LINER LTM9001-AX 16-bit if/baseband receiver subsystem Datasheet

LTM9001-Ax/LTM9001-Bx
16-Bit IF/Baseband
Receiver Subsystem
FEATURES
DESCRIPTION
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The LTM®9001 is an integrated system in a package (SiP)
that includes a high-speed 16-bit A/D converter, matching
network, anti-aliasing filter and a low noise, differential
amplifier with fixed gain. It is designed for digitizing wide
dynamic range signals with an intermediate frequency
(IF) range up to 300MHz. The amplifier allows either ACor DC-coupled input drive. A lowpass or bandpass filter
network can be implemented with various bandwidths.
Contact Linear Technology regarding semi-custom
configurations.
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Integrated 16-Bit, High-Speed ADC, Passive Filter
and Fixed Gain Differential Amplifier
Up to 300MHz IF Range
Lowpass and Bandpass Filter Versions
Low Noise, Low Distortion Amplifiers
Fixed Gain: 8dB, 14dB, 20dB or 26dB
50Ω, 200Ω or 400Ω Input Impedance
75dB SNR, 83dB SFDR (LTM9001-AD)
Integrated Bypass Capacitance, No External
Components Required
Optional Internal Dither
Optional Data Output Randomizer
LVDS or CMOS Outputs
3.3V Single Supply
Power Dissipation: 1.65W
Clock Duty Cycle Stabilizer
11.25mm × 11.25mm × 2.32mm LGA Package
APPLICATIONS
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Telecommunications
High Sensitivity Receivers
Cellular Base Stations
Spectrum Analyzers
The LTM9001 is perfect for IF receivers in demanding
communications applications, with AC performance that
includes 72dBFS noise floor and 82dB spurious free
dynamic range (SFDR) at 162.5MHz (LTM9001-AA).
The digital outputs can be either differential LVDS or singleended CMOS. There are two format options for the CMOS
outputs: a single bus running at the full data rate or two
demultiplexed buses running at half data rate. A separate
output power supply allows the CMOS output swing to
range from 0.5V to 3.3V.
The differential ENC+ and ENC– inputs may be driven with
a sine wave, PECL, LVDS, TTL or CMOS inputs. An optional
clock duty cycle stabilizer allows high performance at full
speed with 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.
TYPICAL APPLICATION
Simplified IF Receiver Channel
VCC
SENSE
64k Point FFT, fIN = 162.4MHz,
–1dBFS, PGA = 1
VDD = 3.3V
0
LTM9001-AA
LTM9001
0VDD = 0.5V TO 3.6V
IN–
RF
ANTI-ALIAS
FILTER
SAW
LO
16-BIT
130Msps ADC
IN+
•
•
•
D0
CLKOUT
OF
DIFFERENTIAL
FIXED GAIN
AMPLIFIER
9001 TA01
ENC+ ENC–
ADC CONTROL PINS
–40
–60
HD3
–80
HD2
–100
OGND
GND
CMOS
OR
LVDS
AMPLITUDE (dBFS)
D15
–20
–120
0
10
50
20
40
30
FREQUENCY (MHz)
60
9001 TA01b
9001fb
1
LTM9001-Ax/LTM9001-Bx
ABSOLUTE MAXIMUM RATINGS
PIN CONFIGURATION
(Notes 1, 2)
Supply Voltage (VCC) ................................ –0.3V to 3.6V
Supply Voltage (VDD) ................................... –0.3V to 4V
Digital Output Supply Voltage (OVDD) .......... –0.3V to 4V
Analog Input Current (IN+, IN–) ............................±10mA
Digital Input Voltage
(Except AMPSHDN) ................. –0.3V to (VDD + 0.3V)
Digital Input Voltage
(AMPSHDN)..............................–0.3V to (VCC + 0.3V)
Digital Output Voltage ................–0.3V to (OVDD + 0.3V)
Operating Temperature Range
LTM9001C................................................ 0°C to 70°C
LTM9001I.............................................–40°C to 85°C
Storage Temperature Range...................–45°C to 125°C
Maximum Junction Temperature........................... 125°C
ALL ELSE
= GND
TOP VIEW
CONTROL
1
2
DATA
3
4
5
6
7
8
OGND
J
IN–
H
IN+
G
9
OVDD
F
VCC E
DNC D
ENC+ C
ENC– B
A
OGND
VDD OGND OVDD
CONTROL
LGA PACKAGE
TJMAX = 125°C, QJA = 15°C/W, QJCtop = 19°C/W
QJA DERIVED FROM 60mm s 70mm PCB WITH 4 LAYERS
WEIGHT = 0.71g
ORDER INFORMATION
LEAD FREE FINISH
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTM9001CV-AA#PBF
LTM9001V-AA
81-Lead (11.25mm × 11.25mm × 2.3mm) LGA
0°C to 70°C
LTM9001IV-AA#PBF
LTM9001V-AA
81-Lead (11.25mm × 11.25mm × 2.3mm) LGA
–40°C to 85°C
LTM9001CV-AD#PBF
LTM9001V-AD
81-Lead (11.25mm × 11.25mm × 2.3mm) LGA
0°C to 70°C
LTM9001IV-AD#PBF
LTM9001V-AD
81-Lead (11.25mm × 11.25mm × 2.3mm) LGA
–40°C to 85°C
LTM9001CV-BA#PBF
LTM9001V-BA
81-Lead (11.25mm × 11.25mm × 2.3mm) LGA
0°C to 70°C
LTM9001IV-BA#PBF
LTM9001V-BA
81-Lead (11.25mm × 11.25mm × 2.3mm) LGA
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
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/
This product is only offered in trays. For more information go to: http://www.linear.com/packaging/
ELECTRICAL 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
GDIFF
Gain
DC, LTM9001-AA
fIN = 162.5MHz (Note 3)
GTEMP
Gain Temperature Drift
MIN
TYP
MAX
UNITS
l
19.1
19.7
19
20.3
dB
dB
DC, LTM9001-AD
fIN = 70MHz (Note 3)
l
13.4
14
13.5
14.7
dB
dB
DC, LTM9001-BA
fIN = 140MHz (Note 3)
l
7.1
8.2
7.8
9.4
dB
dB
VIN = Maximum, (Note 3)
2
mdB/°C
9001fb
2
LTM9001-Ax/LTM9001-Bx
ELECTRICAL 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
VINCM
Input Common Mode Voltage Range
(IN+ + IN–)/2
MIN
TYP
MAX
UNITS
VIN
Input Voltage Range at –1dBFS
LTM9001-AA at 162.5MHz
LTM9001-AD at 70MHz
LTM9001-BA at 140MHz
233
424
820
mVP-P
mVP-P
mVP-P
RINDIFF
Differential Input Impedance
LTM9001-AA
LTM9001-AD
LTM9001-BA
200
200
400
Ω
Ω
Ω
CINDIFF
Differential Input Capacitance
Includes Parasitic
1
pF
VOS
Offset Error (Note 6)
Including Amplifier and ADC (LTM9001-AA)
Including Amplifier and ADC (LTM9001-AD)
Including Amplifier and ADC (LTM9001-BA)
Offset Drift
Including Amplifier and ADC
±10
μV/°C
Full-Scale Drift
Internal Reference
External Reference
±30
±15
ppm/°C
ppm/°C
1.0–1.6
l
l
l
–8
–11
–20
–3.2
–6
–10
V
–0.5
–0.5
–0.5
mV
mV
mV
CMRR
Common Mode Rejection Ratio
ISENSE
SENSE Input Leakage Current
60
IMODE
MODE Pin Pull-Down Current to GND
10
μA
ILVDS
LVDS Pin Pull-Down Current to GND
10
μA
tAP
Sample-and-Hold Acquisition Delay Time
1
ns
tJITTER
Sample-and-Hold Acquisition Delay Time Jitter
70
fsRMS
0V < SENSE < VDD
l
–3
dB
3
μA
CONVERTER CHARACTERISTICS
The l indicates specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C.
PARAMETER
CONDITIONS
MIN
l
Resolution (No Missing Codes)
TYP
MAX
UNITS
16
Bits
Integral Linearity Error
Differential Input LTM9001-Ax (Notes 5, 7)
Differential Input LTM9001-BA (Notes 5, 7)
l
l
±2.4
±8
±10
LSB
LSB
Differential Linearity Error
Differential Input (Notes 5, 7)
l
±0.3
±1
LSB
Transition Noise
External Reference
1
LSBRMS
DYNAMIC ACCURACY
The l indicates specifications which apply over the full operating temperature range,
otherwise specifications are at TA = 25°C. AIN = –1dBFS. (Note 4)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
SNR
Signal-to-Noise Ratio
162.5MHz Input (PGA = 0) LTM9001-AA
162.5MHz Input (PGA = 1) LTM9001-AA
MAX
UNITS
l
67.2
72
68.5
dBFS
dBFS
70MHz Input (PGA = 0) LTM9001-AD
70MHz Input (PGA = 1) LTM9001-AD
l
71.2
75
72
dBFS
dBFS
140MHz Input (PGA = 0) LTM9001-BA
140MHz Input (PGA = 1) LTM9001-BA
l
67
69.2
67.2
dBFS
dBFS
9001fb
3
LTM9001-Ax/LTM9001-Bx
DYNAMIC ACCURACY
The l indicates specifications which apply over the full operating temperature range,
otherwise specifications are at TA = 25°C. AIN = –1dBFS. (Note 4)
SYMBOL
PARAMETER
CONDITIONS
SFDR
Spurious Free Dynamic Range, 2nd or 3rd
Harmonic
162.5MHz Input (PGA = 0) LTM9001-AA
162.5MHz Input (PGA = 1) LTM9001-AA
SFDR
S/(N+D)
SFDR
SFDR
Spurious Free Dynamic Range 4th or Higher
Signal-to-Noise Plus Distortion Ratio
MIN
TYP
l
72
78
82
dBc
dBc
70MHz Input (PGA = 0) LTM9001-AD
70MHz Input (PGA = 1) LTM9001-AD
l
72.6
83
86
dBc
dBc
140MHz Input (PGA = 0) LTM9001-BA
140MHz Input (PGA = 1) LTM9001-BA
l
64
72
82
dBc
dBc
l
86
95
95
dBc
dBc
70MHz Input (PGA = 0) LTM9001-AD
70MHz Input (PGA = 1) LTM9001-AD
l
84.5
95
98
dBc
dBc
140MHz Input (PGA = 0) LTM9001-BA
140MHz Input (PGA = 1) LTM9001-BA
l
86
95
104
dBc
dBc
l
67
71.4
68
dBFS
dBFS
70MHz Input (PGA = 0) LTM9001-AD
70MHz Input (PGA = 1) LTM9001-AD
l
71.2
74.3
72
dBFS
dBFS
140MHz Input (PGA = 0) LTM9001-BA
140MHz Input (PGA = 1) LTM9001-BA
l
64
67.5
66.4
dBFS
dBFS
162.5MHz Input (PGA = 0) LTM9001-AA
162.5MHz Input (PGA = 1) LTM9001-AA
162.5MHz Input (PGA = 0) LTM9001-AA
162.5MHz Input (PGA = 1) LTM9001-AA
MAX
UNITS
Spurious Free Dynamic Range at –25dBFS,
Dither “OFF”
162.5MHz Input (PGA = 0) LTM9001-AA
162.5MHz Input (PGA = 1) LTM9001-AA
90
93
dBFS
dBFS
Spurious Free Dynamic Range at –15dBFS,
Dither “OFF”
70MHz Input (PGA = 0) LTM9001-AD
70MHz Input (PGA = 1) LTM9001-AD
85
87
dBFS
dBFS
Spurious Free Dynamic Range at –15dBFS,
Dither “OFF”
140MHz Input (PGA = 0) LTM9001-BA
140MHz Input (PGA = 1) LTM9001-BA
91
92
dBFS
dBFS
Spurious Free Dynamic Range at –25dBFS,
Dither “ON”
162.5MHz Input (PGA = 0) LTM9001-AA
162.5MHz Input (PGA = 1) LTM9001-AA
95
100
dBFS
dBFS
Spurious Free Dynamic Range at –15dBFS,
Dither “ON”
l
90
70MHz Input (PGA = 0) LTM9001-AD
70MHz Input (PGA = 1) LTM9001-AD
l
90
92
88
dBFS
dBFS
Spurious Free Dynamic Range at –15dBFS,
Dither “ON”
140MHz Input (PGA = 0) LTM9001-BA
140MHz Input (PGA = 1) LTM9001-BA
l
90
95
96
dBFS
dBFS
IMD3
Third Order Intermodulation Distortion;
1MHz Tone Spacing, 2 Tones at –7dBFS
fIN = 162.5MHz LTM9001-AA
fIN = 70MHz LTM9001-AD
fIN = 140MHz LTM9001-BA
–78
–84
–84
dB
dB
dB
IIP3
Equivalent Third Order Input Intercept Point,
2 Tone
fIN = 162.5MHz LTM9001-AA
fIN = 70MHz LTM9001-AD
fIN = 140MHz LTM9001-BA
24
26.5
29.2
dBm
dBm
dBm
DIGITAL INPUTS AND 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
VICM
Common Mode Input Voltage
RIN
Input Resistance
CIN
Input Capacitance
l
Internally Set
Externally Set
(Note 7)
0.2
V
1.6
1.2
3.1
V
V
100
Ω
3
pF
9001fb
4
LTM9001-Ax/LTM9001-Bx
DIGITAL INPUTS AND 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
Logic Inputs (DITH, PGA, ADCSHDN, RAND)
VIH
High Level Input Voltage
VDD = 3.3V
l
VIL
Low Level Input Voltage
VDD = 3.3V
l
IIN
Input Current
VIN = 0V to VDD
l
CIN
Input Capacitance
(Note 7)
2
V
0.8
V
±10
μA
1.5
pF
Logic Inputs (AMPSHDN)
VIH
High Level Input Voltage
VCC = 3.3V
l
VIL
Low Level Input Voltage
VCC = 3.3V
l
2
V
0.8
V
IIH
Input High Current
VIN = 2V
1.3
μA
IIL
Input Low Current
VIN = 0.8V
0.1
μA
CIN
Input Capacitance
(Note 7)
1.5
pF
3.299
3.29
V
V
Logic Outputs (CMOS Mode)
OVDD = 3.3V
VOH
VOL
High Level Output Voltage
Low Level Output Voltage
VDD = 3.3V, IO = –10μA
VDD = 3.3V, IO = –200μA
l
VDD = 3.3V, IO = 10μA
VDD = 3.3V, IO = 1.6mA
l
3.1
0.01
0.1
V
V
0.4
ISOURCE
Output Source Current
VOUT = 0V
–50
mA
ISINK
Output Sink Current
VOUT = 3.3V
50
mA
VOH
High Level Output Voltage
VDD = 3.3V, IO = –200μA
2.49
V
VOL
Low Level Output Voltage
VDD = 3.3V, IO = 1.6mA
0.1
V
VOH
High Level Output Voltage
VDD = 3.3V, IO = –200μA
1.79
V
VOL
Low Level Output Voltage
VDD = 3.3V, IO = 1.6μA
0.1
V
OVDD = 2.5V
OVDD = 1.8V
Logic Outputs (LVDS Mode)
Standard LVDS
VOD
Differential Output Voltage
100Ω Differential Load
l
247
350
454
VOS
Output Common Mode Voltage
100Ω Differential Load
l
1.125
1.2
1.375
VOD
Differential Output Voltage
100Ω Differential Load
l
125
175
250
VOS
Output Common Mode Voltage
100Ω Differential Load
l
1.125
1.2
1.375
mV
V
Low Power LVDS
mV
V
POWER REQUIREMENTS
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
VDD
ADC Analog Supply Voltage
(Note 8)
VCC
Amplifier Supply Voltage
ICC
Amplifier Supply Current
PSHDN
Total Shutdown Power
l
MIN
TYP
MAX
UNITS
3.135
3.3
3.465
V
3.5
V
136
mA
2.85
l
AMPSHDN = ADCSHDN = 3.3V
100
10
mW
9001fb
5
LTM9001-Ax/LTM9001-Bx
POWER REQUIREMENTS
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
3
3.3
3.6
V
Standard LVDS Output Mode
OVDD
Output Supply Voltage
(Note 8)
l
IVDD
Analog Supply Current
LTM9001-Ax
LTM9001-BA
l
l
400
465
500
550
mA
mA
IOVDD
Output Supply Current
l
74
90
mA
PDISS
Power Dissipation
LTM9001-Ax
LTM9001-BA
l
l
1564
1779
1947
2112
mW
mW
Low Power LVDS Output Mode
OVDD
Output Supply Voltage
(Note 8)
l
IVDD
Analog Supply Current
LTM9001-Ax
LTM9001-BA
l
l
IOVDD
Output Supply Current
PDISS
Power Dissipation
OVDD
3
3.3
3.6
V
400
465
500
550
mA
mA
l
41
50
mA
LTM9001-Ax
LTM9001-BA
l
l
1455
1670
1815
1980
mW
mW
Output Supply Voltage
(Note 8)
l
IVDD
Analog Supply Current
LTM9001-Ax
LTM9001-BA
l
l
PDISS
ADC Power Dissipation
LTM9001-Ax
LTM9001-BA
l
l
PDISS(TOTAL)
Total Power Dissipation
LTM9001-Ax
LTM9001-BA
CMOS Output Mode
0.5
3.6
V
380
460
450
530
mA
mA
1320
1584
1650
1914
mW
mW
1650
1914
mW
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
MIN
fS
Sampling Frequency (Note 8)
LTM9001-Ax
LTM9001-BA
l
l
1
1
tL
ENC Low Time (Note 7)
Duty Cycle Stabilizer Off (LTM9001-Ax)
Duty Cycle Stabilizer Off (LTM9001-BA)
Duty Cycle Stabilizer On (LTM9001-Ax)
Duty Cycle Stabilizer On (LTM9001-BA)
l
l
l
l
3.65
2.97
2.6
2.1
tH
ENC High Time (Note 7)
Duty Cycle Stabilizer Off (LTM9001-Ax)
Duty Cycle Stabilizer Off (LTM9001-BA)
Duty Cycle Stabilizer On (LTM9001-Ax)
Duty Cycle Stabilizer On (LTM9001-BA)
l
l
l
l
(Note 7)
TYP
MAX
UNITS
130
160
MHz
MHz
3.846
3.125
3.846
3.125
1000
1000
1000
1000
ns
ns
ns
ns
3.65
2.97
2.6
2.1
3.846
3.125
3.846
3.125
1000
1000
1000
1000
ns
ns
ns
ns
l
1.3
2.7
4
ns
1.3
LVDS Output Mode (Standard and Low Power)
tD
ENC to DATA Delay
tC
ENC to CLKOUT Delay
(Note 7)
l
tSKEW
DATA to CLKOUT Skew
(tC – tD) (Note 7)
l
tRISE
Output Rise Time
0.5
ns
tFALL
Output Fall Time
0.5
ns
Data Latency
2.7
4
ns
4.3
10
ns
7
Cycles
9001fb
6
LTM9001-Ax/LTM9001-Bx
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
MIN
TYP
MAX
tD
ENC to DATA Delay
(Note 7)
tC
ENC to CLKOUT Delay
UNITS
l
1.3
2.7
4
ns
(Note 7)
l
1.3
2.7
4
ns
DATA to CLKOUT Skew
(tC – tD) (Note 7)
l
4.3
10
Data Latency
Full Rate CMOS
Demuxed
CMOS Output Mode
tSKEW
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: Gain is measured from IN+/IN– through the ADC. The amplifier
gain is attenuated by the filter, (See the typical performance characteristics
section for “IF Frequency Response”).
Note 4: VCC = VDD = 3.3V, fSAMPLE = maximum sample frequency, LVDS
outputs, differential ENC+/ENC – = 2VP-P with 1.6V common mode, input
7
7
ns
Cycles
Cycles
range = –1dBFS with PGA = 0 with differential drive, AC-coupled inputs,
unless otherwise noted.
Note 5: Integral nonlinearity is defined as the deviation of a code from
a “best fit straight line” to the transfer curve. The deviation is measured
from the center of the quantization band.
Note 6: Offset error is the voltage applied between the IN+ and IN– pins
required to make the output code flicker between 0000 0000 0000 0000
and 1111 1111 1111 1111.
Note 7: Guaranteed by design, not subject to test.
Note 8: Recommended operating conditions.
TIMING DIAGRAM
LVDS Output Mode Timing
All Outputs are Differential and Have LVDS Levels
tAP
ANALOG
INPUT
N+1
N+4
N
N+3
N+2
tH
tL
ENC–
ENC+
tD
N–7
D0-D15, OF
CLKOUT+
CLKOUT –
N–6
N–5
N–4
N–3
tC
9001 TD01
9001fb
7
LTM9001-Ax/LTM9001-Bx
TIMING DIAGRAM
Full-Rate CMOS Output Mode Timing
All Outputs are Single-Ended and Have CMOS Levels
tAP
ANALOG
INPUT
N+1
N+4
N
N+3
N+2
tH
tL
–
ENC
ENC+
tD
N–7
DA0-DA15, OFA
N–6
N–5
N–4
N–3
tC
CLKOUTA
CLKOUTB
HIGH IMPEDANCE
DB0-DB15, OFB
9001 TD02
Demultiplexed CMOS Output Mode Timing
All Outputs are Single-Ended and Have CMOS Levels
tAP
ANALOG
INPUT
N+1
N
N+4
N+2
N+3
tH
tL
–
ENC
ENC+
tD
DA0-DA15, OFA
N–8
N–6
N–4
N–7
N–5
N–3
tD
DB0-DB15, OFB
tC
CLKOUTA
CLKOUTB
9001 TD03
9001fb
8
LTM9001-Ax/LTM9001-Bx
TYPICAL PERFORMANCE CHARACTERISTICS
Best Fit Integral Non-Linearity
(INL) vs Output Code
Shorted Inputs Histogram with
130k Samples
0.5
5
9000
0.4
4
8000
0.3
3
7000
0.2
2
INL ERROR (LSB)
0.1
0
–0.1
6000
1
COUNT
DNL ERROR (LSB)
Differential Non-Linearity (DNL)
vs Output Code
(LTM9001-AA)
0
–1
5000
4000
–2
3000
–3
2000
–0.4
–4
1000
–0.5
–5
–0.2
–0.3
65536
49152
16384
32768
ADC OUTPUT CODE
0
9001 G01
9001 G03
150
–45
100
0
–2
FILTER GAIN (dB)
MAGNITUDE
PHASE
200
–4
–6
–8
50
10
–90
1000
100
FREQUENCY (MHz)
–10
120 130 140 150 160 170 180 190 200
FREQUENCY (MHz)
9001 G04
64k Point 2-Tone FFT, fIN = 161.5MHz,
and 163.5MHz, –7dBFS, PGA = 0,
RAND “Off”, Dither “Off”
0
0
–20
–20
–20
–40
–60
HD3
HD2
–100
–120
AMPLITUDE (dBFS)
0
AMPLITUDE (dBFS)
AMPLITUDE (dBFS)
9001 G05
64k Point FFT, fIN = 162.4MHz,
–1dBFS, PGA = 1, RAND “Off”,
Dither “Off”
64k Point FFT, fIN = 162.4MHz,
–1dBFS, PGA = 0, RAND “Off”,
Dither “Off”
–80
–40
–60
HD3
–80
HD2
–100
0
10
33544
IF Frequency Response
0
IMPEDANCE PHASE (deg)
IMPEDANCE MAGNITUDE (Ω)
33524
33504
ADC OUTPUT CODE
9001 G02
Input Impedance vs Frequency
250
0
33484
65536
49152
16384
32768
ADC OUTPUT CODE
0
50
20
40
30
FREQUENCY (MHz)
60
9001 G06
–120
–40
–60
–80
–100
0
10
50
20
40
30
FREQUENCY (MHz)
60
9001 G07
–120
0
10
50
20
40
30
FREQUENCY (MHz)
60
9001 G08
9001fb
9
LTM9001-Ax/LTM9001-Bx
TYPICAL PERFORMANCE CHARACTERISTICS
0
0
–20
–20
–20
–60
–80
AMPLITUDE (dBFS)
0
–40
–40
–60
–80
–120
0
10
50
20
40
30
FREQUENCY (MHz)
–120
60
0
10
50
20
40
30
FREQUENCY (MHz)
SFDR (dBc AND dBFS)
120
60
40
10
50
20
40
30
FREQUENCY (MHz)
60
9001 G11
84
SFDR dBc
SFDR dBFS
SFDR (dBc) AND SNR (dBFS)
140
80
0
SFDR and SNR vs Sample Rate,
fIN = 162.4MHz, –1dBFS, PGA = 0,
RAND “Off”, Dither “Off”
SFDR vs Input Level, fIN = 162.4MHz,
PGA = 0, RAND “Off”, Dither = “On”
SFDR dBc
SFDR dBFS
100
–80
9001 G10
SFDR vs Input Level, fIN = 162.4MHz,
PGA = 0, RAND “Off”, Dither = “Off”
120
–60
–120
60
9001 G09
140
–40
–100
–100
–100
SFDR (dBc AND dBFS)
64k Point FFT, fIN = 162.4MHz,
–15dBFS, PGA = 0, RAND “Off”,
Dither “On”
64k Point FFT, fIN = 162.4MHz,
–15dBFS, PGA = 0, RAND “Off”,
Dither “Off”
AMPLITUDE (dBFS)
AMPLITUDE (dBFS)
64k Point 2-Tone FFT, fIN = 161.5MHz,
and 163.5MHz, –15dBFS, PGA = 0,
RAND “Off”, Dither “Off”
(LTM9001-AA)
100
80
60
40
SNR
SFDR
80
76
72
68
20
20
0
–90 –80 –70 –60 –50 –40 –30 –20 –10
INPUT LEVEL (dBFS)
0
–90 –80 –70 –60 –50 –40 –30 –20 –10
INPUT LEVEL (dBFS)
0
64
0
0
200
150
50
100
ADC SAMPLE RATE (Msps)
9001 G14
9001 G13
9001 G12
250
SFDR vs VCC Supply Voltage,
fIN = 162.4MHz, –1dBFS,
PGA = 0
SFDR vs Input Common Mode Voltage,
fIN = 162.4MHz, –1dBFS, PGA = 0
81.0
90
80.5
85
80.0
79.5
SFDR (dBc)
SFDR (dBc)
80
75
70
79.0
78.5
78.0
77.5
77.0
65
76.5
60
0.5
75.5
2.8
76.0
2.5
2.0
1.0
1.5
INPUT COMMON MODE VOLTAGE (V)
3.0
9001 G15
2.9
3.0 3.1 3.2 3.3 3.4
VCC SUPPLY VOLTAGE (V)
3.5
9001 G16
9001fb
10
LTM9001-Ax/LTM9001-Bx
TYPICAL PERFORMANCE CHARACTERISTICS
Differential Non-Linearity (DNL)
vs Output Code
Best Fit Integral Non-Linearity
(INL) vs Output Code
0.8
INL ERROR (LSB)
0.2
0.0
– 0.2
–0.4
–0.6
–0.8
–1.0
16384
49152
32768
OUTPUT CODE
75
74
73
72
71
70
69
68
67
66
0
65536
16384
49152
32768
OUTPUT CODE
65536
65
1
10
100
FREQUENCY (MHz)
1000
9001 G27
9001 G26
9001 G25
Input Impedance vs Frequency
IF Frequency Response
12
200
10
–1
8
–2
160
6
140
4
120
2
100
0
80
–2
60
–4
40
–6
20
0
1
IMPEDANCE PHASE (DEG)
MAGNITUDE
PHASE
180
0
AMPLITUDE (dBFS)
220
IMPEDANCE MAGNITUDE (Ω)
–4
–5
–6
–7
–9
–8
–10
1000
10
100
FREQUENCY (MHz)
–3
–8
–10
40
50
60
70
80
FREQUENCY (MHz)
9001 G28
64k Point FFT, fIN = 70MHz,
–1dBFS, PGA = 0, RAND “Off”,
Dither “Off”
100
64k Point 2-Tone FFT, fIN = 70MHz,
and fin = 74MHz, –7dBFS Per Tone,
PGA = 0, RAND “Off”, Dither “Off”
0
–10
–10
–20
0
–20
–30
–30
–40
–50
–60
–70
HD3
–80
HD2
–90
–100
–110
–120
90
9001 G29
AMPLITUDE (dBFS)
0
AMPLITUDE (dBFS)
DNL ERROR (LSB)
0.6
SNR vs Frequency
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
–3.5
–4.0
SNR (dB)
1.0
0.4
(LTM9001-AD)
–40
–50
–60
–70
–80
–90
–100
–110
0
10
20
30
40
50
FREQUENCY (MHz)
60
9001 G30
–120
0
10
20
30
40
50
FREQUENCY (MHz)
60
9001 G31
9001fb
11
LTM9001-Ax/LTM9001-Bx
TYPICAL PERFORMANCE CHARACTERISTICS
Differential Non-Linearity (DNL)
vs Output Code
Best Fit Integral Non-Linearity
(INL) vs Output Code
0.8
0.4
INL ERROR (LSB)
DNL ERROR (LSB)
0.6
0.2
0.0
– 0.2
–0.4
–0.6
–0.8
–1.0
16384
49152
32768
OUTPUT CODE
65536
SNR vs Frequency
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
–3.5
–4.0
71
69
67
65
SNR (dB)
1.0
0
(LTM9001-BA)
63
61
59
57
55
53
0
16384
49152
32768
OUTPUT CODE
51
65536
1
10
100
FREQUENCY (MHz)
1000
9001 G19
9001 G17
9001 G18
IF Frequency Response
Input Impedance vs Frequency
400
0
0
MAGNITUDE
–5
–8
PHASE
250
200
–16
150
100
–24
AMPLITUDE (dBFS)
300
IMPEDANCE PHASE (°C)
IMPEDANCE MAGNITUDE (Ω)
350
–15
–20
–25
50
0
–10
1
–32
1000
10
100
FREQUENCY (MHz)
–30
1
10
100
FREQUENCY (MHz)
9001 G20
9001 G21
64k Point FFT, fIN = 250MHz,
–1dBFS, PGA = 0, RAND “Off”,
Dither “Off”
64k Point 2-Tone FFT, fIN = 136MHz,
–7dBFS Per Tone, PGA = 0, RAND
“Off”, Dither “Off”
0
0
–10
–10
–20
–20
–20
–30
–30
–30
–40
–50
–60
–70
HD3
HD2
–80
AMPLITUDE (dBFS)
0
–10
AMPLITUDE (dBFS)
AMPLITUDE (dBFS)
64k Point FFT, fIN = 140MHz,
–1dBFS, PGA = 0, RAND “Off”,
Dither “Off”
–40
HD3
–50
–60
HD2
–70
–80
–40
–50
–60
–70
–80
–90
–90
–90
–100
–100
–100
–110
–110
–110
–120
–120
–120
0
10
50
20
30
40
FREQUENCY (MHz)
60
9001 G22
0
1000
10
20
30 40 50 60
FREQUENCY (MHz)
70
80
9001 G23
0
10
50
20
30
40
FREQUENCY (MHz)
60
9001 G24
9001fb
12
LTM9001-Ax/LTM9001-Bx
PIN FUNCTIONS
Supply Pins
VCC (Pins E1, E2): 3.3V Analog Supply Pin for Amplifier.
The voltage on this pin provides power for the amplifier
stage only and is internally bypassed to GND.
VDD (Pins E5, D5): 3.3V Analog Supply Pin for ADC. This
supply is internally bypassed to GND.
OVDD (Pins A6, G9): Positive Supply for the ADC Output
Drivers. This supply is internally bypassed to OGND.
GND (Pins A1, A2, A4, B2, B4, C2, C4, D1, D2, D4, E4, F1,
F2, F4, G2, G4, H2, H4, J1, J2, J4): Analog Ground.
OGND (Pins A5, A9, G8, J9): ADC Output Driver Ground.
Analog Inputs
IN+ (Pin G1): Positive (Non-Inverting) Amplifier Input.
IN– (Pin H1): Negative (Inverting) Amplifier Input.
DNC (Pins C3, D3): Do Not Connect. These pins are used
for testing and should not be connected on the PCB. They
may be soldered to unconnected pads and should be well
isolated. The DNC pins connect to the signal path prior to
the ADC inputs; therefore, care should be taken to keep
other signals away from these sensitive nodes.
ENC+ (Pin C1): Positive Differential Encode Input. The
sampled analog input is held on the rising edge of ENC+.
This input is internally biased to 1.6V through a 6.2k
resistor. Output data can be latched on the rising edge
of ENC+. The Encode pins have a differential 100Ω input
impedance.
ENC – (Pin B1): Negative Differential Encode Input. The
sampled analog input is held on the falling edge of ENC –.
This input is internally biased to 1.6V through a 6.2k resistor.
Bypass to ground with a 0.1μF capacitor for a single-ended
encode signal. The encode pins have a differential 100Ω
input impedance.
Control Inputs
SENSE (Pin J3): Reference Mode Select and External
Reference Input. Tie SENSE to VDD to select the internal
2.5V bandgap reference. An external reference of 2.5V
or 1.25V may be used; both reference values will set the
maximum full-scale input range.
AMPSHDN (Pin H3): Power Shutdown Pin for Amplifier.
This pin is a logic input referenced to analog ground.
AMPSHDN = low results in normal operation. AMPSHDN
= high results in powered down amplifier with typically
3mA amplifier supply current.
MODE (Pin G3): Output Format and Clock Duty Cycle
Stabilizer Selection Pin. Connecting MODE to 0V selects
offset binary output format and disables the clock duty cycle
stabilizer. Connecting MODE to 1/3VDD selects offset binary
output format and enables the clock duty cycle stabilizer.
Connecting MODE to 2/3VDD selects 2’s complement
output format and enables the clock duty cycle stabilizer.
Connecting MODE to VDD selects 2’s complement output
format and disables the clock duty cycle stabilizer.
RAND (Pin F3): Digital Output Randomization Selection
Pin. RAND = low results in normal operation. RAND =
high selects D1 to D15 to be EXCLUSIVE-ORed with D0
(the LSB). The output can be decoded by again applying
an XOR operation between the LSB and all other bits. This
mode of operation reduces the effects of digital output
interference.
PGA (Pin E3): Programmable Gain Amplifier Control Pin.
PGA = low selects the normal (maximum) input voltage
range. PGA = high selects a 3.5dB reduced input range
for slightly better distortion performance at the expense
of SNR.
ADCSHDN (Pin B3): Power Shutdown Pin for ADC.
ADCSHDN = low results in normal operation. ADCSHDN
= high results in powered down analog circuitry and the
digital outputs are placed in a high impedance state.
DITH (Pin A3): Internal Dither Enable Pin. DITH = low
disables internal dither. DITH = high enables internal
dither. Refer to Internal Dither section of this data sheet
for details on dither operation.
LVDS (Pin F5): Data Output Mode Select Pin. Connecting
LVDS to 0V selects full rate CMOS mode. Connecting LVDS
to 1/3VDD selects demultiplexed CMOS mode. Connecting
LVDS to 2/3VDD selects low power LVDS mode. Connecting
LVDS to VDD selects standard LVDS mode.
9001fb
13
LTM9001-Ax/LTM9001-Bx
PIN FUNCTIONS
Digital Outputs
CLKOUTB (Pin E7): Data Valid Output. CLKOUTB will toggle
at the sample rate in full rate CMOS mode or at 1/2 the
sample rate in demultiplexed mode. Latch the data on the
falling edge of CLKOUTB.
For CMOS Mode, Full Rate or Demultiplexed
DA0 to DA15 (Pins E9 to H5): Digital Outputs, A Bus.
DA15 is the MSB. Output bus for full rate CMOS mode
and demultiplexed mode.
OFA (Pin G5): Overflow/Underflow Digital Output for the
A Bus. OFA is high when an overflow or underflow has
occurred on the A bus.
CLKOUTA (Pin E8): Inverted Data Valid Output. CLKOUTA
will toggle at the sample rate in full rate CMOS mode or
at 1/2 the sample rate in demultiplexed mode. Latch the
data on the rising edge of CLKOUTA.
For LVDS Mode, Standard or Low Power
D0–/D0+ to D15–/D15+ (Pins B5 to G6): LVDS Digital Outputs. All LVDS outputs require differential 100Ω termination
resistors at the LVDS receiver. D15+/D15– is the MSB.
OFB (Pin E6): Overflow/Underflow Digital Output for the
B Bus. OFB is high when an overflow or underflow has
occurred on the B bus. OFB is in a high impedance state
in full rate CMOS mode.
CLKOUT –/CLKOUT + (Pins E6, E7): LVDS Data Valid Output.
Latch data on the rising edge of CLKOUT+, falling edge
of CLKOUT –.
DB0 to DB15 (Pins B5 to D9): Digital Outputs, B Bus. DB15
is the MSB. Active in demultiplexed mode. The B bus is in
a high impedance state in full rate CMOS mode.
OF –/OF + (Pins H5, G5): Overflow/Underflow Digital Output.
OF is high when an over or under flow has occurred.
Pin Configuration (LVDS Outputs/CMOS Outputs)
1
2
3
4
5
6
7
8
9
J
GND
GND
SENSE
GND
D14+/DA12
D14–/DA11
D12+/DA8
D12–/DA7
OGND
H
IN–
GND
AMPSHDN
GND
OF–/DA15
D15–/DA13
D13–/DA9
D11–/DA5
D11+/DA6
G
IN+
GND
MODE
GND
OF+/OFA
D15+/DA14
D13+/DA10
OGND
OVDD
D9–/DA1
D9+/DA2
D10–/DA3
D10+/DA4
F
GND
GND
RAND
GND
LVDS
E
VCC
VCC
PGA
GND
VDD
D
GND
GND
DNC
GND
VDD
D6–/DB12
D6+/DB13
D7–/DB14
D7+/DB15
C
ENC+
GND
DNC
GND
D0+/DB1
D4–/DB8
D4+/DB9
D5–/DB10
D5+/DB11
B
ENC–
GND
ADCSHDN
GND
D0–/DB0
D1–/DB2
D1+/DB3
D3+/DB7
D3–/DB6
A
GND
GND
DITH
GND
OGND
OVDD
D2–/DB4
D2+/DB5
OGND
CLKOUT–/OFB CLKOUT+/CLKOUTB D8–/CLKOUTA
D8+/DA0
Top View of LGA Pinout (Looking Through Component)
ALL ELSE
= GND
TOP VIEW
CONTROL
1
2
3
DATA
4
5
6
7
8
9
OGND
J
IN–
H
IN+
G
OVDD
F
VCC E
DNC D
ENC+ C
ENC– B
A
OGND
CONTROL
VDD OGND OVDD
9001 LGA01
9001fb
14
SENSE
AMPSHDN
IN–
IN
+
VCC
PGA
RANGE
SELECT
VOLTAGE
REFERENCE
INPUT
AMPLIFIER
PGA
ANTI-ALIAS
FILTER
GND
ADC
REFERENCE
DITHER
SIGNAL
GENERATOR
INPUT
S/H
ENC+
100Ω
ENC–
DIFFERENTIAL
INPUT
LOW JITTER
CLOCK DRIVER
INTERNAL
CLOCK SIGNALS
FIRST
PIPELINED
ADC STAGE
THIRD
PIPELINED
ADC STAGE
FOURTH
PIPELINED
ADC STAGE
ADCSHDN
RAND MODE LVDS DITH
CONTROL
LOGIC
SHIFT REGISTER AND ERROR CORRECTION
SECOND
PIPELINED
ADC STAGE
OGND
OUTPUT
DRIVERS
FIFTH
PIPELINED
ADC STAGE
9001 BD
OF–
OF+
CLKOUT–
CLKOUT+
D15± … D0±
OVDD
VDD
LTM9001-Ax/LTM9001-Bx
FUNCTIONAL BLOCK DIAGRAM
9001fb
15
LTM9001-Ax/LTM9001-Bx
OPERATION
DYNAMIC PERFORMANCE DEFINITIONS
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.
distortion products at the sum and difference frequencies
of mfa ± nfb, where m and n = 0, 1, 2, 3, etc.
For example, the 3rd order IMD terms include (2fa + fb),
(fa + 2fb), (2fa – fb) and (fa – 2fb). The 3rd order IMD is
defined as the ration of the RMS value of either input tone
to the RMS value of the largest 3rd order IMD product.
Spurious Free Dynamic Range (SFDR)
Signal-to-Noise Ratio
The signal-to-noise (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.
The ratio of the RMS input signal amplitude to the RMS
value of the peak spurious spectral component expressed
in dBc. SFDR may also be calculated relative to full-scale
and expressed in dBFS.
Aperture Delay Time
Total Harmonic Distortion
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:
THD = –20Log ⎛ (V22 + V32 + V42 + ...Vn2 )/V1⎞
⎝
⎠
where V1 is the RMS amplitude of the fundamental
frequency and V2 through Vn are the amplitudes of the
second through nth harmonics.
Aperture delay is 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.
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)
DESCRIPTION
Intermodulation Distortion
If the input signal consists of more than one spectral
component, the 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 input, nonlinearities in the transfer function can create
The LTM9001 is an integrated system in a package (SiP)
μModule ® receiver that includes a high-speed, sampling
16-bit A/D converter, matching network, anti-aliasing filter
and a low noise, differential amplifier with fixed gain. It
is designed for digitizing high frequency, wide dynamic
range signals with an intermediate frequency (IF) range
up to 300MHz.
μModule is a registered trademark of Linear Technology Corporation.
9001fb
16
LTM9001-Ax/LTM9001-Bx
OPERATION
The following sections describe in further detail the functional operation of the LTM9001. The SiP technology allows
the LTM9001 to be customized and this is described in
the first section. The remaining outline follows the basic
functional elements as shown in Figure 1.
AMPLIFIER
ADC
INPUT
NETWORK
ADC
9001 F01
Figure 1. Basic Functional Elements
SEMI-CUSTOM OPTIONS
The μModule construction affords a new level of flexibility in
application-specific standard products. Standard ADC and
amplifier components can be integrated regardless of their
process technology and matched with passive components
to a particular application. The LTM9001-AA, as the first
example, is configured with a 16-bit ADC sampling at rates
up to 130Msps. The amplifier gain is 20dB with an input
impedance of 200Ω and an input range of 233mVP-P. The
matching network is designed to optimize the interface
between the amplifier output and the ADC under these
conditions. Additionally, there is a 2-pole bandpass filter
designed for 162.5MHz ±25MHz.
However, other options are possible through Linear Technology’s semi-custom development program. Linear
Technology has in place a program to deliver other speed,
resolution, IF range, gain and filter configurations for a
wide range of applications. See Table 1 for the LTM9001-AA
configuration and potential options. These semi-custom
designs are based on existing ADCs and amplifiers with
an appropriately modified matching network. The final
subsystem is then tested to the exact parameters defined
for the application. The final result is a fully integrated,
accurately tested and reliable solution. For more details
on the semi-custom receiver subsystem program, contact
Linear Technology.
Note that not all combinations of options in Table 1 are
possible at this time and specified performance may differ
significantly from existing values. This data sheet discusses
devices with LVDS and CMOS outputs. The lower speed
options that only support CMOS outputs are available on
a separate data sheet. The CMOS-only options have a
different pin assignment.
AMPLIFIER INFORMATION
The amplifiers used in the LTM9001 are low noise and low
distortion fully differential ADC drivers. The amplifiers are
very flexible in terms of I/O coupling. They can be AC- or
DC-coupled at the inputs. Users are advised to keep the
input common mode voltage between 1V and 1.6V for
proper operation. If the inputs are AC-coupled, the input
common mode voltage is automatically biased. The input
signal can be either single-ended or differential with almost
no difference in distortion performance.
Table 1. Semi-Custom Options
AMPLIFIER IF AMPLIFIER INPUT
ADC SAMPLE
RANGE
IMPEDANCE
AMPLIFIER GAIN
FILTER
RATE
300MHz
200Ω
20dB
162.5MHz BPF, 50MHz BW
130Msps
300MHz
200Ω
14dB
70MHz BPF, 25MHz BW
130Msps
300MHz
400Ω
8dB
DC-300MHz LPF
160Msps
Select Combination of Options from Columns Below
DC-300MHz
50Ω
26dB
LPF TBD
160Msps
DC-140MHz
200Ω
20dB
BPF TBD
130Msps
DC-70MHz
200Ω
14dB
105Msps
DC-35MHz
400Ω
8dB
80Msps
200Ω
6dB
65Msps
40Msps
25Msps
10Msps
ADC
RESOLUTION
16-bit
16-bit
16-bit
16-bit
14-bit
OUTPUT
LVDS/CMOS
LVDS/CMOS
LVDS/CMOS
PART NUMBER
LTM9001-AA
LTM9001-AD
LTM9001-BA
LVDS/CMOS
LVDS/CMOS
CMOS
CMOS
CMOS
CMOS
CMOS
CMOS
9001fb
17
LTM9001-Ax/LTM9001-Bx
OPERATION
ADC INPUT NETWORK
CONVERTER INFORMATION
The passive network between the amplifier output stage
and the ADC input stage can be configured for bandpass
or lowpass response with different cutoff frequencies and
bandwidths. The LTM9001-AA, for example, implements
a 2-pole bandpass filter centered at 162.5MHz with
50MHz bandwidth. Note that the filter attenuates the
signal at 162.5MHz by 1dB, making the overall gain of
the subsystem 19dB.
The analog-to-digital converter (ADC) is a CMOS pipelined
multistep converter with a front-end PGA. As shown in the
Functional Block Diagram, the converter has five pipelined
ADC stages; a sampled analog input will result in a digitized
value seven cycles later (see the Timing Diagram section).
The encode input is differential for improved common
mode noise immunity.
For production test purposes the filter is designed to allow
DC inputs into the ADC.
APPLICATIONS INFORMATION
INPUT SPAN
The LTM9001 is configured with a fixed input span and
input impedance. With the amplifier gain and the ADC
input network described above for LTM9001-AA, the fullscale input range of the driver circuit is 233mVP-P. The
recommended ADC input span is achieved by tying the
SENSE pin to VDD. However, the ADC input span can be
changed by applying a DC voltage to the SENSE pin.
25Ω
+
–
IN+
LTM9001
ZIN/2
RF
ZIN/2
RF
VIN
RT
25Ω
IN–
Input Impedance and Matching
9001 F02
The differential input impedance of the LTM9001 can be
50Ω, 200Ω or 400Ω. In some applications the differential
inputs may need to be terminated to a lower value impedance, e.g. 50Ω, in order to provide an impedance match
for the source. Several choices are available.
Figure 2. Input Termination for Differential 50Ω Input Impedance
Using Shunt Resistor (See Table 2 for RT Values)
LTM9001
One approach is to use a differential shunt resistor
(Figure 2). Another approach is to employ a wide band
transformer (Figure 3). Both methods provide a wide band
match. The termination resistor or the transformer must
be placed close to the input pins in order to minimize the
reflection due to input mismatch.
Table 2. Differential Amplifier Input Termination Values
ZIN
RT FIG 2
400Ω
57Ω
200Ω
66.5Ω
50Ω
None
25Ω
+
–
VIN
25Ω
IN+
ZIN/2
RF
IN–
ZIN/2
RF
• •
9001 F03
Figure 3. Input Termination for Differential 50Ω
Input Impedance Using a Wideband Transformer
9001fb
18
LTM9001-Ax/LTM9001-Bx
APPLICATIONS INFORMATION
Alternatively, one could apply a narrowband impedance
match at the inputs for frequency selection and/or noise
reduction.
RS
50Ω
+
–
Referring to Figure 4, amplifier inputs can be easily configured for single-ended input without a balun. The signal
is fed to one of the inputs through a matching network
while the other input is connected to the same impedance. In general, the single-ended input impedance and
termination resistor RT are determined by the combination
of RS, ZIN/2 and RF.
LTM9001
IN+
ZIN/2
RF
IN–
ZIN/2
RF
VIN
RT
0.1μF
RS/RT
0.1μF
9001 F04
Figure 4. Input Termination for Differential
50Ω Input Impedance Using Shunt Resistor
Table 3. Single-Ended Amplifier Input Termination Values
ZIN
0.1μF
RT FIG 4
400Ω
59Ω
200Ω
68.5Ω
50Ω
150Ω
Rs/2
The LTM9001 amplifier is stable with all source impedances. The overall differential gain is affected by the source
impedance in Figure 5:
+
–
IN+
LTM9001
ZIN/2
RF
ZIN/2
RF
VIN
RT
AV = | VOUT/VIN | = (1000/(RS + ZIN/2))
The noise performance of the amplifier also depends upon
the source impedance and termination. For example, an
input 1:4 transformer in Figure 3 improves the input noise
figure by adding 6dB voltage gain at the inputs.
Rs/2
IN–
9001 F05
Figure 5. Calculate Differential Gain
Reference and SENSE Pin Operation
Figure 6 shows the converter reference circuitry consisting
of a 2.5V bandgap reference, a programmable gain amplifier
and control circuit. There are three modes of reference
operation: internal reference, 1.25V external reference
or 2.5V external reference. To use the internal reference,
TIE TO VDD TO USE
INTERNAL 2.5V
REFERENCE
OR INPUT FOR
EXTERNAL 2.5V
REFERENCE
OR INPUT FOR
EXTERNAL 1.25V
REFERENCE
tie the SENSE pin to VDD. To use an external reference,
simply apply either a 1.25V or 2.5V reference voltage to the
SENSE input pin. Both 1.25V and 2.5V applied to SENSE
will result in the maximum full-scale range.
RANGE
SELECT
AND GAIN
CONTROL
INTERNAL
ADC
REFERENCE
SENSE
PGA
2.5V
BANDGAP
REFERENCE
9001 F06
Figure 6. Reference Circuit
9001fb
19
LTM9001-Ax/LTM9001-Bx
APPLICATIONS INFORMATION
PGA Pin
The PGA pin selects between two gain settings for the
ADC front-end. PGA = low selects the maximum input
span; PGA = high selects a 3.5dB lower input span. The
high input range has the best SNR. For applications with
high linearity requirements, the low input range will have
improved distortion; however, the SNR will be 1.8dB worse.
See the Typical Performance Characteristics section.
Driving the Encode Inputs
The noise performance of the converter can depend on
the encode signal quality as much as the analog input.
The encode inputs are intended to be driven differentially,
primarily for noise immunity from common mode noise
sources. Each input is biased through a 6k resistor to a
1.6V 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.
Any noise present on the encode signal will result in additional aperture jitter that will be RMS summed with the
inherent ADC aperture jitter. In applications where jitter
is critical (high input frequencies), take the following into
consideration:
1. Differential drive should be used.
2. Use the largest amplitude possible. If using transformer
coupling, use a higher turns ratio to increase the amplitude.
LTM9001
4. Balance the capacitance and series resistance at both
encode inputs such 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 VDD. Each input may be driven from ground to VDD for
single-ended drive.
The encode clock inputs have a differential 100Ω input
impedance. For 50Ω inputs e.g. signal generators, an
additional 100Ω impedance will provide an impedance
match, as shown in Figure 7b.
Maximum and Minimum Encode Rates
The maximum encode rate for the LTM9001-Ax is 130Msps
and 160Msps for LTM9001-BA. For the ADC to operate
properly the encode signal should have a 50% (±5%)
duty cycle. Each half cycle must have at least 3.65ns
(LTM9001-Ax, or 2.97ns for LTM9001-BA) 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. When
using a single-ended encode signal asymmetric rise and fall
times can result in duty cycles that are far from 50%.
VDD
TO INTERNAL
ADC CLOCK
DRIVERS
VDD
3. If the ADC is clocked with a fixed frequency sinusoidal
signal, filter the encode signal to reduce wideband
noise.
1.6V
LTM9001
0.1μF
ENC+
6k
T1
50Ω
100Ω
•
•
+
ENC
8.2pF
100Ω
VDD
0.1μF
1.6V
50Ω
6k
0.1μF
ENC–
ENC–
9001 F07b
T1 = M/A-COM ETC1-1-13
9001 F07a
Figure 7a. Equivalent Encode Input Circuit
Figure 7b. Transformer Driven Encode
9001fb
20
LTM9001-Ax/LTM9001-Bx
APPLICATIONS INFORMATION
An optional clock duty cycle stabilizer can be used if the
input clock does not have a 50% duty cycle. This circuit
uses the rising edge of ENC to sample the analog input.
The falling edge of ENC is ignored and an internal falling
edge is generated by a phase-locked loop. The input clock
duty cycle can vary from 30% to 70% and the clock duty
cycle stabilizer will maintain a constant 50% internal duty
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 must be
connected to 1/3VDD or 2/3VDD using external resistors.
The lower limit of the sample rate is determined by the
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 LTM9001 is 1Msps.
ENC+
VTHRESHOLD = 1.6V
1.6V ENC–
LTM9001
0.1μF
9001F8
Figure 8. Single-Ended ENC Drive,
Not Recommended for Low Jitter
DIGITAL OUTPUTS
Digital Output Modes
The LTM9001 can operate in four digital output modes:
standard LVDS, low power LVDS, full rate CMOS, and
demultiplexed CMOS. The LVDS pin selects the mode of
operation. This pin has a four level logic input, centered at
0, 1/3VDD, 2/3VDD and VDD. An external resistive divider
can be used to set the 1/3VDD and 2/3VDD logic levels.
Table 4 shows the logic states for the LVDS pin.
Table 4. LVDS Pin Function
LVDS
DIGITAL OUTPUT MODE
0V(GND)
Full-Rate CMOS
1/3VDD
Demultiplexed CMOS
2/3VDD
Low Power LVDS
VDD
LVDS
Digital Output Buffers (CMOS Modes)
Figure 10 shows an equivalent circuit for a single output
buffer in CMOS mode, full-rate or demultiplexed. Each
buffer is powered by OVDD and OGND, isolated from the
ADC power and ground. The additional N-channel transistor
in the output driver allows operation down to low voltages.
The internal resistor in series with the output makes the
output appear as 50Ω to external circuitry and eliminates
the need for external damping resistors.
LTM9001
OVDD
VDD
3.3V
MC100LVELT22
3.3V
261Ω
Q0
261Ω
LTM9001
OVDD
ENC+
D0
DATA
FROM
LATCH
100Ω
ENC–
0.5V
TO 3.6V
VDD
PREDRIVER
LOGIC
43Ω
TYPICAL
DATA
OUTPUT
Q0
165Ω
OGND
165Ω
9001 F09
9001 F10
Figure 9. ENC Drive Using a CMOS to PECL Translator
Figure 10. Equivalent Circuit for a Digital Output Buffer
9001fb
21
LTM9001-Ax/LTM9001-Bx
APPLICATIONS INFORMATION
As with all high speed/high resolution converters, the
digital output loading can affect the performance. The
digital outputs of the LTM9001 should drive a minimum
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 ALVCH16373
CMOS latch. For full speed operation the capacitive load
should be kept under 10pF. A resistor in series with the
output may be used but is not required since the ADC has
a series resistor of 43Ω on chip.
Lower OVDD voltages will also help reduce interference
from the digital outputs.
Digital Output Buffers (LVDS Modes)
In low power LVDS mode 1.75mA is steered between
the differential outputs, resulting in ±175mV at the LVDS
receiver’s 100Ω termination resistor. The output common
mode voltage is 1.2V, the same as standard LVDS mode.
Data Format
The LTM9001 parallel digital output can be selected for
offset binary or 2’s complement format. The format is
selected with the MODE pin. This pin has a four level
logic input, centered at 0, 1/3VDD, 2/3VDD and VDD. An
external resistive divider can be used to set the 1/3VDD
and 2/3VDD logic levels. Table 5 shows the logic states
for the MODE pin.
Table 5. MODE Pin Function
Figure 11 shows an equivalent circuit for an LVDS output
pair. 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 1.2V. For proper operation each LVDS output pair
must be terminated with 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.
MODE
OUTPUT FORMAT
CLOCK DUTY CYCLE STABILIZER
0V(GND)
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 (OF) 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
on the B data bus. In LVDS mode, a differential logic high
on OF+/OF– pins indicates an overflow or underflow.
LTM9001
OVDD
3.3V
3.5mA
VDD
VDD
OVDD
43Ω
DATA
FROM
LATCH
PREDRIVER
LOGIC
10k
10k
OVDD
100Ω
LVDS
RECEIVER
43Ω
1.20V
+
–
OGND
9001 F11
Figure 11. Equivalent Output Buffer in LVDS Mode
9001fb
22
LTM9001-Ax/LTM9001-Bx
APPLICATIONS INFORMATION
Output Clock
LTM9001
CLKOUT
The ADC has a delayed version of the encode 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.
CLKOUT
OF
OF
D15
In both CMOS modes, A bus data will be updated as CLKOUTA falls and CLKOUTB rises. In demultiplexed CMOS
mode the B bus data will be updated as CLKOUTA falls
and CLKOUTB rises.
D15/D0
D14
In full rate CMOS mode, only the A data bus is active;
data may be latched on the rising edge of CLKOUTA or
the falling edge of CLKOUTB.
D14/D0
•
•
•
D2
D2/D0
D1
In demultiplexed CMOS mode CLKOUTA and CLKOUTB
will toggle at 1/2 the frequency of the encode signal. Both
the A bus and the B bus may be latched on the rising edge
of CLKOUTA or the falling edge of CLKOUTB.
RAND = HIGH,
RANDOMIZER
ENABLED
D1/D0
RAND
D0
D0
Digital Output Randomizer
Interference from the ADC digital outputs is sometimes
unavoidable. Interference from the digital outputs may
be from capacitive or inductive coupling or coupling
through the ground plane. Even a tiny coupling factor can
result in discernible unwanted tones in the ADC output
spectrum.
9001 F12
Figure 12. Functional Equivalent of Digital Output Randomizer
PC BOARD
FPGA
CLKOUT
OF
By randomizing the digital output before it is transmitted
off chip, these unwanted tones can be randomized, trading
a slight increase in the noise floor for a large reduction in
unwanted tone amplitude.
D15 ⊕ D0
D15
D14 ⊕ D0
The digital output is “randomized” by applying an exclusiveOR logic operation between the LSB and all other data
output bits. To decode, the reverse operation is applied;
that is, an exclusive-OR operation is applied between the
LSB and all other bits. The LSB, OF and CLKOUT output
are not affected. The output randomizer function is active
when the RAND pin is high.
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
D14
LTM9001
D2 ⊕ D0
•
•
•
D2
D1 ⊕ D0
D1
D0
D0
9001 F13
Figure 13. Derandomizing a Randomized Digital Output
9001fb
23
LTM9001-Ax/LTM9001-Bx
APPLICATIONS INFORMATION
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. OVDD can be powered with any logic voltage up
to the 3.6V. OGND can be powered with any voltage from
ground up to 1V and must be less than OVDD. The logic
outputs will swing between OGND and OVDD.
Internal Dither
The LTM9001 is a 16-bit receiver subsystem with a very
linear transfer function; however, at low input levels even
slight imperfections in the transfer function will result in
unwanted tones. Small errors in the transfer function are
usually a result of ADC element mismatches. An optional
internal dither mode can be enabled to randomize the input
location on the ADC transfer curve, resulting in improved
SFDR for low signal levels.
As shown in Figure 14, the output of the sample-and-hold
amplifier is summed with the output of a dither DAC. The
dither DAC is driven by a long sequence pseudo-random
number generator; the random number fed to the dither
DAC is also subtracted from the ADC result. If the dither
DAC is precisely calibrated to the ADC, very little of the
dither signal will be seen at the output. The dither signal
that does leak through will appear as white noise. The dither
DAC will cause a small elevation in the noise floor of the
ADC, as compared to the noise floor with dither off.
For best noise performance with the dither signal on, the
driving impedance connected across pins IN+/IN– should
closely match that of the module (see Table 1). A source
impedance that is resistive and matches that of the module
within 10% will give the best results.
Supply Sequencing
The VCC pin provides the supply to the amplifier and the VDD
pin provides the supply to the ADC. The amplifier and the
ADC are separate integrated circuits within the LTM9001;
however, there are no supply sequencing considerations
beyond standard practice. It is recommended that the
amplifier and ADC both use the same low noise, 3.3V
supply, but the amplifier may be operated from a lower
voltage level if desired. Both devices can operate from the
same 3.3V linear regulator but place a ferrite bead between
the VCC and VDD pins. Separate linear regulators can be
used without additional supply sequencing circuitry if they
have common input supplies.
LTM9001
IN +
IN –
16-BIT
PIPELINED
ADC CORE
S/H
AMP
CLOCK/DUTY
CYCLE
CONTROL
PRECISION
DAC
DIGITAL
SUMMATION
CLKOUT
OF
D15
•
•
•
D0
OUTPUT
DRIVERS
MULTIBIT DEEP
PSEUDO-RANDOM
NUMBER
GENERATOR
9001 F14
ENC+
–
DITH
ENC
DITHER ENABLE
HIGH = DITHER ON
LOW = DITHER OFF
Figure 14. Functional Equivalent Block Diagram of Internal Dither Circuit
9001fb
24
LTM9001-Ax/LTM9001-Bx
APPLICATIONS INFORMATION
Grounding and Bypassing
Recommended Layout
The LTM9001 requires a printed circuit board with a
clean unbroken ground plane; a multilayer board with an
internal ground plane is recommended. The pinout of the
LTM9001 has been optimized for a flow-through layout
so that the interaction between inputs and digital outputs
is minimized. A continuous row of ground pads facilitate
a layout that ensures that digital and analog signal lines
are separated as much as possible.
The high integration of the LTM9001 makes the PC board
layout very simple and easy. However, to optimize its electrical and thermal performance, some layout considerations
are still necessary, see Figures 15-18.
The LTM9001 is internally bypassed with the amplifier (VCC)
and ADC (VDD) supplies returning to a common ground
(GND). The digital output supply (0VDD) is returned to
OGND. Additional bypass capacitance is optional and may
be required if power supply noise is significant.
The 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.
Heat Transfer
Most of the heat generated by the LTM9001 is transferred
through the bottom-side ground pads. For good electrical
and thermal performance, it is critical that all ground pins
are connected to a ground plane of sufficient area with as
many vias as possible.
• Use large PCB copper areas for ground. This helps to
dissipate heat in the package through the board and
also helps to shield sensitive on-board analog signals.
Common ground (GND) and output ground (OGND)
are electrically isolated on the LTM9001, but can be
connected on the PCB underneath the part to provide
a common return path.
• Use multiple ground vias. Using as many vias as possible helps to improve the thermal performance of the
board and creates necessary barriers separating analog
and digital traces on the board at high frequencies.
• Separate analog and digital traces as much as possible, using vias to create high-frequency barriers.
This will reduce digital feedback that can reduce the
signal-to-noise ratio (SNR) and dynamic range of the
LTM9001.
The quality of the paste print is an important factor in
producing high yield assemblies. It is recommended to
use a type 3 or 4 printing no-clean solder paste. The solder
stencil design should follow the guidelines outlined in
Application Note 100.
The LTM9001 employs gold-finished pads for use with
Pb-based or tin-based solder paste. It is inherently Pb-free
and complies with the JEDEC (e4) standard. The materials declaration is available online at http://www.linear.
com/designtools/leadfree/mat_dec.jsp.
9001fb
25
LTM9001-Ax/LTM9001-Bx
APPLICATIONS INFORMATION
Figure 15. Layer 1
Figure 16. Layer 2
Figure 17. Layer 3
Figure 18. Layer 4
9001fb
26
1.270
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.
5.080
3.810
2.540
1.270
0.000
0.9525
1.5875
2.540
3.810
1.5875
1.270
0.9525
SUGGESTED PCB LAYOUT
TOP VIEW
0.000
PACKAGE TOP VIEW
X
3.810
11.250
BSC
Y
aaa Z
1.90 – 2.10
DETAIL A
MOLD
CAP
Z
0.27 – 0.37
SUBSTRATE
LAND DESIGNATION PER JESD MO-222, SPP-010 AND SPP-020
DETAILS OF PAD #1 IDENTIFIER ARE OPTIONAL,
BUT MUST BE LOCATED WITHIN THE ZONE INDICATED.
THE PAD #1 IDENTIFIER MAY BE EITHER A MOLD OR A
MARKED FEATURE
SYMBOL TOLERANCE
aaa
0.15
0.10
bbb
6. THE TOTAL NUMBER OF PADS: 81
1.27
BSC
3
PADS
SEE NOTES
10.160
BSC
4
5. PRIMARY DATUM -Z- IS SEATING PLANE
0.25 × 45°
CHAMFER
×3
9
TRAY PIN 1
BEVEL
COMPONENT
PIN “A1”
0.605 – 0.665
3
2. ALL DIMENSIONS ARE IN MILLIMETERS
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994
DETAIL A
PACKAGE SIDE VIEW
2.17 – 2.47
bbb Z
aaa Z
5.080
4
1.270
PAD 1
CORNER
5.080
11.250
BSC
8
6
5
4
LTMXXXXXX
μModule
PACKAGE BOTTOM VIEW
3
2
LGA 81 1107 REV A
PACKAGE IN TRAY LOADING ORIENTATION
7
10.160
BSC
0.605 – 0.665
1
PAD 1
A
B
C
D
E
F
G
H
J
LTM9001-Ax/LTM9001-Bx
PACKAGE DESCRIPTION
LGA Package
81-Lead (11.25mm × 11.25mm × 2.32mm)
(Reference LTC DWG # 05-08-1809 Rev A)
9001fb
27
5.080
3.810
2.540
2.540
LTM9001-Ax/LTM9001-Bx
TYPICAL APPLICATION
LTM9001 with Ground-Referenced Single-Ended Input
3.3V
GROUND–
REFERENCED
SOURCE
RS
50Ω
75Ω
75Ω
IN+ LTM9001
IN–
+
–
0V
VCC
51.1Ω
9001 TA02
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTC2202
16-Bit, 10Msps ADC
140mW, 81.6dB SNR, 100dB SFDR
LTC2203
16-Bit, 25Msps ADC
220mW, 81.6dB SNR, 100dB SFDR
LTC2204
16-Bit, 40Msps ADC
480mW, 79.1dB SNR, 100dB SFDR
LTC2205
16-Bit, 65Msps ADC
610mW, 79dB SNR, 100dB SFDR
LTC2206
16-Bit, 80Msps ADC
725mW, 77.9dB SNR, 100dB SFDR
LTC2207
16-Bit, 105Msps ADC
900mW, 77.9dB SNR, 100dB SFDR
LTC2208
16-Bit, 130Msps ADC
1250mW, 77.7dB SNR, 100dB SFDR
LTC2209
16-Bit, 160Msps ADC
1450mW, 77.1dB SNR, 100dB SFDR
LTC6400-8/LTC6400-14/
LTC6400-20/LTC6400-26
Low Noise, Low Distortion Differential Amplifier for
300MHz IF, Fixed Gain of 8dB, 14dB, 20dB or 26dB
3V, 90mA, 39.5dBm OIP3 at 300MHz, 6dB NF
LTC6401-8/LTC6401-14/
LTC6401-20/LTC6401-26
Low Noise, Low Distortion Differential Amplifier for
140MHz IF, Fixed Gain of 8dB, 14dB, 20dB 20dB or 26dB
3V, 45mA, 45.5dBm OIP3 at 140MHz, 6dB NF
9001fb
28 Linear Technology Corporation
LT 0509 REV B • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
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