User Manual

ManualsBrandsRainbow Electronics ManualsSensorsADC1173

ADC1173

8-Bit, 3-Volt, 15MSPS, 33mW A/D Converter

General Description

The ADC1173 is a low power, 15 MSPS analog-to-digital

converter that digitizes signals to 8 bits while consuming just

33 mW of power (typ). The ADC1173 uses a unique archi-

tecture that achieves 7.6 Effective Bits. Output formatting is

straight binary coding.

The excellent DC and AC characteristics of this device,

together with its low power consumption and +3V single

supply operation, make it ideally suited for many video,

imaging and communications applications, including use in

portable equipment. Furthermore, the ADC1173 is resistant

to latch-up and the outputs are short-circuit proof. The top

and bottom of the ADC1173’s reference ladder is available

for connections, enabling a wide range of input possibilities.

The ADC1173 is offered in SOIC (EIAJ) and TSSOP. It is

designed to operate over the commercial temperature range

of -40˚C to +75˚C.

Features

n Internal Sample-and-Hold Function

n Single +3V Operation

n Internal Reference Bias Resistors

n Industry Standard Pinout

n TRI-STATE

Outputs

Key Specifications

n Resolution 8 Bits

n Maximum Sampling Frequency 15 MSPS (min)

n THD −54 dB (typ)

n DNL

0.85 LSB (max)

n ENOB at 3.58 MHz Input 7.6 Bits (typ)

n Guaranteed No Missing Codes

n Differential Phase 0.5 Degree (max)

n Differential Gain 1.5% (typ)

n Power Consumption 33mW (typ)

n (excluding reference current)

Applications

n Video Digitization

n Digital Still Cameras

n Set Top Boxes

n Camcorders

n Personal Computer Video

n Digital Television

n CCD Imaging

n Electro-Optics

Pin Configuration

10089001

TRISTATE&

is a registered trademark of National Semiconductor Corporation.

March 2003

ADC1173 8-Bit, 3-Volt, 15MSPS, 33mW A/D Converter

Summary of content (21 pages)

PAGE 1
ADC1173 8-Bit, 3-Volt, 15MSPS, 33mW A/D Converter General Description Features The ADC1173 is a low power, 15 MSPS analog-to-digital converter that digitizes signals to 8 bits while consuming just 33 mW of power (typ). The ADC1173 uses a unique architecture that achieves 7.6 Effective Bits. Output formatting is straight binary coding.
PAGE 2
ADC1173 Ordering Information Industrial (−40˚C ≤ TA ≤ +75˚C) Package ADC1173CIJM SOIC (EIAJ) ADC1173CIJMX SOIC (EIAJ) (tape & reel) ADC1173CIMTC TSSOP ADC1173CIMTCX TSSOP (tape & reel) ADC1173EVAL Evaluation Board Block Diagram 10089002 Pin Descriptions and Equivalent Circuits Pin No. Symbol Description Equivalent Circuit 19 VIN Analog signal input. Conversion range is VRB to VRT. 16 VRTS Reference Top Bias with internal pull-up resistor.
PAGE 3
Pin No. Symbol ADC1173 Pin Descriptions and Equivalent Circuits (Continued) Description Equivalent Circuit VRT Analog Input that is the high (top) side of the reference ladder of the ADC. Nominal range is 1.0V to AVDD. Voltage on VRT and VRB inputs define the VIN conversion range. Bypass well. See Section 2.0 for more information. 23 VRB Analog Input that is the low (bottom) side of the reference ladder of the ADC. Nominal range is 0V to 2.0V.
PAGE 4
ADC1173 Pin Descriptions and Equivalent Circuits Pin No. Symbol (Continued) Description Equivalent Circuit DVSS The ground return for the digital supply. AVSS and DVSS should be connected together close to the ADC1173. 14, 15, 18 AVDD Positive analog supply pin. Connected to a clean, quiet voltage source of +3V. AVDD and DVDD should have a common source and be separately bypassed with a 10 µF capacitor and a 0.1 µF ceramic chip capacitor. See Section 3.0 for more information.
PAGE 5
Operating Ratings(Notes 1, 2) (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. AVDD, DVDD 6.5V Voltage on Any Pin −0.3V to 6.5V VRT, VRB AVDD to VSS CLK, OE Voltage Digital Output Voltage DVSS to DVDD Input Current (Note 3) ± 25mA +2.7V to +3.6V |AVSS -DVSS| 0V to 100 mV VRT 1.0V to AVDD VRB 0V to 2.0V - 1.0V to 2.8V RT −0.5 to (AVDD + 0.
PAGE 6
ADC1173 Converter Electrical Characteristics (Continued) The following specifications apply for AVDD = DVDD = +3.0VDC, OE = 0V, VRT = +2.0V, VRB = 0V, CL = 20 pF, fCLK = 15MHz at 50% duty cycle. Boldface limits apply for TA = TMIN to TMAX; all other limits TA = 25˚C (Notes 7, 8) Symbol VRTS VRBS Typical (Note 9) Limits Units VRT connected to VRTS, VRB connected to VRBS 1.2 1.1 1.3 µAmin µAmax VRT connected to VRTS, VRB connected to VSS 1.
PAGE 7
(Continued) The following specifications apply for AVDD = DVDD = +3.0VDC, OE = 0V, VRT = +2.0V, VRB = 0V, CL = 20 pF, fCLK = 15MHz at 50% duty cycle. Boldface limits apply for TA = TMIN to TMAX; all other limits TA = 25˚C (Notes 7, 8) Symbol Parameter Typical (Note 9) Conditions Limits Units SFDR fIN = 1.31 MHz Spurious Free Dynamic Range fIN = 3.58 MHz fIN = 7.5 MHz 65 55 51 dB THD Total Harmonic Distortion fIN = 1.31 MHz fIN = 3.58 MHz fIN = 7.
PAGE 8
ADC1173 Typical Performance Characteristics INL vs Temperature DNL vs Temperature 10089020 10089021 SNR vs Temperature SNR vs fIN 10089033 10089022 THD vs Temperature SINAD vs Temperature 10089034 10089023 www.national.
PAGE 9
ADC1173 Typical Performance Characteristics (Continued) SINAD vs fIN SFDR vs Temperature 10089035 10089031 SFDR vs fIN Differential Gain vs Temperature 10089026 10089029 Differential Phase vs Temperature SNR vs fIN 10089036 10089027 9 www.national.
PAGE 10
ADC1173 Typical Performance Characteristics (Continued) THD vs fIN SINAD vs fIN 10089038 10089037 SFDR vs fIN SNR vs SUPPLY VOLTAGE 10089039 10089040 THD vs SUPPLY VOLTAGE SINAD vs SUPPLY VOLTAGE 10089041 www.national.
PAGE 11
ADC1173 Typical Performance Characteristics (Continued) SFDR vs SUPPLY VOLTAGE IDDD + IADD vs fCLK 10089032 10089043 TOD vs Temperature Spectral Response 10089025 10089028 11 www.national.
PAGE 12
ADC1173 OUTPUT HOLD TIME is the length of time that the output data is valid after the rise of the input clock. Specification Definitions ANALOG INPUT BANDWIDTH is a measure of the frequency at which the reconstructed output fundamental drops 3 dB below its low frequency value for a full scale input. The test is performed with fIN equal to 100 kHz plus integer multiples of fCLK. The input frequency at which the output is −3 dB relative to the low frequency input signal is the full power bandwidth.
PAGE 13
ADC1173 Timing Diagram 10089011 FIGURE 1. ADC1173 Timing Diagram 10089012 FIGURE 2. tEN, tDISTest Circuit 13 www.national.
PAGE 14
ADC1173 Figure 3 shows an example of an input circuit using the LM6181. This circuit has both gain and offset adjustments. If you desire to eliminate these adjustments, you should reduce the signal swing to avoid clipping at the ADC1173 output that can result from normal tolerances of all system components. With no adjustments, the nominal value for the amplifier feedback resistor is 510Ω and the 5.
PAGE 15
ADC1173 Applications Information (Continued) 10089013 FIGURE 3. Simple, Low Component Count, Self -Bias Reference application. Because of resistor tolerances, the reference voltages can vary by as much as 6%. Choose an amplifier that can drive a dynamic capacitance (see text). The reference self-bias circuit of Figure 3 is very simple and performance is adequate for many applications. Superior performance can generally be achieved by driving the reference pins with a low impedance source.
PAGE 16
ADC1173 Applications Information (Continued) 10089014 FIGURE 4. Better defining the ADC Reference Voltage. Self-bias is still used, but the reference voltages are trimmed by providing a small trim current with the operational amplifiers. 10089015 FIGURE 5. Driving the reference to force desired values requires driving with a low impedance source, provided by the transistors. Note that pins 16 and 22 are not connected. www.national.
PAGE 17
An alternative power-saving technique is to power up the ADC1173 with the clock active, then halt the clock in the low state after two clock cycles. Stopping the clock in the high state is not recommended as a power-saving technique. (Continued) If reference voltages are desired that are more than a few tens of millivolts from the self-bias values, the circuit of Figure 5 will allow forcing the reference voltages to whatever levels are desired.
PAGE 18
ADC1173 Applications Information 7.0 COMMON APPLICATION PITFALLS Driving the inputs (analog or digital) beyond the power supply rails. For proper operation, all inputs should not go more than 50mV below the ground pins or 50mV above the supply pins. Exceeding these limits on even a transient basis can cause faulty or erratic operation. It is not uncommon for high speed digital circuits (e.g., 74F and 74AC devices) to exhibit undershoot that goes more than a volt below ground.
PAGE 19
ADC1173 Applications Information (Continued) 10089018 FIGURE 8. 5.5 MHz Low Pass Filter to Eliminate Harmonics at the Signal Input. 10089019 FIGURE 9. 11 MHz Low Pass filter to eliminate harmonics at the signal input. Use at input frequencies of 5 MHz to 10 MHz 19 www.national.
PAGE 20
ADC1173 Physical Dimensions inches (millimeters) unless otherwise noted 24-Lead Package JM Ordering Number ADC1173CIJM NS Package Number M24D www.national.
PAGE 21
ADC1173 8-Bit, 3-Volt, 15MSPS, 33mW A/D Converter Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 24-Lead Package TC Ordering Number ADC1173CIMTC NS Package Number MTC24 LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1.