LTC2348-18 - Octal, 18-Bit, 200ksps Differential ±10.24V Input SoftSpan ADC with Wide Input

40 Pages·2016·1.6 MB·English

by  Linear Technology Corporation

LTC2348-18
Octal, 18-Bit, 200ksps
Differential ±10.24V Input SoftSpan ADC
with Wide Input Common Mode Range
FeaTures DescripTion
n 200ksps per Channel Throughput The LTC®2348-18 is an 18-bit, low noise 8-channel si-
n Eight Simultaneous Sampling Channels multaneous sampling successive approximation register
n ±3LSB INL (Maximum, ±10.24V Range) (SAR) ADC with differential, wide common mode range
n Guaranteed 18-Bit, No Missing Codes inputs. Operating from a 5V low voltage supply, flexible
n Differential, Wide Common Mode Range Inputs high voltage supplies, and using the internal reference
n Per-Channel SoftSpan Input Ranges: and buffer, each channel of this SoftSpanTM ADC can be
±10.24V, 0V to 10.24V, ±5.12V, 0V to 5.12V independently configured on a conversion-by-conversion
±12.5V, 0V to 12.5V, ±6.25V, 0V to 6.25V basis to accept ±10.24V, 0V to 10.24V, ±5.12V, or 0V to
n 96.7dB Single-Conversion SNR (Typical) 5.12V signals. Individual channels may also be disabled
n −109dB THD (Typical) at f = 2kHz to increase throughput on the remaining channels.
IN
n 118dB CMRR (Typical) at fIN = 200Hz The wide input common mode range and 118dB CMRR of
n Rail-to-Rail Input Overdrive Tolerance the LTC2348-18 analog inputs allow the ADC to directly
n Guaranteed Operation to 125°C digitize a variety of signals, simplifying signal chain de-
n Integrated Reference and Buffer (4.096V) sign. This input signal flexibility, combined with ±3LSB
n SPI CMOS (1.8V to 5V) and LVDS Serial I/O INL, no missing codes at 18 bits, and 96.7dB SNR, makes
n Internal Conversion Clock, No Cycle Latency the LTC2348-18 an ideal choice for many high voltage
n 140mW Power Dissipation (Typical) applications requiring wide dynamic range.
n 48-Lead (7mm x 7mm) LQFP Package
The LTC2348-18 supports pin-selectable SPI CMOS (1.8V
to 5V) and LVDS serial interfaces. Between one and eight
applicaTions
lanes of data output may be employed in CMOS mode,
allowing the user to optimize bus width and throughput.
n Programmable Logic Controllers
n Industrial Process Control L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
SoftSpan is a trademark of Linear Technology Corporation. All other trademarks are the property
n Power Line Monitoring of their respective owners. Protected by U.S. Patents, including 7705765, 7961132, 8319673.
Other Patents pending.
n Test and Measurement
Typical applicaTion
15V 5V 1.8V TO 5V
0.1µF 0.1µF 2.2µF 0.1µF Integral Nonlinearity vs
CMOS OR LVDS Output Code and Channel
I/O INTERFACE
FULLY 2.0
+10VARBITRARY +5VDIFFERENTIAL IINN00+– S/H VCC VDD VDDLBYP OVDD LVDS/CMOPDS 1.5 TRUE BIPOLAR D±R1I0V.E2 4(VIN R– A=N 0GVE)
S/H LTC2348-18 ALL CHANNELS
0V 0V 1.0
–10TVRUE BIPOLAR –5VUNIPOLAR • • • SSS///HHH MUX S1A8R- BAIDTC SSSCDD• • •KOOO07 RROR (LSB) 0.05
+100VV +100VV SS//HH SSCCDKSII INL E––10..05
–1D0IVFFERENTIAL INPU–T1S0 VIN+/IN– WITH IINN77+– S/H VEE REFBUF REFIN GND BUCNSYV SCALOMCPKLE –1.5
WIDE INPUT COMMON MODE RANGE EIGHT SIMULTANEOUS 0.1µF 47µF 0.1µF 234818 TA01a –2–.1031072 –65536OUTPU0T CODE65536 131072
SAMPLING CHANNELS –15V 234818 TA01b
234818fa
1
For more information www.linear.com/LTC2348-18
LTC2348-18
absoluTe MaxiMuM raTings pin conFiguraTion
(Notes 1, 2)
Supply Voltage (V ) .....................–0.3V to (V + 40V) TOP VIEW
CC EE
P
SSuuppppllyy VVoollttaaggee (DVifEfEe)r .e..n..c..e. .(..V..C..C.. .–.. .V..E.E..). ...........–..1..7...4..V... .t.o.. .04.03VV +IN7–IN7GNDVEEGNDVDDVDDGNDVDDLBYCSBUSYSDI
876543210987
Supply Voltage (V ) ..................................................6V 444444444333
DD
Supply Voltage (OV ) ................................................6V
DD
Internal Regulated Supply Bypass (V ) ... (Note 3) IN6– 1 36SDO7
DDLBYP IN6+ 2 35SDO–/SDO6
Analog Input Voltage IN5– 3 34SDO+/SDO5
IN0+ to IN7+, IN5+– 4 33SCKO+–/SDO4
IN4 5 32SCKO /SCKO
IN0– to IN7– (Note 4) .........(VEE – 0.3V) to (VCC + 0.3V) IINN43+– 67 3310OGVNDDD
REFIN ....................................................–0.3V to 2.8V IN3+ 8 29SCKI–/SCKI
IN2– 9 28SCKI+/SDO3
REFBUF, CNV (Note 5) .............–0.3V to (VDD + 0.3V) IINN21+–1101 2276SSDDII–+//SSDDOO21
Digital Input Voltage (Note 5) .....–0.3V to (OV + 0.3V) +
DD IN1 12 25SDO0
Digital Output Voltage (Note 5) ..–0.3V to (OV + 0.3V)
DD
Power Dissipation ..............................................500mW
345678901234
O pLeTraCt2in3g4 8TeCm ..p..e..r..a.t..u.r..e.. .R..a..n..g..e.......................0°C to 70°C –1IN0+1IN0GND1V1CCV1EEGND1REFIN1GND2EFBUF2PD2CMOS2CNV2
R S/
LTC2348I .............................................–40°C to 85°C VD
L
LTC2348H ..........................................–40°C to 125°C
LX PACKAGE
Storage Temperature Range ..................–65°C to 150°C 48-LEAD (7mm × 7mm) PLASTIC LQFP
TJMAX = 150°C, θJA = 53°C/W
orDer inForMaTion
LEAD FREE FINISH TRAY PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC2348CLX-18#PBF LTC2348CLX-18#PBF LTC2348LX-18 48-Lead (7mm × 7mm) Plastic LQFP 0°C to 70°C
LTC2348ILX-18#PBF LTC2348ILX-18#PBF LTC2348LX-18 48-Lead (7mm × 7mm) Plastic LQFP –40°C to 85°C
LTC2348HLX-18#PBF LTC2348HLX-18#PBF LTC2348LX-18 48-Lead (7mm × 7mm) Plastic LQFP –40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
234818fa
2
For more information www.linear.com/LTC2348-18
LTC2348-18
elecTrical characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T = 25°C. (Note 6)
A
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V + Absolute Input Range (Note 7) l V V – 4 V
IN EE CC
(IN0+ to IN7+)
V – Absolute Input Range (Note 7) l V V – 4 V
IN EE CC
(IN0– to IN7–)
V + – V – Input Differential Voltage SoftSpan 7: ±2.5 • V Range (Note 7) l –2.5 • V 2.5 • V V
IN IN REFBUF REFBUF REFBUF
Range SoftSpan 6: ±2.5 • V /1.024 Range (Note 7) l –2.5 • V /1.024 2.5 • V /1.024 V
REFBUF REFBUF REFBUF
SoftSpan 5: 0V to 2.5 • V Range (Note 7) l 0 2.5 • V V
REFBUF REFBUF
SoftSpan 4: 0V to 2.5 • V /1.024 Range (Note 7) l 0 2.5 • V /1.024 V
REFBUF REFBUF
SoftSpan 3: ±1.25 • V Range (Note 7) l –1.25 • V 1.25 • V V
REFBUF REFBUF REFBUF
SoftSpan 2: ±1.25 • V /1.024 Range (Note 7) l –1.25 • V /1.024 1.25 • V /1.024 V
REFBUF REFBUF REFBUF
SoftSpan 1: 0V to 1.25 • V Range (Note 7) l 0 1.25 • V V
REFBUF REFBUF
V Input Common Mode Voltage (Note 7) l V V – 4 V
CM EE CC
Range
V + – V – Input Differential Overdrive (Note 8) l −(V − V ) (V − V ) V
IN IN CC EE CC EE
Tolerance
I Analog Input Leakage Current l –1 1 µA
IN
C Analog Input Capacitance Sample Mode 50 pF
IN
Hold Mode 10 pF
CMRR Input Common Mode V + = V − = 18V 200Hz Sine l 100 118 dB
IN IN P-P
Rejection Ratio
V CNV High Level Input Voltage l 1.3 V
IHCNV
V CNV Low Level Input Voltage l 0.5 V
ILCNV
I CNV Input Current V = 0V to V l –10 10 μA
INCNV IN DD
converTer characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T = 25°C. (Note 9)
A
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Resolution l 18 Bits
No Missing Codes l 18 Bits
Transition Noise SoftSpans 7 and 6: ±10.24V and ±10V Ranges 1.3 LSB
RMS
SoftSpans 5 and 4: 0V to 10.24V and 0V to 10V Ranges 2.6 LSB
RMS
SoftSpans 3 and 2: ±5.12V and ±5V Ranges 2.0 LSB
RMS
SoftSpan 1: 0V to 5.12V Range 4.0 LSB
RMS
INL Integral Linearity Error SoftSpans 7 and 6: ±10.24V and ±10V Ranges (Note 10) l –3 ±1 3 LSB
SoftSpans 5 and 4: 0V to 10.24V and 0V to 10V Ranges (Note 10) l –4 ±1.5 4 LSB
SoftSpans 3 and 2: ±5.12V and ±5V Ranges (Note 10) l –2.5 ±0.75 2.5 LSB
SoftSpan 1: 0V to 5.12V Range (Note 10) l –2.5 ±0.75 2.5 LSB
DNL Differential Linearity Error (Note 11) l −0.9 ±0.2 0.9 LSB
ZSE Zero-Scale Error (Note 12) l −550 ±80 550 μV
Zero-Scale Error Drift ±2 μV/°C
FSE Full-Scale Error (Note 12) l −0.1 ±0.025 0.1 %FS
Full-Scale Error Drift ±2.5 ppm/°C
234818fa
3
For more information www.linear.com/LTC2348-18
LTC2348-18
DynaMic accuracy
The l denotes the specifications which apply over the full operating temperature range,
otherwise specifications are at T = 25°C. A = –1dBFS. (Notes 9, 13)
A IN
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
SINAD Signal-to-(Noise + SoftSpans 7 and 6: ±10.24V and ±10V Ranges, f = 2kHz l 93.0 96.5 dB
IN
Distortion) Ratio SoftSpans 5 and 4: 0V to 10.24V and 0V to 10V Ranges, f = 2kHz l 87.6 90.6 dB
IN
SoftSpans 3 and 2: ±5.12V and ±5V Ranges, f = 2kHz l 90.0 93.2 dB
IN
SoftSpan 1: 0V to 5.12V Range, f = 2kHz l 84.2 87.3 dB
IN
SNR Signal-to-Noise Ratio SoftSpans 7 and 6: ±10.24V and ±10V Ranges, f = 2kHz l 93.7 96.7 dB
IN
SoftSpans 5 and 4: 0V to 10.24V and 0V to 10V Ranges, f = 2kHz l 87.7 90.7 dB
IN
SoftSpans 3 and 2: ±5.12V and ±5V Ranges, f = 2kHz l 90.2 93.2 dB
IN
SoftSpan 1: 0V to 5.12V Range, f = 2kHz l 84.3 87.3 dB
IN
THD Total Harmonic Distortion SoftSpans 7 and 6: ±10.24V and ±10V Ranges, f = 2kHz l –109 –101 dB
IN
SoftSpans 5 and 4: 0V to 10.24V and 0V to 10V Ranges, f = 2kHz l –111 –104 dB
IN
SoftSpans 3 and 2: ±5.12V and ±5V Ranges, f = 2kHz l –113 –104 dB
IN
SoftSpan 1: 0V to 5.12V Range, f = 2kHz l –114 –103 dB
IN
SFDR Spurious Free Dynamic SoftSpans 7 and 6: ±10.24V and ±10V Ranges, f = 2kHz l 101 110 dB
IN
Range SoftSpans 5 and 4: 0V to 10.24V and 0V to 10V Ranges, f = 2kHz l 105 112 dB
IN
SoftSpans 3 and 2: ±5.12V and ±5V Ranges, f = 2kHz l 105 114 dB
IN
SoftSpan 1: 0V to 5.12V Range, f = 2kHz l 105 115 dB
IN
Channel-to-Channel One Channel Converting 18V 200Hz Sine in ±10.24V Range, −109 dB
P-P
Crosstalk Crosstalk to All Other Channels
–3dB Input Bandwidth 7 MHz
Aperture Delay 1 ns
Aperture Delay Matching 150 ps
Aperture Jitter 3 ps
RMS
Transient Response Full-Scale Step, 0.005% Settling 360 ns
inTernal reFerence characTerisTics
The l denotes the specifications which apply over the full
operating temperature range, otherwise specifications are at T = 25°C. (Note 9)
A
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V Internal Reference Output Voltage 2.043 2.048 2.053 V
REFIN
Internal Reference Temperature Coefficient (Note 14) l 5 20 ppm/°C
Internal Reference Line Regulation V = 4.75V to 5.25V 0.1 mV/V
DD
Internal Reference Output Impedance 20 kΩ
V REFIN Voltage Range REFIN Overdriven (Note 7) 1.25 2.2 V
REFIN
reFerence buFFer characTerisTics
The l denotes the specifications which apply over the full
operating temperature range, otherwise specifications are at T = 25°C. (Note 9)
A
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V Reference Buffer Output Voltage REFIN Overdriven, V = 2.048V l 4.091 4.096 4.101 V
REFBUF REFIN
REFBUF Voltage Range REFBUF Overdriven (Notes 7, 15) l 2.5 5 V
REFBUF Input Impedance V = 0V, Buffer Disabled 13 kΩ
REFIN
I REFBUF Load Current V = 5V, 8 Channels Enabled (Notes 15, 16) l 1.5 1.9 mA
REFBUF REFBUF
V = 5V, Acquisition or Nap Mode (Note 15) 0.39 mA
REFBUF
234818fa
4
For more information www.linear.com/LTC2348-18
LTC2348-18
DigiTal inpuTs anD DigiTal ouTpuTs
The l denotes the specifications which apply over the
full operating temperature range, otherwise specifications are at T = 25°C. (Note 9)
A
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
CMOS Digital Inputs and Outputs
V High Level Input Voltage l 0.8 • OV V
IH DD
V Low Level Input Voltage l 0.2 • OV V
IL DD
I Digital Input Current V = 0V to OV l –10 10 μA
IN IN DD
C Digital Input Capacitance 5 pF
IN
V High Level Output Voltage I = –500μA l OV  – 0.2 V
OH OUT DD
V Low Level Output Voltage I = 500μA l 0.2 V
OL OUT
I Hi-Z Output Leakage Current V = 0V to OV l –10 10 μA
OZ OUT DD
I Output Source Current V = 0V –50 mA
SOURCE OUT
I Output Sink Current V = OV 50 mA
SINK OUT DD
LVDS Digital Inputs and Outputs
V Differential Input Voltage l 200 350 600 mV
ID
R On-Chip Input Termination CS = 0V, V = 1.2V l 90 106 125 Ω
ID ICM
Resistance CS = OV 10 MΩ
DD
V Common-Mode Input Voltage l 0.3 1.2 2.2 V
ICM
I Common-Mode Input Current V + = V – = 0V to OV l –10 10 μA
ICM IN IN DD
V Differential Output Voltage R = 100Ω Differential Termination l 275 350 425 mV
OD L
V Common-Mode Output Voltage R = 100Ω Differential Termination l 1.1 1.2 1.3 V
OCM L
I Hi-Z Output Leakage Current V = 0V to OV l –10 10 μA
OZ OUT DD
power requireMenTs
The l denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T = 25°C. (Note 9)
A
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V Supply Voltage l 0 38 V
CC
V Supply Voltage l –16.5 0 V
EE
V − V Supply Voltage Difference l 10 38 V
CC EE
V Supply Voltage l 4.75 5.00 5.25 V
DD
I Supply Current 200ksps Sample Rate, 8 Channels Enabled l 1.8 2.2 mA
VCC
Acquisition Mode l 3.8 4.5 mA
Nap Mode l 0.7 0.9 mA
Power Down Mode l 1 15 μA
I Supply Current 200ksps Sample Rate, 8 Channels Enabled l –2.8 –2.2 mA
VEE
Acquisition Mode l –4.9 –4.0 mA
Nap Mode l –1.1 –0.8 mA
Power Down Mode l –15 –1 μA
CMOS I/O Mode
OV Supply Voltage l 1.71 5.25 V
DD
I Supply Current 200ksps Sample Rate, 8 Channels Enabled l 15.2 17.5 mA
VDD
200ksps Sample Rate, 8 Channels Enabled, V = 5V (Note 15) l 13.4 15.4 mA
REFBUF
Acquisition Mode l 1.6 2.1 mA
Nap Mode l 1.4 1.9 mA
Power Down Mode (C-Grade and I-Grade) l 65 175 μA
Power Down Mode (H-Grade) l 65 450 µA
234818fa
5
For more information www.linear.com/LTC2348-18
LTC2348-18
power requireMenTs
The l denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T = 25°C. (Note 9)
A
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I Supply Current 200ksps Sample Rate, 8 Channels Enabled (C = 25pF) l 1.6 2.6 mA
OVDD L
Acquisition or Nap Mode l 1 20 μA
Power Down Mode l 1 20 μA
P Power Dissipation 200ksps Sample Rate, 8 Channels Enabled l 140 169 mW
D
Acquisition Mode l 125 152 mW
Nap Mode l 30 40 mW
Power Down Mode (C-Grade and I-Grade) l 0.36 1.4 mW
Power Down Mode (H-Grade) l 0.36 2.8 mW
LVDS I/O Mode
OV Supply Voltage l 2.375 5.25 V
DD
I Supply Current 200ksps Sample Rate, 8 Channels Enabled l 17.7 20.4 mA
VDD
200ksps Sample Rate, 8 Channels Enabled, V = 5V (Note 15) l 16.1 18.5 mA
REFBUF
Acquisition Mode l 3.2 3.8 mA
Nap Mode l 3.0 3.7 mA
Power Down Mode (C-Grade and I-Grade) l 65 175 μA
Power Down Mode (H-Grade) l 65 450 µA
I Supply Current 200ksps Sample Rate, 8 Channels Enabled (R = 100Ω) l 7 8.5 mA
OVDD L
Acquisition or Nap Mode (R = 100Ω) l 7 8.0 mA
L
Power Down Mode l 1 20 μA
P Power Dissipation 200ksps Sample Rate, 8 Channels Enabled l 166 199 mW
D
Acquisition Mode l 151 180 mW
Nap Mode l 55 69 mW
Power Down Mode (C-Grade and I-Grade) l 0.36 1.4 mW
Power Down Mode (H-Grade) l 0.36 2.8 mW
aDc TiMing characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T = 25°C. (Note 9)
A
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
f Maximum Sampling Frequency 8 Channels Enabled l 200 ksps
SMPL
7 Channels Enabled l 225 ksps
6 Channels Enabled l 266 ksps
5 Channels Enabled l 300 ksps
4 Channels Enabled l 375 ksps
3 Channels Enabled l 450 ksps
2 Channels Enabled l 625 ksps
1 Channel Enabled l 1000 ksps
t Time Between Conversions 8 Channels Enabled, f = 200ksps l 5000 ns
CYC SMPL
7 Channels Enabled, f = 225ksps l 4444 ns
SMPL
6 Channels Enabled, f = 266ksps l 3750 ns
SMPL
5 Channels Enabled, f = 300ksps l 3333 ns
SMPL
4 Channels Enabled, f = 375ksps l 2666 ns
SMPL
3 Channels Enabled, f = 450ksps l 2222 ns
SMPL
2 Channels Enabled, f = 625ksps l 1600 ns
SMPL
1 Channel Enabled, f = 1000ksps l 1000 ns
SMPL
t Conversion Time N Channels Enabled, 1 ≤ N ≤ 8 l 450•N 500•N 550•N ns
CONV
t Acquisition Time 8 Channels Enabled, f = 200ksps l 570 980 ns
ACQ SMPL
(t = t – t – t ) 7 Channels Enabled, f = 225ksps l 564 924 ns
ACQ CYC CONV BUSYLH SMPL
6 Channels Enabled, f = 266ksps l 420 730 ns
SMPL
5 Channels Enabled, f = 300ksps l 553 813 ns
SMPL
4 Channels Enabled, f = 375ksps l 436 646 ns
SMPL
3 Channels Enabled, f = 450ksps l 542 702 ns
SMPL
2 Channels Enabled, f = 625ksps l 470 580 ns
SMPL
1 Channel Enabled, f = 1000ksps l 420 480 ns
SMPL
234818fa
6
For more information www.linear.com/LTC2348-18
LTC2348-18
aDc TiMing characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T = 25°C. (Note 9)
A
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
t CNV High Time l 40 ns
CNVH
t CNV Low Time l 420 ns
CNVL
tBUSYLH CNV↑ to BUSY Delay CL = 25pF l 30 ns
tQUIET Digital I/O Quiet Time from CNV↑ l 20 ns
t PD High Time l 40 ns
PDH
t PD Low Time l 40 ns
PDL
t REFBUF Wake-Up Time C = 47μF, C = 0.1μF 200 ms
WAKE REFBUF REFIN
CMOS I/O Mode
t SCKI Period (Notes 17, 18) l 10 ns
SCKI
t SCKI High Time l 4 ns
SCKIH
t SCKI Low Time l 4 ns
SCKIL
tSSDISCKI SDI Setup Time from SCKI↑ (Note 17) l 2 ns
tHSDISCKI SDI Hold Time from SCKI↑ (Note 17) l 1 ns
tDSDOSCKI SDO Data Valid Delay from SCKI↑ CL = 25pF (Note 17) l 7.5 ns
tHSDOSCKI SDO Remains Valid Delay from SCKI↑ CL = 25pF (Note 17) l 1.5 ns
t SDO to SCKO Skew (Note 17) l –1 0 1 ns
SKEW
tDSDOBUSYL SDO Data Valid Delay from BUSY↓ CL = 25pF (Note 17) l 0 ns
tEN Bus Enable Time After CS↓ (Note 17) l 15 ns
tDIS Bus Relinquish Time After CS↑ (Note 17) l 15 ns
LVDS I/O Mode
t SCKI Period (Note 19) l 4 ns
SCKI
t SCKI High Time (Note 19) l 1.5 ns
SCKIH
t SCKI Low Time (Note 19) l 1.5 ns
SCKIL
t SDI Setup Time from SCKI (Notes 11, 19) l 1.2 ns
SSDISCKI
t SDI Hold Time from SCKI (Notes 11, 19) l –0.2 ns
HSDISCKI
t SDO Data Valid Delay from SCKI (Notes 11, 19) l 6 ns
DSDOSCKI
t SDO Remains Valid Delay from SCKI (Notes 11, 19) l 1 ns
HSDOSCKI
t SDO to SCKO Skew (Note 11) l –0.4 0 0.4 ns
SKEW
tDSDOBUSYL SDO Data Valid Delay from BUSY↓ (Note 11) l 0 ns
tEN Bus Enable Time After CS↓ l 50 ns
tDIS Bus Relinquish Time After CS↑ l 15 ns
234818fa
7
For more information www.linear.com/LTC2348-18
LTC2348-18
aDc TiMing characTerisTics
Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 10: Integral nonlinearity is defined as the deviation of a code from a
may cause permanent damage to the device. Exposure to any Absolute straight line passing through the actual endpoints of the transfer curve.
Maximum Rating condition for extended periods may affect device The deviation is measured from the center of the quantization band.
reliability and lifetime. Note 11: Guaranteed by design, not subject to test.
Note 2: All voltage values are with respect to ground. Note 12: For bipolar SoftSpan ranges 7, 6, 3, and 2, zero-scale error
Note 3: V is the output of an internal voltage regulator, and should is the offset voltage measured from –0.5LSB when the output code
DDLBYP
only be connected to a 2.2μF ceramic capacitor to bypass the pin to GND, flickers between 00 0000 0000 0000 0000 and 11 1111 1111 1111 1111.
as described in the Pin Functions section. Do not connect this pin to any Full-scale error for these SoftSpan ranges is the worst-case deviation of
external circuitry. the first and last code transitions from ideal and includes the effect of
Note 4: When these pin voltages are taken below V or above V , they offset error. For unipolar SoftSpan ranges 5, 4, and 1, zero-scale error is
EE CC
will be clamped by internal diodes. This product can handle input currents the offset voltage measured from 0.5LSB when the output code flickers
of up to 100mA below V or above V without latch-up. between 00 0000 0000 0000 0000 and 00 0000 0000 0000 0001. Full-
EE CC
scale error for these SoftSpan ranges is the worst-case deviation of the
Note 5: When these pin voltages are taken below ground or above V or
DD
last code transition from ideal and includes the effect of offset error.
OV , they will be clamped by internal diodes. This product can handle
DD
currents of up to 100mA below ground or above V or OV without Note 13: All specifications in dB are referred to a full-scale input in the
DD DD
latch-up. relevant SoftSpan input range, except for crosstalk, which is referred to
the crosstalk injection signal amplitude.
Note 6: –16.5V ≤ V ≤ 0V, 0V ≤ V ≤ 38V, 10V ≤ (V – V ) ≤ 38V,
EE CC CC EE
V = 5V, unless otherwise specified. Note 14: Temperature coefficient is calculated by dividing the maximum
DD 
change in output voltage by the specified temperature range.
Note 7: Recommended operating conditions.
Note 15: When REFBUF is overdriven, the internal reference buffer must
Note 8: Exceeding these limits on any channel may corrupt conversion
be disabled by setting REFIN = 0V.
results on other channels. Refer to Absolute Maximum Ratings section for
pin voltage limits related to device reliability. Note 16: IREFBUF varies proportionally with sample rate and the number of
active channels.
Note 9: V = 15V, V = –15V, V = 5V, OV = 2.5V, f = 200ksps,
CC EE DD DD  SMPL
internal reference and buffer, true bipolar input signal drive in bipolar Note 17: Parameter tested and guaranteed at OVDD = 1.71V, OVDD = 2.5V,
SoftSpan ranges, unipolar signal drive in unipolar SoftSpan ranges, unless and OVDD = 5.25V.
otherwise specified. Note 18: A t period of 10ns minimum allows a shift clock frequency of
SCKI
up to 100MHz for rising edge capture.
Note 19: V = 1.2V, V = 350mV for LVDS differential input pairs.
ICM ID
CMOS Timings
0.8 • OVDD tWIDTH
0.2 • OVDD
tDELAY tDELAY 50% 50%
0.8 • OVDD 0.8 • OVDD 234818 F01
0.2 • OVDD 0.2 • OVDD
LVDS Timings (Differential)
+200mV
tWIDTH
–200mV
tDELAY tDELAY 0V 0V
+200mV +200mV 234818 F01b
–200mV –200mV
Figure 1. Voltage Levels for Timing Specifications
234818fa
8
For more information www.linear.com/LTC2348-18
LTC2348-18
Typical perForMance characTerisTics
T = 25°C, V  = +15V, V  = –15V, V  = 5V,
A CC EE DD
OV  = 2.5V, Internal Reference and Buffer (V  = 4.096V), f = 200ksps, unless otherwise noted.
DD REFBUF SMPL
IInntteeggrraall NNoonnlliinneeaarriittyy IInntteeggrraall NNoonnlliinneeaarriittyy DDiiffffeerreennttiiaall NNoonnlliinneeaarriittyy
vvss OOuuttppuutt CCooddee and Channel vvss OOuuttppuutt CCooddee and Channel vvss OOuuttppuutt CCooddee and Channel
2.0 2.0 0.5
±10.24V RANGE ±10.24V RANGE ALL RANGES
1.5 TRUE BIPOLAR DRIVE (IN– = 0V) 1.5 FULLY DIFFERENTIAL DRIVE (IN– = –IN+) 0.4 ALL CHANNELS
ALL CHANNELS ALL CHANNELS 0.3
1.0 1.0
0.2
R (LSB) 0.5 R (LSB) 0.5 R (LSB) 0.1
RO 0 RO 0 RO 0.0
R R R
NL E–0.5 NL E–0.5 NL E–0.1
I I D–0.2
–1.0 –1.0
–0.3
–1.5 –1.5
–0.4
–2.0 –2.0 –0.5
–131072 –65536 0 65536 131072 –131072 –65536 0 65536 131072 0 65536 131072 196608 262144
OUTPUT CODE OUTPUT CODE OUTPUT CODE
234818 G01 234818 G02 234818 G03
IInntteeggrraall NNoonnlliinneeaarriittyy IInntteeggrraall NNoonnlliinneeaarriittyy IInntteeggrraall NNoonnlliinneeaarriittyy
vvss OOuuttppuutt CCooddee and Range vvss OOuuttppuutt CCooddee and Range vvss OOuuttppuutt CCooddee and Range
2.0 2.0 2.0
TRUE BIPOLAR DRIVE (IN– = 0V) FULLY DIFFERENTIAL DRIVE (IN– = –IN+) UNIPOLAR DRIVE (IN– = 0V)
1.5 ONE CHANNEL 1.5 ONE CHANNEL 1.5 ONE CHANNEL
1.0 ±10.24V AND ±10V 1.0 ±10.24V, ±10V, 1.0
LSB) 0.5 RANGES ±R5A.N12GVE SAND ±5V LSB) 0.5 ±R5A.N12GVE, SAND ±5V LSB) 0.5 R0VA NTGOE 5.12V
R ( R ( R (
O 0 O 0 O 0
R R R
R R R
E E E
L –0.5 L –0.5 L –0.5
N N N
I I I
–1.0 –1.0 –1.0
–1.5 –1.5 –1.5 0V TO 10.24V AND 0V TO 10V
RANGES
–2.0 –2.0 –2.0
–131072 –65536 0 65536 131072 –131072 –65536 0 65536 131072 0 65536 131072 196608 262144
OUTPUT CODE OUTPUT CODE OUTPUT CODE
234818 G04 234818 G05 234818 G06
IInntteeggrraall NNoonnlliinneeaarriittyy
vvss OOuuttppuutt CCooddee DDCC HHiissttooggrraamm ((ZZeerroo--SSccaallee)) DDCC HHiissttooggrraamm ((NNeeaarr FFuullll-–SSccaallee))
2.0 90000 90000
±10.24V RANGE ±10.24V RANGE ±10.24V RANGE
1.5 80000 σ = 1.3 80000 σ = 1.4
TRUE BIPOLAR DRIVE (IN– = 0V)
1.0 70000 70000
B) 60000 60000
S 0.5
L
R ( TS50000 TS50000
O 0 N N
R U U
R O40000 O40000
E C C
L –0.5
IN 30000 30000
–1.0 ARBITRARY DRIVE
IN+/IN– COMMON MODE 20000 20000
–1.5 SWEPT –10.24V to 10.24V 10000 10000
–2.0 0 0
–131072 –65536 0 65536 131072 –6 –4 –2 0 2 4 6 131056 131059 131062 131065 131068
OUTPUT CODE CODE CODE
234818 G07 234818 G08 234818 G09
234818fa
9
For more information www.linear.com/LTC2348-18
LTC2348-18
Typical perForMance characTerisTics
T = 25°C, V  = +15V, V  = –15V, V  = 5V,
A CC EE DD
OV  = 2.5V, Internal Reference and Buffer (V  = 4.096V), f = 200ksps, unless otherwise noted.
DD REFBUF SMPL
3322kk PPooiinntt TAwrboi-tTroanrye TFwFoT- TfSoMnPeL F =F T
f3f3II2N2N k k== PP  22ookkiiHHnntztz FFFFTT ffSSMMPPLL  ==  220000kkHHzz,, f33fII2N2N k k== P P 22ookkiiHHnntztz FFFFTT ffSSMMPPLL  ==  220000kkHHzz,, I2fSNS0iMn–0 ePk=L,H  –I=zN7, 2 d–I0 BN=0F+ k– S=H7 3dz–.,B71 IFdkNSBH+ Fz 3=S .S 1 –2ikn7kHedHzBz FS SSiin n2eek,Hz
0 0 0
±10.24V RANGE ±10.24V RANGE ±10.24V RANGE
–20 TRUE BIPOLAR DRIVE (IN– = 0V) –20 FULLY DIFFERENTIAL DRIVE (IN– = –IN+) –20 ARBITRARY DRIVE
–40 SNR = 96.7dB –40 SNR = 96.7dB –40 SFDR = 119dB
DE (dBFS) ––8600 SITSNHFADDDR == = –9 11601.590dddBBB DE (dBFS) ––8600 SITSNHFADDDR = = =– 911612.906dddBBB DE (dBFS) ––8600 SNR = 96.7dB
MPLITU––112000 MPLITU––112000 MPLITU––112000 6.2kHz
A A A
–140 –140 –140
–160 –160 –160
–180 –180 –180
0 20 40 60 80 100 0 20 40 60 80 100 0 20 40 60 80 100
FREQUENCY (kHz) FREQUENCY (kHz) FREQUENCY (kHz)
234818 G10 234818 G11 234818 G12
3322kk PPooiinntt FFFFTT ffSSMMPPLL == 220000kkHHzz,, SNR, SINAD vs VREFBUF, TTHHDD,, HHaarrmmoonniiccss vvss VVRREEFFBBUUFF,,
ffIINN  ==  22kkHHzz fSINN R= ,2 SkIHNzAD vs VREFBUF, fIN = 2kHz ffIINN  ==  22kkHHzz
0 100.0 –100.0
–20 TRUE BIPOLAR DR±I5V.E1 2(VIN R– A=N 0GVE) TRUE BIPO L±A2R.5 D• RVIRVEEF B (UINF –R A=N 0GVE) TRUE BIPO L±A2R.5 D• RVIRVEEF B (UINF –R A=N 0GVE)
–105.0
AMPLITUDE (dBFS)––11–––2086400000 SITSSNHFNADDRDR = == =– 99113311..3422ddddBBBB SNR, SINAD (dBFS) 999468...000 SSINNARD D, HARMONICS (dBFS)–––111211050...000 2ND THD 3RD
H
–140 T
92.0
–125.0
–160
–180 90.0 –130.0
0 20 40 60 80 100 2.5 3 3.5 4 4.5 5 2.5 3 3.5 4 4.5 5
FREQUENCY (kHz) REFBUF VOLTAGE (V) REFBUF VOLTAGE (V)
234818 G13 234818 G14 234818 G15
SSNNRR,, SSIINNAADD TTHHDD,, HHaarrmmoonniiccss TTHHDD,, HHaarrmmoonniiccss vvss IInnppuutt
vvss IInnppuutt FFrreeqquueennccyy vvss IInnppuutt FFrreeqquueennccyy CCoommmmoonn MMooddee,, ffIINN == 22kkHHzz
102.0 –70.0 0
±10.24V RANGE ±10.24V RANGE ±10.24V RANGE
98.0 TRUE BIPOLAR DRIVE (IN– = 0V) –80.0 TRUE BIPOLAR DRIVE (IN– = 0V) –20 2VP-P FULLY DIFFERENTIAL DRIVE
dBFS) 94.0 SNR S (dBFS) –90.0 S (dBFS) ––6400 –14.5V ≤ VCM ≤ 10.5V
SNR, SINAD ( 8960..00 SINAD THD, HARMONIC––111000..00 THD 2ND THD, HARMONIC––11–208000
THD
82.0 –120.0
3RD –140 3RD
2ND
78.0 –130.0 –160
100 1k 10k 100k 100 1k 10k 100k –15 –10 –5 0 5 10 15
FREQUENCY (Hz) FREQUENCY (Hz) INPUT COMMON MODE (V)
234818 G16 234818 G17 234818 G18
234818fa
10
For more information www.linear.com/LTC2348-18