®
®
ADS-117
12-Bit, 2MHz, Low-Power Sampling A/D Converters
PRODUCT OVERVIEW
DATEL's ADS-117 is a functionally complete,
12-bit, 2MHz, sampling A/D converter. Its stan-
dard, 24-pin, double-width DIP contains a fast-
settling sample-hold amplifier, a 12-bit subranging
(two-step) A/D converter, a precision reference,
three-state output register and all the timing and
control logic necessary to operate from a single
start convert pulse. Digital input and output levels
are TTL.
Total harmonic distortion (THD) and signal-
to-noise ratio (including distortion) typically run
–78dB and 70dB, respectively, with full scale
inputs up to 100kHz. The ADS-117 requires ±15V
and +5V power supplies and typically consumes
1.6 Watts. Models are available for use in either
commercial (0 to +70°C) or military (–55 to
+125°C) operating temperature ranges and
extended commerical (–40 to +85°C).
FEATURES
12-bit resolution
missing codes
No
2MHz minimum throughput
Functionally complete
Small 24-pin DDIP
Low-power, 1.6 Watts
Three-state output buffers
Samples to Nyquist frequencies
PIN
1
2
3
4
5
6
7
8
9
10
11
12
FUNCTION
BIT 11
BIT 10
BIT 9
BIT 8
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
INPUT/OUTPUT CONNECTIONS
PIN FUNCTION
24
23
22
21
20
19
18
17
16
15
14
13
–15V Supply
ANALOG GROUND
+15V SUPPLY
+10V REFERENCE
BIPOLAR
ANALOG INPUT
COMP BIN
ENABLE (1-12)
START CONVERT
EOC
DIGITAL GROUND
+5V SUPPLY
BIT 12 (LSB)
BIT 1 (MSB)
BLOCK DIAGRAM
17 ENABLE (1-12)
DAC
12 BIT 1 (MSB)
+10V REF. 21
S
2
S/H
S
1
BIPOLAR 20
BUFFER
FLASH
ADC
REF
11 BIT 2
DIGITAL CORRECTION LOGIC
3-STATE OUTPUT REGISTER
10 BIT 3
9
8
7
6
5
4
3
2
1
BIT 4
BIT 5
BIT 6
BIT 7
BIT 8
BIT 9
BIT 10
BIT 11
BIT 12 (LSB)
ANALOG INPUT 19
–
+
COMP BIN 18
START CONVERT 16
EOC 15
TIMING AND
CONTROL LOGIC
13
+5V SUPPLY
14
DIGITAL GROUND
22
+15V SUPPLY
REGISTER
23
ANALOG GROUND
REGISTER
24
–15V SUPPLY
Figure 1. ADS-117 Functional Block Diagram
DATEL
•
11 Cabot Boulevard, Mansfield, MA 02048-1151 USA •
Tel: (508) 339-3000
•
www.datel.com
• e-mail: help@datel.com
26 Sep 2012 MDA_ADS-117.C01
Page 1 of 7
®
®
ADS-117
12-Bit, 2MHz, Low-Power Sampling A/D Converters
UNITS
Volts
Volts
Volts
Volts
Volts
°C
ABSOLUTE MAXIMUM RATINGS
PARAMETERS
LIMITS
+15V Supply
(Pin 22)
0 to +16
–15V Supply
(Pin 24)
0 to –16
+5V Supply
(Pin 13)
0 to +6.0
Digital Inputs
(Pin 16, 17, 18)
–0.3 to +V
DD
+0.3
Analog Input (Pin 19)
–9 to +15
Lead Temp. (10 seconds)
+300
FUNCTIONAL SPECIFICATIONS
(T
A
= +25°C, ±V
CC
= +15V, +V
DD
=+5V, 2MHz sampling rate, and a minimum 3 minute
warmup unless otherwise specified.)
ANALOG INPUTS
Input Voltage Range
➀
Bipolar
Unipolar
Input Impedence
Input Capacitance
Logic Levels
Logic "1"
Logic "0"
Logic Loading "1"
Logic Loading "0"
Resolution
No Missing Codes
(12 Bits; f
in
= 1MHz)
Integral Non-Linearity
0 to +70°C
–55 to +125°C
Differential Non-Linearity
0 to +70°C
–55 to +125°C / –45 to +85°C
Full Scale Absolute Accuracy
(see Tech Note 1)
0 to +70°C
–55 to +125°C / –45 to +85°C
Unipolar/Bipolar Zero Error
0 to +70°C (see Tech Note 1)
–55 to +125°C / –45 to +85°C
Bipolar Offset Error
0 to +70°C (see Tech Note 1)
–55 to +125°C / –45 to +85°C
Gain Error
(see Tech Note 1)
0 to +70°C
–55 to +125°C / –45 to +85°C
Internal Reference Voltage
0 to +70°C
–55 to +125°C / –45 to +85°C
External Current
MIN.
—
—
4.5
—
TYP.
±5
0 to +10
5
6
MAX.
—
—
—
15
UNITS
Volts
Volts
kΩ
pF
DIGITAL INPUTS
+2.0
—
—
—
—
—
—
—
—
+0.8
+5
–600
Volts
Volts
µA
µA
PERFORMANCE
12 Bits
0 to +70°C
—
—
—
—
±1/2
±1
±1/2
±1
±3
±4
±0.95
+1.5
LSB
LSB
LSB
LSB
DYNAMIC PERF. (cont)
Input Bandwith
(–3dB)
Small Signal (–20dB input)
Large Signal (–0.5dB input)
Feedthrough
(1MHz)
SNR
(wo/distortion, –0.5dB)
dc to 100kHz
0 to +70°C
–55 to +125°C / –45 to +85°C
100kHz to 500kHz
0 to +70°C
–55 to +125°C / –45 to +85°C
500kHz to 1MHz
0 to +70°C
–55 to +125°C / –45 to +85°C
SNR
(and distort., –0.5dB)
➂
dc to 100kHz
0 to +70°C
–55 to +125°C / –45 to +85°C
100kHz to 500kHz
0 to +70°C
–55 to +125°C / –45 to +85°C
500kHz to 1MHz
0 to +70°C
–55 to +125°C / –45 to +85°C
Two-tone Intermodulation Distortion
(f
in
= 970kHz, 990kHz,
f
s
= 2Mhz, –0.5dB)
Slew Rate
Effect. Aperture Delay Time
Overvoltage Recovery Time;
20%
S/H Acq. Time,
(to ±0.01%)
0 to +70°C
–55 to +125°C / –45 to +85°C
Conversion Rate
Output Coding
Pin 18 High
Pin 18 Low
Logic Level
Logic "1"
Logic "0"
Logic Loading "1"
Logic Loading "0"
Power Supply Ranges
➃
+15V Supply
–15V Supply
+5V Supply
Power Supply Current
+15V Supply
–15V Supply
+5V Supply
Power Dissipation
Power Supply Rejection
MIN.
8
7
–72
TYP.
10
9
–74
MAX.
—
—
—
UNITS
MHz
MHz
dB
—
—
65
65
—
—
72
72
70
70
70
70
—
—
—
—
—
—
dB
dB
dB
dB
dB
dB
—
—
64
62
—
—
70
69
70
69
69
69
—
—
—
—
—
—
dB
dB
dB
dB
dB
dB
—
—
—
—
—
—
2
–68
±210
—
—
155
165
—
—
—
16
500
165
190
—
dB
V/µs
ns
ns
ns
ns
MHz
—
—
—
—
—
—
—
—
+9.97
+9.95
—
±0.13
±0.25
±0.07
±0.22
±0.1
±0.53
±0.1
±0.53
+10.0
—
—
±0.44
±0.73
±0.38
±0.73
±0.38
±0.73
±0.38
±0.73
+10.03
+10.05
1.5
%FSR
%FSR
%FSR
%FSR
%FSR
%FSR
%
%
Volts
Volts
mA
OUTPUTS
Staight binary/Offset binary
Complementary binary
Complementary offset binary
+2.4
—
—
—
—
—
—
—
—
+0.4
–160
+6.4
Volts
Volts
µA
mA
POWER REQUIREMENTS
+14.25
–14.25
+4.75
—
—
—
—
—
+15.0
–15.0
+5.0
+48
–35
+75
1.6
—
+15.75
–15.75
+5.25
+64
–50
+95
2.0
±0.07
Volts
Volts
Volts
mA
mA
mA
Watts
%FSR%V
DYNAMIC PERFORMANCE
Spurious Free Dynamic Range
(–0.5dB)
➁
dc to 100kHz
—
–81
100kHz to 500kHz
—
–75
500kHz to 1MHz
—
–70
Total Harm. Distort.
(–0.5dB)
dc to 100kHz
—
–78
100kHz to 500kHz
—
–73
500kHz to 1MHz
—
–71
➀
See Table 1 also
➁
Same specifications for in-band harmonics.
DATEL
•
—
–70
—
—
–68
—
dB
dB
dB
dB
dB
dB
➂
Effective bits is equal to:
(SNR + Distortion) – 1.76 + 20 log
6.02
➃
For ±12V, +5V operation, contact DATEL.
11 Cabot Boulevard, Mansfield, MA 02048-1151 USA •
Tel: (508) 339-3000
•
www.datel.com
• e-mail: help@datel.com
Full Scale Amplitude
Actual Input Amplitude
26 Sep 2012 MDA_ADS-117.C01
Page 2 of 7
®
®
ADS-117
12-Bit, 2MHz, Low-Power Sampling A/D Converters
FUNCTIONAL SPECIFICATIONS. CONT.
PHYSICAL/ENVIRONMENTAL
Operating Temp. Range, Case
ADS-117MC
0
—
+70
°C
ADS-117ME
–45
—
+85
°C
ADS-117MM, 883
–55
—
+125
°C
Storage Temperature Range
–65
—
+150
°C
Thermal Impedance
θjc
—
3
—
°C/W
θca
—
23
—
°C/W
Package Type
24-pin, metal-sealed, ceramic DDIP
Weight
0.42 ounces (12 grams)
TECHNICAL NOTES
1. Applications which are unaffected by endpoint errors or remove them
through software will use the typical connections shown in Figure 3.
Remove system errors or adjust the small initial errors of the ADS-117
to zero using the optional external circuitry shown in Figure 4. The
external adjustment circuit has no effect on the throughput rate.
2. Always connect the analog and digital grounds to a ground plane
beneath the converter for best performance. The analog and digital
grounds are not connected to each other internally.
3. Bypass the analog and digital supplies and the +10V reference (pin 21)
to ground with 4.7μF, 25V tantalum electrolytic capacitors in parallel
with 0.1μF ceramic capacitors. Bypass the +10V reference (pin 21) to
ANALOG GROUND (pin 23).
4. Obtain straight binary/offset binary output coding by tying COMP BIN
(pin 18) to +5V or leaving it open. The device has an internal pull-up
resistor on this pin. To obtain complementary binary or complementary
offset binary output coding, tie pin 18 to ground. The pin 18 signal
N
START
CONVERT
50ns typ.,
30ns min., 60ns max.
10ns min.
25ns max.
INTERNAL S/H
Hold
10ns min.
17ns max.
EOC
Conversion Time
325ns typ.
Acquisition Time
165ns typ.
170ns max.
60ns max.
is compatible with CMOS/TTL logic levels for those users desiring
dynamic control of this function. Do not change COMP BIN status while
EOC is high.
5. To enable the three-state outputs, connect ENABLE (pin 17) to a logic
"0" (low). To disable, connect pin 17 to a logic "1" (high).
6. To meet the guaranteed conversion rate, a maximum start convert pulse
is specified. A wider start convert pulse will result in slower conversion
rates. An initial start convert pulse is required before performing an
actual conversion after power-up to assure the sample-hold is in the
acquisition mode.
Figure 2 shows the relationship between the various input signals. The
timing shown applies over the operating temperature range and over
the operating power supply range.
7. Re-initiating the START CONVERT (pin 16) while EOC is a logic "1" (high)
will result in a new conversion sequence.
N+1
35ns max.
OUTPUT
DATA
DATA N-1 VALID
350ns min.
INVALID
DATA
150ns max.
DATA N VALID
INVALID
DATA
Note: Scale is approximately 25ns per division.
Figure 2. ADS-117 Timing Diagram
DATEL
•
11 Cabot Boulevard, Mansfield, MA 02048-1151 USA •
Tel: (508) 339-3000
•
www.datel.com
• e-mail: help@datel.com
26 Sep 2012 MDA_ADS-117.C01
Page 3 of 7
®
®
ADS-117
12-Bit, 2MHz, Low-Power Sampling A/D Converters
R2
➀
CALIBRATION PROCEDURE
1. Connect the converter per Figure 3, Figure 4, and Table 1 for the ap-
propriate input range. Apply a pulse of 150 nanoseconds to the START
CONVERT input (pin 16) at a rate of 250kHz. This rate is chosen to
reduce flicker if LED’s are used on the outputs for calibration purposes.
2.
Zero Adjustments
Apply a precision voltage reference source between the amplifier’s
analog input and ground. Adjust the output of the reference source per
Table 2. For unipolar, adjust the zero trimming potentiometer so that
the output code flickers equally between 0000 0000 0000 and 0000
0000 0001 with the pin 18 tied high (straight binary) or between 1111
1111 1111 and 1111 1111 1110 with the pin 18 tied low (complemen-
tary binary).
For bipolar operation, adjust the potentiometer such that the code flick-
ers equally between 1000 0000 0000 and 1000 0000 0001 with pin 18
tied high (offset binary) or between 0111 1111 1111 and 0111 1111
1110 with pin 18 tied low (complementary offset binary).
3.
Full-Scale Adjustment
Set the output of the voltage reference used in step 2 to the value
shown in Table 1. Adjust the gain trimming potentiometer so that the
output code flickers equally between 1111 1111 1110 and 1111 1111
1111 for pin 18 tied high or between 0000 0000 0001 and 0000 0000
0000 for pin 18 tied low.
4. To confirm proper operation of the device, vary the precision reference
voltage source to obtain the output coding listed in Table 3.
R1
SIGNAL
INPUT
➀
+15V
5kΩ
50Ω
GAIN
ADJUST
5kΩ
10kΩ
ZERO/
OFFSET
ADJUST
–15V
To Pin19
of ADS-117
➀
For values of R1 and R2 refer to Table 1.
Figure 4. Optional Calibration Circuit
Table 1. Input Connections (using external calibration)
INPUT RANGE
0 +10V, ±5
0 to 5V, ±2.5V
0 to +2.5V, ±1.25V
R1
2
2
2
R2
2
6
14
UNIT
kΩ
kΩ
kΩ
Table 2. Zero and Gain Adjustments
INPUT RANGE
0 to +10V
±5V
ZERO ADJUST
+1/2 LSB
+1.22mV
+1.22mV
GAIN ADJUST
RANGE
+9.9963V
+4.9963V
UNIPOLAR
OPERATION
20 BIPOLAR INPUT
21 +10V REF.
+
0.1µF
4.7µF
12 BIT 1 (MSB)
11
10
9
8
7
6
5
4
3
2
1
15
17
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
BIT 8
BIT 9
BIT 10
BIT 11
BIT 12 (LSB)
EOC
ENABLE (1-12)
–15V
4.7µF
+
4.7µF
+15V
+5V
4.7µF
+
0.1µF
0.1µF
24
ADS-117
23
22
13
16 START CONVERT
19 ANALOG INPUT
+
0.1µF
14
COMP BIN 18
+5V
NOTE: For unipolar operation, ground pin 20.
For bipolar operation, connect pin 20 to pin 21.
Always bypass pin 21 as shown for both unipolar
and bipolar operation.
Figure 3. ADS-117 Connection Diagram
DATEL
•
11 Cabot Boulevard, Mansfield, MA 02048-1151 USA •
Tel: (508) 339-3000
•
www.datel.com
• e-mail: help@datel.com
26 Sep 2012 MDA_ADS-117.C01
Page 4 of 7
®
®
ADS-117
12-Bit, 2MHz, Low-Power Sampling A/D Converters
Table 3. Output Coding
STRAIGHT BIN.
COMP. BINARY
MSB
1111
0000
0000
0000
0000
0000
0001
0000
0000
0001
0011
0111
1011
1101
1111
1111
0000
1111
1111
1111
1111
1111
1111
1111
LSB
0000
1111
1111
1111
1111
1111
1110
1111
INPUT RANGE
±5V
+4.9976
+3.7500
+2.5000
0.0000
–2.5000
–3.7500
–4.9976
–5.0000
BIPOLAR
SCALE
+FS –1 LSB
+3/4FS
+1/2FS
0
–1/2FS
–3/4FS
–FS+1LSB
–FS
UNIPOLAR
SCALE
+FS – 1 LSB
+7/8 FS
+3/4 FS
+1/2 FS
+1/4 FS
+1/8 FS
+1 LSB
0
INPUT RANGE
0 to +10V
+9.9976
+8.7500
+7.5000
+5.0000
+2.5000
+1.2500
+0.0024
0.0000
OUTPUT CODING
MSB
1111
1110
1100
1000
0100
0010
0000
0000
LSB
1111
0000
0000
0000
0000
0000
0000
0000
OFF. BINARY
COMP. OFF. BIN.
0
–10
Amplitude Relative to Full Scale (dB)
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
–130
–140
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Frequency (MHz)
(fs = 2MHz, fin = 980kHz, Vin = –0.5dB, 4,096-point FFT)
Figure 5. FFT Analysis of ADS-117
DATEL
•
11 Cabot Boulevard, Mansfield, MA 02048-1151 USA •
Tel: (508) 339-3000
•
www.datel.com
• e-mail: help@datel.com
26 Sep 2012 MDA_ADS-117.C01
Page 5 of 7
