Datasheet ADS-945EX, ADS-945 Datasheet (DATEL)

® ®

3-STATE OUTPUT REGISTER

DIGITAL CORRECTION LOGIC

SUPPLY

SUPPLY

SUPPLY

GROUND

CONNECT

SUPPLY

FEATURES

• 14-bit resolution

• 10MHz minimum throughput

• Functionally complete

• No missing codes

• Low power, 4.2W

• Excellent dynamic performance

• Internally clamped input

• Edge triggered

• TTL compatible

• 2" x 4" module

• Very low profile

GENERAL DESCRIPTION

The low-cost ADS-945 is a high-performance, 14-bit, 10MHz
sampling A/D converter. This device accurately samples
full-scale input signals up to Nyquist frequencies with no
missing codes. The dynamic performance of the ADS-945
has been optimized to achieve a THD of –82dB and a
SNR of 79dB.

Packaged in a 2" x 4" module, the functionally complete
ADS-945 contains a fast-settling sample/hold amplifier, a
subranging (two-pass) A/D converter, a precise voltage
reference, timing/control logic, three-state outputs, and
error-correction circuitry. Digital inputs and outputs are TTL
compatible (except for pins 29 and 30 which are ECL).

Requiring ±15V, +5V and –5.2V supplies, the ADS-945
typically dissipates 4.2W. The unit is offered with a bipolar
input range of ±1.25V. Models are available for use in either
commercial (0 to +70°C) or military (–55 to +125°C) operating
temperature ranges. Typical applications include radar signal
analysis, medical/graphic imaging, and FFT spectrum
analysis.

ADS-945

14-Bit, 10MHz

Sampling A/D Converters

INPUT/OUTPUT CONNECTIONS

PIN FUNCTION PIN FUNCTION

1 ANALOG GROUND 70-76 ANALOG GROUND
4 ANALOG INPUT 69 +5V ANALOG SUPPLY

5-6 ANALOG GROUND 64-68 ANALOG GROUND

7 +10V REFERENCE OUT 63 –5.2V ANALOG SUPPLY
8 ANALOG GROUND 62 ANALOG GROUND
9 GAIN ADJUST 61 NO CONNECT

10-11 DO NOT CONNECT 58-60 DIGITAL GROUND

12 –15V SUPPLY 57 –5.2V DIGITAL SUPPLY
13 ANALOG GROUND 56 DO NOT CONNECT
14 +15V SUPPLY 55 +5V DIGITAL SUPPLY

15-17 ANALOG GROUND 54 DIGITAL GROUND

18 OFFSET ADJUST 53 BIT 1 (MSB)

19-25 ANALOG GROUND 52 BIT 2

26 MISSING PIN 51 BIT 3
27 DIGITAL GROUND 50 BIT 4
28 DIGITAL GROUND 49 BIT 5
29 T/H STATUS 48 BIT 6
30 T/H STATUS 47 BIT 7
31 DIGITAL GROUND 46 BIT 8
32 START CONVERT 45 BIT 9
33 OVERFLOW 44 BIT 10
34 OUTPUT ENABLE (OE) 43 BIT 11
35 DIGITAL GROUND 42 BIT 12
36 O.S. 3 * 41 BIT 13
37 DIGITAL GROUND 40 BIT 14 (LSB)
38 DIGITAL GROUND 39 DIGITAL GROUND

* Refer to Timing Diagram notes

33 OVERFLOW

53

BIT 1 (MSB)

52

BIT 2

51

BIT 3

50

BIT 4

49

BIT 5

48

BIT 6

47

BIT 7

46

BIT 8

45

BIT 9

44

BIT 10

43

BIT 11

42

BIT 12

41

BIT 13

40

BIT 14 (LSB)

34 OUTPUT ENABLE
26 MISSING PIN

10,11,56 DO NOT CONNECT

57

ANALOG INPUT 4

GAIN ADJUST 9

+10 REF. OUT 7

1,2,3,5,6,8,13,15,17,

19-25,62,64-68,70-76

ANALOG GROUND

OFFSET ADJUST 18

START CONVERT 32

T/H STATUS 29
T/H STATUS 30

CASE

AGND

12

–15V

+1

T/H

GAIN

CIRCUIT

DGND

OFFSET
CIRCUIT

TIMING AND

CONTROL LOGIC

36

+15V

O.S. 3

Σ

AMP

14

27,28,31,35,37-39,54,58-60

BUFFER

REF

DIGITAL

FLASH

ADC

1

DAC

FLASH

ADC

2

61

NO

55

+5V DIGITAL

–5.2V DIGITAL

Figure 1. ADS-945 Functional Block Diagram

DATEL, Inc., 11 Cabot Boulevard, Mansfield, MA 02048-1151 (U.S.A.) • Tel: [phone] Fax: [phone] • For immediate assistance: [phone]

ADS-945

® ®

ABSOLUTE MAXIMUM RATINGS

PARAMETERS LIMITS UNITS

+15V Supply (Pins 14) 0 to +17 Volts
–15V Supply (Pin 12) 0 to –17 Volts
+5V Supply (Pins 55, 69) 0 to +6 Volts
–5V Supply (Pin 57, 63) 0 to –6 Volts
Digital Input (Pin 32, 34) –0.3 to +V
Analog Input (Pin 4) –5 to +5 Volts
Lead Temperature (10 seconds) +300 °C

DD +0.3 Volts

PHYSICAL/ENVIRONMENTAL

PARAMETERS MIN. TYP. MAX. UNITS

Operating Temp. Range, Case

ADS-945 0 — +70 °C
ADS-945EX –55 — +125 °C

Thermal Impedance

θjc — 10 — °C/Watt
θca — 8 — °C/Watt

Storage Temperature Range –65 — +150 °C
Package Type 2" x 4" module

Weight 2.1 oz. (60 grams)

FUNCTIONAL SPECIFICATIONS

(TA = +25°C, ±VCC = ±15V, +VDD = +5V, VDD = –5.2V, 10MHz sampling rate, and a minimum 10 minute warmup ➀ unless otherwise specified.)

+25°C 0 to +70°C –55 to +125°C

ANALOG INPUT MIN. TYP. MAX. MIN. TYP. MAX. MIN. TYP. MAX. UNITS

Input Voltage Range ➁ — ±1.25 — — ±1.25 — — ±1.25 — Volts
Input Resistance 300 500 — 300 550 — 300 500 — kΩ
Input Capacitance — 10 15 — 10 15 — 10 15 pF
Input Bias Current — ±3 — — ±3 — — ±3 — µA

DIGITAL INPUT

Logic Levels

Logic "1" +2.0 — — +2.0 — — +2.0 — — Volts
Logic "0" — — +0.8 — — +0.8 — — +0.8 Volts
Logic Loading "1" — — +20 — — +20 — — +20 µA
Logic Loading "0" — — –20 — — –20 — — –20 µA

Start Convert Positive Pulse Width ➂ 10 50 — 10 50 — 10 50 — ns

STATIC PERFORMANCE

Resolution — 14 — — 14 — — 14 — Bits
Integral Nonlinearity (f
Differential Nonlinearity (f

in = 10kHz) — ±0.5 — — ±0.75 — — ±0.75 — LSB

in = 10kHz) — ±0.5 ±0.75 — ±0.5 ±0.75 –0.95 ±0.75 +1.5 LSB

Full Scale Absolute Accuracy — ±0.2 ±0.4 — ±0.3 ±0.5 — ±0.3 ±0.7 %FSR
Bipolar Offset Error (Tech Note 2) — ±0.15 ±0.25 — ±0.25 ±0.5 — ±0.3 ±0.7 %FSR
Gain Error (Tech Note 2) — ±0.1 ±0.2 — ±0.2 ±0.4 — ±0.3 ±0.7 %
No Missing Codes (f

in = 10kHz) 14 — — 14 — — 14 — — Bits

DYNAMIC PERFORMANCE

Peak Harmonics (–0.5dB)

dc to 1mHz — –86 –78 — –86 –78 — –80 –72 dB
1MHz to 2.5MHz — –82 –75 — –82 –75 — –79 –70 dB

2.5MHz to 5MHz — –79 –74 — –79 –74 — –78 –70 dB

Total Harmonic Distortion (–0.5dB)

dc to 1MHz — –82 –76 — –82 –76 — –78 –70 dB
1MHz to 2.5MHz — –80 –74 — –80 –74 — –76 –68 dB

2.5MHz to 5MHz — –78 –73 — –78 –73 — –76 –68 dB

Signal-to-Noise Ratio

(w/o distortion, –0.5dB)
dc to 1MHz 76 79 — 76 79 — 70 78 — dB
100kHz to 2.5MHz 76 78 — 76 78 — 70 77 — dB

2.5MHz to 5MHz 75 77 — 75 77 — 70 75 — dB

Signal-to-Noise Ratio ➃

(& distortion, –0.5dB)
dc to 100kHz 73 77 — 73 77 — 67 74 — dB
1MHz to 2.5MHz 72 76 — 72 76 — 67 74 — dB

2.5MHz to 5MHz 71 74 — 71 74 — 66 72 — dB

Noise — 110 — — 110 — — 110 — µVrms
Two-tone Intermodulation

Distortion (f

2.45MHz, f

in = 1.975MHz,

s = 10MHz, –0.5dB) — –84 — — –84 — — –84 — dB

Input Bandwidth (–3dB)

Small Signal (–20dB input) — 100 — — 100 — — 100 — MHz
Large Signal (–0.dB input) — 50 — — 50 — — 50 — MHz

Feedthrough Rejection (f

in = 4.85MHz) — 90 — — 90 — — 90 — dB

Slew Rate — ±850 — — ±850 — — ±850 — V/µs
Aperture Delay Time — +8 — — +8 — — +8 — ns
Aperture Uncertainty — 2 — — 2 — — 2 — ps rms

2

® ®

ADS-945

+25°C 0 to +70°C –55 to +125°C

DYNAMIC PERFORMANCE cont. MIN. TYP. MAX. MIN. TYP. MAX. MIN. TYP. MAX. UNITS

S/H Acquisition Time

( to ±0.003%FSR, 2.5V step) — 40 — — 40 — — 40 — ns

Overvoltage Recovery Time ➄ — 30 100 — 30 100 — 30 100 ns
A/D Conversion Rate 10 — — 10 — — 10 — — MHz

ANALOG OUTPUT

Reference Output +9.99 +10 +10.01 +9.99 +10 +10.01 +9.99 +10 +10.01 Volts
Reference Temperature Drift — ±40 — — ±40 — — ±40 — ppm/°C
Reference Load Curent — — 2.0 — — 2.0 — — 2.0 mA

DIGITAL OUTPUTS

Logic Levels

Logic "1" +2.7 — — +2.7 — — +2.7 — — Volts
Logic "0" — — +0.5 — — +0.5 — — +0.5 Volts
Logic Loading "1" — — –0.4 — — –0.4 — — –0.4 mA
Logic Loading "0" — — +8 — — +8 — — +8 mA

Delay, Falling Edge of T/H

to Output Data Valid — 55 — — 55 — — 55 — ns

Delay, Edge of ENABLE

to Output Data Valid/Invalid — — 18 — — 18 — — 18 ns

Output Coding

POWER REQUIREMENTS

Complementary Offset Binary

Power Supply Ranges

+15V Supply +14.25 +15.0 +15.75 +14.25 +15.0 +15.75 +14.25 +15.0 +15.75 Volts
–15V Supply –14.25 –15.0 –15.75 –14.25 –15.0 –15.75 –14.25 –15.0 –15.75 Volts
+5V Supply +4.75 +5.0 +5.25 +4.75 +5.0 +5.25 +4.75 +5.0 +5.25 Volts
–5.2V Supply –4.95 –5.2 –5.45 –4.95 –5.2 –5.45 –4.95 –5.2 –5.45 Volts

Power Supply Currents ➅

+15V Supply — +35 +45 — +35 +45 — +35 +45 mA
–15V Supply — –55 –65 — –55 –65 — –55 –65 mA
+5V Supply — +140 +160 — +140 +160 — +140 +160 mA
–5.2V Supply — –430 –460 — –430 –460 — –430 –460 mA

Power Dissipation — 4.2 4.5 — 4.2 4.5 — 4.2 4.5 Watts
Power Supply Rejection — — ±0.04 — — ±0.04 — — ±0.04 %FSR/%V

Footnotes:

➀ All power supplies should be on before applying a start convert pulse. All

supplies and the clock (start convert pulses) must be present during warmup
periods. The device must be continuously converting during this time.

➁ The input to the ADS-945 is internally clamped at ±2.3V.
➂ An 50ns wide start convert pulse is used for all production testing. For

applications requiring less than a 10MHz sampling rate, a wider start convert
can be used.

TECHNICAL NOTES

1. Obtaining fully specified performance from the ADS-945
requires careful attention to pc-card layout and power
supply decoupling. The device's analog and digital ground
systems are connected to each other internally. For optimal
performance, tie all ground pins directly to a large analog
ground plane beneath the package.

Bypass all power supplies to ground with 10µF tantalum
capacitors in parallel with 0.1µF ceramic capacitors. The

bypass capacitors should be located as close to the
unit as possible.

2. The ADS-945 achieves its specified accuracies without the
need for external calibration. If required, the device's small
initial offset and gain errors can be reduced to zero using

➃ Effective bits is equal to:

(SNR + Distortion) – 1.76 + 20 log

➄ This is the time required before the A/D output is valid after the analog input is

back within its range.

➅ Typical +5V and –5.2V current drain breakdowns are as follows:

Analog = +100mA –5.2VAnalog= –210mA

+5V

Digital = +40mA –5.2VDigital = –220mA

+5V
+5VTotal = +140mA –5.2VTotal = –430mA

Full Scale Amplitude

Actual Input Amplitude

6.02

the adjustment circuitry shown in Figure 2. The typical
adjustment range is ±0.2%FSR for this circuitry.

When using this circuitry, or any similar offset and gain­calibration hardware, make adjustments following warmup.
To avoid interaction, always adjust offset before gain.

3. To enable the three-state outputs, apply a logic "0" (low) to
OUTPUT ENABLE (pin 34). To disable, apply a logic "1"
(high) to pin 34.

4. A passive bandpass filter (Allen Avionics F4202 Series) is
used at the input of the A/D for all production testing.

5. The ADS-945's digital outputs should not be directly
connected to a noisy data bus. Drive the bus with 573 or
574 type latches and use "low-noise" logic, such as the
74LS series.

3

ADS-945

+ +

+ +

+ +

–15V

® ®

CALIBRATION PROCEDURE

(Refer to Figure 2 and Table 1)

Note: Connect pin 18 to ANALOG GROUND (pin 19) for
operation without zero/offset adjustment. Connect pin 9 to
ANALOG GROUND (pin 8) for operation without gain
adjustment.

Any offset and/or gain calibration procedures should not be
implemented until devices are fully warmed up. To avoid
interaction, offset must be adjusted before gain. The ranges of
adjustment for the circuit in Figure 2 are guaranteed to
compensate for the ADS-945's initial accuracy errors and may
not be able to compensate for additional system errors.

A/D converters are calibrated by positioning their digital
outputs exactly on the transition point between two adjacent
digital output codes. This can be accomplished by connecting
LED's to the digital outputs and adjusting until certain LED's
"flicker" equally between on and off. Other approaches
employ digital comparators or microcontrollers to detect when
the outputs change from one code to the next.

For the ADS-945, offset adjusting is normally accomplished at
the point where the MSB is a 1 and all other output bits are 0's
and the LSB just changes from a 0 to a 1. This digital output
transition ideally occurs when the applied analog input is
+½ LSB (+76.3

Gain adjusting is accomplished when all bits are 0's and the
LSB just changes from a 0 to a 1. This transition ideally
occurs when the analog input is at +full scale minus 1 ½ LSB's
(+1.249771V) .

Note: Due to inherent system noise, the averaging of
several conversions may be needed to accurately
adjust both offset and gain to 1LSB of accuracy.

µV).

Zero/Offset Adjust Procedure

1. Apply a train of pulses to the START CONVERT input
(pin 32) so the converter is continuously converting.

2. Apply +76.3

µV to the ANALOG INPUT (pin 4).

3. Adjust the offset potentiometer until the output bits are
10 0000 0000 0000 and the LSB flickers between 0 and 1.

Gain Adjust Procedure

1. Apply +1.249771V to the ANALOG INPUT (pin 4).

2. Adjust the gain potentiometer until all output bits are 0's
and the LSB flickers between 0 and 1.

3. To confirm proper operation of the device, vary the applied
input voltage to obtain the output coding listed in Table 1.

Note: A single +5V supply can be used for both the +5V
ANALOG and the +5V DIGITAL. If separate supplies are
used, the difference between the two can not exceed
100mV. This also applies to the –5.2V supply requirements.

Datel recommends using ferrite beads to separate the analog
and digital supplies (FAIR-RITE # 2643000301.)

Table 1. Output Coding

OUTPUT CODING INPUT RANGE BIPOLAR
MSB LSB ±1.25V SCALE

00 0000 0000 0000 +1.249847 +FS –1 LSB
00 0111 1111 1111 +0.937500 +3/4 FS
00 1111 1111 1111 +0.625000 +1/2FS
01 1111 1111 1111 0.000000 0
10 1111 1111 1111 –0.625000 –1/2FS
11 0111 1111 1111 –0.937500 –3/4FS
11 1111 1111 1110 –1.249847 –FS +1 LSB
11 1111 1111 1111 –1.250000 –FS

COMP. OFF. BINARY

BIT 1 (MSB)

53

BIT 2

52

BIT 3

51

BIT 4

50

BIT 5

49

BIT 6

48

BIT 7

47
46

BIT 8

45

BIT 9

44

BIT 10

43

BIT 11
BIT 12

42

BIT 13

41

BIT 14 (LSB)

40

OUTPUT ENABLE

34

OVERFLOW

33

T/H STATUS

30

T/H STATUS

29

ANALOG INPUT

4

32START CONVERT

7

+15V

9

0.1µF

20k

Ω

+5V

10µF

0.1µF

10µF

10µF

10µF

10µF

10µF

+15V

20kΩ

–15V

0.1µF

0.1µF

0.1µF

0.1µF

0.1µF

–5.2V

+5V

–5.2V

+15V

–15V

55

54
58-60

57

69

64-68

63

12

13
15-17

13

18

DIGITAL
SUPPLY

DIGITAL
GROUND

DIGITAL
SUPPLY

ANALOG
SUPPLY

ANALOG
GROUND

ANALOG
SUPPLY

ANALOG
GROUND

OFFSET
ADJUST

ADS-945

+10 REF. OUT

GAIN

ADJUST

Figure 2. ADS-945 Connection Diagram

4

®®

ADS-945

AGND

BIT 8

BIT 7

BIT 6

BIT 5

129

147

Q5Q4Q3Q2Q1

ALS573

8D7D6D5D4D

813

615

-5.2VA
C20

L11

L10

SG3

-5.2VD

OFFSET

P2

CONNECTOR

DATA OUTPUT

34 33

1

DATA

Q8Q7Q6

OC

10

GND

CP

11

+5VA

C21

SG1

+5VD

DNC

+5VD

-5.2VD

32 31

30 29

28 27

26 25

24 23

22 21

20 19

C28

LATCHES

BIT 1

BIT 2

(MSB)

BIT 3

BIT 4

20

219

BIT 6

BIT 5

T/H

Q1

+5V
1D

BIT 7

T/H

DGND

SG4

AGND

SG2

MSB BIT 1

DGND

L7

C27

C29

D
+5V

+5VA

76757473727170696867666564636261605958575655545352515049484746454443424140

U1

ADS945

IN

1

+

C18

+5VA

GAIN

VREF

9

8765432

10

BIT 3

BIT 2

183

20

+5V

3D

2D

1D

417

219

C19

-5.2VA

+15V

-15V

BIT 4

165

U6

-5.2VA

18 17

16 15

14 13

BIT 9

BIT 10

BIT 11

165

183

U7

3D

2D

417

BIT 9

BIT 8

BIT 10

CLOCK

O.F.

9

87

12 11

10

BIT 12

BIT 13

LSB BIT 14

147

ALS573

813

615

BIT 13

BIT 12

BIT 11

ENABLE

ENABLE

65

43

21

EOC

CLOCK

OVERFLOW

1

129

Q8Q7Q6Q5Q4Q3Q2

OC

10

GND

CP

8D7D6D5D4D

11

3938

(LSB) BIT 14

OS3

373635343332313029282726252423222120191817161514131211

10K

R12

C16

+15V

C15

-15V

CW

C14

3

2

R1

20K

1

GAIN

+15V

51.1

R5

2

3

1

JPR3

NC

P3

-5.2VA

+15V+5VA+5V

-5.2VA-5.2V -15V

0.1" GRID

D

HOLE PATTERN

D

C17

CW

-15V

3

OFFSET

R2

20K

2

D

1

+15V

-15V

C1

+

D1

P1

POWER SUPPLY

+5V

C22

+5VA/350MA

C2

+

D2

L2

L3

L1

-5.2V

+5VD

-5.2VD

CONNECTOR

26 25

24 23

22 21

20 19

18 17

16 15

14 13

+V

-V

3

2

1

U4

LT1016

6

5

7

8

D
+5V

-15V/80MA

C3

+

D3

L5

L4

-15V

+15V

12 11

10 9

87

65

4

C23

L6

43

C9

10PF

(OPT)

D

-5.2V

INT
1

X1

8

10MHZ

14

1,7

C26

+15V/50MA

C4

+

D4

+5VA

21

EXT

2

1

2

EXT
3

JPR2

CLOCK

3

JPR1

OUTPUT ENABLE

INT

ALL RESISTORS ARE IN OHMS RN55C.

UNLESS OTHERWISE SPECIFIED.

1.

NOTES:

10UFD 25V.

ALL POLORIZED CAPACITORS ARE

R3

51.1

P4

EXT. CLOCK

0.1UFD 50V.

N.C. POSITION.

2UHY.

1N4001.

ALL NON POLORIZED CAPACITORS ARE

C9 NOT TO BE INSTALLED.

INSTALL IN SOCKET (ITEM 34).

FOR X1 USE MONITOR OSCILLATOR TYPE 970T,

ALL CHOKES ARE

ALL DIODES ARE

ALL SWITCHES ARE SHOWN IN THE

2.

3.

4. REMOVE X1 IF USING EXTERNAL CLOC K .

Figure 3. ADS-945 Evaluation Board Schematic (DATEL Dwg. #A-23442)

5

ADS-945

Digital Output Code

CONVERT

Note: Scale is approximately 10ns per division.

DATA

Amplitude Relative to Full Scale (dB)

(fs = 10MHz, fin = 4.85MHz, Vin = –0.5dB, 16,384-point FFT)

kHz MHz MHz MHz MHz MHz MHz MHz MHz MHz

® ®

N

START

50ns typ.

10ns typ.

T/H

60ns typ.

T/H

OUTPUT

DATA

Hold

DATA N-1 VALID

Figure 4. ADS-945 Timing Diagram

Timing Notes:

1. The ADS-945 is an edge-triggered device requiring no
additional external timing signals. The rising edge of the
start convert pulse initiates a conversion.

2. A start convert pulse of 50ns is recommended when
sampling at 10MHz.

55ns typ.

INVALID

N+1

N+2

Acquisition Time

Hold

40ns typ.

Hold

10ns typ.

DATA N VALID

90ns typ.

DATA N+1 VALID

3. The falling edge of the subsequent start convert pulse
(N+1) or the rising edge of the N+2 pulse can be used to
latch data from conversion N (1 pipeline delay).

4. For a sampling rate of 10MHz, do not connect pin 36.

5. For sampling rates between 7.75 and 8.25MHz, place a
22pF capacitor to digital ground on pin 36.

0
–10
–20
–30
–40
–50
–60
–70
–80
–90

–100
–110
–120
–130
–140
–150

0 500 1 1.5 2 2.5 3 3.5 4 4.5 5

Frequency

Figure 5. ADS-945 FFT Analysis

9000

8000

7000

6000

5000

4000

3000

2000

1000

0

Figure 6. ADS-945 Grounded Input Histogram

This histogram represents the typical peak-to-peak noise
(including quantization noise) associated with the ADS-945.
16,384 conversions were processed with the input to the
ADS-945 tied to analog ground.

6

® ®

Peak Harmonic (–dB)

SNR (dB)

SNR+D (dB)

THD (–dB)

1 10 100 1000 10000 100000

Frequency (kHz)

Peak Harmonic (–dB)

THD (–dB)

1 10 100 1000 10000 100000

Frequency (kHz)

Number of Occurences

Digital Output Code

16,384

DNL (LSB's)

ADS-945

+0.39

0

–0.29

0

Digital Output Code

0

16,384

Figure 7. ADS-945 Histogram and Differential Nonlinearity

90

80

70

60

50

40

30

20

10

0

1 10 100 1000 10000 100000

90

80

70

60

50

40

30

20

10

0

1 10 100 1000 10000 100000

PH vs. Input Frequency

Frequency (kHz)

90

80

70

60

50

40

30

20

10

0

90

80

70

60

50

40

30

20

10

0

THD vs. Input Frequency

Frequency (kHz)

SNR+D vs. Input FrequencySNR vs. Input Frequency

Figure 8. ADS-945 Dynamic Performance vs. Input Frequency at +25°C

7

ADS-945

ISO 9001

REGISTERED

(FR-4) base

39

1.80

(45.72)

0.100 (2.54) TYP.

MECHANICAL DIMENSIONS INCHES (mm)

0.29 MAX.
(7.37)

0.15 MIN.
(3.81)

0.06 (1.52)

2.06 MAX.
(52.32)

® ®

76

3.700

(93.98)

1

Missing pin 26
is for keying
purposes

0.25 Square

38

Insulated surface with
internal ground plane

(6.35) TYP.

Epoxy glass

4.02

(102.11)

MAX.

Metal case

2.02 MAX.
(51.31)

4.06

(103.12)

MAX.

MODEL NUMBER OPERATING TEMP. RANGE
ADS-945 0 to +70°C

ADS-945EX –55 to +125°C

DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151
Tel: [phone] [phone] Fax: [phone]
Internet: www.datel.com E-mail:[e-mail]
Data Sheet Fax Back: [phone]

DATEL makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein
do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. The DATEL logo is a registered DATEL, Inc. trademark.

ORDERING INFORMATION

ACCESSORIES
ADS-945 Evaluation Board (without ADS-945)

ISO 9001

DS-0237E 01/96

DATEL (UK) LTD. Tadley, England Tel: [phone]
DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: [phone]
DATEL GmbH München, Germany Tel: [phone]
DATEL KK Tokyo, Japan Tel: [phone], Osaka Tel: [phone]