P
O7N
O7P
O6N
O6P
O5N
O5P
O4N
O4P
O3N
O3P
O2N
O2P
O1N
O1P
VC1
VC2
VC3
VC4
VC5
VE1
VE2
VE3
VE4
VE5
1
2
23
36
37
12
25
26
47
48
VBB
I8N
I8P
I7N
I7P
I6N
I6P
I5N
I5P
I4N
I4P
I3N
I3P
I2N
I2P
I1N
I1P
U3 FINII08
EN12
EN34
EN56
EN78
EN
O8N
O8P
O7N
O7P
O6N
O6P
O5N
O5P
O4N
O4P
O3N
O3P
O2N
O2P
O1N
O1P
VC1
VC2
VC3
VC4
VC5
VE1
VE2
VE3
VE4
VE5
24
1
2
23
36
37
29
28
31
30
33
32
35
34
39
38
41
40
43
42
45
44
29
28
31
30
33
32
35
34
39
38
41
40
43
42
45
44
8
SCL
SDA
WP
A2
A1
A0
6
5
7
3
2
1
C27
0.1μF
R29
4990Ω
2.5V
24LC02ST
224010 AI01
4
GND
VCC
55
57
59
61
63
65
67
69
71
73
75
77
79
81
83
85
87
89
91
93
95
97
99
56
58
60
62
64
66
68
70
72
74
76
78
80
82
84
86
88
90
92
94
96
98
100
R16
100k
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
41
43
45
47
49
51
53
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
54
R26
4990Ω
R46
4990Ω
APPLICATIONS INFORMATION
ARRAY
EEPROM
Evaluation Circuit Schematic of the LTC2240-10
LTC2240-10
224010fb
LTC2240-10
APPLICATIONS INFORMATION
Silkscreen Top
Layer 2 GND Plane
Layer 1 Component Side
Layer 3 Power/Ground Plane
224010fb
25
LTC2240-10
APPLICATIONS INFORMATION
Layer 4 Power/Ground Planes
Layer Back Solder Side
Layer 5 Power/Ground Planes
Silk Screen Back, Solder Side
224010fb
26
LTC2240-10
PACKAGE DESCRIPTION
UP Package
64-Lead Plastic QFN (9mm × 9mm)
(Reference LTC DWG # 05-08-1705)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
0.70 ±0.05
7.15 ±0.05
8.10 ±0.05 9.50 ±0.05
(4 SIDES)
NOTE:
1. DRAWING CONFORMS TO JEDEC PACKAGE
OUTLINE MO-220 VARIATION WNJR-5
2. ALL DIMENSIONS ARE IN MILLIMETERS
3. DIMENSIONS OF EXPOSED PAD ON BOTTOM
OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT,
SHALL NOT EXCEED 0.20mm ON ANY SIDE, IF PRESENT
4. EXPOSED PAD SHALL BE SOLDER PLATED
5. SHADED AREA IS ONLY A REFERENCE FOR PIN 1
LOCATION ON THE TOP AND BOTTOM OF PACKAGE
6. DRAWING NOT TO SCALE
PACKAGE OUTLINE
0.25 ±0.05
0.50 BSC
9 .00 ± 0.10
(4 SIDES)
BOTTOM VIEW—EXPOSED PAD
R = 0.115
TYP
0.75 ± 0.05
63 64
0.40 ± 0.10
PIN 1 TOP MARK
(SEE NOTE 5)
1
2
PIN 1
CHAMFER
7.15 ± 0.10
(4-SIDES)
(UP64) QFN 1003
0.200 REF
0.00 – 0.05
0.25 ± 0.05
0.50 BSC
224010fb
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.
27
LTC2240-10
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
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LTC2208
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LTC2221
12-Bit, 135Msps, 3.3V ADC, LVDS Outputs
660mW, 67.8dB SNR, 84dB SFDR, 64-Pin QFN
LTC2224
12-Bit, 135Msps, 3.3V ADC, High IF Sampling
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LTC2230
10-Bit, 170Msps, 3.3V ADC, LVDS Outputs
890mW, 61.2dB SNR, 78dB SFDR, 64-Pin QFN
LTC2231
10-Bit, 135Msps, 3.3V ADC, LVDS Outputs
660mW, 61.2dB SNR, 78dB SFDR, 64-Pin QFN
LTC2240-12
12-Bit, 170Msps, 2.5V ADC, LVDS Outputs
445mW, 65.6dB SNR, 80dB SFDR, 64-Pin QFN
LTC2241-10
10-Bit, 210Msps, 2.5V ADC, LVDS Outputs
585mW, 60.6dB SNR, 78dB SFDR, 64-Pin QFN
LTC2241-12
12-Bit, 210Msps, 2.5V ADC, LVDS Outputs
585mW, 65.6dB SNR, 80dB SFDR, 64-Pin QFN
LTC2242-10
10-Bit, 250Msps, 2.5V ADC, LVDS Outputs
740mW, 60.5dB SNR, 78dB SFDR, 64-Pin QFN
LTC2242-12
12-Bit, 250Msps, 2.5V ADC, LVDS Outputs
745mW, 65.6dB SNR, 80dB SFDR, 64-Pin QFN
LTC2255
14-Bit, 125Msps, 3V ADC, Lowest Power
395mW, 72.5dB SNR, 88dB SFDR, 32-Pin QFN
LTC2284
14-Bit, Dual, 105Msps, 3V ADC, Low Crosstalk
540mW, 72.4dB SNR, 88dB SFDR, 64-Pin QFN
LT5512
DC to 3GHz High Signal Level Downconverting Mixer
DC to 3GHz, 21dBm IIP3, Integrated LO Buffer
LT5514
Ultralow Distortion IF Amplifier/ADC Driver with Digitally
Controlled Gain
450MHz to 1dB BW, 47dB OIP3, Digital Gain Control
10.5dB to 33dB in 1.5dB/Step
LT5515
1.5GHz to 2.5GHz Direct Conversion Quadrature Demodulator
High IIP3: 20dBm at 1.9GHz, Integrated LO
Quadrature Generator
LT5516
800MHz to 1.5GHz Direct Conversion Quadrature Demodulator
High IIP3: 21.5dBm at 900MHz, Integrated LO
Quadrature Generator
LT5517
40MHz to 900MHz Direct Conversion Quadrature Demodulator
High IIP3: 21dBm at 800MHz, Integrated LO
Quadrature Generator
LT5522
600MHz to 2.7GHz High Linearity Downconverting Mixer
4.5V to 5.25V Supply, 25dBm IIP3 at 900MHz, NF = 12.5dB,
50Ω Single-Ended RF and LO Ports
224010fb
28 Linear Technology Corporation
LT 1107 REV B • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2006
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