ADS 949
14 Bit, 12.8MHz Sampling A/D Converters
FEATURES
• • • • • • • • • 14-bit resolution 12.8MHz minimum sampling rate No missing codes over full military temperature range Ideal for both time and frequency-domain applications Excellent THD (–81dB) and SNR (78dB) Edge-triggered Small, 32-pin, side-brazed, ceramic TDIP or SMT Low-power, 2 Watts Low cost
PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
INPUT/OUTPUT CONNECTIONS
FUNCTION ViN A ViN B –5V oFFSET ADj. RANgE REF. 2.5V REF. START CoNVERT EoC ENABLE BiT 14 (LSB) BiT 13 BiT 12 BiT 11 BiT 10 BiT 9 BiT 8 PIN 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 FUNCTION RANgE gAiN ADjUST +5V ANALog ANALog gND +15V +5V DigiTAL DigiTAL gND oVERFLoW MSB BiT 1 (MSB) BiT 2 BiT 3 BiT 4 BiT 5 BiT 6 BiT 7
GENERAL DESCRIPTION
The low-cost ADS-949 is a 14-bit, 12.8MHz sampling A/D converter. This device accurately samples full-scale input signals up to Nyquist frequencies with no missing codes. Excellent differential nonlinearity error (DNL), signal-to-noise ratio (SNR), and total harmonic distortion (THD) make the ADS-949 the ideal choice for both time-domain (CCD/FPA imaging, scanners, process control) and frequency-domain (radar, telecommunications, spectrum analysis) applications. The functionally complete ADS-949 contains a fast-settling sample/hold amplifier, a subranging A/D converter, an internal reference, timing/control logic, and error-correction circuitry. Digital input and output levels are TTL. The ADS-949 only requires the rising edge of a start convert pulse to operate. Requiring only +15V, +5V and –5V supplies, the ADS-949 typically dissipates just 2 Watts. The device is offered with a Bipolar input range of ±2.5V and Unipolar range of 0 to 5 volts. Models are available for use in either commercial (0 to +70°C) or military (–55 to +125°C) operating temperature ranges.
A proprietary, auto-calibrating, error-correcting circuit allows the device to achieve specified performance over the full military temperature range.
OFFSET ADJUST 4 BUFFER VIN A VIN B 1 2 – + S/H 10 BIT 14 (LSB) FLASH ADC 1 REGISTER 2.5 V REF 6 11 BIT 13 12 BIT 12 DIGITAL CORRECTION LOGIC 13 BIT 11 OUTPUT REGISTER 14 BIT 10 15 BIT 9 16 BIT 8 17 BIT 7 18 BIT 6 19 BIT 5 20 BIT 4 21 BIT 3 22 BIT 2 23 BIT 1 (MSB) 24 MSB TIMING AND CONTROL LOGIC 9 ENABLE
POWER AND GROUNDING GAIN ADJUST +5V ANALOG SUPPLY +5V DIGITAL SUPPLY V RANGE –5.2V SUPPLY +15V SUPPLY ANALOG GROUND DIGITAL GROUND 31 30 27 32 3 28 29 26 AMP FLASH ADC 2 REGISTER REF
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DAC
START CONVERT 7 EOC 8
25 OVERFLOW
Figure 1. ADS-949 Functional Block Diagram
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Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
MDC_ADS-949.B01 Page 1 of 8
ADS 949
PHYSICAL/ENVIRONMENTAL
PARAMETERS Operating Temp. Range, Case ADS-949MC, GC ADS-949MM, GM, Thermal Impedance θjc θca Storage Temperature Range Package Type Weight MIN. 0 –55 TYP. — — MAX. +70 +125 UNITS °C °C
14 Bit, 12.8MHz Sampling A/D Converters
ABSOLUTE MAXIMUM RATINGS
PARAMETERS +5V Supply (Pins 27, 30) +15V Supply (Pin 28) –5V Supply (Pin 3) Digital Input (Pin 7) Analog Input (Pins 1, 2) Lead Temperature (10 seconds) LIMITS 0 to +6 0 to +16 0 to –5.5V –0.3 to +VDD +0.3 ±5 +300 UNITS Volts Volts Volts Volts Volts °C
— 6 — °C/Watt — 23 — °C/Watt –65 — +150 °C 32-pin, side-brazed, ceramic TDIP or SMT 0.46 ounces (13 grams)
FUNCTIONAL SPECIFICATIONS
(TA = +25°C, +VDD = +5V, –VDD = –5V, +Vcc = +15V, 12.8MHz sampling rate, ±2.5V input range, and a minimum 3 minute warmup ➀ unless otherwise specified.) +25°C ANALOG INPUT Bipolar Input Voltage Range ➁ Unipolar Input Voltage Range ➁ Input Resistance (Vin A) Input Capacitance DIGITAL INPUT Logic Levels Logic "1" Logic "0" Logic Loading "1" Logic Loading "0" Start Convert Positive Pulse Width ➂ STATIC PERFORMANCE Resolution Integral Nonlinearity Differential Nonlinearity (fin = 10kHz) Full Scale Absolute Accuracy Bipolar Zero Error (Tech Note 2) Gain Error (Tech Note 2) No Missing Codes (fin = 10kHz) DYNAMIC PERFORMANCE Peak Harmonics (–0.5dB) dc to 1MHz 1MHz to 2.5MHz 2.5MHz to 5MHz Total Harmonic Distortion (–0.5dB) dc to 1MHz 1MHz to 2.5MHz 2.5MHz to 5MHz Signal-to-Noise Ratio (w/o distortion, –0.5dB) dc to 1MHz 1MHz to 2.5MHz 2.5MHz to 5MHz Signal-to-Noise Ratio ➃ (& distortion, –0.5dB) dc to 1MHz 1MHz to 2.5MHz 2.5MHz to 5MHz Noise Two-tone Intermodulation Distortion (fin = 2.45MHz, 1.975MHz, fs = 10MHz, –0.5dB) Input Bandwidth (–3dB) Small Signal (–20dB input) Large Signal (–0.5dB input) Feedthrough Rejection (fin = 5MHz) Slew Rate Aperture Delay Time Aperture Uncertainty — — — — — — 72 72 72 70 70 69 — — — — — — — — –83 –78 –76 –81 –76 –74 78 77 76 77 74 73 150 –82 30 20 85 ±400 +5 2 –76 –72 –71 –74 –71 –69 — — — — — — — — — — — — — — — — — — — — 72 72 72 70 70 69 — — — — — — — — –83 –78 –76 –81 –76 –74 78 77 76 74 74 73 150 –82 30 20 85 ±400 +5 2 –75 –72 –71 –74 –71 –69 — — — — — — — — — — — — — — — — — — — — 70 70 70 68 66 65 — — — — — — — — –79 –73 –71 –77 –72 –69 78 77 76 73 71 70 150 –82 30 20 85 ±400 +5 2 –71 –68 –65 –70 –66 –63 — — — — — — — — — — — — — — dB dB dB dB dB dB dB dB dB dB dB dB µVrms dB MHz MHz dB V/µs ns ps rms — — –0.95 — — — 14 14 ±0.75 ±0.5 ±0.15 ±0.1 ±0.2 — — — +1.25 ±0.4 ±0.3 ±0.4 — — — –0.95 — — — 14 14 ±0.75 ±0.5 ±0.15 ±0.1 ±0.2 — — — +1.25 ±0.4 ±0.3 ±0.4 — — — –0.95 — — — 14 14 ±1 ±0.5 ±0.4 ±0.3 ±0.4 — — — +1.5 ±0.8 ±0.6 ±1.5 — Bits LSB LSB %FSR %FSR % Bits +2.0 — — — — — — — — 50 — +0.8 +20 –20 — +2.0 — — — — — — — — 50 — +0.8 +20 –20 — +2.0 — — — — — — — — 50 — +0.8 +20 –20 — Volts Volts µA µA ns MIN. ±1 0 to 2 — — TYP. — — 400 6 MAX. ±2.5 0 to 5 — 15 MIN. ±1 0 to 2 — — 0 to +70°C TYP. — — 400 6 MAX. ±2.5 0 to 5 — 15 MIN. ±1 0 to 2 — — –55 to +125°C TYP. — — 400 6 MAX. ±2.5 0 to 5 — 15 UNITS Volts Volts Ω pF
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Technical enquiries email: sales@murata-ps.com, tel: +1 508 339 3000
MDC_ADS-949.B01 Page 2 of 8
ADS 949
14 Bit, 12.8MHz Sampling A/D Converters
+25°C DYNAMIC PERFORMANCE (Cont.) S/H Acquisition Time ( to ±0.003%FSR, 5V step) Overvoltage Recovery Time A/D Conversion Rate DIGITAL OUTPUTS Logic Levels Logic "1" Logic "0" Logic Loading "1" Logic Loading "0" Output Coding DIGITAL OUTPUTS Power Supply Ranges +5V Supply –5.2V Supply +15V Supply Power Supply Currents +5V Supply –5.2V Supply +15V Supply Power Dissipation Power Supply Rejection +4.75 –4.75 +14.5 — — +14.5 — — +5.0 –5.2 +15 +250 –200 +15 2.0 — +5.25 –5.45 +15.5 +260 –210 +15.5 2.25 ±0.1 +4.75 –4.75 +14.5 — — +14.5 — — +5.0 –5.2 +15 +250 –200 +15 2.0 — +5.25 –5.45 +15.5 +260 –210 +15.5 2.25 ±0.1 +4.9 –4.9 +14.5 — — +14.5 — — +5.0 –5.2 +15 +250 –200 +15 2.0 — +5.25 –5.45 +15.5 +260 –210 +15.5 2.25 ±0.1 Volts Volts Volts mA mA Volts Watts %FSR/%V +2.4 — — — — — — — — +0.4 –4 +4 +2.4 — — — — — — — — +0.4 –4 +4 +2.4 — — — — — — — — +0.4 –4 +4 Volts Volts mA mA MIN. — — 12.8 TYP. 40 — — MAX. 45 100 — MIN. — — 12.8 0 to +70°C TYP. 40 — — MAX. 45 100 — MIN. — — 12.8 –55 to +125°C TYP. 40 — — MAX. 45 100 — UNITS ns ns MHz
Straight Binary, Offset Binary
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 Contact Murata Power Solutions for other input voltage ranges. ➂ A 50ns wide start convert pulse is used for all production testing. For applications requiring less than an 12.8MHz sampling rate, wider start convert pulses can be used. The rising edge of the start convert pulse needs to be as sharp as possible (
