ADC128S102
8-Channel, 500 kSPS to 1 MSPS, 12-Bit A/D Converter
General Description
The ADC128S102 is a low-power, eight-channel CMOS 12-
bit analog-to-digital converter specified for conversion
throughput rates of 500 kSPS to 1 MSPS. The converter is
based on a successive-approximation register architecture
with an internal track-and-hold circuit. It can be configured to
accept up to eight input signals at inputs IN0 through IN7.
The output serial data is straight binary and is compatible
with several standards, such as SPI
TM
, QSPI
TM
, MICROW-
IRE
TM
, and many common DSP serial interfaces.
The ADC128S102 may be operated with independent ana-
log and digital supplies. The analog supply (V
A
) can range
from +2.7V to +5.25V, and the digital supply (V
D
) can range
from +2.7V to V
A
. Normal power consumption using a +3V or
+5V supply is 2.3 mW and 10.7 mW, respectively. The
power-down feature reduces the power consumption to 0.06
W using a +3V supply and 0.25 W using a +5V supply.
The ADC128S102 is packaged in a 16-lead TSSOP pack-
age. Operation over the extended industrial temperature
range of -40C to +105C is guaranteed.
Features
n
Eight input channels
n
Variable power management
n
Independent analog and digital supplies
n
SPI/QSPI/MICROWIRE/DSP compatible
n
Packaged in 16-lead TSSOP
Key Specifications
n
Conversion Rate
500 kSPS to 1 MSPS
n
DNL (V
A
= V
D
= 5.0 V)
+1.5 / -0.9 LSB (max)
n
INL (V
A
= V
D
= 5.0 V)
1.2 LSB (max)
n
Power Consumption
-- 3V Supply
2.3 mW (typ)
-- 5V Supply
10.7 mW (typ)
Applications
n
Automotive Navigation
n
Portable Systems
n
Medical Instruments
n
Mobile Communications
n
Instrumentation and Control Systems
Connection Diagram
20136105
Ordering Information
Order Code
Temperature Range
Description
ADC128S102CIMT
-40C to +105C
16-Lead TSSOP Package
ADC128S102CIMTX
-40C to +105C
16-Lead TSSOP Package, Tape & Reel
ADC128S102EVAL
Evaluation Board
TRI-STATE
is a trademark of National Semiconductor Corporation.
MICROWIRE
TM
is a trademark of National Semiconductor Corporation.
QSPI
TM
and SPI
TM
are trademarks of Motorola, Inc.
August 2005
ADC128S102
8-Channel,
500
kSPS
to
1
MSPS,
12-Bit
A/D
Converter
2005 National Semiconductor Corporation
DS201361
www.national.com
Block Diagram
20136107
Pin Descriptions and Equivalent Circuits
Pin No.
Symbol
Equivalent Circuit
Description
ANALOG I/O
4 - 11
IN0 to IN7
Analog inputs. These signals can range from 0V to V
REF
.
DIGITAL I/O
16
SCLK
Digital clock input. The guaranteed performance range of
frequencies for this input is 8 MHz to 16 MHz. This clock
directly controls the conversion and readout processes.
15
DOUT
Digital data output. The output samples are clocked out of this
pin on the falling edges of the SCLK pin.
14
DIN
Digital data input. The ADC128S102's Control Register is
loaded through this pin on rising edges of the SCLK pin.
1
CS
Chip select. On the falling edge of CS, a conversion process
begins. Conversions continue as long as CS is held low.
POWER SUPPLY
2
V
A
Positive analog supply pin. This voltage is also used as the
reference voltage. This pin should be connected to a quiet
+2.7V to +5.25V source and bypassed to GND with 1 F and
0.1 F monolithic ceramic capacitors located within 1 cm of
the power pin.
13
V
D
Positive digital supply pin. This pin should be connected to a
+2.7V to V
A
supply, and bypassed to GND with a 0.1 F
monolithic ceramic capacitor located within 1 cm of the power
pin.
3
AGND
The ground return for the analog supply and signals.
12
DGND
The ground return for the digital supply and signals.
ADC128S102
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2
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Analog Supply Voltage V
A
-0.3V to 6.5V
Digital Supply Voltage V
D
-0.3V to V
A
+ 0.3V,
max 6.5V
Voltage on Any Pin to GND
-0.3V to V
A
+0.3V
Input Current at Any Pin (Note 3)
10 mA
Package Input Current(Note 3)
20 mA
Power Dissipation at T
A
= 25C
See (Note 4)
ESD Susceptibility (Note 5)
Human Body Model
Machine Model
2500V
250V
Soldering Temperature, Infrared,
10 seconds (Note 6)
260C
Junction Temperature
+150C
Storage Temperature
-65C to +150C
Operating Ratings
(Notes 1, 2)
Operating Temperature
-40C
T
A
+105C
V
A
Supply Voltage
+2.7V to +5.25V
V
D
Supply Voltage
+2.7V to V
A
Digital Input Voltage
0V to V
A
Analog Input Voltage
0V to V
A
Clock Frequency
8 MHz to 16 MHz
Package Thermal Resistance
Package
JA
16-lead TSSOP on
4-layer, 2 oz. PCB
96C / W
Soldering process must comply with National Semiconduc-
tor's Reflow Temperature Profile specifications. Refer to
www.national.com/packaging. (Note 6)
ADC128S102 Converter Electrical Characteristics
(Note 8)
The following specifications apply for AGND = DGND = 0V, f
SCLK
= 8 MHz to 16 MHz, f
SAMPLE
= 500 kSPS to 1 MSPS, C
L
=
50pF, unless otherwise noted. Boldface limits apply for T
A
= T
MIN
to T
MAX
: all other limits T
A
= 25C.
Symbol
Parameter
Conditions
Typical
Limits
(Note 7)
Units
STATIC CONVERTER CHARACTERISTICS
Resolution with No Missing Codes
12
Bits
INL
Integral Non-Linearity (End Point
Method)
V
A
= V
D
= +3.0V
0.4
1
LSB (max)
V
A
= V
D
= +5.0V
0.5
1.2
LSB (max)
DNL
Differential Non-Linearity
V
A
= V
D
= +3.0V
+0.4
+0.9
LSB (max)
-0.2
-0.7
LSB (min)
V
A
= V
D
= +5.0V
+0.7
+1.5
LSB (max)
-0.4
-0.9
LSB (min)
V
OFF
Offset Error
V
A
= V
D
= +3.0V
+0.8
2.3
LSB (max)
V
A
= V
D
= +5.0V
+1.1
2.3
LSB (max)
OEM
Offset Error Match
V
A
= V
D
= +3.0V
0.1
1.5
LSB (max)
V
A
= V
D
= +5.0V
0.3
1.5
LSB (max)
FSE
Full Scale Error
V
A
= V
D
= +3.0V
+0.8
2.0
LSB (max)
V
A
= V
D
= +5.0V
+0.3
2.0
LSB (max)
FSEM
Full Scale Error Match
V
A
= V
D
= +3.0V
0.1
1.5
LSB (max)
V
A
= V
D
= +5.0V
0.3
1.5
LSB (max)
DYNAMIC CONVERTER CHARACTERISTICS
FPBW
Full Power Bandwidth (-3dB)
V
A
= V
D
= +3.0V
8
MHz
V
A
= V
D
= +5.0V
11
MHz
SINAD
Signal-to-Noise Plus Distortion Ratio
V
A
= V
D
= +3.0V,
f
IN
= 40.2 kHz, -0.02 dBFS
73
70
dB (min)
V
A
= V
D
= +5.0V,
f
IN
= 40.2 kHz, -0.02 dBFS
73
70
dB (min)
SNR
Signal-to-Noise Ratio
V
A
= V
D
= +3.0V,
f
IN
= 40.2 kHz, -0.02 dBFS
73
70.8
dB (min)
V
A
= V
D
= +5.0V,
f
IN
= 40.2 kHz, -0.02 dBFS
73
70.8
dB (min)
ADC128S102
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ADC128S102 Converter Electrical Characteristics
(Note 8) (Continued)
The following specifications apply for AGND = DGND = 0V, f
SCLK
= 8 MHz to 16 MHz, f
SAMPLE
= 500 kSPS to 1 MSPS, C
L
=
50pF, unless otherwise noted. Boldface limits apply for T
A
= T
MIN
to T
MAX
: all other limits T
A
= 25C.
Symbol
Parameter
Conditions
Typical
Limits
(Note 7)
Units
DYNAMIC CONVERTER CHARACTERISTICS
THD
Total Harmonic Distortion
V
A
= V
D
= +3.0V,
f
IN
= 40.2 kHz, -0.02 dBFS
-88
-74
dB (max)
V
A
= V
D
= +5.0V,
f
IN
= 40.2 kHz, -0.02 dBFS
-90
-74
dB (max)
SFDR
Spurious-Free Dynamic Range
V
A
= V
D
= +3.0V,
f
IN
= 40.2 kHz, -0.02 dBFS
91
75
dB (min)
V
A
= V
D
= +5.0V,
f
IN
= 40.2 kHz, -0.02 dBFS
92
75
dB (min)
ENOB
Effective Number of Bits
V
A
= V
D
= +3.0V,
f
IN
= 40.2 kHz
11.8
11.3
Bits (min)
V
A
= V
D
= +5.0V,
f
IN
= 40.2 kHz, -0.02 dBFS
11.8
11.3
Bits (min)
ISO
Channel-to-Channel Isolation
V
A
= V
D
= +3.0V,
f
IN
= 20 kHz
82
dB
V
A
= V
D
= +5.0V,
f
IN
= 20 kHz, -0.02 dBFS
84
dB
IMD
Intermodulation Distortion, Second
Order Terms
V
A
= V
D
= +3.0V,
f
a
= 19.5 kHz, f
b
= 20.5 kHz
-89
dB
V
A
= V
D
= +5.0V,
f
a
= 19.5 kHz, f
b
= 20.5 kHz
-91
dB
Intermodulation Distortion, Third
Order Terms
V
A
= V
D
= +3.0V,
f
a
= 19.5 kHz, f
b
= 20.5 kHz
-88
dB
V
A
= V
D
= +5.0V,
f
a
= 19.5 kHz, f
b
= 20.5 kHz
-88
dB
ANALOG INPUT CHARACTERISTICS
V
IN
Input Range
0 to V
A
V
I
DCL
DC Leakage Current
1
A (max)
C
INA
Input Capacitance
Track Mode
33
pF
Hold Mode
3
pF
DIGITAL INPUT CHARACTERISTICS
V
IH
Input High Voltage
V
A
= V
D
= +2.7V to +3.6V
2.1
V (min)
V
A
= V
D
= +4.75V to +5.25V
2.4
V (min)
V
IL
Input Low Voltage
V
A
= V
D
= +2.7V to +5.25V
0.8
V (max)
I
IN
Input Current
V
IN
= 0V or V
D
0.01
1
A (max)
C
IND
Digital Input Capacitance
2
4
pF (max)
ADC128S102
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4
ADC128S102 Converter Electrical Characteristics
(Note 8) (Continued)
The following specifications apply for AGND = DGND = 0V, f
SCLK
= 8 MHz to 16 MHz, f
SAMPLE
= 500 kSPS to 1 MSPS, C
L
=
50pF, unless otherwise noted. Boldface limits apply for T
A
= T
MIN
to T
MAX
: all other limits T
A
= 25C.
Symbol
Parameter
Conditions
Typical
Limits
(Note 7)
Units
ANALOG INPUT CHARACTERISTICS
DIGITAL OUTPUT CHARACTERISTICS
V
OH
Output High Voltage
I
SOURCE
= 200 A,
V
A
= V
D
= +2.7V to +5.25V
V
D
- 0.5
V (min)
V
OL
Output Low Voltage
I
SINK
= 200 A to 1.0 mA,
V
A
= V
D
= +2.7V to +5.25V
0.4
V (max)
I
OZH
, I
OZL
Hi-Impedance Output Leakage
Current
V
A
= V
D
= +2.7V to +5.25V
1
A (max)
C
OUT
Hi-Impedance Output Capacitance
(Note 8)
2
4
pF (max)
Output Coding
Straight (Natural) Binary
POWER SUPPLY CHARACTERISTICS (C
L
= 10 pF)
V
A
, V
D
Analog and Digital Supply Voltages
V
A
V
D
2.7
V (min)
5.25
V (max)
I
A
+ I
D
Total Supply Current
Normal Mode ( CS low)
V
A
= V
D
= +2.7V to +3.6V,
f
SAMPLE
= 1 MSPS, f
IN
= 40 kHz
0.76
1.5
mA (max)
V
A
= V
D
= +4.75V to +5.25V,
f
SAMPLE
= 1 MSPS, f
IN
= 40 kHz
2.13
3.1
mA (max)
Total Supply Current
Shutdown Mode (CS high)
V
A
= V
D
= +2.7V to +3.6V,
f
SCLK
= 0 kSPS
20
nA
V
A
= V
D
= +4.75V to +5.25V,
f
SCLK
= 0 kSPS
50
nA
P
C
Power Consumption
Normal Mode ( CS low)
V
A
= V
D
= +3.0V
f
SAMPLE
= 1 MSPS, f
IN
= 40 kHz
2.3
4.5
mW (max)
V
A
= V
D
= +5.0V
f
SAMPLE
= 1 MSPS, f
IN
= 40 kHz
10.7
15.5
mW (max)
Power Consumption
Shutdown Mode (CS high)
V
A
= V
D
= +3.0V
f
SCLK
= 0 kSPS
0.06
W
V
A
= V
D
= +5.0V
f
SCLK
= 0 kSPS
0.25
W
AC ELECTRICAL CHARACTERISTICS
f
SCLK
MIN
Minimum Clock Frequency
V
A
= V
D
= +2.7V to +5.25V
0.8
8
MHz (min)
f
SCLK
Maximum Clock Frequency
V
A
= V
D
= +2.7V to +5.25V
16
MHz (max)
f
S
Sample Rate
Continuous Mode
V
A
= V
D
= +2.7V to +5.25V
50
500
kSPS (min)
1
MSPS (max)
t
CONVERT
Conversion (Hold) Time
V
A
= V
D
= +2.7V to +5.25V
13
SCLK cycles
DC
SCLK Duty Cycle
V
A
= V
D
= +2.7V to +5.25V
30
40
% (min)
70
60
% (max)
t
ACQ
Acquisition (Track) Time
V
A
= V
D
= +2.7V to +5.25V
3
SCLK cycles
Throughput Time
Acquisition Time + Conversion Time
V
A
= V
D
= +2.7V to +5.25V
16
SCLK cycles
t
AD
Aperture Delay
V
A
= V
D
= +2.7V to +5.25V
4
ns
ADC128S102
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