LTC2312-14
14-Bit, 500ksps Serial
Sampling ADC in TSOT
FEATURES
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DESCRIPTION
The
LTC
®
2312-14
is a 14-bit, 500ksps, serial sampling
A/D converter that draws only 3.2mA from a single 3V
or 5V supply. The LTC2312-14 contains an integrated
low drift reference and reference buffer providing a low
cost, high performance (20ppm/°C maximum) and space
saving solution. The LTC2312-14 achieves outstanding
AC performance of 77dB SINAD and –85dB THD while
sampling at 500ksps. The extremely high sample rate-to-
power ratio makes the LTC2312-14 ideal for compact, low
power, high speed systems. The supply current decreases
at lower sampling rates as the device automatically enters
nap mode after conversions.
The LTC2312-14 has a high speed SPI-compatible serial
interface that supports 1.8V, 2.5V, 3V and 5V logic. The
fast 500ksps throughput with no-cycle latency makes
the LTC2312-14 ideally suited for a wide variety of high
speed applications.
Complete 14-/12-Bit Pin-Compatible SAR ADC Family
500ksps
14-Bit
12-Bit
2.5Msps
4.5Msps
5Msps
LTC2315-12
LTC2312-14 LTC2313-14 LTC2314-14
LTC2312-12 LTC2313-12
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500ksps Throughput Rate
No Cycle Latency
Guaranteed 14-Bit No Missing Codes
Single 3V or 5V Supply
Low Noise: 77.5dB SNR
Low Power: 9mW at 500ksps and 3V Supply
Low Drift (20ppm/°C Maximum) 2.048V or 4.096V
Internal Reference
Sleep Mode with < 1µA Typical Supply Current
Nap Mode with Quick Wake-Up < 1 Conversion
Separate 1.8V to 5V Digital I/O Supply
High Speed SPI-Compatible Serial I/O
Guaranteed Operation from –40°C to 125°C
8-Lead TSOT-23 Package
APPLICATIONS
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Communication Systems
High Speed Data Acquisition
Handheld Terminal Interface
Medical Imaging
Uninterrupted Power Supplies
Battery Operated Systems
Automotive
Power 3V/5V 9mW/15mW 14mW/25mW 18mW/31mW 19mW/32mW
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
5V Supply, Internal Reference, 500ksps, 14-Bit Sampling ADC
5V
2.2µF
2.2µF
REF
GND
ANALOG INPUT
0V TO 4.096V
A
IN
SCK
SDO
OV
DD
2.2µF
LTC2312-14
AMPLITUDE (dBFS)
V
DD
CONV
SERIAL DATA LINK TO
ASIC, PLD, MPU, DSP
OR SHIFT REGISTERS
16k Point FFT, f
S
= 500ksps, f
IN
= 259kHz
0
–20
–40
–60
–80
–100
–120
–140
–160
0
50
100
200
150
INPUT FREQUENCY (kHz)
250
231214
TA01b
V
DD
= 5V
SNR = 77.5dBFS
SINAD = 77dBFS
THD = –85dB
SFDR = 88dB
DIGITAL OUTPUT SUPPLY
1.8V TO 5V
231214 TA01
231214fa
For more information
www.linear.com/LTC2312-14
1
LTC2312-14
ABSOLUTE MAXIMUM RATINGS
(Notes 1, 2)
PIN CONFIGURATION
TOP VIEW
V
DD
REF
GND
A
IN
1
2
3
4
8
7
6
5
CONV
SCK
SDO
OV
DD
Supply Voltage (V
DD
, OV
DD
) .......................................6V
Reference (REF) and Analog Input (A
IN
) Voltage
(Note 3) ......................................(–0.3V) to (V
DD
+ 0.3V)
Digital Input Voltage (Note 3) ... (–0.3V) to (OV
DD
+ 0.3V)
Digital Output Voltage ............. (–0.3V) to (OV
DD
+ 0.3V)
Power Dissipation ...............................................100mW
Operating Temperature Range
LTC2312C ................................................ 0°C to 70°C
LTC2312I..............................................–40°C to 85°C
LTC2312H .......................................... –40°C to 125°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature Range (Soldering, 10 sec)........ 300°C
TS8 PACKAGE
8-LEAD PLASTIC TSOT-23
T
JMAX
= 150°C,
θ
JA
= 195°C/W
ORDER INFORMATION
Lead Free Finish
TAPE AND REEL (MINI)
LTC2312CTS8-14#TRMPBF
LTC2312ITS8-14#TRMPBF
TAPE AND REEL
LTC2312CTS8-14#TRPBF
LTC2312ITS8-14#TRPBF
PART MARKING*
LTFZK
LTFZK
PACKAGE DESCRIPTION
8-Lead Plastic TSOT-23
8-Lead Plastic TSOT-23
TEMPERATURE RANGE
0°C to 70°C
–40˚C to 85˚C
–40˚C to 125˚C
LTC2312HTS8-14#TRMPBF
LTC2312HTS8-14#TRPBF
LTFZK
8-Lead Plastic TSOT-23
TRM = 500 pieces. *Temperature grades are identified by a label on the shipping container.
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on 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/
2
231214fa
For more information
www.linear.com/LTC2312-14
LTC2312-14
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 4)
SYMBOL PARAMETER
V
AIN
V
IN
I
IN
C
IN
Absolute Input Range
Input Voltage Range
Analog Input DC Leakage Current
Analog Input Capacitance
Sample Mode
Hold Mode
(Note 11)
CONDITIONS
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ELECTRICAL CHARACTERISTICS
MIN
–0.05
0
–1
TYP
MAX
V
DD
+ 0.05
V
REF
1
UNITS
V
V
µA
pF
pF
13
3
CONVERTER CHARACTERISTICS
SYMBOL PARAMETER
Resolution
No Missing Codes
Transition Noise
INL
DNL
Integral Linearity Error
Differential Linearity Error
Offset Error
Full-Scale Error
Total Unadjusted Error
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 4)
CONDITIONS
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MIN
14
14
TYP
MAX
UNITS
Bits
Bits
(Note 6)
V
DD
= 5V (Note 5)
V
DD
= 3V (Note 5)
V
DD
= 5V
V
DD
= 3V
V
DD
= 5V
V
DD
= 3V
V
DD
= 5V
V
DD
= 3V
V
DD
= 5V
V
DD
= 3V
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0.7
–3.75
–4
–0.99
–0.99
–9
–18
–18
–34
–22
–38
±1
±1.5
±0.3
±0.4
±2
±4
±5
±7
±6
±8
3.75
4
0.99
0.99
9
18
18
34
22
38
LSB
RMS
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
DYNAMIC ACCURACY
SYMBOL PARAMETER
SINAD
SNR
THD
SFDR
IMD
The
l
denotes the specifications which apply over the full operating temperature range,
otherwise specifications are at T
A
= 25°C and A
IN
= –1dBFS. (Note 4)
CONDITIONS
f
IN
= 20kHz, V
DD
= 5V
f
IN
= 20kHz, V
DD
= 3V
f
IN
= 20kHz, V
DD
= 5V
f
IN
= 20kHz, V
DD
= 3V
f
IN
= 20kHz, V
DD
= 5V
f
IN
= 20kHz, V
DD
= 3V
f
IN
= 20kHz, V
DD
= 5V
f
IN
= 20kHz, V
DD
= 3V
f
IN1
= 53kHz, f
IN2
= 58kHz,
A
IN1
, A
IN2
= –7dBFS
At 3dB
At 0.1dB
SINAD ≥ 74dB
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MIN
72.5
69
73.5
69.5
TYP
77
72.6
77.5
73
–85
–85
MAX
UNITS
dB
dB
dB
dB
Signal-to-(Noise + Distortion) Ratio
Signal-to-Noise Ratio
Total Harmonic Distortion
First 5 Harmonics
Spurious Free Dynamic Range
Intermodulation Distortion
2nd Order Terms
3rd Order Terms
Full Power Bandwidth
–3dB Input Linear Bandwidth
–76
–76
dB
dB
dB
dB
dBc
dBc
MHz
MHz
MHz
ns
ps
RMS
78
76
88
88
–80
–92
130
20
5
1
10
t
AP
t
JITTER
Aperture Delay
Aperture Jitter
231214fa
For more information
www.linear.com/LTC2312-14
3
LTC2312-14
REFERENCE INPUT/OUTPUT
SYMBOL PARAMETER
V
REF
V
REF
Output Voltage
V
REF
Temperature Coefficient
V
REF
Output Resistance
V
REF
Line Regulation
V
REF
2.048V/4.096V Supply Threshold
V
REF
2.048V/4.096V Supply Threshold Hysteresis
V
REF
Input Voltage Range
(External Reference Input)
2.7V ≤ V
DD
≤ 3.6V
4.75 ≤ V
DD
≤ 5.25V
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The
l
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 4)
CONDITIONS
2.7V ≤ V
DD
≤ 3.6V
4.75 ≤ V
DD
≤ 5.25V
Normal Operation, I
LOAD
= 0mA to 5mA
Overdrive Condition
(V
REFIN
≥ V
REFOUT
+ 50mV)
2.7V ≤ V
DD
≤ 3.6V
4.75 ≤ V
DD
≤ 5.25V
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MIN
2.040
4.080
TYP
2.048
4.096
7
1
52
0.4
0.2
4.15
150
MAX
2.056
4.112
20
UNITS
V
V
ppm/°C
Ω
kΩ
mV/V
mV/V
V
mV
V
REF
+ 50mV
V
REF
+ 50mV
V
DD
4.3
V
V
The
l
denotes the specifications which apply over the
full operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 4)
SYMBOL PARAMETER
V
IH
V
IL
I
IN
C
IN
V
OH
V
OL
I
OZ
C
OZ
I
SOURCE
I
SINK
High Level Input Voltage
Low Level Input Voltage
Digital Input Current
Digital Input Capacitance
High Level Output Voltage
Low Level Output Voltage
Hi-Z Output Leakage Current
Hi-Z Output Capacitance
Output Source Current
Output Sink Current
I
O
= –500µA (Source)
I
O
= 500µA (Sink)
V
OUT
= 0V to OV
DD
, CONV = High
CONV = High
V
OUT
= 0V, OV
DD
= 1.8V
V
OUT
= OV
DD
= 1.8V
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DIGITAL INPUTS AND DIGITAL OUTPUTS
CONDITIONS
MIN
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TYP
MAX
0.2 • OV
DD
UNITS
V
V
μA
pF
V
0.8 • OV
DD
–10
5
OV
DD
–0.2
0.2
–10
4
–20
20
10
10
V
IN
= 0V to OV
DD
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V
µA
pF
mA
mA
The
l
denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 4)
SYMBOL
V
DD
OV
DD
I
TOTAL
=
I
VDD +
I
OVDD
P
D
PARAMETER
Supply Voltage
3V Operational Range
5V Operational Range
Digital Output Supply Voltage
Supply Current, Static Mode
Operational Mode
Nap Mode
Sleep Mode
Power Dissipation, Static Mode
Operational Mode
Nap Mode
Sleep Mode
CONV = 0V, SCK = 0V
CONDITIONS
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POWER REQUIREMENTS
MIN
2.7
4.75
1.71
TYP
3
5
3.4
3.2
2
0.2
17
16
10
1
MAX
3.6
5.25
5.25
4.3
4
5
21.5
20
25
UNITS
V
V
V
mA
mA
mA
µA
mW
mW
mW
µW
CONV = 0V, SCK = 0V
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231214fa
For more information
www.linear.com/LTC2312-14
LTC2312-14
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 4)
SYMBOL
f
SCK
t
SCK
t
CONV
t
ACQ
t
1
t
2
t
3
t
4
t
5
t
6
t
7
t
8
t
9
t
WAKE
_
NAP
t
WAKE
_
SLEEP
PARAMETER
Shift Clock Frequency
Shift Clock Period
Conversion Time
Acquisition Time
Minimum CONV Pulse Width
SCK↑ Setup Time After CONV↓
SDO Enable Time After CONV↓
SDO Data Valid Access Time after SCK↓
SCK Low Time
SCK High Time
SDO Data Valid Hold Time After SCK↓
SDO into Hi-Z State Time After CONV↑
CONV↑ Quiet Time After 14th SCK↓
Power-Up Time from Nap Mode
Power-Up Time from Sleep Mode
(Notes 7, 8, 9)
(Notes 7, 8, 10)
(Note 7)
See Nap Mode Section
See Sleep Mode Section
(Note 7), Valid for Nap and Sleep Modes Only
(Note 7)
(Notes 7, 8)
(Notes 7, 8, 9)
CONDITIONS
(Notes 7, 8)
(Notes 7, 8)
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ADC TIMING CHARACTERISTICS
f
SAMPLE(MAX)
Maximum Sampling Frequency
MIN
TYP
MAX
500
20
UNITS
kHz
MHz
ns
ns
ns
ns
ns
ns
50
2000
1300
700
10
10
10
11
10
10
1
3
15
50
1.1
10
t
THROUGHPUT
Minimum Throughput Time, t
ACQ
+ t
CONV
ns
ns
ns
ns
ns
ns
ns
ns
ms
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 V
DD
(A
IN
, REF) or OV
DD
(SCK, CONV, SDO) they will be clamped by internal
diodes. This product can handle input currents up to 100mA below ground
or above V
DD
or OV
DD
without latch-up.
Note 4.
V
DD
= 5V, OV
DD
= 2.5V, f
SMPL
= 500kHz, f
SCK
= 20MHz, A
IN
=
–1dBFS and internal reference unless otherwise noted.
Note 5.
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 6.
Typical RMS noise at code transitions.
Note 7.
Parameter tested and guaranteed at OV
DD
= 2.5V. All input signals
are specified with t
r
= t
f
= 1ns (10% to 90% of OV
DD
) and timed from a
voltage level of OV
DD
/2.
Note 8.
All timing specifications given are with a 10pF capacitance load.
Load capacitances greater than this will require a digital buffer.
Note 9.
The time required for the output to cross the V
OH
or V
OL
voltage.
Note 10.
Guaranteed by design, not subject to test.
Note 11.
Recommended operating conditions.
231214fa
For more information
www.linear.com/LTC2312-14
5
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