DATASHEET
ISL267450
12-Bit, 1MSPS SAR ADCs
The ISL267450 is a 12-bit, 1MSPS sampling SAR-type ADC
with a differential input span of 2*V
REF
volts. The ISL267450
features excellent linearity over supply and temperature
variations and is drop-in compatible with the AD7450. The
device can operate from a supply voltage of either 5V or 3V
and maintain measurement accuracy with input signals up to
the supply rails.
The serial digital interface is SPI compatible and is easily
interfaced to popular FPGAs and microcontrollers. Power
dissipation is 9.0mW at a sampling rate of 1MSPS, and just
5µW between conversions utilizing Auto Power-Down mode
(with a 3V supply).
The ISL267450 is available in 8 Ld SOIC or MSOP packages,
and are specified for operation over the Industrial temperature
range (–40°C to +85°C).
FN8341
Rev 0.00
August 10, 2012
Features
• Drop-in Compatible with AD7450
• Differential Input
• Simple SPI-compatible Serial Digital Interface
• Guaranteed No Missing Codes
• 1MHz Sampling Rate
• 3V or 5V Operation
• Low Operating Current
- 1.25mA at 833kSPS with 3V Supplies
- 1.7mA at 1MSPS with 5V Supplies
• Power-down Current between Conversions: 1µA
• Excellent Differential Non-Linearity
• Low THD: -83dB (typ)
• Pb-Free (RoHS Compliant)
• Available in SOIC and MSOP Packages
Applications
• Remote Data Acquisition
• Battery Operated Systems
• Industrial Process Control
• Energy Measurement
• Data Acquisition Systems
• Pressure Sensors
• Flow Controllers
Block Diagram
+V
DD
V
REF
V
IN+
V
IN-
ADC
SERIAL
INTERFACE
SCLK
SDATA
CS
GND
FN8341 Rev 0.00
August 10, 2012
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ISL267450
Typical Connection Diagram
V
REF
0.1µF
0.1µF
+
10µF
+3V/5V
SUPPLY
V
REF
V
REF(P-P)
V
REF(P-P)
V
IN+
V
IN–
GND
V
DD
SCLK
SDATA
CS
µP/µC
SERIAL
INTERFACE
Pin Configuration
ISL267450
(8 LD SOIC, MSOP)
TOP VIEW
V
REF
V
IN+
V
IN-
1
2
3
8
7
6
5
V
DD
SCLK
SDATA
CS
GND 4
Pin Description
ISL267450
PIN NAME
V
DD
SCLK
SDATA
CS
GND
V
IN–
V
IN+
V
REF
PIN NUMBER
8
7
6
5
4
3
2
1
Supply voltage, +2.7V to 5.25V.
Serial clock input. Controls digital I/O timing and clocks the conversion.
Digital conversion output.
Chip select input. Controls the start of a conversion when going low.
Ground
Negative analog input.
Positive analog input.
Reference voltage.
DESCRIPTION
FN8341 Rev 0.00
August 10, 2012
Page 2 of 19
ISL267450
Ordering Information
PART NUMBER
(Notes 1, 2, 3)
ISL267450IBZ
ISL267450IUZ
NOTES:
1. Add “-T*” suffix for tape and reel. Please refer to
TB347
for details on reel specifications.
2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte
tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil
Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
3. For Moisture Sensitivity Level (MSL), please see device information page for
ISL267450.
For more information on MSL please see techbrief
TB363.
PART MARKING
267450 IBZ
67450
VDD RANGE
(V)
2.7 to 5.25
2.7 to 5.25
TEMP RANGE
(°C)
-40 to +85
-40 to +85
PACKAGE
(PB-free)
8 Ld SOIC
8 Ld MSOP
PKG.
DWG. #
M8.15
M8.118
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ISL267450
Table of Contents
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Thermal Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Typical Performance Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
ADC Transfer Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Analog Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Voltage Reference Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Converter Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Acquisition Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Short Cycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power vs Throughput Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14
14
14
14
14
Serial Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Application Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Grounding and Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Signal-to-(Noise + Distortion) Ratio (SINAD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Total Harmonic Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Peak Harmonic or Spurious Noise (SFDR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Intermodulation Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Aperture Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Aperture Jitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Full Power Bandwidth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Common-Mode Rejection Ratio (CMRR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Integral Nonlinearity (INL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Differential Nonlinearity (DNL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Zero-Code Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Positive Gain Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Negative Gain Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Track and Hold Acquisition Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Power Supply Rejection Ratio (PSRR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Package Outline Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Package Outline Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
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August 10, 2012
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ISL267450
Absolute Maximum Ratings
Any Pin to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6.0V
Analog Input to GND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to V
DD
+0.3V
Digital I/O to GND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to V
DD
+0.3V
Digital Input Voltage to GND . . . . . . . . . . . . . . . . . . . . . . . -0.3V to V
DD
+0.3V
Maximum Current In to Any Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10mA
ESD Rating
Human Body Model (Tested per JESD22-A114F) . . . . . . . . . . . . . . . . 8kV
Machine Model (Tested per JESD22-A115B) . . . . . . . . . . . . . . . . . 400V
Charged Device Model (Tested per JESD22-C101E). . . . . . . . . . . . 1.5kV
Latch Up (Tested per JESD78C; Class 2, Level A) . . . . . . . . . . . . . . . 100mA
Thermal Information
Thermal Resistance (Typical)
JA
(°C/W)
JC
(°C/W)
8 Ld SOIC Package (Notes 4, 5). . . . . . . . . .
120
64
8 Ld MSOP Package (Notes 4, 5). . . . . . . . .
165
64
Operating Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C
Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .+150°C
Pb-Free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see link below
http://www.intersil.com/pbfree/Pb-FreeReflow.asp
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product
reliability and result in failures not covered by warranty.
NOTES:
4.
JA
is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief
TB379
for details.
5. For
JC
, the “case temp” location is taken at the package top center.
Electrical Specifications
V
DD
= +3.0V to +3.3V, F
SCLK
= 15MHz, F
S
= 833kSPS, V
REF
= 1.25V, F
IN
= 200kHz; V
DD
= +4.75V to
+5.25V, F
SCLK
= 18MHz, F
S
= 1MSPS, V
REF
= 2.5V, F
IN
= 300kHz; V
CM
= V
REF
, T
A
= T
MIN
to T
MAX
unless otherwise noted. Typical values are at
T
A
= +25°C. Boldface limits apply over the operating temperature range, -40°C to +85°C.
SYMBOL
PARAMETER
TEST CONDITIONS
MIN
(Note 6)
TYP
MAX
(Note 6)
UNITS
DYNAMIC PERFORMANCE
SINAD
Signal-to (Noise + Distortion) Ratio
V
DD
= 5V
V
DD
= 3V
THD
Total Harmonic
Distortion
Spurious Free Dynamic Range
V
DD
= 5V
V
DD
= 3V
V
DD
= 5V
V
DD
= 3V
IMD
Intermodulation Distortion
2nd Order Terms
3rd Order Terms
tpd
tpd
3dB
Aperture Delay
Aperture Jitter
Full Power Bandwidth
@ –3dB
@ –0.1dB
PSRR
Power Supply Rejection Ratio
70
67
-80
-78
-82
-80
–89
-85
10
50
20
2.5
-87
-75
-73
-75
-73
dB
dB
dB
dB
dB
dB
dB
dB
ns
ps
MHz
MHz
dB
SFDR
DC ACCURACY
N
INL
DNL
OFFSET
Resolution
Integral Nonlinearity
Differential Nonlinearity
Zero-Code Error
Guaranteed no missed codes to 12 bits
V
DD
= 5V
V
DD
= 3V
GAIN
Positive Gain Error
V
DD
= 5V
V
DD
= 3V
Negative Gain Error
V
DD
= 5V
V
DD
= 3V
12
-1
-0.95
-3
-6
-3
-6
-3
-6
1
0.95
3
6
3
6
3
6
Bits
LSB
LSB
LSB
LSB
LSB
LSB
LSB
LSB
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August 10, 2012
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