ADS8519 www.ti.com SLAS462 – JUNE 2007 16-BIT 250-KSPS SERIAL CMOS SAMPLING ANALOG-TO-DIGITAL CONVERTER FEATURES 1 • • • • • • • 0-V to 8.192-V, ±5-V, and ±10-V Input Ranges 90-dB SNR With 20-kHz Input ±2.0 LSB Max INL ±1 LSB Max DNL; 16-Bits No Missing Codes SPI Compatible Serial Output with Daisy-Chain (TAG) Feature and 3-State Bus 5-V Analog Supply, 5.25 V ~ 1.65 V I/O Supply Pinout Similar to ADS7809 (Low Speed) and 12-Bit ADS7808/8508 No External Precision Resistors Required Uses Internal or External Reference 100-mW Typ Power Dissipation at 250 KSPS 32-Pin 5x5 QFN and 28-Pin SSOP Packages Simple DSP Interface The ADS8519 is a complete 16-bit sampling analog-to-digital (A/D) converter using state-of-the-art CMOS structures. It contains a complete 16-bit, capacitor- based, successive approximation register (SAR) A/D converter with sample-and-hold, reference, clock, and a serial data interface. Data can be output using the internal clock or can be synchronized to an external data clock. The ADS8519 also provides an output synchronization pulse for ease of use with standard DSP processors. The ADS8519 is specified at a 250-kHz sampling rate over the full temperature range. Precision resistors provide various input ranges including ±10 V and 0 V to 5 V, while the innovative design allows operation from a single 5-V supply with power dissipation under 100 mW. The ADS8519 is available in 32-pin 5x5 QFN and 28-pin SSOP packages, both fully specified for operation over the industrial -40°C to 85°C temperature range. APPLICATIONS • • • • • DESCRIPTION Industrial Process Control Data Acquisition Systems Digital Signal Processing Medical Equipment Instrumentation Successive Approximation Register Clock CDAC 7 kΩ R1IN 7 kΩ EXT/INT BUSY 25.67 kΩ R2IN 2.87 kΩ R3IN Comparator CAP Buffer 4 kΩ REF Internal +4.096 V Ref Serial Data Out & Control DATACLK TAG DATA R/C SB/BTC CS PWRD 1 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. PRODUCT PREVIEW information concerns products in the formative or design phase of development. Characteristic data and other specifications are design goals. Texas Instruments reserves the right to change or discontinue these products without notice. Copyright © 2007, Texas Instruments Incorporated PRODUCT PREVIEW • • • • • ADS8519 www.ti.com SLAS462 – JUNE 2007 These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. PACKAGE/ORDERING INFORMATION (1) MINIMUM INL (LSB) PRODUCT ADS8519IB NO MISSING CODE ±2 MINIMUM SINAD (dB) 16 SPECIFICATION TEMPERATURE RANGE 90 PACKAGE LEAD PACKAGE DESIGNATOR 5x5 QFN-32 RHB –40°C to 85°C SSOP-28 5x5 QFN-32 ADS8519I ±3 15 87 (1) ADS8519IBRHB ADS8519IBRHBR ADS8519IBDB DB ADS8519IBDBR RHB –40°C to 85°C SSOP-28 ORDERING NUMBER ADS8519IRHB ADS8519IRHBR ADS8519IDB DB ADS8519IDBR TRANSPORT MEDIA, QTY Tube, 50 Tape and Reel, 2000 Tube, 50 Tape and Reel, 2000 Tube, 50 Tape and Reel, 2000 Tube, 50 Tape and Reel, 2000 For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI website at www.ti.com. PRODUCT PREVIEW ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range (unless otherwise noted) (1) UNIT Analog inputs R1IN ±25 V R2IN ±25 V R3IN ±25 V REF +VANA + 0.3 V to AGND2 - 0.3 V DGND, AGND2 Ground voltage differences ±0.3 V VANA 6V VDIG to VANA 0.3 V VDIG 6V Digital inputs –0.3 V to +VDIG + 0.3 V Maximum junction temperature 165°C Internal power dissipation 700 mW Lead temperature (soldering, 10s) (1) 300°C All voltage values are with respect to network ground terminal. ELECTRICAL CHARACTERISTICS At TA = –40°C to 85°C, fs = 250 kHz, VDIG = VANA = 5 V, using internal reference (unless otherwise specified) ADS8519I PARAMETER ADS8519IB TEST CONDITIONS UNIT MIN TYP Resolution MAX MIN TYP 16 MAX 16 Bits ANALOG INPUT Voltage ranges (1) Impedance (1) Capacitance 50 50 pF THROUGHPUT SPEED Conversion cycle time Acquire and convert Throughput rate 4 250 4 250 μs kHz DC ACCURACY INL Integral linearity error –3 3 –2 2 LSB (2) DNL Differential linearity error –2 2 –1 1 LSB (1) (2) 2 ±10 V, ±5 V, 0 V to 8.192 V, etc. (see Table 3) LSB means least significant bit. For the ±10-V input range, one LSB is 305 μV. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS8519 ADS8519 www.ti.com SLAS462 – JUNE 2007 ELECTRICAL CHARACTERISTICS (continued) At TA = –40°C to 85°C, fs = 250 kHz, VDIG = VANA = 5 V, using internal reference (unless otherwise specified) ADS8519I PARAMETER UNIT MIN No missing codes MIN TYP MAX 16 Bits 0.67 LSB –0.05 ±0.5 0.05 –0.05 ±0.5 0.05 –0.5 TBD 0.5 –0.5 TBD 0.5 –0.05 0.05 –0.05 0.05 –0.5 0.5 –0.5 0.5 4 –2 Int. Ref. All other ranges %FSR Int. Ref. ±10 V range ±7 ±7 ppm/°C Ext. Ref. All other ranges Full-scale error drift %FSR Ext. Ref. Bipolar zero error (4) ±2 –4 Bipolar zero error drift Unipolar zero error (4) MAX 0.67 ±10 V range Full-scale error drift Full-scale error (4) (5) TYP 15 Transition noise (3) Full-scale error (4) (5) ADS8519IB TEST CONDITIONS ±2 ±2 8.192 V –20 Unipolar zero error drift Recovery to rated accuracy after power down 1-μF Capacitor to CAP Power supply sensitivity (VDIG = VANA = VD) +4.75 V < VD < +5.25 V –8 95 ppm/°C 2 ±2 20 –20 20 ±0.4 ±0.4 1 1 8 –8 mV ppm/°C mV ppm/°C ms 8 LSB SFDR Spurious-free dynamic range fI = 20 kHz THD Total harmonic distortion fI = 20 kHz SINAD Signal-to-(noise+distortion) fI = 20 kHz –100 87 –60-dB Input SNR Signal-to-noise ratio fI = 20 kHz 102 97 –94 91 30 88 Full-power bandwidth (7) 92 90 500 dB (6) 102 –100 89 PRODUCT PREVIEW AC ACCURACY –96 dB 91 dB 32 dB 92 dB 500 kHz SAMPLING DYNAMICS Aperture delay Transient response 5 FS Step 5 2 Overvoltage recovery (8) ns 2 150 150 μs ns REFERENCE Internal reference voltage No load 4.076 4.096 4.116 4.076 4.096 4.116 V Internal reference source current (must use external buffer) 1 1 μA Internal reference drift 8 8 ppm/°C External reference voltage range for specified linearity External reference current drain 2.5 Ext. 4.096-V Ref. 4.096 4.1 2.5 100 4.096 4.1 V 100 μA V DIGITAL INPUTS Logic levels VIL Low-level input voltage VDIG = 1.65 V ~ 5.25 V –0.3 0.8, 0.35 xVDIG –0.3 0.8, 0.35 xVDIG VIH High-level input voltage VDIG = 1.65 V ~ 5.25 V 2.0, 0.65 xVDIG VDIG +0.3 V 2.0, 0.65 xVDIG VDIG +0.3 V V IIL Low-level input current VIL = 0 V ±10 ±10 μA IIH High-level input current VIH = 5 V ±10 ±10 μA DIGITAL OUTPUTS Data format (Serial 16-bits) Data coding (Binary 2's complement or straight binary) Pipeline delay (Conversion results only available after completed conversion.) (3) (4) (5) (6) (7) (8) Typical rms noise at worst case transitions and temperatures. As measured with circuit shown in Figure 25 and Figure 26. For bipolar input ranges, full-scale error is the worst case of –full-scale or +full-scale uncalibrated deviation from ideal first and last code transitions, divided by the transition voltage (not divided by the full-scale range) and includes the effect of offset error. For unipolar input ranges, full-scale error is the deviation of the last code transition divided by the transition voltage. It also includes the effect of offset error. All specifications in dB are referred to a full-scale ±10-V input. Full-power bandwidth is defined as the full-scale input frequency at which signal-to-(noise + distortion) degrades to 60 dB. Recovers to specified performance after 2 x FS input overvoltage. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 3 ADS8519 www.ti.com SLAS462 – JUNE 2007 ELECTRICAL CHARACTERISTICS (continued) At TA = –40°C to 85°C, fs = 250 kHz, VDIG = VANA = 5 V, using internal reference (unless otherwise specified) ADS8519I PARAMETER ADS8519IB TEST CONDITIONS UNIT MIN TYP MAX MIN TYP MAX Data clock (Selectable for internal or external data clock) Internal clock (output only when transmitting data) External clock (can run continually but not recommended for optimum performance) EXT/INT Low 9 9 MHz EXT/INT High 0.1 26 0.1 26 MHz VOL Low-level output voltage ISINK = 1.6 mA, VDIG = 1.65 V ~ 5.25 V VOH High-level output voltage ISOURCE = 500 μA, VDIG = 1.65 V ~ 5.25 V Leakage current Hi-Z state, VOUT = 0 V to VDIG ±5 ±5 μA Output capacitance Hi-Z state 15 15 pF 5.25 V 0.45 VDIG-0.45 0.45 VDIG-0.45 V V POWER SUPPLIES PRODUCT PREVIEW VDIG Digital input voltage 1.65 VANA Analog input voltage 4.75 IDIG Digital input current IANA Analog input current Must be ≤ VANA 5.25 1.65 5 5.25 4.75 0.1 5 5.25 1 0.1 1 mA V 20 25 20 25 mA 100 125 100 125 mW POWER DISSIPATION PWRD Low fS = 250 kHz PWRD High 50 μW 50 TEMPERATURE RANGE Specified performance –40 85 –40 85 °C Derated performance (9) –55 125 –55 125 °C Storage –65 150 –65 150 °C THERMAL RESISTANCE (ΘJA) 67 67 °C/W 35.861 35.861 °C/W SSOP QFN (9) 4 The internal reference may not be started correctly beyond the industrial temperature range (–40°C to 85°C), therefore use of an external reference is recommended. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 ADS8519 www.ti.com SLAS462 – JUNE 2007 TIMING REQUIREMENTS, TA = –40°C to 85°C MIN TYP MAX 6 20 ns 2.2 μs tw1 Pulse duration, convert td1 Delay time, BUSY from R/C low tw2 Pulse duration, BUSY low td2 Delay time, BUSY, after end of conversion 5 td3 Delay time, aperture 5 tconv Conversion time tacq Acquisition time tconv + tacq 40 UNIT ns ns ns 2.2 μs μs 1.8 Cycle time 4 μs td4 Delay time, R/C Low to internal DATACLK output 270 ns tc1 Cycle time, internal DATACLK 110 ns td5 Delay time, data valid to internal DATACLK high 15 35 ns td6 Delay time, data valid after internal DATACLK low 20 35 ns tc2 Cycle time, external DATACLK 35 ns tw3 Pulse duration, external DATACLK high 15 ns tw4 Pulse duration, external DATACLK low 15 ns tsu1 Setup time, R/C rise/fall to external DATACLK high 15 ns tsu2 Setup time, R/C transition to CS transition 10 td7 Delay time, SYNC, after external DATACLK high 3 35 ns td8 Delay time, data valid from external DATACLK high 2 20 ns td9 Delay time, CS rising edge to external DATACLK rising edge td10 tsu3 td11 Delay time, final external DATACLK to BUSY rising edge tsu3 Setup time, TAG valid 0 ns th1 Hold time, TAG valid 2 ns ns 10 ns Delay time, previous data available after CS, R/C low 2 μs Setup time, BUSY transition to first external DATACLK 5 TAG NC NC DATACLK 23 NC VANA 28 13 SYNC 22 NC R1IN 29 12 DGND AGND1 30 11 EXT/INT R2IN 31 10 SB/BTC R3IN 32 1 9 21 R/C 20 NC 18 NC 17 DATA 16 DATACLK Note: 15 SYNC Thermal Pad 2 3 4 5 6 7 8 NC 24 CS NC 11 DGND 14 CS NC R/C 14 19 TAG EXT/INT 13 NC 27 NC 10 SB/BTC 12 NC DATA VDIG 25 BUSY NC AGND2 9 PWRD 15 AGND2 NC 8 NC 26 BUSY NC REF 7 24 23 22 21 20 19 18 17 25 16 26 PWRD REF CAP 6 27 VANA NC R3IN 4 NC 5 28 VDIG CAP R2IN 3 μs RHB PACKAGE (TOP VIEW) NC R1IN 1 AGND1 2 ns 1 DB PACKAGE (TOP VIEW) PRODUCT PREVIEW PARAMETER NC The package thermal pad must be soldered to the printed circuit board for thermal and mechanical performance. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 5 ADS8519 www.ti.com SLAS462 – JUNE 2007 Terminal Functions TERMINAL NAME DESCRIPTION SSOP NO. QFN NO. I/O AGND1 2 30 – Analog ground. Used internally as ground reference point. Minimal current flow. AGND2 9 6 – Analog ground BUSY 25 25 O Busy output. Falls when a conversion is started, and remains low until the conversion is completed and the data is latched into the output shift register. CS 24 22 – Chip select. Internally ORed with R/C. PRODUCT PREVIEW CAP 6 3 DATA 17 15 O Serial data output. Data is synchronized to DATACLK, with the format determined by the level of SB/BTC. In the external clock mode, after 16 bits of data, the ADS8519 outputs the level input on TAG as long as CS is low and R/C is high (see Figure 8 and Figure 9). If EXT/INT is low, data is valid on both the rising and falling edges of DATACLK, and between conversions DATA stays at the level of the TAG input when the conversion was started. DATACLK 16 14 I/O Either an input or an output depending on the EXT/INT level. Output data is synchronized to this clock. If EXT/INT is low, DATACLK transmits 16 pulses after each conversion, and then remains low between conversions. DGND 14 12 – Digital ground EXT/INT 13 11 – Selects external or internal clock for transmitting data. If high, data is output synchronized to the clock input on DATACLK. If low, a convert command initiates the transmission of the data from the previous conversion, along with 16-clock pulses output on DATACLK. – No connect NC 5, 8, 10, 1, 2, 5, 7, 11, 18, 8, 9, 16, 20, 22, 17, 19, 23 21, 23, 24 PWRD 26 26 I Power down input. If high, conversions are inhibited and power consumption is significantly reduced. Results from the previous conversion are maintained in the output shift register. R/C 21 20 I Read/convert input. With CS low, a falling edge on R/C puts the internal sample-and-hold into the hold state and starts a conversion. When EXT/INT is low, this also initiates the transmission of the data results from the previous conversion. If EXT/INT is high, a rising edge on R/C with CS low, or a falling edge on CS with R/C high, transmits a pulse on SYNC and initiates the transmission of data from the previous conversion. REF 7 4 I/O Reference input/output. Outputs internal 4.096-V reference. Can also be driven by external system reference. In both cases, bypass to ground with a 2.2-μF tantalum capacitor. R1IN 1 29 I Analog input. See Table 3 for input range connections. R2IN 3 31 I Analog input. See Table 3 for input range connections. R3IN 4 32 I Analog input. See Table 3 for input range connections. SB/BTC 12 10 O Select straight binary or binary 2's complement data output format. If high, data is output in a straight binary format. If low, data is output in a binary 2's complement format. SYNC 15 13 O Sync output. This pin is used to supply a data synchronization pulse when the EXT level is high and at least one external clock pulse has occured when not in the read mode. See the external clock modes desciptions. TAG 19 18 I Tag input for use in the external clock mode. If EXT is high, digital data input from TAG is output on DATA with a delay that is dependent on the external clock mode. See Figure 8 and Figure 9. VANA 27 28 I Analog supply input. Nominally +5 V. Connect directly to pin 20, and decouple to ground with 0.1-μF ceramic and 10-μF tantalum capacitors. VDIG 28 27 I Digital supply input. Connect directly to pin 19. Must be ≤ VANA. 6 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 ADS8519 www.ti.com SLAS462 – JUNE 2007 PARAMETER MEASUREMENT INFORMATION CS R/C R/C CS tsu1 tsu1 tsu1 External DATACLK tsu1 External DATACLK CS Set Low, Discontinuous Ext DATACLK R/C Set Low, Discontinuous Ext DATACLK BUSY CS tsu2 tsu2 tsu3 1 External DATACLK R/C 2 CS Set Low, Discontinuous Ext DATACLK tw1 PRODUCT PREVIEW Figure 1. Critical Timing tw1 R/C td1 td1 tw2 tw2 BUSY td2 td3 STATUS Nth Conversion Error Correction tconv td4 td2 td11 td3 td11 Error (N+1)th Conversion Correction (N+1)th Accquisition tconv tacq tc1 (N+2)th Accquisition tacq td4 Internal 1 DATACLK TAG = 0 16 1 2 16 td6 td5 DATA 2 D15 D0 (N−1)th Conversion Data CS, EXT/INT, and TAG are tied low TAG = 0 D15 D0 TAG = 0 Nth Conversion Data 8 starts READ Figure 2. Basic Conversion Timing - Internal DATACLK (Read Previous Data During Conversion) Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 7 ADS8519 www.ti.com SLAS462 – JUNE 2007 PARAMETER MEASUREMENT INFORMATION (continued) tw1 tw1 R/C td1 td1 tw2 tw2 BUSY td2 td3 STATUS Error Correction Nth Conversion td2 td3 td11 td11 (N+1)th Accquisition (N+1)th Conversion tacq tconv (N+2)th Accquisition tacq tconv tsu3 tsu1 Error Correction tsu3 tsu1 External 1 DATACLK DATA TAG = 0 16 2 1 No more data to shift out TAG = 0 1 16 Nth Data PRODUCT PREVIEW EXT/INT tied high, CS and TAG are tied low TAG = 0 16 2 1 No more data to shift out TAG = 0 16 (N+1)th Data TAG = 0 tw1 + tsu1 starts READ Figure 3. Basic Conversion Timing - External DATACLK tw1 R/C td1 tsu1 tw2 td1 BUSY td2 td3 STATUS td3 td11 Nth Conversion Error Correction (N+1) th Accquisition tsu3 tconv tacq tc2 tw3 External DATACLK tsu1 tw4 0 1 2 3 4 5 10 11 12 13 14 15 16 SYNC = 0 td8 T00 EXT/INT tied high, CS tied low D14 D13 D12 D11 D10 D05 D04 D03 D02 D01 D00 Null T00 Txx T02 T03 T04 T05 T06 T11 T12 T13 T14 T15 T16 Null T17 Tyy th1 tsu3 TAG td8 Nth Conversion Data D15 DATA T01 tw1 + tsu1 starts READ Figure 4. Read After Conversion (Discontinuous External DATACLK) 8 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 ADS8519 www.ti.com SLAS462 – JUNE 2007 PARAMETER MEASUREMENT INFORMATION (continued) tw1 R/C td1 tw2 BUSY td10 td3 td2 Error Correction Nth Conversion STATUS tsu3 tconv tc2 tsu1 External tw3 td11 tw4 1 0 DATACLK 2 3 4 5 10 11 12 13 14 15 16 SYNC = 0 Nth Conversion Data D15 D14 D13 D12 D11 D10 D05 D04 D03 td8 D02 D01 D00 PRODUCT PREVIEW td8 DATA Rising DATACLK change DATA, tw1 + tsu1 Starts READ TAG is not recommended for this mode. There is not enough time to do so without violating td11. EXT/INT tied high, CS and TAG tied low Figure 5. Read During Conversion (Discontinuous External DATACLK) tw1 R/C td1 tsu1 td1 tsu1 tw2 BUSY td2 td3 Error Nth Conversion Correction STATUS td3 td11 (N+1)th Accquisition tconv tacq tc2 tsu3 tsu1 External DATACLK 0 1 tsu1 tw4 tw3 2 3 4 5 6 7 12 13 14 15 16 17 18 tc2 td7 SYNC =0 td8 Nth Conversion Data D15 DATA D13 D12 D11 D10 D05 D04 D03 D02 D01 D00 Null T02 T03 T04 T05 T06 T11 T12 T13 T14 T15 T16 T17 T00 Txx th1 tsu3 TAG td8 D14 T00 EXT/INT tied high, CS tied low T01 Tyy tw1 + tsu1 starts READ Figure 6. Read After Conversion With SYNC (Discontinuous External DATACLK) Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 9 ADS8519 www.ti.com SLAS462 – JUNE 2007 PARAMETER MEASUREMENT INFORMATION (continued) tw1 R/C td1 tw2 BUSY td3 td10 td2 Error Correction Nth Conversion STATUS tsu3 tconv tsu1 tsu1 External tw3 tsu1 0 DATACLK tc2 tw4 1 2 3 td11 4 5 6 7 12 13 14 15 16 17 18 td7 tc2 SYNC = 0 td8 PRODUCT PREVIEW DATA EXT/INT tied high, CS and TAG tied low td8 Nth Conversion Data D15 D14 D13 D12 D11 D10 D05 D04 D03 D02 D01 D00 tw1 + tsu1 Starts READ TAG is not recommended for this mode. There is not enough time to do so without violating td11. Figure 7. Read During Conversion With SYNC (Discontinuous External DATACLK) 10 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 ADS8519 www.ti.com SLAS462 – JUNE 2007 Tag 18 Tag 17 Tag 16 PRODUCT PREVIEW Tag 15 Tag 2 Tag 0 Tag 1 Bit 15 (MSB) t c2 t su2 t su1 0 TAG DATA SYNC BUSY R/C CS External DATACLK t w1 t su2 t d1 t w3 t d7 1 t c2 t w4 2 t d8 3 Bit 14 4 Bit 1 17 18 Bit 0 (LSB) Tag 0 t d9 Tag 1 Tag 19 PARAMETER MEASUREMENT INFORMATION (continued) Figure 8. Conversion and Read Timing with Continuous External DATACLK (EXT/INT Tied High) Read After Conversions (Not Recommended) Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 11 ADS8519 www.ti.com SLAS462 – JUNE 2007 Tag 18 Tag 17 Tag 16 Tag 1 TAG DATA SYNC t d1 BUSY R/C CS External DATACLK t su2 t w3 t c2 t w1 t w4 t su1 t su1 Tag 0 t c2 t d8 t d10 PRODUCT PREVIEW Bit 15 (MSB) Bit 0 (LSB) Tag 0 t d8 Tag 1 Tag 19 PARAMETER MEASUREMENT INFORMATION (continued) Figure 9. Conversion and Read Timing with Continous External DATACLK (EXT/INT Tied High) Read Previous Conversion Results During Conversion (Not Recommended) 12 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 ADS8519 www.ti.com SLAS462 – JUNE 2007 POSITIVE INL DISTRIBUTION NEGATIVE INL DISTRIBUTION Figure 10. Figure 11. POSITIVE DNL DISTRIBUTION NEGATIVE DNL DISTRIBUTION Figure 12. Figure 13. AC vs FREE-AIR TEMPERATURE SIGNAL-TO-NOISE AND DISTORTION vs INPUT FREQUENCY Figure 14. Figure 15. DC CODE REFERENCE DRIFT Figure 16. Figure 17. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 PRODUCT PREVIEW TYPICAL CHARACTERISTICS 13 ADS8519 www.ti.com SLAS462 – JUNE 2007 TYPICAL CHARACTERISTICS (continued) INL Figure 18. DNL PRODUCT PREVIEW Figure 19. FFT (100 kHz Input) Figure 20. FFT (10 kHz Input) Figure 21. 14 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 ADS8519 www.ti.com SLAS462 – JUNE 2007 BASIC OPERATION Two signals control conversion in the ADS8519: CS and R/C. These two signals are internally ORed together. To start a conversion the chip must be selected, CS low, and the conversion signal must be active, R/C low. Either signal can be brought low first. Conversion starts on the falling edge of the second signal. BUSY goes low when conversion starts and returns high after the data from that conversion is shifted into the internal storage register. Sampling begins when BUSY goes high. To reduce the number of control pins CS can be tied low permanently. The R/C pin now controls conversion and data reading exclusively. In the external clock mode this means that the ADS8519 will clock out data whenever R/C is brought high and the external clock is active. In the internal clock mode data is clocked out every convert cycle regardless of the states of CS and R/C. The ADS8519 provides a TAG input for cascading multiple converters together. READING DATA Data can be clocked out with either the internally generated clock or with an external clock. The EXT/INT pin controls this function. If external clock is used the TAG input can be used to daisy-chain multiple ADS8519 data pins together. INTERNAL DATACLK In the internal clock mode data for the previous conversion is clocked out during each conversion period. The internal data clock is synchronized to the internal conversion clock so that is does not interfere with the conversion process. The DATACLK pin becomes an output when EXT/INT is low. 16 clock pulses are generated at the beginning of each conversion after timing t8 is satisfied, i.e. you can only read previous conversion result during conversion. DATACLK returns to low when it is inactive. The 16 bits of serial data are shifted out the DATA pin synchronous to this clock with each bit available on a rising and then a falling edge. DATA pin returns to the state of TAG pin input sensed at the start of transmission. EXTERNAL DATACLK The external clock mode offers several ways to retrieve conversion results. However, since the external clock cannot be synchronized to the internal conversion clock care must be taken to avoid corrupting the data. When EXT/INT is set high, the R/C and CS signals control the read state. When the read state is initiated the result from the previously completed conversion is shifted out the DATA pin synchronous to the external clock that is connected to the DATACLK pin. Each bit is available on a falling and then a rising edge. The maximum external clock speed of 28.5 MHz allows data shifted out quickly either at the beginning of conversion or the beginning of sampling. There are several modes of operation available when using an external clock. It is recommended that the external clock run only while reading data. This is the discontinuous clock mode. Since the external clock is not synchronized to the internal clock that controls conversion slight changes in the external clock can cause conflicts that can corrupt the conversion process. Specifications with a continuously running external clock cannot be guaranteed. It is especially important that the external clock does not run during the second half of the conversion cycle (approximately the time period specified by td11, see timing table). In the discontinuous clock mode data can be read during conversion or during sampling, with or without a SYNC pulse. Data read during a conversion must meet the td11 timing specification. Data read during sampling must be complete before starting a conversion. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 15 PRODUCT PREVIEW The conversion result is available as soon as BUSY returns to high therefore, data always represents the conversion previously completed even when it is read during a conversion. The ADS8519 outputs serial data in either straight binary or binary two’s compliment format. The SB/BTC pin controls the format. Data is shifted out MSB first. The first conversion immediately following a power-up will not produce a valid conversion result. ADS8519 www.ti.com SLAS462 – JUNE 2007 Whether reading during sampling or during conversion a SYNC pulse is generated whenever at least one rising edge of the external clock occurs while the part is not in the read state. In the discontinuous external clock with SYNC mode a SYNC pulse follows the first rising edge after the read command. The data is shifted out after the SYNC pulse. The first rising clock edge after the read command generates a SYNC pulse. The SYNC pulse can be detected on the next falling edge and then the next rising edge. Successively, each bit can be read first on the falling edge and then on the next rising edge. Thus 17 clock pulses after the read command are required to read on the falling edge. 18 clock pulses are necessary to read on the rising edge. Table 2. DATACLK Pulses DATACLK PULSES REQUIRED DESCRIPTION WITH SYNC WITHOUT SYNC Read on falling edge of DATACLK 17 16 Read on rising edge of DATACLK 18 17 If the clock is entirely inactive when not in the read state no SYNC, pulse is generated. In this case the first rising clock edge shifts out the MSB. The MSB can be read on the first falling edge or on the next rising edge. In this discontinuous external clock mode with no SYNC 16 clocks are necessary to read the data on the falling edge and 17 clocks for reading on the rising edge. Data always represents the conversion already completed. PRODUCT PREVIEW TAG FEATURE The TAG feature allows the data from multiple ADS8519 converters to be read on a single serial line. The converters are cascaded together using the DATA pins as outputs and the TAG pins as inputs as illustrated in Figure 22. The DATA pin of the last converter drives the processor's serial data input. Data is then shifted through each converter, synchronous to the externally supplied data clock, onto the serial data line. The internal clock cannot be used for this configuration. The preferred timing uses the discontinuous, external, data clock during the sampling period. Data must be read during the sampling period because there is not sufficient time to read data from multiple converters during a conversion period without violating the td11 constraint (see the EXTERNAL DATACLOCK section). The sampling period must be sufficiently long to allow all data words to be read before starting a new conversion. Note, in Figure 22, that a NULL bit separates the data word from each converter. The state of the DATA pin at the end of a READ cycle reflects the state of the TAG pin at the start of the cycle. This is true in all READ modes, including the internal clock mode. For example, when a single converter is used in the internal clock mode the state of the TAG pin determines the state of the DATA pin after all 16 bits have shifted out. When multiple converters are cascaded together this state forms the NULL bit that separates the words. Thus, with the TAG pin of the first converter grounded as shown in Figure 22 the NULL bit becomes a zero between each data word. 16 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 ADS8519 www.ti.com Processor SLAS462 – JUNE 2007 ADS8519A DATA CS R/C DATACLK TAG SCLK ADS 8519B TAG(A) DATA CS R/C DATACLK TAG TAG(B) GPIO GPIO SDI Null D A00 Q D Q D Null D A15 Q D Q D B00 DATA (A) A16 Q D Q D B15 Q B16 DATA (B) Q DATACLK R/C (both A & B) BUSY (both A & B) SYNC (both A & B) 1 2 3 4 16 17 DATA ( A ) A15 A14 A13 A01 A00 DATA ( B ) B15 B14 B13 B01 B00 EXT/INT tied high, CS of both converter A and B, TAG input of converter A are tied low. 18 19 20 21 Null TAG(A) = 0 A Nth Conversion Data Null A15 A14 A13 B 34 A01 35 36 A00 Null A TAG(A) = 0 . Figure 22. Timing of TAG Feature With Single Conversion (Using External DATACLK) ANALOG INPUTS The ADS8519 has three analog input ranges as shown in Table 3. The offset specification is factory calibrated with internal resistors. The gain specification is factory calibrated with 0.1%, 0.25-W, external resistors as shown in Figure 25 and Figure 26. The external resistors can be omitted if a larger gain error is acceptable or if using software calibration. The hardware trim circuitry shown in Figure 25 and Figure 26 can reduce the error to zero. The analog input pins R1IN, R2IN, and R3IN have ±25-V overvoltage protection. The input signal must be referenced to AGND1. This will minimized the ground loop problem typical to analog designs. The analog input should be driven by a low impedance source. A typical driving circuit using OPA627 or OPA132 is shown in Figure 26. The ADS8519 can operate with its internal 4.096-V reference or an external reference. An external reference connected to pin 6 (REF) bypasses the internal reference. The external reference must drive the 4-kΩ resistor that separates pin 6 from the internal reference (see the illustration on page 1). The load will vary with the difference between the internal and external reference voltages. The external reference voltage can vary from 3.9 V to 4.2 V. The internal reference will be approximately 4.096 V. The reference, whether internal or external, is buffered internally with a buffer with its output on pin 5 (CAP). The ADS8519 is factory tested with 2.2-μF capacitors connected to pins 5 and 6 (CAP and REF). Each capacitor should be placed as close as possible to its pin. The capacitor on pin 6 band limits the internal reference noise. A smaller capacitor can be used but it may degrade SNR and SINAD The capacitor on pin 5 stabilizes the reference buffer and provides switching charge to the CDAC during conversion. Capacitors smaller than 1 μF can cause the buffer to become unstable may not hold sufficient charge for the CDAC. The parts are tested to specifications with 2.2 μF so larger capacitors are not necessary. The ESR (equivalent series resistance) of these compensation capacitors is also critical. Keep the total ESR under 3 Ω. See the TYPICAL CHARACTERISTICS section concerning how ESR affects performance. Neither the internal reference nor the buffer should be used to drive an external load. Such loading can degrade performance. Any load on the internal reference causes a voltage drop across the 4-kΩ resistor and will affect gain. The internal buffer is capable of driving ±2-mA loads but any load can cause perturbations of the reference at the CDAC, degrading performance. It should be pointed out that, unlike other competitor’s parts with similar input structure, the ADS8519 does not require a second high speed amplifier used as buffer to isolate the CAP pin from the signal dependent current in the R3IN pin but can tolerate it if one do exist. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 17 PRODUCT PREVIEW External DATACLK ADS8519 www.ti.com SLAS462 – JUNE 2007 The external reference voltage can vary from 3.9 V to 4.2 V. The reference voltage determines the size of the least significant bit (LSB). The larger reference voltages produce a larger LSB, which can improve SNR. Smaller reference voltages can degrade SNR. +15V 2.2 mF 22 pF ADS8519 100 nF R1IN GND 2 kW Pin 7 2 kW Pin 2 Vin 22 pF Pin3 AGND Pin 1 − OPA627 or OPA132 + R2IN Pin6 R3IN Pin4 CAP 2.2 mF GND AGND2 2.2 mF GND 100 nF 2.2 mF PRODUCT PREVIEW −15 V GND Figure 23. Typical Driving Circuitry (±10 V, No Trim) 18 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 ADS8519 www.ti.com SLAS462 – JUNE 2007 Table 3. Input Range Connections (see Figure 25 and Figure 26 for complete information) ANALOG INPUT RANGE CONNECT R1IN TO CONNECT R2IN TO CONNECT R3 TO IMPEDANCE ±10 V VIN AGND CAP 8.88 kΩ ±10 V AGND VIN CAP 8.88 kΩ ±5 V VIN VIN CAP 6.08 kΩ 0 V to 8.192 V AGND AGND VIN 5.95 kΩ Table 4. Control Truth Table Initiate conversion and output data using external clock No actions Power down CS R/C BUSY EXT/INT DATACLK PWRD SB/BTC OPERATION 1>0 0 1 0 Output 0 x 0 1>0 1 0 Output 0 x Initiates conversion n. Data from conversion n - 1 clocked out on DATA synchronized to 16 clock pulses output on DATACLK. 1>0 0 1 1 Input 0 x Initiates conversion n. 0 1>0 1 1 Input 0 x Initiates conversion n. 1>0 1 1 1 Input x x Outputs data with or without SYNC pulse. See section Reading Data. 1>0 1 0 1 Input 0 x 0 0>1 0 1 Input 0 x Outputs data with or without SYNC pulse. See section Reading Data. 0 0 0>1 x x 0 x This is an acceptable condition. x x x x x 0 x Analog circuitry powered. Conversion can proceed.. x x x x x 1 x Analog circuitry disabled. Data from previous conversion maintained in output registers. x x x x x x 0 Serial data is output in binary 2s complement format. x x x x x x 1 Serial data is output in straight binary format. Selecting output format PRODUCT PREVIEW SPECIFIC FUNCTION Initiate conversion and output data using internal clock Table 5. Output Codes and Ideal Input Voltages DIGITAL OUTPUT DESCRIPTION BINARY 2's COMPLEMENTS (SB/BTC LOW) ANALOG INPUT STRAIGHT BINARY (SB/BTC HIGH) BINARY CODE HEX CODE BINARY CODE HEX CODE 8.191875 V 0111 1111 1111 1111 7FFF 1111 1111 1111 1111 FFFF 4.096 V 0000 0000 0000 0000 0000 1000 0000 0000 0000 8000 153 μV 4.095975 V 1111 1111 1111 1111 FFFF 0111 1111 1111 1111 7FFF -5 V 0V 1000 0000 0000 0000 8000 0000 0000 0000 0000 0000 Full-scale range ±10 ±5 0 V to 8.192 V Least significant bit (LSB) 305 μV 153 μV 125 μV Full scale (FS - 1LSB) 9.999695 V 4.999847 V Midscale 0V 0V One LSB below midscale -305 μV -Full scale -10 V Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 19 ADS8519 www.ti.com SLAS462 – JUNE 2007 1 ±10 V 2 +5 V 2.2 µF + 175 kΩ 20 kΩ 4 + Gain 2.2 µF 30 kΩ 3 5 1 ±10 V VIN 2 AGND1 2.2 µF + REF 3 4 CAP 2.2 µF AGND1 REF CAP + 5 AGND2 (a) ±10 V With Hardware Trim VIN AGND2 (b) ±10 V Without Hardware Trim Note: Use 1% metal film resistors. Figure 24. Gain Adjust Trim PRODUCT PREVIEW Input Range With Trim (Adjust Gain) Without Trim 0 V − 8.192 V R1IN AGND1 AGND1 R2IN R2IN R3IN VIN 2.2 µF R1IN CAP + 2.2 µF + REF R3IN VIN 2.2 µF + CAP +5V 576 kΩ 50 kΩ 2.2 µF AGND2 + REF AGND2 Figure 25. Offset/Gain Circuits for Unipolar Input Ranges 20 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 ADS8519 www.ti.com SLAS462 – JUNE 2007 With Trim (Adjust Gain) Without Trim VIN R1IN ±10 V + 2.2 µF AGND1 AGND1 R2IN R2IN R3IN R3IN +5 V CAP 2.2 µF + R1IN VIN 2.2 µF 576 kΩ + 2.2 µF + CAP REF REF 50 kΩ AGND2 VIN AGND2 R1IN R1IN AGND1 AGND1 VIN R2IN ±5V R3IN + R2IN 2.2 µF +5 V CAP PRODUCT PREVIEW Input Range R3IN + CAP 576 kΩ 2.2 µF 2.2 µF + 50 kΩ REF REF + AGND2 2.2 µF AGND2 Figure 26. Offset/Gain Circuits for Bipolar Input Ranges Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated ADS8519 21 PACKAGE OPTION ADDENDUM www.ti.com 29-Jun-2007 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty Lead/Ball Finish MSL Peak Temp (3) ADS8519IBDB PREVIEW SSOP DB 28 50 TBD Call TI Call TI ADS8519IBDBR PREVIEW SSOP DB 28 2000 TBD Call TI Call TI ADS8519IDB PREVIEW SSOP DB 28 50 TBD Call TI Call TI ADS8519IDBR PREVIEW SSOP DB 28 2000 TBD Call TI Call TI (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. 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. 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 1 MECHANICAL DATA MSSO002E – JANUARY 1995 – REVISED DECEMBER 2001 DB (R-PDSO-G**) PLASTIC SMALL-OUTLINE 28 PINS SHOWN 0,38 0,22 0,65 28 0,15 M 15 0,25 0,09 8,20 7,40 5,60 5,00 Gage Plane 1 14 0,25 A 0°–ā8° 0,95 0,55 Seating Plane 2,00 MAX 0,10 0,05 MIN PINS ** 14 16 20 24 28 30 38 A MAX 6,50 6,50 7,50 8,50 10,50 10,50 12,90 A MIN 5,90 5,90 6,90 7,90 9,90 9,90 12,30 DIM 4040065 /E 12/01 NOTES: A. B. C. D. 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