ADS5203IPFBRG4

Not Recommended For New Designs
 www.ti.com SBAS258A – JUNE 2002 – REVISED JULY 2002    

  
 ! ! FEATURES D 3.3V Single-Supply Operation D Dual Simultaneous Sample-and-Hold Inputs D Differential or Single-Ended Analog Inputs D Single or Dual Parallel Bus Output D 60dB SNR at fIN = 10.5MHz D 73dB SFDR at fIN = 10.5MHz D Low Power: 240mW D 300MHz Analog Input Bandwidth D 3.3V TTL/CMOS-Compatible Digital I/O D Internal or External Reference D Adjustable Reference Input Range D Power-Down (Standby) Mode D TQFP-48 Package APPLICATIONS D Digital Communications (Baseband Sampling) D Video Processing D Portable Instrumentation D Ultrasound DESCRIPTION The ADS5203 is a dual 10-bit, 40MSPS Analog-to-Digital Converter (ADC). It simultaneously converts each analog input signal into a 10-bit, binary coded digital word up to a maximum sampling rate of 40MSPS per channel. All digital inputs and outputs are 3.3V TTL/CMOS compatible. An innovative dual-pipeline architecture implemented in a CMOS process and the 3.3V supply results in very low power dissipation. In order to provide maximum flexibility, both top and bottom voltage references can be set from user-supplied voltages. Alternatively, if no external references are available, the on-chip internal references can be used. Both ADCs share a common reference to improve offset and gain matching. If external reference voltage levels are available, the internal references can be powered down independently from the rest of the chip, resulting in even greater power savings. The ADS5203 is characterized for operation from –40°C to +85°C and is available in a TQFP-48 package. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. !" 

$%& $ ' ($ ' % )* ( $ + , +(' ($%&  ')(%( $' ) - &' % . ' $'&$' ' $+ +   $/, +($ )(''$0 +' $ $(''  / $( + '$0 % )  &', Copyright  2002, Texas Instruments Incorporated Not Recommended For New Designs
 www.ti.com SBAS258A – JUNE 2002 – REVISED JULY 2002 ORDERING INFORMATION PRODUCT PACKAGE–LEAD PACKAGE DESIGNATOR(1) SPECIFIED TEMPERATURE RANGE PACKAGE MARKING ORDERING NUMBER ADS5203 TQFP–48 PFB –40°C to +85°C AZ5203 ADS5203IPFB ADS5203 TQFP–48 PFB –40°C to +85°C AZ5203 ADS5203IPFBR (1) For the most current specifications and package information, refer to our web site at www.ti.com. TRANSPORT MEDIA, QUANTITY Tray, 250 Tape and Reel, 1000 This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range unless otherwise noted(1). Supply Voltage: AVDD to AGND, DVDD to DGND . . . . . . . . . . –0.5V to 3.6V Supply Voltage: AVDD to DVDD, AGND to DGND . . . . . . . . . . –0.5V to 0.5V Digital Input Voltage Range to DGND . . . . . . . . . . . . –0.5V to DVDD + 0.5V Analog Input Voltage Range to AGND . . . . . . . . . . . . . –0.5V to AVDD + 0.5V Digital Output Voltage Applied from Ext. Source to DGND . . . . . . . –0.5V to DVDD + 0.5V Reference Voltage Input Range to AGND: VREFT, VREFB . . . . . . –0.5V to AVDD + 0.5V Operating Free-Air Temperature Range, TA (ADS5203I) . . . –40°C to +85°C Storage Temperature Range, TSTG . . . . . . . . . . . . . . . . . . –65°C to +150°C Soldering Temperature 1.6mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . 300°C (1) Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not implied. RECOMMENDED OPERATING CONDITIONS over operating free-air temperature range, TA, unless otherwise noted. PARAMETER CONDITIONS MIN NOM MAX UNIT 3.0 3.3 3.6 V Power Supply AVDD DVDD DRVDD Supply Su ly Voltage Analog and Reference Inputs Reference Input Voltage (top) Reference Input Voltage (bottom) Reference Voltage Differential VREFT VREFB VREFT – VREFB Reference Input Resistance Reference Input Current Analog Input Voltage, Differential Analog Input Voltage, Single–Ended(1) Analog Input Capacitance Clock Input(2) RREF IREF fCLK = 1MHz to 80MHz fCLK = 1MHz to 80MHz fCLK = 1MHz to 80MHz fCLK = 80MHz 1.9 2.0 2.15 V 0.95 1.0 1.1 V 0.95 1.0 1.1 V fCLK = 80MHz VIN VIN CI 1650 Ω 0.62 mA –1 1 CML – 1.0 CML + 1.0 8 0 V V pF AVDD V Analog Outputs CML Voltage AVDD/2 2.3 CML Output Resistance V kΩ Digital Inputs High-Level Input Voltage Low-Level Input Voltage VIH VIL 2.4 Input Capacitance Clock Period DVDD 0.8 DGND 5 V pF 12.5 ns Clock HIGH or LOW 5.25 ns 25 ns Pulse Duration tw(CLKH) , tw(CLKL) (40MHz) Clock HIGH or LOW (1) Applies only when the signal reference input connects to CML. (2) Clock pin is referenced to AVDD/AVSS. 11.25 ns Pulse Duration Clock Period 2 tc (80MHz) tw(CLKH), tw(CLKL) (80MHz) tc (40MHz) V Not Recommended For New Designs
 www.ti.com SBAS258A – JUNE 2002 – REVISED JULY 2002 ELECTRICAL CHARACTERISTICS over recommended operating conditions with fCLK = 80MHz and use of internal voltage references, unless otherwise noted. PARAMETER TEST CONDITIONS MIN TYP MAX UNIT Power Supply AVDD DVDD DRVDD IDD O Operating erating Su Supply ly Current Power Dissipation Standby Power PD PD(STBY) tPD 56 62 AVDD = DVDD = DRVDD = 3 3.3V, 3V CL = 10pF 10pF, fIN = 3.5MHz, 3 5MHz –1dBFS 1.7 2.2 15 26 PWDN_REF = ‘L’ 240 290 PWDN_REF = ‘H’ 220 240 95 150 STDBY = ‘H’, CLK Held HIGH or LOW Power-Up Time for All References from Standby Wake Up Time tWU External Reference mA mW µW 550 ms 40 µs Digital Inputs High-Level Input Current on Digital Inputs incl. CLK Low-Level Input Current on Digital Inputs incl. CLK IIH IIL AVDD = DVDD = DRVDD = 3.6V 3 6V –1 1 µA –1 1 µA Digital Outputs High-Level Output Voltage VOH Low-Level Output Voltage VOL Output Capacitance High-Impedance State Output Current to High-Level High-Impedance State Output Current to Low-Level CO IOZH IOZL AVDD = DVDD = DRVDD = 3.0V at IOH = 50µA, Digital Outputs Forced HIGH AVDD = DVDD = DRVDD = 3.0V at IOL = 50µA, Digital Outputs Forced LOW 2.8 0.04 V 0.2 V +1 µA +1 µA 5 AVDD = DVDD = DRVDD = 3.6V 3 6V –1 –1 CLOAD = 10pF, Single–Bus Mode CLOAD = 10pF, Dual–Bus Mode Data Output Rise Rise-and-Fall and Fall Time 2.96 pF 3 ns 5 ns Reference Outputs Reference Top Voltage Reference Bottom Voltage Differential Reference Votage VREFTO VREFBO REFT – REFB 1.9 2 2.1 V 0.95 1 1.05 V 0.95 1.0 1.05 V TA = –40°C 40°C to +85°C –1.5 15 ±0 4 ±0.4 +1 +1.5 5 LSB TA = –40°C to +85°C –0.9 ±0.5 +1 LSB 0.12 ±1.5 %FS 0.28 ±1.5 %FS 0.24 ±1.5 %FS Absolute Min/Max Values Valid and Tested for AVDD = 3.3V DC Accuracy Integral Nonlinearity, Nonlinearity End Point Differential Nonlinearity Missing Codes Zero Error(3) Full–Scale Error Gain Error INL DNL Internal References(1) Internal References(2) No Missing Codes Assured AVDD = DVDD = DRVDD = 3 3.3V 3V External References (3) (1) Integral nonlinearity refers to the deviation of each individual code from a line drawn from zero to full-scale. The point used as zero occurs ½LSB before the first code transition. The full-scale point is defined as a level ½LSB beyond the last code transition. The deviation is measured from the center of each particular code to the best-fit line between these two endpoints. (2) An ideal ADC exhibits code transitions that are exactly 1LSB apart. DNL is the deviation from this ideal value. Therefore, this measure indicates how uniform the transfer function step sizes are. The ideal step size is defined here as the step size for the device under test, (i.e., (last transition level – first transition level)/(2n – 2)). Using this definition for DNL separates the effects of gain and offset error. A minimum DNL better than –1LSB ensures no missing codes. (3) Zero error is defined as the difference in analog input voltage—between the ideal voltage and the actual voltage—that will switch the ADC output from code 0 to code 1. The ideal voltage level is determined by adding the voltage corresponding to ½LSB to the bottom reference level. The voltage corresponding to 1LSB is found from the difference of top and bottom references divided by the number of ADC output levels (1024). Full-scale error is defined as the difference in analog input voltage—between the ideal voltage and the actual voltage—that will switch the ADC output from code 1022 to code 1023. The ideal voltage level is determined by subtracting the voltage corresponding to 1.5LSB from the top reference level. The voltage corresponding to 1LSB is found from the difference of top and bottom references divided by the number of ADC output levels (1024). 3 Not Recommended For New Designs
 www.ti.com SBAS258A – JUNE 2002 – REVISED JULY 2002 DYNAMIC PERFORMANCE(1) TA = TMIN to TMAX, AVDD = DVDD = DRVDD = 3.3V, fIN = –1dBFS, Internal Reference, fCLK = 80MHz, fS = 40MSPS, and Differential Input Range = 2Vp–p, unless otherwise noted. PARAMETER Effective Number of Bits Total Harmonic Distortion Signal-to-Noise g Ratio Signal-to-Noise g Ratio + Distortion TEST CONDITIONS ENOB THD SNR SINAD fIN = 3.5MHz fIN = 10.5MHz SFDR Analog Input Bandwidth 2-Tone Intermodulation Distortion A/B Channel Crosstalk A/B Channel Offset Mismatch IMD 9.3 fIN = 20MHz fIN = 3.5MHz TYP MAX UNIT 9.7 Bits 9.7 Bits 9.6 Bits –71 dB fIN = 10.5MHz fIN = 20MHz –71 –68 dB fIN = 3.5MHz fIN = 10.5MHz 60.5 dB 60.5 dB fIN = 20MHz fIN = 3.5MHz 60 dB 60 dB 60 dB 60 dB 75 dB 73 dB fIN = 10.5MHz fIN = 20MHz Spurious-Free Dynamic y Range g MIN fIN = 3.5MHz fIN = 10.5MHz 57 69 –66 dB fIN = 20MHz See Note (2) 70.5 dB 300 MHz f1 = 9.5MHz, f2 = 9.9MHz –68 dBc –75 0.016 dBc 1.75 % FS A/B Channel Full-Scale Error Mismatch 0.016 1.0 % FS (1) These specifications refer to a 25Ω series resistor and 15pF differential capacitor between A/B+ and A/B– inputs; any source impedance will bring the bandwidth down. (2) Analog input bandwidth is defined as the frequency at which the sampled input signal is 3dB down on unity gain and is limited by the input switch impedance. 4 Not Recommended For New Designs
 www.ti.com SBAS258A – JUNE 2002 – REVISED JULY 2002 PIN CONFIGURATION Terminal Functions TERMINAL NAME I/O DESCRIPTION DA 9..0 NO. 1,13 12, 24 14-23 DB 9..0 2-11 O 48 26 I O Output Enable. A LOW on this terminal will enable the data output bus, COUT and COUT. O I I I Inverted Latch Clock or multiplexer control for the Data Outputs. COUT is in tri-state during power–down. DVSS CLK 25 44 43 47 DVDD AVDD 45 27,37,41 I I MODE REFT 46 28,36,40 35 34 31 I I I I I/O REFB 30 I/O CML 32 O PDWN_REF 33 42 39 38 29 I I I I DRVDD DRVSS OE COUT COUT SELB AVSS B– B+ STBY A– A+ TP I I O Supply Voltage for Output Drivers Digital Ground for Output Drivers Data Outputs for Bus A. D9 is MSB. This is the primary bus. Data from both input channels can be output on this bus or data from the A channel only. Pins SELB and MODE select the output mode. The data outputs are in tri-state during power-down (refer to Timing Options table). Data Outputs for Bus B. D9 is MSB. This is the second bus. Data is output from the B-channel when dual bus output mode is selected. The data outputs are in tri-state during power-down and single-bus modes (refer to Timing Options table). Latch Clock for the Data Outputs. COUT is in tri-state during power-down. Selects either single-bus data output or dual-bus data output. A LOW selects dual-bus data output. Digital Ground Clock Input. The input is sampled on each rising edge of CLK when using a 40MHz input and alternate rising edges when using an 80MHz input. The clock pin is referenced to AVDD and AVSS to reduce noise coupling from digital logic. Digital Supply Voltage Analog Supply Voltage Selects the COUT and COUT output mode. Analog Ground Negative Input for the Analog B Channel Positive Input for the Analog B Channel Reference Voltage Top. The voltage at this terminal defines the top reference voltage for the ADC. Sufficient filtering should be applied to this input: the use of 0.1µF capacitor between REFT and AVSS is recommended. Additionally a 0.1µF capacitor should be connected between REFT and REFB. Reference Voltage Bottom. The voltage at this terminal defines the bottom reference voltage for the ADC. Sufficient filtering should be applied to this input: the use of 0.1µF capacitor between REFB and AVSS is recommended. Additionally a 0.1µF capacitor should be connected between REFT and REFB. Common-Mode Level. This voltage is equal to (AVDD – AVSS)/2. An external capacitor of 0.1µF should be connected between this terminal and AVSS when CML is used as a bias voltage. No capacitor is required if CML is not used. Power-Down for Internal Reference Voltages. A HIGH on this terminal disables the internal reference circuit. Standby Input. A HIGH on this terminal will power down the device. Negative Input for the Analog A Channel Positive Input for Analog A Channel This pin must be connected to DVDD. It should not be left floating. 5 Not Recommended For New Designs
 www.ti.com SBAS258A – JUNE 2002 – REVISED JULY 2002 TIMING REQUIREMENTS PARAMETER Input Clock Rate TEST CONDITIONS MIN fCLK Conversion Rate MAX UNIT 1 TYP 80 MHz 1 40 MSPS Clock Duty Cycle (40MHz) 45 50 55 % Clock Duty Cycle (80MHz) 42 50 58 % 9 14 ns Output Delay Time td(o) CL = 10pF Mux Setup Time ts(m) 9 10.4 ns Mux Hold Time th(m) 1.7 2.1 ns Output Setup Time ts(o) CL = 10pF 9 10.4 ns Output Hold Time th(o) CL = 10pF 1.5 2.2 ns Pipeline Delay (latency, channels A and B) td(pipe) MODE = 0, SELB = 0 8 CLK Cycles Pipeline Delay (latency, channels A and B) td(pipe) MODE = 1, SELB = 0 4 CLK Cycles Pipeline Delay (latency, channel A) td(pipe) MODE = 0, SELB = 1 8 CLK Cycles Pipeline Delay (latency, channel B) td(pipe) MODE = 0, SELB = 1 9 CLK Cycles Pipeline Delay (latency, channel A) td(pipe) MODE = 1, SELB = 1 8 CLK Cycles Pipeline Delay (latency, channel B) td(pipe) MODE = 1, SELB = 1 9 CLK Cycles ns Aperture Delay Time td(a) 3 Aperture Jitter tJ(a) 1.5 Disable Time, OE Rising to Hi–Z tdis 5 8 ns Enable Time, OE Falling to Valid Data ten 5 8 ns ps, rms TIMING OPTIONS MODE SELB TIMING DIAGRAM FIGURE 80MHz Input Clock, Dual-Bus Output, COUT = 40MHz OPERATING MODE 0 0 1 40MHz Input Clock, Dual-Bus Output, COUT = 40MHz 1 0 2 80MHz Input Clock, Single-Bus Output, COUT = 40MHz 0 1 3 80MHz Input Clock, Single-Bus Output, COUT = 80MHz 1 1 4 6 Not Recommended For New Designs
 www.ti.com SBAS258A – JUNE 2002 – REVISED JULY 2002 TIMING DIAGRAMS Sample A1 and B1 Analog_A Analog_B 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 CLK(1) CLK40INT(2) td(pipe) ADCOUTA[9:0](3) A1 A2 A3 A4 A5 B1 td(o) B2 B3 B4 B5 td(pipe) ADCOUTB[9:0](3) DA[9:0] A1 A2 A3 A4 A5 B1 B2 B3 B4 B5 A&B 4 A&B 5 td(o) DB[9:0] DAB[19:0] is used to illustrate the placement of the busses DA and DB DAB[19:0] A&B 1 A&B 2 ts(o) th(o) A&B 3 COUT COUT NOTES: (1) In this option CLK = 80MHz. (2) CLK40INT refers to 40MHz Internal Clock, per channel. (3) Internal signal only. Figure 1. Dual Bus Output—Option 1. Sample A1 and B1 Analog_A Analog_B 1 2 3 4 5 6 7 8 9 10 CLK(1) td(pipe) ADCOUTA[9:0](2) A1 A2 A3 A4 A5 B1 td(o) B2 B3 B4 B5 td(pipe) ADCOUTB[9:0](2) DA[9:0] A1 A2 A3 A4 A5 B1 B2 B3 B4 B5 A&B 3 A&B 4 A&B 5 td(o) DB[9:0] DAB[19:0] is used to illustrate the combined busses DA and DB DAB[19:0] A&B 1 A&B 2 ts(o) th(o) COUT COUT NOTE: (1) In this option CLK = 40MHz, per channel. (2) Internal signal only Figure 2. Dual Bus Output—Option 2. 7 Not Recommended For New Designs
 www.ti.com SBAS258A – JUNE 2002 – REVISED JULY 2002 TIMING DIAGRAMS (Cont.) Sample A1 and B1 Analog_A Analog_B 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 CLK(1) CLK40INT(2) td(pipe) ADCOUTA[9:0](3) A1 A2 A3 A4 A5 B1 td(o) B2 B3 B4 B5 td(pipe) ADCOUTB[9:0](3) td(o) DA[9:0] A1 B1 A2 B2 A3 B3 th(o) A4 B4 A5 B5 ts(o) COUT th(o) ts(o) COUT NOTES: (1) In this option CLK = 80MHz. (2) CLK40INT refers to 40MHz Internal Clock, per channel. (3) Internal signal only. Figure 3. Single Bus Output—Option 1. Sample A1 and B1 Analog_A Analog_B 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 CLK(1) CLK40INT(2) td(pipe) ADCOUTA[9:0](3) A1 A2 A3 A4 A5 B1 td(o) B2 B3 B4 B5 td(pipe) ADCOUTB[9:0](3) td(o) DA[9:0] A1 B1 th(o) A2 B2 A3 B3 A4 B4 A5 B5 ts(o) COUT ts(m) th(m) COUT NOTES: (1) In this option CLK = 80MHz. (2) CLK40INT refers to 40MHz Internal Clock, per channel. (3) Internal signal only. Figure 4. Single Bus Output—Option 2. 8 Not Recommended For New Designs
 www.ti.com SBAS258A – JUNE 2002 – REVISED JULY 2002 TYPICAL CHARACTERISTICS At TA = 25°C, AVDD = DVDD = DRVDD = 3.3V, fIN = –0.5dBFS, Internal Reference, fCLK = 80MHz, fS = 40MSPS, Differential Input Range = 2Vp-p, 25Ω series resistor, and 15pF differential capacitor at A/B+ and A/B– inputs, unless otherwise noted. 9 
 Not Recommended For New Designs www.ti.com SBAS258A – JUNE 2002 – REVISED JULY 2002 Typical Characteristics (Cont.) At TA = 25°C, AVDD = DVDD = DRVDD = 3.3V, fIN = –0.5dBFS, Internal Reference, fCLK = 80MHz, fS = 40MSPS, Differential Input Range = 2Vp-p, 25Ω series resistor, and 15pF differential capacitor at A/B+ and A/B– inputs, unless otherwise noted. 10 Not Recommended For New Designs
 www.ti.com SBAS258A – JUNE 2002 – REVISED JULY 2002 PRINCIPLE OF OPERATION The ADS5203 implements a dual high-speed, 10-bit, 40MSPS converter in a cost-effective CMOS process. The differential inputs on each channel are sampled simultaneously. Signal inputs are differential and the clock signal is single-ended. The clock signal is either 80MHz or 40MHz, depending on the device configuration set by the user. Powered from 3.3V, the dual-pipeline design architecture ensures low-power operation and 10-bit resolution. The digital inputs are 3.3V TTL/CMOS compatible. Internal voltage references are included for both bottom and top voltages. Alternatively, the user may apply externally generated reference voltages. In doing so, the input range can be modified to suit the application. The ADC is a 5-stage pipelined ADC with 4 stages of fully-differential switched capacitor sub-ADC/MDAC pairs and a single sub-ADC in stage 5. All stages deliver 2 bits of the final conversion result. A digital error correction is used to compensate for modest comparator offsets in the sub-ADCs. The analog input signal is sampled on capacitors CSP and CSN while the internal device clock is low. The sampled voltage is transferred to capacitors CHP and CHN and held on these while the internal device clock is high. The SHA can sample both single-ended and differential input signals. The load presented to the AIN pin consists of the switched input sampling capacitor CS (approximately 2pF) and its various stray capacitances. A simplified equivalent circuit for the switched capacitor input is shown in Figure 6. The switched capacitor circuit is modeled as a resistor RIN. fCLK is the clock frequency, which is 40MHz at full speed, and CS is the sampling capacitor. Using 25Ω series resistors and a differential 15pF capacitor at the A/B+ and A/B– inputs is recommended to reduce noise. NOTE: AIN can be any variation of A or B inputs. fCLK = 40MHz SAMPLE-AND-HOLD AMPLIFIER Figure 5 shows the internal SHA architecture. The circuit is balanced and fully differential for good supply noise rejection. The sampling circuit has been kept as simple as possible to obtain good performance for high-frequency input signals. VCM VCM = 0.5 S (V(A/B+) + V(A/B–)) Figure 6. Equivalent Circuit for the Switched Capacitor Input. ANALOG INPUT, DIFFERENTIAL CONNECTION Figure 5. SHA Architecture. The analog input of the ADS5203 is a differential architecture that can be configured in various ways depending on the signal source and the required level of performance. A fully differential connection will deliver the best performance from the converter. The analog inputs must not go below AVSS or above AVDD. The inputs can be biased with any common-mode voltage provided that the minimum and maximum input voltages stay within the range AVSS to AVDD. It is recommended to bias the inputs with a common-mode voltage around AVDD/2. This can be accomplished easily with the output voltage source CML, which is equal to AVDD/2. CML is made available to the user to help simplify circuit design. This output voltage source is not designed to be a reference or to be loaded but makes an excellent DC bias source and stays well within the analog input common-mode voltage range over temperature. 11 
 Not Recommended For New Designs www.ti.com SBAS258A – JUNE 2002 – REVISED JULY 2002 Table 1 lists the digital outputs for the corresponding analog input voltages. Table 1. Output Format for Differential Configuration DIFFERENTIAL INPUT VIN = (A+/B+) – (A–/B–), REFT – REFB = 1V ANALOG INPUT VOLTAGE DIGITAL OUTPUT CODE VIN = +1V 3FFH VIN = 0 200H VIN = –1V 000H DC–COUPLED DIFFERENTIAL ANALOG INPUT CIRCUIT Driving the analog input differentially can be achieved in various ways. Figure 7 gives an example where a single-ended signal is converted into a differential signal by using a fully differential amplifier such as the THS4141. The input voltage applied to VOCM of the THS4141 shifts the output signal into the desired common-mode level. VOCM can be connected to CML of the ADS5203, the common-mode level is shifted to AVDD/2. Figure 8. AC-Coupled Differential Transformer. Input with ANALOG INPUT, SINGLE–ENDED CONFIGURATION For a single-ended configuration, the input signal is applied to only one of the two inputs. The signal applied to the analog input must not go below AVSS or above AVDD. The inputs can be biased with any common-mode voltage provided that the minimum and maximum input voltage stays within the range AVSS to AVDD. It is recommended to bias the inputs with a common-mode voltage around AVDD/2. This can be accomplished easily with the output voltage source CML, which is equal to AVDD/2. An example for this is shown in Figure 9. Figure 7. Single-Ended to Differential Conversion Using the THS4141. Figure 9. AC–Coupled, Single-Ended Configuration. AC–COUPLED DIFFERENTIAL ANALOG INPUT CIRCUIT Driving the analog input differentially can be achieved by using a transformer-coupling, as illustrated in Figure 8. The center tap of the transformer is connected to the voltage source CML, which sets the common-mode voltage to AVDD/2. No buffer is required at the output of CML since the circuit is balanced and no current is drawn from CML. 12 The signal amplitude to achieve full scale is 2Vp-p. The signal, which is applied at A/B+ is centered at the bias voltage. The input A/B– is also centered at the bias voltage. The CML output is connected via a 4.7kΩ resistor to bias the input signal. There is a direct DC-coupling from CML to A/B– while this input is AC-decoupled through the 10µF and 0.1µF capacitors. The decoupling minimizes the coupling of A/B+ into the A/B– path. Not Recommended For New Designs
 www.ti.com SBAS258A – JUNE 2002 – REVISED JULY 2002 Table 2 lists the digital outputs for the corresponding analog input voltages. Table 2. Output Format for Single-Ended Configuration. SINGLE–ENDED INPUT, REFT – REFB = 1V ANALOG INPUT VOLTAGE DIGITAL OUTPUT CODE V(A/B+) = VCML + 1V 3FFH V(A/B+) = VCML 200H V(A/B+) = VCML – 1V 000H REFERENCE TERMINALS The ADS5203’s input range is determined by the voltages on its REFB and REFT pins. The ADS5203 has an internal voltage reference generator that sets the ADC reference voltages REFB = 1V and REFT = 2V. The internal ADC references must be decoupled to the PCB AVSS plane. The recommended decoupling scheme is shown in Figure 10. The internal reference voltages commonmode voltage is 1.5V. DIGITAL INPUTS Digital inputs are CLK, STDBY, PWDN_REF, OE, MODE, and SELB. These inputs don’t have a pull-down resistor to ground, therefore, they should not be left floating. The CLK signal at high frequencies should be considered as an ‘analog’ input. CLK should be referenced to AVDD and AVSS to reduce noise coupling from the digital logic. Overshoot/undershoot should be minimized by proper termination of the signal close to the ADS5203. An important cause of performance degradation for a high-speed ADC is clock jitter. Clock jitter causes uncertainty in the sampling instant of the ADC, in addition to the inherent uncertainty on the sampling instant caused by the part itself, as specified by its aperture jitter. There is a theoretical relationship between the frequency f and resolution (2N) of a signal that needs to be sampled on one hand, and on the other hand the maximum amount of aperture error dtmax that is tolerable. It is given by the following relation: dtmax = 1/[π f 2(N+1)] As an example, for a 10-bit converter with a 20MHz input, the jitter needs to be kept less than 7.8ps in order not to have changes in the LSB of the ADC output due to the total aperture error. DIGITAL OUTPUTS Figure 10. Recommended External Decoupling for the Internal ADC Reference. External ADC references can also be chosen. The ADS5203 internal references must be disabled by tying PWDN_REF HIGH before applying the external reference sources to the REFT and REFB pins. The external reference voltages common-mode voltage should be 1.5V for best ADC performance. The output of ADS5203 is an unsigned binary code. Capacitive loading on the output should be kept as low as possible (a maximum loading of 10pF is recommended) to ensure best performance. Higher output loading causes higher dynamic output currents and can, therefore, increase noise coupling into the part’s analog front end. To drive higher loads, the use of an output buffer is recommended. When clocking output data from ADS5203, it is important to observe its timing relation to COUT. Please refer to the timing section for detailed information on the pipeline latency in the different modes. For safest system timing, COUT and COUT should be used to latch the output data, (see Figures 1 to 4). In Figure 4, COUT can be used by the receiving device to identify whether the data presently on the bus is from channel A or B. LAYOUT, DECOUPLING, AND GROUNDING RULES Figure 11. External ADC Reference Configuration. Proper grounding and layout of the PCB on which the ADS5203 is populated is essential to achieve the stated performance. It is advised to use separate analog and digital ground planes that are spliced underneath the IC. The ADS5203 has digital and analog pins on opposite sides of the package to make this easier. Since there is no connection internally between analog and digital grounds, they have to be joined on the PCB. It is advised to do this at one point in close proximity to the ADS5203. 13 
 Not Recommended For New Designs www.ti.com SBAS258A – JUNE 2002 – REVISED JULY 2002 As for power supplies, separate analog and digital supply pins are provided on the part (AVDD/DVDD). The supply to the digital output drivers is kept separate as well (DRVDD). Lowering the voltage on this supply to 3.0V instead of the nominal 3.3V improves performance because of the lower switching noise caused by the output buffers. Due to the high sampling rate and switched-capacitor architecture, the ADS5203 generates transients on the supply and reference lines. Proper decoupling of these lines is, therefore, essential. NOTES 1. Integral Nonlinearity (INL)—Integral nonlinearity refers to the deviation of each individual code from a line drawn from zero to full-scale. The point used as zero occurs ½LSB before the first code transition. The full-scale point is defined as a level ½LSB beyond the last code transition. The deviation is measured from the center of each particular code to the true straight line between these two endpoints. 2. Differential Nonlinearity (DNL)—An ideal ADC exhibits code transitions that are exactly 1LSB apart. DNL is the deviation from this ideal value. Therefore, this measure indicates how uniform the transfer function step sizes are. The ideal step size is defined here as the step size for the device under test (i.e., (last transition level – first transition level)/(2n – 2)). Using this definition for DNL separates the effects of gain and offset error. A minimum DNL better than –1LSB ensures no missing codes. 3. Zero and Full-Scale Error—Zero error is defined as the difference in analog input voltage—between the ideal voltage and the actual voltage—that will switch the ADC output from code 0 to code 1. The ideal voltage level is determined by adding the voltage corresponding to ½LSB to the bottom reference level. The voltage corresponding to 1LSB is found from the difference of top and bottom references divided by the number of ADC output levels (1024). Full-scale error is defined as the difference in analog input voltage—between the ideal voltage and the actual voltage—that will switch the ADC output from code 1022 to code 1023. The ideal voltage level is determined by subtracting the voltage corresponding to 1.5LSB from the top reference level. The voltage corresponding to 1LSB is found from the difference of top and bottom references divided by the number of ADC output levels (1024). 14 4. Analog Input Bandwidth—The analog input bandwidth is defined as the max. frequency of a 1dBFS input sine that can be applied to the device for which an extra 3dB attenuation is observed in the reconstructed output signal. 5. Output Timing—Output timing td(o) is measured from the 1.5V level of the CLK input falling edge to the 10%/90% level of the digital output. The digital output load is not higher than 10pF. Output hold time th(o) is measured from the 1.5V level of the COUT input rising edge to the 10%/90% level of the digital output. The digital output is load is not less than 2pF. Aperture delay td(A) is measured from the 1.5V level of the CLK input to the actual sampling instant. The OE signal is asynchronous. OE timing tdis is measured from the VIH(MIN) level of OE to the high-impedance state of the output data. The digital output load is not higher than 10pF. OE timing ten is measured from the VIL(MAX) level of OE to the instant when the output data reaches VOH(min) or VOL(max) output levels. The digital output load is not higher than 10pF. 6. Pipeline Delay (latency)—The number of clock cycles between conversion initiation on an input sample and the corresponding output data being made available from the ADC pipeline. Once the data pipeline is full, new valid output data is provided on every clock cycle. The first valid data is available on the output pins after the latency time plus the output delay time td(o) through the digital output buffers. Note that a minimum td(o) is not guaranteed because data can transition before or after a CLK edge. It is possible to use CLK for latching data, but at the risk of the prop delay varying over temperature, causing data to transition one CLK cycle earlier or later. The recommended method is to use the latch signals COUT and COUT which are designed to provide reliable setup and hold times with respect to the data out. 7. Wake-Up Time—Wake-up time is from the power-down state to accurate ADC samples being taken, and is specified for external reference sources applied to the device and an 80MHz clock applied at the time of release of STDBY. Cells that need to power up are the bandgap, bias generator, SHAs, and ADCs. 8. Power-Up Time—Power-up time is from the power-down state to accurate ADC samples being taken with an 80MHz clock applied at the time of release of STDBY. Cells that need to power up are the bandgap, internal reference circuit, bias generator, SHAs, and ADCs. PACKAGE OPTION ADDENDUM www.ti.com 5-Oct-2015 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (°C) Device Marking (4/5) ADS5203IPFB OBSOLETE TQFP PFB 48 TBD Call TI Call TI -40 to 85 ADS5203IPFBG4 OBSOLETE TQFP PFB 48 TBD Call TI Call TI -40 to 85 ADS5203IPFBR OBSOLETE TQFP PFB 48 TBD Call TI Call TI -40 to 85 ADS5203IPFBRG4 OBSOLETE TQFP PFB 48 TBD Call TI Call TI -40 to 85 AZ5203 AZ5203 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com 5-Oct-2015 In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 2 MECHANICAL DATA MTQF019A – JANUARY 1995 – REVISED JANUARY 1998 PFB (S-PQFP-G48) PLASTIC QUAD FLATPACK 0,27 0,17 0,50 36 0,08 M 25 37 24 48 13 0,13 NOM 1 12 5,50 TYP 7,20 SQ 6,80 9,20 SQ 8,80 Gage Plane 0,25 0,05 MIN 0°– 7° 1,05 0,95 Seating Plane 0,75 0,45 0,08 1,20 MAX 4073176 / B 10/96 NOTES: A. All linear dimensions are in millimeters. B. This drawing is subject to change without notice. C. Falls within JEDEC MS-026 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All semiconductor products (also referred to herein as “components”) are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in TI’s terms and conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. 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