LTC2326-16
1
232616fa
For more information www.linear.com/LTC2326-16
+10.24V
–10.24V
–
+
SAMPLE CLOCK
232616 TA01a
10µF 0.1µF
5V
REF
1.8V TO 5V
47µF
REFBUF GND
CHAIN
RDL/SDI
SDO
SCK
BUSY
CNV
LTC2326-16
LT®1468
VDD
2.2µF
100nF
REFIN
VDDLBYP OVDD
IN+
IN–
Typical applicaTion
FeaTures DescripTion
16-Bit, 250ksps, ±10.24V
True Bipolar, Pseudo-Differential
Input ADC with 93.5dB SNR
The LTC
®
2326-16 is a low noise, high speed 16-bit suc-
cessive approximation register (SAR) ADC with pseudo-
differential inputs. Operating from a single 5V supply, the
LTC2326-16 has a ±10.24V true bipolar input range, making
it ideal for high voltage applications which require a wide
dynamic range. The LTC2326-16 achieves ±1.5LSB INL
maximum, no missing codes at 16 bits with 93.5dB SNR.
The LTC2326-16 has an onboard single-shot capable
reference buffer and low drift (20ppm/°C max) 2.048V
temperature compensated reference. The LTC2326-16
also has a high speed SPI-compatible serial interface that
supports 1.8V, 2.5V, 3.3V and 5V logic while also featuring
a daisy-chain mode. The fast 250ksps throughput with
no cycle latency makes the LTC2326-16 ideally suited
for a wide variety of high speed applications. An internal
oscillator sets the conversion time, easing external timing
considerations. The LTC2326-16 dissipates only 28mW
and automatically naps between conversions, leading to
reduced power dissipation that scales with the sampling
rate. A sleep mode is also provided to reduce the power
consumption of the LTC2326-16 to 300μW for further
power savings during inactive periods.
L, LT, LT C , LT M, Linear Technology and the Linear logo are registered trademarks and
SoftSpan is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners. Protected by U.S. Patents, including 7705765, 7961132.
applicaTions
n 250ksps Throughput Rate
n ±1.5LSB INL (Max)
n Guaranteed 16-Bit No Missing Codes
n Pseudo-Differential Inputs
n True Bipolar Input Ranges ±6.25V, ±10.24V, ±12.5V
n 93.5dB SNR (Typ) at fIN = 2kHz
n –111dB THD (Typ) at fIN = 2kHz
n Guaranteed Operation to 125°C
n Single 5V Supply
n Low Drift (20ppm/°C Max) 2.048V Internal Reference
n Onboard Single-Shot Capable Reference Buffer
n No Pipeline Delay, No Cycle Latency
n 1.8V to 5V I/O Voltages
n SPI-Compatible Serial I/O with Daisy-Chain Mode
n Internal Conversion Clock
n Power Dissipation 28mW (Typ)
n 16-Lead MSOP Package
n Programmable Logic Controllers
n Industrial Process Control
n High Speed Data Acquisition
n Portable or Compact Instrumentation
n ATE
32k Point FFT fS = 250ksps,
fIN = 2kHz
FREQUENCY (kHz)
–180
AMPLITUDE (dBFS)
–60
–40
–20
–80
–100
–120
–140
–160
0
232616 TA01b
SNR = 93.5dB
THD = –113dB
SINAD = 93.4dB
SFDR = –117dB
0 25 50 75 125100
LTC2326-16
2
232616fa
For more information www.linear.com/LTC2326-16
pin conFiguraTionabsoluTe MaxiMuM raTings
Supply Voltage (VDD) ..................................................6V
Supply Voltage (OVDD) ................................................6V
Supply Bypass Voltage (VDDLBYP) ...........................3.2V
Analog Input Voltage
IN+, IN– ..............................................–16.5V to 16.5V
REFBUF ...................................................................6V
REFIN ..................................................................2.8V
Digital Input Voltage
(Note 3) ........................... (GND –0.3V) to (OVDD + 0.3V)
Digital Output Voltage
(Note 3) ........................... (GND –0.3V) to (OVDD + 0.3V)
Power Dissipation .............................................. 500mW
Operating Temperature Range
LTC2326C ................................................ 0°C to 70°C
LTC2326I .............................................–40°C to 85°C
LTC2326H .......................................... –40°C to 125°C
Storage Temperature Range .................. –65°C to 150°C
(Notes 1, 2)
1
2
3
4
5
6
7
8
VDDLBYP
VDD
GND
IN+
IN–
GND
REFBUF
REFIN
16
15
14
13
12
11
10
9
GND
OVDD
SDO
SCK
RDL/SDI
BUSY
CHAIN
CNV
TOP VIEW
MS PACKAGE
16-LEAD PLASTIC MSOP
TJMAX = 150°C, θJA = 110°C/W
orDer inForMaTion
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC2326CMS-16#PBF LTC2326CMS-16#TRPBF 232616 16-Lead Plastic MSOP 0°C to 70°C
LTC2326IMS-16#PBF LTC2326IMS-16#TRPBF 232616 16-Lead Plastic MSOP –40°C to 85°C
LTC2326HMS-16#PBF LTC2326HMS-16#TRPBF 232616 16-Lead Plastic MSOP –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.
Consult LTC Marketing for information on nonstandard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/. Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
http://www.linear.com/product/LTC2326-16#orderinfo
LTC2326-16
3
232616fa
For more information www.linear.com/LTC2326-16
elecTrical characTerisTics
converTer characTerisTics
DynaMic accuracy
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. (Note 4)
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. (Note 4)
The l denotes the specifications which apply over the full operating temperature range,
otherwise specifications are at TA = 25°C and AIN = –1dBFS. (Notes 4, 8)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN+Absolute Input Range (IN+) (Note 5) l–2.5 • VREFBUF – 0.5 2.5 • VREFBUF + 0.5 V
VIN–Absolute Input Range (IN–) (Note 5) l–0.5 0.5 V
VIN+ – VIN–Input Differential Voltage Range VIN = VIN+ – VIN– l–2.5 • VREFBUF 2.5 • VREFBUF V
IIN Analog Input Current l–7.8 4.8 mA
CIN Analog Input Capacitance 5 pF
RIN Analog Input Resistance 2.083 kΩ
CMRR Input Common Mode Rejection Ratio fIN = 125kHz 66 dB
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Resolution l16 Bits
No Missing Codes l16 Bits
Transition Noise 0.5 LSBRMS
INL Integral Linearity Error (Note 6) l–1.5 ±0.25 1.5 LSB
DNL Differential Linearity Error l–1 ±0.1 1 LSB
BZE Bipolar Zero-Scale Error (Note 7) l–10 0 10 LSB
Bipolar Zero-Scale Error Drift 0.01 LSB/°C
FSE Bipolar Full-Scale Error VREFBUF = 4.096V (REFBUF Overdriven)
(Notes 7, 9)
l–35 –35 LSB
REFIN = 2.048V (Note 7) l–45 45 LSB
Bipolar Full-Scale Error Drift ±0.5 ppm/°C
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
SINAD Signal-to-(Noise + Distortion) Ratio ±6.25V Range, fIN = 2kHz, REFIN = 1.25V l87.1 90.4 dB
±10.24V Range, fIN = 2kHz, REFIN = 2.048V l90.2 93.4 dB
±12.5V Range, fIN = 2kHz, REFBUF = 5V l90.5 94.2 dB
SNR Signal-to-Noise Ratio ±6.25V Range, fIN = 2kHz, REFIN = 1.25V l87.5 90.5 dB
±10.24V Range, fIN = 2kHz, REFIN = 2.048V l91 93.5 dB
±12.5V Range, fIN = 2kHz, REFBUF = 5V l92 94.5 dB
THD Total Harmonic Distortion ±6.25V Range, fIN = 2kHz, REFIN = 1.25V l–108 –98 dB
±10.24V Range, fIN = 2kHz, REFIN = 2.048V l–111 –98 dB
±12.5V Range, fIN = 2kHz, REFBUF = 5V l–106 –96 dB
SFDR Spurious Free Dynamic Range ±6.25V Range, fIN = 2kHz, REFIN = 1.25V l98 110 dB
±10.24V Range, fIN = 2kHz, REFIN = 2.048V l98 113 dB
±12.5V Range, fIN = 2kHz, REFBUF = 5V l96 108 dB
–3dB Input Linear Bandwidth 7 MHz
Aperture Delay 500 ps
Aperture Jitter 4 psRMS
Transient Response Full-Scale Step 1 µs
LTC2326-16
4
232616fa
For more information www.linear.com/LTC2326-16
inTernal reFerence characTerisTics
reFerence buFFer characTerisTics
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)
The l denotes the specifications which apply over the full
operating temperature range, otherwise specifications are at TA = 25°C. (Note 4)
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
VREFIN Internal Reference Output Voltage 2.043 2.048 2.053 V
VREFIN Temperature Coefficient (Note 14) l2 20 ppm/°C
REFIN Output Impedance 15 kΩ
VREFIN Line Regulation VDD = 4.75V to 5.25V 0.08 mV/V
REFIN Input Voltage Range (REFIN Overdriven) (Note 5) 1.25 2.4 V
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VREFBUF Reference Buffer Output Voltage VREFIN = 2.048V l4.091 4.096 4.101 V
REFBUF Input Voltage Range (REFBUF Overdriven) (Notes 5, 9) l2.5 5 V
REFBUF Output Impedance VREFIN = 0V 13 kΩ
IREFBUF REFBUF Load Current VREFBUF = 5V (REFBUF Overdriven) (Notes 9, 10)
VREFBUF = 5V, Nap Mode (REFBUF Overdriven) (Note 9)
l0.56
0.39
0.6 mA
mA
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIH High Level Input Voltage l0.8 • OVDD V
VIL Low Level Input Voltage l0.2 • OVDD V
IIN Digital Input Current VIN = 0V to OVDD l–10 10 μA
CIN Digital Input Capacitance 5 pF
VOH High Level Output Voltage IO = –500µA lOVDD – 0.2 V
VOL Low Level Output Voltage IO = 500µA l0.2 V
IOZ Hi-Z Output Leakage Current VOUT = 0V to OVDD l–10 10 µA
ISOURCE Output Source Current VOUT = 0V –10 mA
ISINK Output Sink Current VOUT = OVDD 10 mA
LTC2326-16
5
232616fa
For more information www.linear.com/LTC2326-16
aDc TiMing characTerisTics
power requireMenTs
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. (Note 4)
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
VDD Supply Voltage l4.75 5 5.25 V
OVDD Supply Voltage l1.71 5.25 V
IVDD
IOVDD
INAP
ISLEEP
Supply Current
Supply Current
Nap Mode Current
Sleep Mode Current
250ksps Sample Rate (IN+ = –10.24V, IN– = 0V)
250ksps Sample Rate (IN+ = IN– = 0V)
250ksps Sample Rate (CL = 20pF)
Conversion Done (IVDD + IOVDD, IN+ = –10.24V, IN– = 0V)
Sleep Mode (IVDD + IOVDD)
l
l
l
9.9
5.6
0.1
8.4
60
11.5
10
225
mA
mA
mA
mA
μA
PDPower Dissipation
Nap Mode
Sleep Mode
250ksps Sample Rate (IN+ = –10.24V, IN– = 0V)
250ksps Sample Rate (IN+ = IN– = 0V)
Conversion Done (IVDD + IOVDD, IN+ = –10.24V, IN– = 0V)
Sleep Mode (IVDD + IOVDD)
l
l
l
50
28
42
0.3
57.5
50
1.1
mW
mW
mW
mW
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
fSMPL Maximum Sampling Frequency l250 ksps
tCONV Conversion Time l1.9 3 µs
tACQ Acquisition Time tACQ = tCYC – tHOLD (Note 11) l3.460 µs
tHOLD Maximum Time between Acquisitions l540 ns
tCYC Time Between Conversions l4 µs
tCNVH CNV High Time l20 ns
tBUSYLH CNV↑ to BUSY Delay CL = 20pF l13 ns
tCNVL Minimum Low Time for CNV (Note 12) l20 ns
tQUIET SCK Quiet Time from CNV↑(Note 11) l20 ns
tSCK SCK Period (Notes 12, 13) l10 ns
tSCKH SCK High Time l4 ns
tSCKL SCK Low Time l4 ns
tSSDISCK SDI Setup Time From SCK↑(Note 12) l4 ns
tHSDISCK SDI Hold Time From SCK↑(Note 12) l1 ns
tSCKCH SCK Period in Chain Mode tSCKCH = tSSDISCK + tDSDO (Note 12) l13.5 ns
tDSDO SDO Data Valid Delay from SCK↑ CL = 20pF, OVDD = 5.25V
CL = 20pF, OVDD = 2.5V
CL = 20pF, OVDD = 1.71V
l
l
l
7.5
8
9.5
ns
ns
ns
tHSDO SDO Data Remains Valid Delay from SCK↑CL = 20pF (Note 11) l1 ns
tDSDOBUSYL SDO Data Valid Delay from BUSY↓CL = 20pF (Note 11) l5 ns
tEN Bus Enable Time After RDL↓(Note 12) l16 ns
tDIS Bus Relinquish Time After RDL↑(Note 12) l13 ns
tWAKE REFBUF Wake-Up Time CREFBUF = 47μF, CREFIN = 100nF 200 ms
LTC2326-16
6
232616fa
For more information www.linear.com/LTC2326-16
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.
Note 3: When these pin voltages are taken below ground or above VDD or
OVDD, they will be clamped by internal diodes. This product can handle
input currents up to 100mA below ground or above VDD or OVDD without
latch-up.
Note 4: VDD = 5V, OVDD = 2.5V, ±10.24V Range, REFIN = 2.048V,
fSMPL = 250kHz.
Note 5: Recommended operating conditions.
Note 6: Integral nonlinearity is defined as the deviation of a code from a
straight line passing through the actual endpoints of the transfer curve.
The deviation is measured from the center of the quantization band.
Note 7: Bipolar zero error is the offset voltage measured from –0.5LSB
when the output code flickers between 0000 0000 0000 0000 and 1111
1111 1111 1111. Full-scale bipolar error is the worst-case of –FS or +FS
untrimmed deviation from ideal first and last code transitions and includes
the effect of offset error.
Note 8: All specifications in dB are referred to a full-scale ±10.24V input
with REFIN = 2.048V.
Note 9: When REFBUF is overdriven, the internal reference buffer must be
turned off by setting REFIN = 0V.
Note 10: fSMPL = 250kHz, IREFBUF varies proportionally with sample rate.
Note 11: Guaranteed by design, not subject to test.
Note 12: Parameter tested and guaranteed at OVDD = 1.71V, OVDD = 2.5V
and OVDD = 5.25V.
Note 13: tSCK of 10ns maximum allows a shift clock frequency up to
100MHz for rising edge capture.
Note 14: Temperature coefficient is calculated by dividing the maximum
change in output voltage by the specified temperature range.
Figure 1. Voltage Levels for Timing Specifications
0.8 • OVDD
0.2 • OVDD
50% 50%
232616 F01
0.2 • OVDD
0.8 • OVDD
0.2 • OVDD
0.8 • OVDD
tDELAY
tWIDTH
tDELAY
elecTrical characTerisTics
LTC2326-16
7
232616fa
For more information www.linear.com/LTC2326-16
Typical perForMance characTerisTics
32k Point FFT fS = 250ksps,
fIN = 2kHz SNR, SINAD vs Input Frequency
THD, Harmonics vs Input
Frequency
SNR, SINAD vs Input Level,
fIN = 2kHz
SNR, SINAD vs Temperature,
fIN = 2kHz
THD, Harmonics vs Temperature,
fIN = 2kHz
Integral Nonlinearity
vs Output Code
Differential Nonlinearity
vs Output Code DC Histogram
TA = 25°C, VDD = 5V, OVDD = 2.5V, REFIN = 2.048V,
fSMPL = 250ksps, unless otherwise noted.
OUTPUT CODE
–1.0
INL ERROR (LSB)
0.8
0.6
0.4
0
–0.8
–0.6
–0.4
–0.2
0.2
1.0
232616 G01
–32768 –16384 0 16384 32768
OUTPUT CODE
–0.5
DNL ERROR (LSB)
0.4
0.3
0.2
0.1
0
–0.4
–0.3
–0.2
–0.1
0.5
232616 G02
–32768 –16384 0 16384 32768
CODE
–1 012
0
COUNTS
7000
3000
4000
5000
2000
1000
9000
8000
6000
233616 G03
σ = 0.5
INPUT LEVEL (dB)
–40
92
MAGNITUDE (dBFS)
94
93
95
96
–30 –20
232616 G07
–10
SNR
SINAD
0
FREQUENCY (kHz)
–180
AMPLITUDE (dBFS)
–60
–40
–20
–80
–100
–120
–140
–160
0
232616 G04
SNR = 93.5dB
THD = –113dB
SINAD = 93.4dB
SFDR = –117dB
0 25 50 75 125100
FREQUENCY (kHz)
0
60
SNR, SINAD (dBFS)
70
80
90
100
25 50
232616 G05
75 100 125
SINAD
SNR
FREQUENCY (kHz)
THD, HARMONICS (dBFS)
–70
–80
232616 G06
–150
–120
–140
–130
–110
–100
–90
0 25 50 10075 125
3RD
2ND
THD
TEMPERATURE (°C)
–40
90
SNR, SINAD (dBFS)
91
93
94
95
–10 20 35 50 125
232616 G08
92
–25 565 80 95 110
96
SINAD
SNR
TEMPERATURE (°C)
THD, HARMONICS (dBFS)
–105
–110
232616 G09
–125
–120
–115
3RD
2ND
THD
–40 –10 20 35 50 125
–25 565 80 95 110
LTC2326-16
8
232616fa
For more information www.linear.com/LTC2326-16
Typical perForMance characTerisTics
Supply Current vs Temperature Sleep Current vs Temperature
Internal Reference Output vs
Temperature
Internal Reference Output
Temperature Coefficient
Distribution CMRR vs Input Frequency Supply Current vs Sampling Rate
INL/DNL vs Temperature Full-Scale Error vs Temperature Offset Error vs Temperature
TA = 25°C, VDD = 5V, OVDD = 2.5V, REFIN = 2.048V,
fSMPL = 250ksps, unless otherwise noted.
DRIFT (ppm/°C)
–10
0
NUMBER OF PARTS
5
15
20
25
35
–8 04
232616 G16
10
30
–2 810
–6 –4 2 6
FREQUENCY (kHz)
0
50
CMRR (dB)
55
60
65
70
75
80
25 50 75 100 125
232616 G17
SAMPLING FREQUENCY (kHz)
0
0
SUPPLY CURRENT (mA)
2
4
6
8
10
12
50 100 150 200
232616 G18
250
OVDD
VDD (IN+ = –10.24V)
VDD (IN+ = 10.24V)
VDD (IN+ = 0V)
TEMPERATURE (°C)
INL, DNL ERROR (LSB)
1.0
0.8
0.6
0.4
232616 G10
–1.0
–0.8
–0.6
–0.4
0
0.2
–0.2
MAX INL
MAX DNL
MIN INL
MIN DNL
–40 –10 20 35 50 125
–25 565 80 95 110
232616 G11
TEMPERATURE (°C)
FULL-SCALE ERROR (LSB)
20
15
10
5
–20
–15
–10
–5
0
–40 –10 20 35 50 125
–25 565 80 95 110
232616 G12
TEMPERATURE (°C)
OFFSET ERROR (LSB)
5
4
3
2
1
–5
–4
–3
–2
–1
0
–40 –10 20 35 50 125
–25 565 80 95 110
TEMPERATURE (°C)
CURRENT (µA)
120
232616 G14
0
20
40
60
80
100
–40 –10 20 35 50 125
–25 565 80 95 110
232616 G15
TEMPERATURE (°C)
INTERNAL REFERENCE OUTPUT (V)
2.0484
2.0483
2.0482
2.0481
2.0476
2.0477
2.0478
2.0479
2.0480
–40 –10 20 35 50 125
–25 565 80 95 110
TEMPERATURE (°C)
CURRENT (mA)
6
232616 G13
0
1
2
3
4
5VDD
(IN+ = IN– = 0V)
OVDD
–40 –10 20 35 50 125
–25 565 80 95 110
