ADS5517 www.ti.com SLWS203 – DECEMBER 2007 11-BIT, 200 MSPS ADC FEATURES 1 • • • • • • • • • • • • Maximum Sample Rate: 200 MSPS 11-Bit Resolution No Missing Codes Total Power Dissipation 1.23 W Internal Sample and Hold 67-dBFS SNR at 70-MHz IF 84-dBc SFDR at 70-MHz IF, 0-dB Gain High Analog Bandwidth up to 800 MHz Double Data Rate (DDR) LVDS and Parallel CMOS Output Options Programmable Gain up to 6 dB for SNR/SFDR Trade-Off at High IF Reduced Power Modes at Lower Sample Rates Supports Input Clock Amplitude Down to 400 mVPP DESCRIPTION ADS5517 is a high performance 11-bit, 200-MSPS A/D converter. It offers state-of-the art functionality and performance using advanced techniques to minimize board space. With high analog bandwidth and low jitter input clock buffer, the ADC supports both high SNR and high SFDR at high input frequencies. It features programmable gain options that can be used to improve SFDR performance at lower full-scale analog input ranges. • • • • • • Clock Duty Cycle Stabilizer No External Reference Decoupling Required Internal and External Reference Support Programmable Output Clock Position to Ease Data Capture 3.3-V Analog and Digital Supply 48-QFN Package (7 mm × 7 mm) APPLICATIONS • Wireless Communications Infrastructure • Software Defined Radio • Power Amplifier Linearization • 802.16d/e • Test and Measurement Instrumentation • High Definition Video • Medical Imaging • Radar Systems In a compact 48-pin QFN, the device offers fully differential LVDS DDR (Double Data Rate) interface while parallel CMOS outputs can also be selected. Flexible output clock position programmability is available to ease capture and trade-off setup for hold times. At lower sampling rates, the ADC can be operated at scaled down power with no loss in performance. The ADS5517 includes an internal reference, while eliminating the traditional reference pins and associated external decoupling. The device also supports an external reference mode. The device is specified over temperature range (-40°C to 85°C). the industrial ADS5517 PRODUCT FAMILY 210 MSPS 190 MSPS 170 MSPS 14 bit ADS5547 ADS5546 ADS5545 12 bit ADS5527 - ADS5525 11 bit ADS5517 (200MSPS) 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. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2007, Texas Instruments Incorporated ADS5517 www.ti.com SLWS203 – DECEMBER 2007 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. CLKP DRGND DRVDD AGND AVDD 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. CLKOUTP CLOCKGEN CLKM CLKOUTM LOW_D0_P LOW_D0_M D1_D2_P D1_D2_M D3_D4_P D3_D4_M Digital Encoder and Serializer INP 11-Bit ADC SHA INM D5_D6_P D5_D6_M D7_D8_P D7_D8_M D9_D10_P D9_D10_M VCM Control Interface Reference MODE OE DFS RESET SEN SDATA SCLK IREF OVR LVDS MODE PACKAGE/ORDERING INFORMATION (1) PRODUCT ADS5517 (1) (2) 2 PACKAGELEAD QFN-48 (2) PACKAGE DESIGNATOR RGZ SPECIFIED TEMPERATURE RANGE –40°C to 85°C PACKAGE MARKING ORDERING NUMBER TRANSPORT MEDIA, QUANTITY ADS5517IRGZT Tape and Reel, 250 ADS5517IRGZR Tape and Reel, 2500 AZ5517 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. For thermal pad size on the package, see the mechanical drawings at the end of this data sheet. θJA = 25.41°C/W (0 LFM air flow), θJC = 16.5°C/W when used with 2 oz. copper trace and pad soldered directly to a JEDEC standard four layer 3 in x 3 in (7.62 cm x 7.62 cm) PCB. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 ABSOLUTE MAXIMUM RATINGS (1) over operating free-air temperature range (unless otherwise noted) VALUE UNIT Supply voltage range, AVDD –0.3 to 3.9 V Supply voltage range, DRVDD –0.3 to 3.9 V Voltage between AGND and DRGND -0.3 to 0.3 V Voltage between AVDD to DRVDD -0.3 to 3.3 V Voltage applied to VCM pin (in external reference mode) -0.3 to 1.8 V –0.3 to minimum (3.6, AVDD + 0.3) V Voltage applied to analog input pins, INP and INM Voltage applied to input clock pins, CLKP and CLKM TA Operating free-air temperature range TJ Operating junction temperature range Tstg Storage temperature range (1) -0.3 to AVDD + 0.3 V –40 to 85 °C 125 °C –65 to 150 °C Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute maximum rated conditions for extended periods may affect device reliability. RECOMMENDED OPERATING CONDITIONS over operating free-air temperature range (unless otherwise noted) MIN TYP MAX UNIT Analog supply voltage, AVDD 3 3.3 3.6 V Digital supply voltage, DRVDD 3 3.3 3.6 V SUPPLIES ANALOG INPUTS Differential input voltage range 2 Input common-mode voltage VPP 1.5 ±0.1 Voltage applied on VCM in external reference mode 1.45 1.5 V 1.55 V CLOCK INPUT Input clock sample rate (1) MSPS DEFAULT SPEED mode 50 200 1 60 LOW SPEED mode MSPS Input clock amplitude differential (V(CLKP) - V(CLKM)) Sine wave, ac-coupled 0.4 1.5 VPP LVPECL, ac-coupled 1.6 VPP LVDS, ac-coupled 0.7 VPP LVCMOS, single-ended, ac-coupled 3.3 V Input clock duty cycle (See Figure 25) 35% 50% 65% DIGITAL OUTPUTS CL Maximum external load capacitance from each output pin to DRGND (LVDS and CMOS modes) Without internal termination (default after reset) With 100 Ω internal termination RL (2) Differential load resistance between the LVDS output pairs (LVDS mode) Operating free-air temperature (1) (2) 5 pF 10 pF Ω 100 –40 85 °C See the section on Low Sampling Frequency Operation for more information. See the section on LVDS Buffer Internal termination for more information. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 3 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 ELECTRICAL CHARACTERISTICS Typical values are at 25°C, min and max values are across the full temperature range TMIN = –40°C to TMAX = 85°C, AVDD = DRVDD = 3.3 V, sampling rate = 200 MSPS, sine wave input clock, 1.5 VPP differential clock amplitude, 50% clock duty cycle, –1 dBFS differential analog input, internal reference mode, 0-db gain, DDR LVDS data output (unless otherwise noted) PARAMETER TEST CONDITIONS MIN Resolution TYP MAX UNIT 11 bits Differential input voltage range 2 VPP Differential input capacitance 7 pF ANALOG INPUT Analog input bandwidth 800 MHz Analog input common mode current (per input pin) 342 µA V REFERENCE VOLTAGES V(REFB) Internal reference bottom voltage Internal reference mode 0.5 V(REFT) Internal reference top voltage Internal reference mode 2.5 ΔV(REF) Internal reference error V(REFT) - V(REFB) VCM Common mode output voltage Internal reference mode 1.5 V VCM output current capability Internal reference mode ±4 mA -60 ±25 V 60 mV DC ACCURACY No Missing Codes Specified DNL Differential non-linearity -0.6 ±0.3 1.0 LSB INL Integral non-linearity -1.5 ±0.6 1.5 LSB Offset error -10 5 10 mV Offset temperature coefficient Gain error due to internal reference error alone 0.002 (ΔV(REF) / 2.0V)% Gain error excluding internal reference error (1) Gain temperature coefficient PSRR DC Power supply rejection ratio ppm/°C -3 ±1 3 %FS -2 ±1 2 %FS 0.01 Δ%/°C 0.6 mV/V POWER SUPPLY I(AVDD) I(DRVDD) ICC (1) 4 Analog supply current Digital supply current 306 mA LVDS mode, IO = 3.5 mA, RL = 100 Ω, CL = 5 pF 66 mA CMOS mode, FIN = 2.5 MHz, CL = 5 pF 47 mA mA Total supply current LVDS mode 372 Total power dissipation LVDS mode 1.23 1.4 W Standby power In STANDBY mode with clock stopped 100 150 mW Clock stop power With input clock stopped 100 150 mW Gain error is specified from design and characterization; it is not tested in production. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 ELECTRICAL CHARACTERISTICS Typical values are at 25°C, min and max values are across the full temperature range TMIN = –40°C to TMAX = 85°C, AVDD = DRVDD = 3.3 V, sampling rate = 200 MSPS, sine wave input clock, 1.5 VPP differential clock amplitude, 50% clock duty cycle, –1 dBFS differential analog input, internal reference mode, 0-db gain, DDR LVDS data output (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT AC CHARACTERISTICS FIN = 20 MHz 67.1 FIN = 70 MHz 64.5 FIN = 100 MHz SNR Signal to noise ratio 66.8 FIN = 170 MHz FIN = 230 MHz FIN = 400 MHz 66.6 0 dB gain, 2 VPP FS (1) 66 3 dB gain, 1.4 VPP FS 65.4 0 dB gain, 2 VPP FS 3 dB gain, 1.4 VPP FS 64.5 86 FIN = 70 MHz 75 FIN = 100 MHz FIN = 230 MHz FIN = 300 MHz FIN = 400 MHz 79 0 dB gain, 2 VPP FS 75 3 dB gain, 1.4 VPP FS 78 0 dB gain, 2 VPP FS 74 3 dB gain, 1.4 VPP FS 76 0 dB gain, 2 VPP FS 68 3 dB gain, 1.4 VPP FS 70 FIN = 20 MHz 64 FIN = 100 MHz Signal to noise and distortion ratio FIN = 400 MHz 66.4 0 dB gain, 2 VPP FS 65 3 dB gain, 1.4 VPP FS 62.8 3 dB gain, 1.4 VPP FS 62.9 91 FIN = 70 MHz Second harmonic 88 87 FIN = 170 MHz 87 FIN = 300 MHz FIN = 400 MHz (1) 75 FIN = 100 MHz FIN = 230 MHz dBFS 65 0 dB gain, 2 VPP FS FIN = 20 MHz HD2 66.8 66.6 FIN = 170 MHz FIN = 230 MHz dBc 67 FIN = 70 MHz SINAD 84 78 FIN = 170 MHz Spurious free dynamic range dBFS 65 FIN = 20 MHz SFDR 66.9 0 dB gain, 2 VPP FS 86 3 dB gain, 1.4 VPP FS 88 0 dB gain, 2 VPP FS 78 3 dB gain, 1.4 VPP FS 80 0 dB gain, 2 VPP FS 69 3 dB gain, 1.4 VPP FS 71 dBc FS = Full scale range Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 5 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 ELECTRICAL CHARACTERISTICS (continued) Typical values are at 25°C, min and max values are across the full temperature range TMIN = –40°C to TMAX = 85°C, AVDD = DRVDD = 3.3 V, sampling rate = 200 MSPS, sine wave input clock, 1.5 VPP differential clock amplitude, 50% clock duty cycle, –1 dBFS differential analog input, internal reference mode, 0-db gain, DDR LVDS data output (unless otherwise noted) PARAMETER TEST CONDITIONS MIN FIN = 20 MHz Third harmonic 78 79 FIN = 400 MHz 0 dB gain, 2 VPP FS 75 3 dB gain, 1.4 VPP FS 78 0 dB gain, 2 VPP FS 74 3 dB gain, 1.4 VPP FS 76 0 dB gain, 2 VPP FS 68 3 dB gain, 1.4 VPP FS 70 FIN = 20 MHz 95 FIN = 70 MHz 92 FIN = 100 MHz 92 FIN = 170 MHz 90 FIN = 230 MHz 90 FIN = 300 MHz 88 FIN = 400 MHz 87 FIN = 20 MHz 83 FIN = 70 MHz THD ENOB IMD PSRR 6 Total harmonic distortion Effective number of bits Two-tone intermodulation distortion UNIT 84 FIN = 170 MHz FIN = 300 MHz Worst harmonic (other than HD2, HD3) 75 FIN = 100 MHz FIN = 230 MHz MAX 86 FIN = 70 MHz HD3 TYP 73 76 FIN = 170 MHz 77 FIN = 230 MHz 73 FIN = 300 MHz 72 FIN = 400 MHz 65 10.3 FIN1 = 50.03 MHz, FIN2 = 46.03 MHz, -7 dBFS each tone dBc 82 FIN = 100 MHz FIN = 70 MHz dBc 10.8 dBc bits 91 dBFS FIN1 = 190.1 MHz, FIN2 = 185.02 MHz, -7 dBFS each tone 86 AC power supply rejection ratio 30 MHz, 200 mVPP signal on 3.3-V supply 35 dBc Voltage overload recovery time Recovery to 1% (of final value) for 6-dB overload with sine-wave input at Nyquist frequency 1 Clock cycles Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 DIGITAL CHARACTERISTICS (1) The DC specifications refer to the condition where the digital outputs are not switching, but are permanently at a valid logic level 0 or 1 AVDD = DRVDD = 3.3 V, IO = 3.5 mA, RL = 100 Ω (2) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT DIGITAL INPUTS High-level input voltage 2.4 V Low-level input voltage 0.8 V High-level input current 33 µA Low-level input current –33 µA 4 pF High-level output voltage 3.3 V Low-level output voltage 0 V 2 pF 1375 mV Input capacitance DIGITAL OUTPUTS – CMOS MODE Output capacitance Output capacitance inside the device, from each output to ground DIGITAL OUTPUTS – LVDS MODE High-level output voltage Low-level output voltage 1025 Output differential voltage, |VOD| 225 VOS Output offset voltage, single-ended Common-mode voltage of OUTP and OUTM Output capacitance Output capacitance inside the device, from either output to ground (1) (2) 350 mV 425 mV 1200 mV 2 pF All LVDS and CMOS specifications are characterized, but not tested at production. IO refers to the LVDS buffer current setting, RL is the differential load resistance between the LVDS output pair. TIMING CHARACTERISTICS – LVDS AND CMOS MODES (1) Typical values are at 25°C, min and max values are across the full temperature range TMIN = –40°C to TMAX = 85°C, AVDD = DRVDD = 3.3 V, sampling frequency = 200 MSPS, sine wave input clock, 1.5 VPP clock amplitude, CL = 5 pF (2), IO = 3.5 mA, RL = 100 Ω (3), no internal termination, unless otherwise noted. For timings at lower sampling frequencies, see the Output Timing section in the APPLICATION INFORMATION of this data sheet. PARAMETER TEST CONDITIONS MIN TYP MAX UNIT ta Aperture delay 1.2 ns tj Aperture jitter 150 fs rms Wake-up time Time to valid data after coming out of STANDBY mode 100 Time to valid data after stopping and restarting the input clock 100 µs 14 clock cycles 1.0 1.5 ns 0.35 0.8 ns Latency DDR LVDS MODE (4) tsu th (1) (2) (3) (4) (5) (6) Data setup time (5) Data hold time (5) Data valid (6) to zero-cross of CLKOUTP Zero-cross of CLKOUTP to data becoming invalid (6) Timing parameters are specified by design and characterization and not tested in production. CL is the effective external single-ended load capacitance between each output pin and ground. IO refers to the LVDS buffer current setting; RL is the differential load resistance between the LVDS output pair. Measurements are done with a transmission line of 100 Ω characteristic impedance between the device and the load. Setup and hold time specifications take into account the effect of jitter on the output data and clock. These specifications also assume that the data and clock paths are perfectly matched within the receiver. Any mismatch in these paths within the receiver would appear as reduced timing margin. Data valid refers to logic high of +50 mV and logic low of –50 mV. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 7 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 TIMING CHARACTERISTICS – LVDS AND CMOS MODES (continued) For timings at lower sampling frequencies, see the Output Timing section in the APPLICATION INFORMATION of this data sheet. PARAMETER TEST CONDITIONS MIN TYP MAX Clock propagation delay (7) Input clock rising edge zero-cross to output clock rising edge zero-cross 3.7 4.4 5.1 LVDS bit clock duty cycle Duty cycle of differential clock, (CLKOUTP-CLKOUTM) 80 ≤ Fs ≤ 200 MSPS 45% 50% 55% tr , tf Data rise time, Data fall time Rise time measured from –50 mV to 50 mV Fall time measured from 50 mV to –50 mV 1 ≤ Fs ≤ 200 MSPS 50 100 200 ps tCLKRISE, tCLKFALL Output clock rise time, Output clock fall time Rise time measured from –50 mV to 50 mV Fall time measured from 50 mV to –50 mV 1 ≤ Fs ≤ 200 MSPS 50 100 200 ps Output clock jitter Cycle-to-cycle jitter Output enable (OE) to valid data delay Time to valid data after OE becomes active tPDI tOE 120 UNIT ns ps pp 1 µs PARALLEL CMOS MODE Data valid (8) to 50% of CLKOUT rising edge 1.8 2.6 50% of CLKOUT rising edge to data becoming invalid (8) 0.4 0.8 Clock propagation delay (7) Input clock rising edge zero-cross to 50% of CLKOUT rising edge 2.6 3.4 Output clock duty cycle Duty cycle of output clock (CLKOUT) 80 ≤ Fs ≤ 200 MSPS Data rise time, Data fall time Rise time measured from 20% to 80% of DRVDD Fall time measured from 80% to 20% of DRVDD 1 ≤ Fs ≤ 200 MSPS 0.8 tCLKRISE, tCLKFALL Output clock rise time, Output clock fall time Rise time measured from 20% to 80% of DRVDD Fall time measured from 80% to 20% of DRVDD 1 ≤ Fs ≤ 200 MSPS 0.4 tOE Output enable (OE) to valid data delay Time to valid data after OE becomes active tsu Data setup time th Data hold time tPDI tr , tf (7) (8) 8 (5) (5) ns ns 4.2 ns 1.5 2.0 ns 0.8 1.2 ns 50 ns 45% To use the input clock as the data capture clock, it is necessary to delay the input clock by a delay (tD) to get the desired setup and hold times. Use either of these equations to calculate tD: Desired setup time = tD - (tPDI - tsu ) Desired hold time = (tPDI + th ) - tD Data valid refers to logic high of 2 V and logic low of 0.8 V Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 N+4 N+3 N+2 N+1 Sample N N+17 N+16 N+15 N+14 Input Signal ta Input Clock CLKP CLKM CLKOUTM CLKOUTP tsu Output Data DXP, DXM O E – Even Bits D0,D2,D4,D6,D8,D10 O – Odd Bits D1,D3,D5,D7,D9 E O E N–14 O E N–13 O E N–12 O tPDI th 14 Clock Cycles DDR LVDS E N–11 O N–10 E O E O E N N–1 O O E E N+2 N+1 tPDI CLKOUT tsu Parallel CMOS 14 Clock Cycles Output Data D0–D10 N–14 N–13 N–12 N–11 th N–10 N–1 N N+1 N+2 Figure 1. Latency Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 9 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 CLKM Input Clock CLKP tPDI CLKOUTP Output Clock CLKOUTM tsu th tsu Output Data Pair Dn_Dn+1_P, Dn_Dn+1_M A. Dn – Bits D1, D3, D5, D7, and D9 B. Dn+1 – Bits D0, D2, D4, D6, D8, and D10 th Dn (Note A) Dn+1 (Note B) Figure 2. LVDS Mode Timing Input Clock CLKM CLKP tPDI Output Clock CLKOUT th tsu Output Data A. Dn Dn (Note A) Dn – Bits D0–D10 Figure 3. CMOS Mode Timing 10 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 DEVICE PROGRAMMING MODES ADS5517 offers flexibility with several programmable features that are easily configured. The device can be configured independently using either parallel interface control or serial interface programming. In addition, the device supports a third configuration mode, where both the parallel interface and the serial control registers are used. In this mode, the priority between the parallel and serial interfaces is determined by a priority table (Table 2). If this additional level of flexibility is not required, the user can select either the serial interface programming or the parallel interface control. USING PARALLEL INTERFACE CONTROL ONLY To control the device using parallel interface, keep RESET tied to high (DRVDD). Pins DFS, MODE, SEN, SCLK, and SDATA are used to directly control certain modes of the ADC. The device is configured by connecting the parallel pins to the correct voltage levels (as described in Table 3 to Table 7). There is no need to apply reset. In this mode, SEN, SCLK, and SDATA function as parallel interface control pins. Frequently used functions are controlled in this mode—standby, selection between LVDS/CMOS output format, internal/external reference, two's complement/straight binary output format, and position of the output clock edge. Table 1 has a description of the modes controlled by the parallel pins. Table 1. Parallel Pin Definition PIN DFS MODE CONTROL MODES DATA FORMAT and the LVDS/CMOS output interface Internal or external reference SEN CLKOUT edge programmability SCLK LOW SPEED mode control for low sampling frequencies (< 50 MSPS) SDATA STANDBY mode – Global (ADC, internal references and output buffers are powered down) USING SERIAL INTERFACE PROGRAMMING ONLY To program using the serial interface, the internal registers must first be reset to their default values, and the RESET pin must be kept low. In this mode, SEN, SDATA, and SCLK function as serial interface pins and are used to access the internal registers of ADC. The registers are reset either by applying a pulse on the RESET pin, or by a high setting on the <RST> bit (D1 in register 0x6C). The serial interface section describes the register programming and register reset in more detail. Since the parallel pins DFS and MODE are not used in this mode, they must be tied to ground. USING BOTH THE SERIAL INTERFACE AND PARALLEL CONTROLS For increased flexibility, a combination of serial interface registers and parallel pin controls (DFS, MODE) can also be used to configure the device. The serial registers must first be reset to their default values and the RESET pin must be kept low. In this mode, SEN, SDATA, and SCLK function as serial interface pins and are used to access the internal registers of ADC. The registers are reset either by applying a pulse on RESET pin or by a high setting on the <RST> bit (D1 in register 0x6C). The serial interface section describes the register programming and register reset in more detail. The parallel interface control pins DFS and MODE are used and their function is determined by the appropriate voltage levels as described in Table 6 and Table 7. The voltage levels are derived by using a resistor string as illustrated in Figure 4. Since some functions are controlled using both the parallel pins and serial registers, the priority between the two is determined by a priority table (Table 2). Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 11 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 Table 2. Priority Between Parallel Pins and Serial Registers PIN FUNCTIONS SUPPORTED MODE PRIORITY Internal/External reference When using the serial interface, bit <REF> (register 0x6D, bit D4) controls this mode, ONLY if the MODE pin is tied low. DATA FORMAT When using the serial interface, bit <DF> (register 0x63, bit D3) controls this mode, ONLY if the DFS pin is tied low. LVDS/CMOS When using the serial interface, bit <ODI> (register 0x6C, bits D3-D4) controls LVDS/CMOS selection independent of the state of DFS pin DFS AVDD (2/3) AVDD R (2/3) AVDD GND R AVDD (1/3) AVDD (1/3) AVDD R To Parallel Pin Figure 4. Simple Scheme to Configure Parallel Pins 12 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 DESCRIPTION OF PARALLEL PINS Table 3. SCLK Control Pin SCLK (Pin 29) DESCRIPTION 0 LOW SPEED mode Disabled - Use for sampling frequencies above 50 MSPS. DRVDD LOW SPEED mode Enabled - Use for sampling frequencies below 50 MSPS. Table 4. SDATA Control Pin SDATA (Pin 28) 0 DRVDD DESCRIPTION Normal operation (Default) STANDBY. This is a global power down, where ADC, internal references and the output buffers are powered down. Table 5. SEN Control Pin SEN (Pin 27) 0 (1) ; LVDS mode: CLKOUT edge aligned with data transition (1/3)DRVDD CMOS mode: CLKOUT edge later by (2/12)Ts ; LVDS mode: CLKOUT edge aligned with data transition (2/3)DRVDD CMOS mode: CLKOUT edge later by (1/12)Ts ; LVDS mode: CLKOUT edge earlier by (1/12)Ts DRVDD (1) DESCRIPTION CMOS mode: CLKOUT edge later by (3/12)Ts Default CLKOUT position Ts = 1/Sampling Frequency Table 6. DFS Control Pin DFS (Pin 6) 0 DESCRIPTION 2's complement data and DDR LVDS output (Default) (1/3)DRVDD 2's complement data and parallel CMOS output (2/3)DRVDD Offset binary data and parallel CMOS output DRVDD Offset binary data and DDR LVDS output Table 7. MODE Control Pin MODE (Pin 23) DESCRIPTION 0 Internal reference (1/3)AVDD External reference (2/3)AVDD External reference AVDD Internal reference SERIAL INTERFACE The ADC has a set of internal registers, which can be accessed through the serial interface formed by pins SEN (Serial interface Enable), SCLK (Serial Interface Clock), SDATA (Serial Interface Data) and RESET. After device power-up, the internal registers must be reset to their default values by applying a high-going pulse on RESET (of width greater than 10 ns). Serial shift of bits into the device is enabled when SEN is low. Serial data SDATA is latched at every falling edge of SCLK when SEN is active (low). The serial data is loaded into the register at every 16th SCLK falling edge when SEN is low. If the word length exceeds a multiple of 16 bits, the excess bits are ignored. Data is loaded in multiples of 16-bit words within a single active SEN pulse. The first 8 bits form the register address and the remaining 8 bits form the register data. The interface can work with SCLK frequency from 20 MHz down to very low speeds (few Hertz) and also with non-50% SCLK duty cycle. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 13 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 REGISTER INITIALIZATION After power-up, the internal registers must be reset to their default values. This is done in one of two ways: 1. Either through hardware reset by applying a high-going pulse on RESET pin (of width greater than 10 ns) as shown in Figure 5. OR 2. By applying software reset. Using the serial interface, set the <RST> bit (D1 in register 0x6C) to high. This initializes the internal registers to their default values and then self-resets the <RST> bit to low. In this case the RESET pin is kept low. Register Address SDATA A7 A6 A5 A4 A3 A2 Register Data A1 A0 D7 t(SCLK) D6 D5 D4 D3 D2 D1 D0 t(DH) t(DSU) SCLK t(SLOADH) t(SLOADS) SEN RESET Figure 5. Serial Interface Timing Diagram SERIAL INTERFACE TIMING CHARACTERISTICS Typical values at 25°C, min and max values across the full temperature range TMIN = –40°C to TMAX = 85°C, AVDD = DRVDD = 3.3 V (unless otherwise noted) MIN TYP UNIT 20 MHz SCLK frequency tSLOADS SEN to SCLK setup time 25 ns tSLOADH SCLK to SEN hold time 25 ns tDSU SDATA setup time 25 ns tDH SDATA hold time 25 ns 14 > DC MAX fSCLK Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 RESET TIMING Typical values at 25°C, min and max values across the full temperature range TMIN = –40°C to TMAX = 85°C, AVDD = DRVDD = 3.3 V (unless otherwise noted) PARAMETER TEST CONDITIONS t1 Power-on delay Delay from power-up of AVDD and DRVDD to RESET pulse active MIN t2 Reset pulse width t3 tPO TYP MAX UNIT 5 ms Pulse width of active RESET signal 10 ns Register write delay Delay from RESET disable to SEN active 25 ns Power-up time Delay from power-up of AVDD and DRVDD to output stable 6.5 ms Power Supply AVDD, DRVDD t1 RESET t2 t3 SEN NOTE: A high-going pulse on RESET pin is required in serial interface mode in case of initialization through hardware reset. For parallel interface operation, RESET has to be tied permanently HIGH. Figure 6. Reset Timing Diagram Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 15 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 SERIAL REGISTER MAP Table 8 gives a summary of all the modes that can be programmed through the serial interface. Table 8. Summary of Functions Supported by Serial Interface REGISTER ADDRESS IN HEX A7 – A0 REGISTER FUNCTIONS D7 65 D6 D5 D4 <DATA POSN> OUTPUT DATA POSITION PROGRAMMABILITY 62 63 D3 <LOW SPEED> ENABLE LOW SAMPLING FREQUENCY OPERATION <STBY> GLOBAL POWER DOWN D1 <DF> DATA FORMAT 2's COMP or STRAIGHT BINARY <GAIN> GAIN PROGRAMMING <GAIN> - 1 dB to 6 dB <CUSTOM A> CUSTOM PATTERN (D7 TO D0) 6A <CUSTOM B> CUSTOM PATTERN (D13 TO D8) 6B <CLKIN GAIN> INPUT CLOCK BUFFER GAIN PROGRAMMABILITY <ODI> OUTPUT DATA INTERFACE - DDR LVDS or PARALLEL CMOS 6C 6D <SCALING> POWER SCALING 7E <DATA TERM> INTERNAL TERMINATION – DATA OUTPUTS 7F D0 <TEST PATTERN> – ALL 0S, ALL 1s, TOGGLE, RAMP, CUSTOM PATTERN 69 16 D2 <CLKOUT POSN> OUTPUT CLOCK POSITION PROGRAMMABILITY 68 (1) (2) (1) (2) <RST> SOFTWARE RESET <REF> INTERNAL or EXTERNAL REFERENCE <CLKOUT TERM> INTERNAL TERMINATION – OUTPUT CLOCK <LVDS CURR> LVDS CURRENT PROGRAMMABILITY <CURR DOUBLE> LVDS CURRENT DOUBLE The unused bits in each register (shown by blank cells in above table) must be programmed as ‘0’. Multiple functions in a register can be programmed in a single write operation. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 DESCRIPTION OF SERIAL REGISTERS Each register function is explained in detail below. Table 9. Serial Register A A7 – A0 (hex) 62 D7 D6 D5 <DATA POSN> OUTPUT DATA POSITION PROGRAMMABILITY D4 D3 D2 D1 D0 <CLKOUT POSN> OUTPUT CLOCK POSITION PROGRAMMABILITY D4 — D0 <CLKOUT POSN> Output clock position programmability 00001 Default CLKOUT position after reset. Setup/hold timings with this clock position are specified in the timing characteristics table. XX011 CMOS – Falling edge later by (1/12) Ts LVDS – Falling edge earlier by (1/12) Ts XX101 CMOS – Falling edge later by (3/12) Ts LVDS – Falling edge aligned with data transition XX111 CMOS – Falling edge later by (2/12) Ts LVDS – Falling edge aligned with data transition 01XX1 CMOS – Rising edge later by (1/12) Ts LVDS – Rising edge earlier by (1/12) Ts 10XX1 CMOS – Rising edge later by (3/12) Ts LVDS – Rising edge aligned with data transition 11XX1 CMOS – Rising edge later by (2/12) Ts LVDS – Rising edge aligned with data transition D6 — D5 <DATA POSN> Output Switching Noise and Data Position Programmability (in CMOS mode ONLY) (Only in CMOS mode) 00 Data Position 1 – Default output data position after reset. Setup/hold timings with this data position are specified in the timing characteristics table. 01 Data Position 2 – Setup time increases by (2/36) Ts 10 Data Position 3 – Setup time increases by (5/36) Ts 11 Data Position 4 – Setup time decreases by (6/36) Ts Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 17 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 Table 10. Serial Register B A7 – A0 (hex) 63 D7 D6 D5 <STBY> GLOBAL POWER DOWN D4 D3 <LOW SPEED> ENABLE LOW SAMPLING FREQUENCY OPERATION <DF> DATA FORMAT 2's COMP or STRAIGHT BINARY D2 D3 <DF> Output data format 0 2's complement 1 Straight binary D4 <LOW SPEED> Low sampling frequency operation 0 Default SPEED mode for 50 < Fs ≤ 200 MSPS 1 Low SPEED mode 1≤ Fs ≤ 50 MSPS D7 <STBY> Global power down 0 Normal operation 1 Global power down (includes ADC, internal references and output buffers) D1 D0 D1 D0 Table 11. Serial Register C A7 – A0 (hex) 65 D7 D6 D5 D4 D3 D2 <TEST PATTERNS> — ALL 0S, ALL 1s, TOGGLE, RAMP, CUSTOM PATTERN D7 — D5 <TEST PATTERN> Outputs selected test pattern on data lines 000 Normal operation 001 All 0s 010 All 1s 011 Toggle pattern – alternate 1s and 0s on each data output and across data outputs 100 Ramp pattern – Output data ramps from 0x0000 to 0x3FFF by one code every clock cycle 101 Custom pattern – Outputs the custom pattern in CUSTOM PATTERN registers A and B 111 Unused 18 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 Table 12. Serial Register D A7 – A0 (hex) D7 D6 D5 D4 D3 68 D2 D1 D0 <GAIN> GAIN PROGRAMMING <GAIN> - 1 dB to 6 dB D3 — D0 <GAIN> Gain programmability 1000 0 dB gain, default after reset 1001 1 dB 1010 2 dB 1011 3 dB 1100 4 dB 1101 5 dB 1110 6 dB Table 13. Serial Register E A7 – A0 (hex) D7 69 D6 D5 D4 D3 D2 D1 D0 <CUSTOM A> CUSTOM PATTERN (D4 TO D0) 6A <CUSTOM B> CUSTOM PATTERN (D10 TO D5) Reg 69 D7 — D3 Program bits D4 to D0 of custom pattern Reg 6A D5 — D0 Program bits D10 to D5 of custom pattern Table 14. Serial Register F A7 – A0 (hex) D7 D6 D5 6B D4 D3 D2 D1 D0 <CLKIN GAIN> INPUT CLOCK BUFFER GAIN PROGRAMMABILITY D5 - D0 <CLKIN GAIN> Input clock buffer gain programming 110010 Gain 4, maximum gain 101010 Gain 3 100110 Gain 2 100000 Gain1, default after reset 100011 Gain 0 minimum gain Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 19 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 Table 15. Serial Register G A7 – A0 (hex) D7 D6 D5 D4 D3 D2 <ODI> OUTPUT DATA INTERFACE - DDR LVDS OR PARALLEL CMOS 6C D1 <RST> Software resets the ADC 1 Resets all registers to default values D4 — D3 <ODI> Output data interface 00 DDR LVDS outputs, default after reset 01 DDR LVDS outputs 11 Parallel CMOS outputs D1 D0 <RST> SOFTWARE RESET Table 16. Serial Register H A7 – A0 6D D7 D6 D5 <SCALING> POWER SCALING D4 D3 D2 D1 D0 D1 D0 <REF> INTERNAL or EXTERNAL REFERENCE D4 <REF> Reference 0 Internal reference 1 External reference mode, force voltage on Vcm to set reference. D7 — D5 <SCALING> Program power scaling at lower sampling frequencies 001 Use for Fs > 150 MSPS, default after reset 011 Power Mode 1, use for 105 < Fs ≤ 150 MSPS 101 Power Mode 2, use for 50 < Fs ≤ 105 111 Power Mode 3, use for Fs ≤ 50 MSPS Table 17. Serial Register I A7 – A0 D7 D6 D5 <DATA TERM> INTERNAL TERMINATION – DATA OUTPUTS 7E D4 D2 <CLKOUT TERM> INTERNAL TERMINATION – OUTPUT CLOCK D1 — D0 <LVDS CURR> LVDS buffer current programming 00 3.5 mA, default 01 2.5 mA 10 4.5 mA 11 1.75 mA 20 D3 Submit Documentation Feedback <LVDS CURR> LVDS CURRENT PROGRAMMABILITY Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 D4 — D2 <CLKOUT TERM> LVDS internal termination for output clock pin (CLKOUT) 000 No internal termination 001 325 Ω 010 200 Ω 011 125 Ω 100 170 Ω 101 120 Ω 110 100 Ω 111 75 Ω D7 — D5 <DATA TERM> LVDS internal termination for output data pins 000 No internal termination 001 325 Ω 010 200 Ω 011 125 Ω 100 170 Ω 101 120 Ω 110 100 Ω 111 75 Ω Table 18. Serial Register J A7 – A0 7F D7 D6 D5 D4 D3 D2 D1 D0 <CURR DOUBLE> LVDS CURRENT DOUBLE D7 — D6 <CURR DOUBLE> LVDS buffer current double 00 Value specified by <LVDS CURR> 01 2x data, 2x clockout currents 10 1x data, 2x clockout currents 11 2x data, 4x clockout currents Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 21 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 PIN CONFIGURATION (LVDS MODE) 37 LOW_D0_M 38 LOW_D0_P 39 D1_D2_M 40 D1_D2_P 41 D3_D4_M 42 D3_D4_P 43 D5_D6_M 44 D5_D6_P 45 D7_D8_M 46 D7_D8_P 47 D9_D10_M 48 D9_D10_P RGZ PACKAGE (TOP VIEW) DRGND 1 36 DRGND DRVDD 2 35 DRVDD Thermal Pad OVR 3 34 NC CLKOUTM 4 33 NC CLKOUTP 5 32 NC DFS 6 31 NC OE 7 30 RESET AVDD 24 MODE 23 AVDD 22 25 AGND IREF 21 AGND 12 AVDD 20 26 AVDD AGND 19 CLKM 11 AVDD 18 27 SEN AGND 17 CLKP 10 INM 16 28 SDATA INP 15 AGND 9 AGND 14 29 SCLK VCM 13 AVDD 8 Figure 7. LVDS Mode Pinout PIN ASSIGNMENTS – LVDS Mode PIN NAME DESCRIPTION PIN TYPE PIN NUMBER NUMBER OF PINS AVDD Analog power supply I 8, 18, 20, 22, 24, 26 6 AGND Analog ground I 9, 12, 14, 17, 19, 25 6 CLKP, CLKM Differential clock input I 10, 11 2 INP, INM Differential analog input I 15, 16 2 VCM Internal reference mode – Common-mode voltage output. External reference mode – Reference input. The voltage forced on this pin sets the internal references. I/O 13 1 IREF Current-set resistor, 56.2-kΩ resistor to ground. I 21 1 RESET Serial interface RESET input. When using the serial interface mode, the user MUST initialize internal registers through hardware RESET by applying a high-going pulse on this pin, or by using the software reset option. See the SERIAL INTERFACE section. In parallel interface mode, the user has to tie the RESET pin permanently HIGH. (SDATA and SEN are used as parallel pin controls in this mode) The pin has an internal 100-kΩ pull-down resistor. I 30 1 22 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 PIN ASSIGNMENTS – LVDS Mode (continued) PIN TYPE PIN NUMBER NUMBER OF PINS I 29 1 I 28 1 SEN This pin functions as serial interface enable input when RESET is low. It functions as CLKOUT edge programmability when RESET is tied high. See Table 5 for detailed information. The pin has an internal 100-kΩ pull-up resistor to DRVDD. I 27 1 OE Output buffer enable input, active high. The pin has an internal 100-kΩ pull-up resistor to DRVDD. I 7 1 DFS Data Format Select input. This pin sets the DATA FORMAT (Twos complement or Offset binary) and the LVDS/CMOS output mode type. See Table 6 for detailed information. I 6 1 MODE Mode select input. This pin selects the Internal or External reference mode. See Table 7 for detailed information. I 23 1 CLKOUTP Differential output clock, true O 5 1 CLKOUTM Differential output clock, complement O 4 1 LOW_D0_P Differential output data LOW and D0 multiplexed, true O 38 1 LOW_D0_M Differential output data LOW and D0 multiplexed, complement O 37 1 D1_D2_P Differential output data D1 and D2 multiplexed, true O 40 1 D1_D2_M Differential output data D1 and D2 multiplexed, complement O 39 1 D3_D4_P Differential output data D3 and D4 multiplexed, true O 42 1 D3_D4_M Differential output data D3 and D4 multiplexed, complement O 41 1 D5_D6_P Differential output data D5 and D6 multiplexed, true O 44 1 D5_D6_M Differential output data D5 and D6 multiplexed, complement O 43 1 D7_D8_P Differential output data D7 and D8 multiplexed, true O 46 1 D7_D8_M Differential output data D7 and D8 multiplexed, complement O 45 1 D9_D10_P Differential output data D9 and D10 multiplexed, true O 48 1 D9_D10_M Differential output data D9 and D10 multiplexed, complement O 47 1 OVR Out-of-range indicator, CMOS level signal O 3 1 DRVDD Digital and output buffer supply I 2, 35 2 DRGND Digital and output buffer ground I 1, 36 2 31, 32, 33, 34 4 0 1 PIN NAME SCLK DESCRIPTION This pin functions as serial interface clock input when RESET is low. It functions as LOW SPEED control pin when RESET is tied high. Tie SCLK to LOW for Fs > 50 MSPS and SCLK to HIGH for Fs ≤ 50 MSPS. See Table 3. The pin has an internal 100-kΩ pull-down resistor. This pin functions as serial interface data input when RESET is low. It functions as STANDBY control pin when RESET is tied high. SDATA See Table 4 for detailed information. The pin has an internal 100 kΩ pull-down resistor. NC Do not connect PAD Connect the pad to the ground plane. See Board Design Considerations in application information section. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 23 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 PIN CONFIGURATION (CMOS MODE) 37 NC 38 D0 39 D1 40 D2 41 D3 42 D4 43 D5 44 D6 45 D7 46 D8 47 D9 48 D10 RGZ PACKAGE (TOP VIEW) DRGND 1 36 DRGND DRVDD 2 35 DRVDD Thermal Pad OVR 3 34 NC UNUSED 4 33 NC CLKOUT 5 32 NC DFS 6 31 NC OE 7 30 RESET AVDD 24 MODE 23 AVDD 22 25 AGND IREF 21 AGND 12 AVDD 20 26 AVDD AGND 19 CLKM 11 AVDD 18 27 SEN AGND 17 CLKP 10 INM 16 28 SDATA INP 15 AGND 9 AGND 14 29 SCLK VCM 13 AVDD 8 Figure 8. CMOS Mode Pinout PIN ASSIGNMENTS – CMOS Mode PIN NAME DESCRIPTION PIN TYPE PIN NUMBER NUMBER OF PINS AVDD Analog power supply I 8, 18, 20, 22, 24, 26 6 AGND Analog ground I 9, 12, 14, 17, 19, 25 6 CLKP, CLKM Differential clock input I 10, 11 2 INP, INM Differential analog input I 15, 16 2 VCM Internal reference mode – Common-mode voltage output. External reference mode – Reference input. The voltage forced on this pin sets the internal references. I/O 13 1 IREF Current-set resistor, 56.2-kΩ resistor to ground. I 21 1 I 30 1 I 29 1 Serial interface RESET input. RESET When using the serial interface mode, the user MUST initialize internal registers through hardware RESET by applying a high-going pulse on this pin, or by using the software reset option. See the SERIAL INTERFACE section. In parallel interface mode, the user has to tie RESET pin permanently HIGH. (SDATA and SEN are used as parallel pin controls in this mode). The pin has an internal 100-kΩ pull-down resistor. SCLK 24 This pin functions as serial interface clock input when RESET is low. It functions as LOW SPEED control pin when RESET is tied high. Tie SCLK to LOW for Fs > 50 MSPS and SCLK to HIGH for Fs ≤ 50 MSPS. See Table 3. The pin has an internal 100-kΩ pull-down resistor. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 PIN ASSIGNMENTS – CMOS Mode (continued) PIN NAME DESCRIPTION PIN TYPE PIN NUMBER NUMBER OF PINS I 28 1 I 27 1 This pin functions as serial interface data input when RESET is low. It functions as STANDBY control pin when RESET is tied high. SDATA See Table 4 for detailed information. The pin has an internal 100 kΩ pull-down resistor. SEN This pin functions as serial interface enable input when RESET is low. It functions as CLKOUT edge programmability when RESET is tied high. See Table 5 for detailed information. The pin has an internal 100-kΩ pull-up resistor to DRVDD. OE Output buffer enable input, active high. The pin has an internal 100-kΩ pull-up resistor to DRVDD. I 7 1 DFS Data Format Select input. This pin sets the DATA FORMAT (Twos complement or Offset binary) and the LVDS/CMOS output mode type. See Table 6 for detailed information. I 6 1 MODE Mode select input. This pin selects the internal or external reference mode. See Table 7 for detailed information. I 23 1 CLKOUT CMOS output clock O 5 1 D0 CMOS output data D0 (LSB) O 38 1 D1 CMOS output data D1 O 39 1 D2 CMOS output data D2 O 40 1 D3 CMOS output data D3 O 41 1 D4 CMOS output data D4 O 42 1 D4 CMOS output data D5 O 43 1 D6 CMOS output data D6 O 44 1 D7 CMOS output data D7 O 45 1 D8 CMOS output data D8 O 46 1 D9 CMOS output data D9 O 47 1 D10 CMOS output data D10 (MSB) O 48 1 OVR Out-of-range indicator, CMOS level signal O 3 1 DRVDD Digital and output buffer supply I 2, 35 2 DRGND Digital and output buffer ground I 1, 36 2 UNUSED Unused pin in CMOS mode NC Do not connect PAD Connect the pad to the ground plane. See Board Design Considerations in application information section. 4 1 31, 32, 33, 34, 37 5 0 1 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 25 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 TYPICAL CHARACTERISTICS All plots are at 25°C, AVDD = DRVDD = 3.3 V, sampling frequency = 200 MSPS, sine wave input clock, 1.5 VPP differential clock amplitude, 50% clock duty cycle, –1 dBFS differential analog input, internal reference mode, 0 dB gain, DDR LVDS data output (unless otherwise noted) FFT for 20 MHz INPUT SIGNAL FFT for 70 MHz INPUT SIGNAL 0 0 SFDR = 86.68 dBc, SNR = 67.27 dBFS, SINAD = 67.19 dBFS THD = 83.31 dBc -40 SFDR = 89.4 dBc, SNR = 66.91 dBFS, SINAD = 66.84 dBFS THD = 84.11 dBc -20 Amplitude - dB Amplitude - dB -20 -60 -80 -100 -120 -40 -60 -80 -100 -120 -140 -140 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 f - Frequency - MHz Figure 9. FFT for 130 MHz INPUT SIGNAL 70 80 90 100 90 100 FFT for 270 MHz INPUT SIGNAL SFDR = 82.5 dBc, SNR = 66.82 dBFS, SINAD = 66.69 dBFS THD = 81.18 dBc -40 SFDR = 74.46 dBc, SNR = 66.09 dBFS, SINAD = 65.13 dBFS THD = 71.17 dBc -20 Amplitude - dB Amplitude - dB 60 0 -20 -60 -80 -100 -120 -40 -60 -80 -100 -120 -140 -140 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 Figure 11. FFT for 430 MHz INPUT SIGNAL Amplitude - dB SFDR = 66.56 dBc, SNR = 65.04 dBFS, SINAD = 62.77 dBFS THD = 65.61 dBc -40 50 60 70 80 Figure 12. 0 -20 40 f - Frequency - MHz f - Frequency - MHz Amplitude - dB 50 Figure 10. 0 -60 -80 -100 INTERMODULATION DISTORTION (IMD) vs FREQUENCY 0 fIN1 = 185.3 MHz, -7 dBFS, -20 fIN2 = 190.1 MHz, -7 dBFS, SFDR = 98 dBFS, -40 2-Tone IMD, 87 dBFS -60 -80 -100 -120 -120 -140 -140 0 10 20 30 40 50 60 70 80 90 100 0 10 f - Frequency - MHz 20 30 40 50 60 70 80 90 100 f - Frequency - MHz Figure 13. 26 40 f - Frequency - MHz Figure 14. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 TYPICAL CHARACTERISTICS (continued) All plots are at 25°C, AVDD = DRVDD = 3.3 V, sampling frequency = 200 MSPS, sine wave input clock, 1.5 VPP differential clock amplitude, 50% clock duty cycle, –1 dBFS differential analog input, internal reference mode, 0 dB gain, DDR LVDS data output (unless otherwise noted) SFDR vs INPUT FREQUENCY SNR vs INPUT FREQUENCY 69 86 68 SNR − dBFS 90 78 74 70 67 66 65 64 63 66 62 62 61 0 100 150 200 250 300 350 400 450 500 50 0 50 100 150 200 250 300 350 400 450 500 fIN − Input Frequency − MHz fIN - Input Frequency - MHz Figure 15. Figure 16. SFDR vs GAIN 96 1 dB 92 SNR vs GAIN 68 3 dB 5 dB 2 dB 0 dB 4 dB 2 dB 3 dB 67 SNR − dBFS SFDR − dBc 88 84 80 6 dB 0 dB 76 66 65 72 5 dB 68 64 6 dB 0 64 50 100 150 200 250 300 350 400 450 500 0 50 100 150 200 250 350 400 450 fIN − Input Frequency − MHz Figure 18. PERFORMANCE vs DRVDD 70 87 69 86 70 SFDR FIN = 50.1 MHz DRVDD = 3.3 V 82 68 SNR 80 3.2 3.3 3.4 3.5 3.6 SNR - dBFS SFDR − dBc SFDR 84 SFDR - dBc 300 Figure 17. PERFORMANCE vs AVDD 3.1 4 dB fIN − Input Frequency − MHz 86 78 3 1 dB 69 fIN = 50.1 MHz AVDD = 3.3 V 85 68 SNR 67 84 66 83 SNR − dBFS SFDR - dBc 82 67 66 3.0 3.1 AVDD - Supply Voltage - V 3.2 3.3 3.4 3.5 3.6 DRVDD − Supply Voltage − V Figure 19. Figure 20. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 27 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 TYPICAL CHARACTERISTICS (continued) All plots are at 25°C, AVDD = DRVDD = 3.3 V, sampling frequency = 200 MSPS, sine wave input clock, 1.5 VPP differential clock amplitude, 50% clock duty cycle, –1 dBFS differential analog input, internal reference mode, 0 dB gain, DDR LVDS data output (unless otherwise noted) SNR vs SAMPLING FREQUENCY (Across Power Scaling Modes) PERFORMANCE vs TEMPERATURE 90 69 70 fIN = 50.1 MHz 69 68 86 SNR 84 67 67 Power Mode 2 66 SNR- dBFS SFDR SNR − dBFS SFDR − dBc 88 65 64 63 62 82 −40 −15 10 66 85 50 35 Power Mode 1 Default 68 Power Mode 3 61 60 o TA − Free-Air Temperature − C 40 60 80 100 120 140 160 180 200 FS − Sampling Frequency − MSPS Figure 21. Figure 22. PERFORMANCE vs INPUT AMPLITUDE PERFORMANCE vs CLOCK AMPLITUDE 71 fIN = 50.1 MHz SFDR (dBc) 68 65 67 SNR (dBFS) 55 66 45 65 35 64 −10 69 fIN = 20.1 MHz Sine Wave Input Clock 83 81 0.3 0 0.5 0.8 1.1 1.3 Figure 23. 66 Input Clock Duty Cycle − % 60 65 1029 82 20 10 0 1028 67 1027 SNR 83 1026 68 1023 84 55 66 2.8 70 60 50 40 30 1022 69 50 2.5 110 100 90 80 1021 85 Occurence − % SFDR − dBc SFDR SNR − dBFS 70 86 45 2.3 OUTPUT NOISE HISTOGRAM WITH INPUTS TIED TO COMMON-MODE fIN = 20.1 MHz 40 2.1 Figure 24. PERFORMANCE vs INPUT CLOCK DUTY CYCLE 71 35 1.8 Clock Amplitude - VPP Input Amplitude − dBFS 87 1.5 68 67 SNR 1025 −20 84 82 63 −30 70 85 69 75 25 −40 SFDR 1024 SFDR − dBc 85 71 70 SNR − dBFS SFDR - dBc 95 86 SNR - dBFS 105 Output Code Figure 25. 28 Figure 26. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 TYPICAL CHARACTERISTICS (continued) All plots are at 25°C, AVDD = DRVDD = 3.3 V, sampling frequency = 200 MSPS, sine wave input clock, 1.5 VPP differential clock amplitude, 50% clock duty cycle, –1 dBFS differential analog input, internal reference mode, 0 dB gain, DDR LVDS data output (unless otherwise noted) 87 PERFORMANCE IN EXTERNAL REFERENCE MODE 71 COMMON-MODE REJECTION RATIO vs FREQUENCY -35 85 69 fIN = 20 MHz 68 84 -40 CMRR − dBc 70 SNR − dBFS SFDR − dBc SFDR 86 -45 -50 -55 -60 SNR 83 67 82 1.4 66 -65 1.45 1.5 1.55 -70 0 1.6 Voltage Forced on the CM Pin − V 60 80 Figure 28. POWER DISSIPATION vs SAMPLING FREQUENCY DIGITAL CURRENT vs SAMPLING FREQUENCY (Parallel CMOS) 100 100 1.18 LVDS Mode 1.12 Default 1.06 1.00 0.94 Power Mode 1 0.88 0.82 Power Mode 2 0.76 Power Mode 3 0 20 40 60 80 100 120 140 160 180 200 DRVDD Current − mA PD − Power Dissipation − W 40 Figure 27. 1.24 0.70 0.64 20 f - Frequency of AC Common-Mode Voltage - MHz CMOS 10-pF Load Cap 90 80 70 60 50 40 DDR LVDS CMOS 0-pF Load Cap 30 20 10 0 CMOS 5-pF Load Cap 0 20 FS − Sampling Frequency − MSPS Figure 29. 40 60 80 100 120 140 160 180 200 f − Frequency − MSPS Figure 30. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 29 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 TYPICAL CHARACTERISTICS (continued) All plots are at 25°C, AVDD = DRVDD = 3.3 V, sampling frequency = 200 MSPS, sine wave input clock, 1.5 VPP differential clock amplitude, 50% clock duty cycle, –1 dBFS differential analog input, internal reference mode, 0 dB gain, DDR LVDS data output (unless otherwise noted) 200 65.5 fS - Sampling Frequency - MSPS 180 66.5 160 140 64.5 65.5 120 66.5 100 80 64.5 65.5 66.5 63.5 60 66.5 64.5 65.5 40 10 50 100 150 200 250 61.5 62.5 63.5 300 350 400 450 500 fIN - Input Frequency - MHz 60 61 62 63 64 SNR - dBFS 65 66 67 Figure 31. SNR Contour in dBFS 200 82 fS - Sampling Frequency - MSPS 180 82 78 82 82 160 74 66 70 62 86 140 86 58 78 120 82 86 74 70 100 66 62 58 82 80 86 78 86 60 40 10 74 82 50 100 150 62 66 70 fIN - Input Frequency - MHz 200 250 300 54 350 400 450 500 fIN - Input Frequency - MHz 50 55 60 65 70 75 80 85 90 SFDR - dBc Figure 32. SFDR Contour in dBc 30 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 APPLICATION INFORMATION THEORY OF OPERATION ADS5517 is a low power 11-bit 200 MSPS pipeline ADC in a CMOS process. ADS5517 is based on switched capacitor technology and runs off a single 3.3-V supply. The conversion process is initiated by a rising edge of the external input clock. Once the signal is captured by the input sample and hold, the input sample is sequentially converted by a series of lower resolution stages, with the outputs combined in a digital correction logic block. At every clock edge, the sample propagates through the pipeline resulting in a data latency of 14 clock cycles. The output is available as 11-bit data, in DDR LVDS or CMOS and coded in either straight offset binary or binary 2’s complement format. ANALOG INPUT The analog input consists of a switched-capacitor based differential sample and hold architecture, shown in Figure 33. This differential topology results in good ac-performance even for high input frequencies at high sampling rates. The INP and INM pins have to be externally biased around a common-mode voltage of 1.5 V available on VCM pin 13. For a full-scale differential input, each input pin INP, INM has to swing symmetrically between VCM + 0.5 V and VCM – 0.5 V, resulting in a 2-VPP differential input swing. The maximum swing is determined by the internal reference voltages REFP (2.5 V nominal) and REFM (0.5 V, nominal). Sampling Switch Lpkg 6 nH Sampling Capacitor R-C-R Filter INP Cbond 2 pF 10 W 50 W Resr 200 W 1.6 pF Lpkg 6 nH Cpar2 1 pF Ron 15 W Ron 10 W Cpar1 0.8 pF 50 W Ron 15 W 10 W Csamp 2.4 pF Csamp 2.4 pF INM Cbond 2 pF Resr 200 W Sampling Capacitor Cpar2 1 pF Sampling Switch Figure 33. Input Stage The input sampling circuit has a high 3-dB bandwidth that extends up to 800 MHz (measured from the input pins to the voltage across the sampling capacitors) Drive Circuit Requirements The input sampling circuit of the ADS5517 has a high 3-dB analog bandwidth of 800 MHz making it possible to sample input signals up to very high frequencies. To get best performance, it is recommended to have an external R-C-R filter across the input pins (Figure 34). This helps to filter the glitches due to the switching of the sampling capacitors. The R-C-R filter has to be designed to provide adequate filtering (for good performance) and at the same time ensure sufficient bandwidth over the desired frequency range. In addition, it is recommended to have a 15-Ω series resistor on each input line to damp out ringing caused by the package parasitic. At higher input frequencies (> 100 MHz), a lower series resistance around 5 Ω to 10 Ω should be used. It is also necessary to present low impedance (< 50 Ω) for the common-mode switching currents. For example, this could be achieved by using two resistors from each input terminated to the common-mode voltage (Vcm). Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 31 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 Using 10-Ω series resistance and 25 Ω-3.3 pF-25 Ω as the R-C-R filter, high effective bandwidth (700 MHz) can be achieved, (see Figure 35, transfer function from the analog input pins to the voltage across the sampling capacitors). In addition to the above ADC requirements, the drive circuit may have to be designed to provide a low insertion loss over the desired frequency range and matched impedance to the source. For this, the ADC input impedance has to be taken into account (Figure 36). Example Drive Circuits A suitable configuration using RF transformers and including the R-C-R filter is shown in Figure 34. Note the 15-Ω series resistors and the low common-mode impedance (using 33-Ω resistors terminated to VCM). Zi and TFADC 0.1 mF WBC1-1TLB 15 W (Note A) WBC1-1TLB INP 100 W 25 W 33 W 0.1 mF 3.3 pF 33 W 25 W 100 W INM 1:1 15 W (Note A) 1:1 VCM A. Use lower series resistance (≈ 5 Ω to 10 Ω) at high input frequencies (> 100 MHz) Figure 34. Example Drive Circuit With RF Transformers 2 500 450 400 0 Magnitude − W Magnitude − dB 1 -1 -2 -3 -4 300 250 200 150 100 -5 -6 350 0 100 200 300 400 500 600 700 800 900 1000 50 0 0 100 f − Frequency − MHz 300 400 500 600 700 800 900 1000 f − Frequency − MHz Figure 35. Analog Input Bandwidth, TFADC (Actual Silicon Data) 32 200 Submit Documentation Feedback Figure 36. Input Impedance, ZI Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 Using RF transformers For optimum performance, the analog inputs have to be driven differentially. This improves the common-mode noise immunity and even order harmonic rejection. The single-ended signal is fed to the primary winding of the RF transformer. The transformer is terminated on the secondary side. Putting the termination on the secondary side helps to shield the kickbacks caused by the sampling circuit from the RF transformer’s leakage inductances. The termination is accomplished by two resistors connected in series, with the center point connected to the 1.5 V common-mode (VCM pin 13). At higher input frequencies, the mismatch in the transformer parasitic capacitance (between the windings) results in degraded even-order harmonic performance. Connecting two identical RF transformers back to back helps minimize this mismatch and good performance is obtained for high frequency input signals. An additional termination resistor pair (Figure 34) may be required between the two transformers to improve the balance between the P and M sides. The center point of this termination must be connected to ground. (Note that the drive circuit has to be tuned to account for this additional termination, to get the desired S11 and impedance match). Using Differential Amplifier Drive Circuits Figure 37 shows a drive circuit using a differential amplifier (TI's THS4509) to convert a single-ended input to differential output that can be interface to the ADC analog input pins. In addition to the single-ended to differential conversion, the amplifier also provides gain (10 dB in Figure 37). RFIL helps to isolate the amplifier outputs from the switching input of the ADC. Together with CFIL, it forms a low-pass filter that band-limits the noise (and signal) at the ADC input. As the amplifier output is ac-coupled, the common-mode voltage of the ADC input pins is set using two 200 Ω resistors connected to VCM. The amplifier output can also be dc-coupled. Using the output common-mode control of the THS4509, the ADC input pins can be biased to 1.5 V. In this case, use +4 V and -1 V supplies for the THS4509 so that its output common-mode voltage (1.5 V) is at mid-supply. RF +VS 500 W 0.1 mF RS 0.1 mF 10 mF RFIL 0.1 mF 5W INP RG 0.1 mF RT CFIL 200 W CFIL 200 W CM THS4509 RG RFIL INM 5W 0.1 mF 500 W RS || RT VCM 0.1 mF –VS ADS5517 0.1 mF 10 mF 0.1 mF RF Figure 37. Drive Circuit Using the THS4509 See the EVM User Guide (SLWU028) for more information. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 33 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 Input Common-Mode To ensure a low-noise common-mode reference, the VCM pin is filtered with a 0.1-µF low-inductance capacitor connected to ground. The VCM pin is designed to directly drive the ADC inputs. The input stage of the ADC sinks a common-mode current in the order of 342 µA (at 200 MSPS). Equation 1 describes the dependency of the common-mode current and the sampling frequency. (342 mA) x Fs 200 MSPS (1) This equation helps to design the output capability and impedance of the CM driving circuit accordingly. Reference ADS5517 has built-in internal references REFP and REFM, requiring no external components. Design schemes are used to linearize the converter load seen by the references; this and the integration of the requisite reference capacitors on-chip eliminates the need for external decoupling. The full-scale input range of the converter can be controlled in the external reference mode as explained below. The internal or external reference modes can be selected by controlling the MODE pin 23 (see Table 7 for details) or by programming the serial interface register bit <REF> (Table 16). INTREF Internal Reference VCM INTREF EXTREF REFM REFP Figure 38. Reference Section Internal Reference When the device is in internal reference mode, the REFP and REFM voltages are generated internally. Common-mode voltage (1.5 V nominal) is output on VCM pin, which can be used to externally bias the analog input pins. 34 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 External Reference When the device is in external reference mode, the VCM acts as a reference input pin. The voltage forced on the VCM pin is buffered and gained by 1.33 internally, generating the REFP and REFM voltages. The differential input voltage corresponding to full-scale is given by Equation 2. Full−scale differential input pp + (Voltage forced on VCM) 1.33 (2) In this mode, the 1.5 V common-mode voltage to bias the input pins has to be generated externally. There is no change in performance compared to internal reference mode. Low Sampling Frequency Operation For best performance at high sampling frequencies, ADS5517 uses a clock generator circuit to derive internal timing for the ADC. The clock generator operates from 200 MSPS down to 50 MSPS in the DEFAULT SPEED mode. The ADC enters this mode after applying reset (with serial interface configuration) or by tying SCLK pin to low (with parallel configuration). For low sampling frequencies (below 50 MSPS), the ADC must be put in the LOW SPEED mode. This mode can be entered by: • setting the register bit <LOW SPEED> through the serial interface, OR • tying the SCLK pin to high (see Table 3) using the parallel configuration. Clock Input ADS5517 clock inputs can be driven differentially (SINE, LVPECL or LVDS) or single-ended (LVCMOS), with little or no difference in performance between configurations. The common-mode voltage of the clock inputs is set to VCM using internal 5-kΩ resistors as shown in Figure 39. This allows the use of transformer-coupled drive circuits for sine wave clock, or ac-coupling for LVPECL, LVDS clock sources (Figure 40 and Figure 41) VCM VCM 5 kW 5 kW CLKP CLKM Figure 39. Internal Clock Buffer Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 35 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 For best performance, it is recommended to drive the clock inputs differentially, reducing susceptibility to common-mode noise. In this case, it is best to connect both clock inputs to the differential input clock signal with 0.1-µF capacitors, as shown in Figure 40. 0.1 mF CLKP Differential Sine-Wave or PECL or LVDS Clock Input 0.1 mF CLKM Figure 40. Differential Clock Driving Circuit A single-ended CMOS clock can be ac-coupled to the CLKP input, with CLKM (pin 11) connected to ground with a 0.1-µF capacitor, as shown in Figure 41. 0.1 mF CMOS Clock Input CLKP 0.1 mF CLKM Figure 41. Single-Ended Clock Driving Circuit For best performance, the clock inputs have to be driven differentially, reducing susceptibility to common-mode noise. For high input frequency sampling, the use a clock source with low jitter is recommended. Bandpass filtering of the clock source can help reduce the effect of jitter. There is no change in performance with a non-50% duty cycle clock input. Figure 25 shows the performance variation of the ADC versus clock duty cycle Clock Buffer Gain When using a sinusoidal clock input, the noise contributed by clock jitter improves as the clock amplitude is increased. Therefore, using a large amplitude clock is recommended. In addition, the clock buffer has a programmable gain option to amplify the input clock. The clock buffer gain can be set by programming the register bits <CLKIN GAIN> (Table 14). The clock buffer gain decreases monotonically from Gain 4 to Gain 0 settings. 36 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 Programmable Gain ADS5517 has programmable gain from 0 dB to 6 dB in steps of 1 dB. The corresponding full-scale input range varies from 2 VPP down to 1 VPP, with 0 dB being the default gain. At high IF, this is especially useful as the SFDR improvement is significant with marginal degradation in SNR. The gain can be programmed using the serial interface (bits D3-D0 in register 0x68). Power Down ADS5517 has three power-down modes – global STANDBY, output buffer disabled, and input clock stopped. Global STANDBY This mode can be initiated by controlling SDATA (pin 28) or by setting the register bit <STBY> (Table 10) through the serial interface. In this mode, the A/D converter, reference block and the output buffers are powered down and the total power dissipation reduces to about 100 mW. The output buffers are in high impedance state. The wake-up time from the global power down to data becoming valid normal mode is maximum 100 µs. Output Buffer Disable The output buffers can be disabled using OE pin 7 in both the LVDS and CMOS modes, reducing the total power by about 100 mW. With the buffers disabled, the outputs are in high impedance state. The wake-up time from this mode to data becoming valid in normal mode is maximum 1 µs in LVDS mode and 50 ns in CMOS mode. Input Clock Stop The converter enters this mode when the input clock frequency falls below 1 MSPS. The power dissipation is about 100 mW and the wake-up time from this mode to data becoming valid in normal mode is maximum 100 µs. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 37 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 Power Scaling Modes ADS5517 has a power scaling mode in which the device can be operated at reduced power levels at lower sampling frequencies with no difference in performance. (See Figure 29) (1) There are four power scaling modes for different sampling clock frequency ranges, using the serial interface register bits <SCALING> (Table 16). Only the AVDD power is scaled, leaving the DRVDD power unchanged. Table 19. Power Scaling vs Sampling Speed Sampling Frequency MSPS (1) Power Scaling Mode Analog Power (Typical) Analog Power in Default Mode > 150 Default 1010 mW at 200 MSPS 1010 mW at 200 MSPS 105 to 150 Power Mode 1 841 mW at 150 MSPS 917 mW at 150 MSPS 50 to 105 Power Mode 2 670 mW at 105 MSPS 830 mW at 105 MSPS < 50 Power Mode 3 525 mW at 50 MSPS 760 mW at 50 MSPS The performance in the power scaling modes is from characterization and not tested in production. Power Supply Sequence During power-up, the AVDD and DRVDD supplies can come up in any sequence. The two supplies are separated inside the device. Externally, AVDD and DRVDD can be driven from separate supplies or from a single supply. Digital Output Information ADS5517 provides 11-bit data, an output clock synchronized with the data and an out-of-range indicator that goes high when the output reaches the full-scale limits. In addition, output enable control (OE pin 7) is provided to power down the output buffers and put the outputs in high-impedance state. Output Interface Two output interface options are available – Double Data Rate (DDR) LVDS and parallel CMOS. The options are selected using the DFS (see Table 6) or the serial interface register bit <ODI> (Table 15). 38 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 DDR LVDS Outputs In this mode, the 11 data bits and the output clock are available as LVDS (Low Voltage Differential Signal) levels. Two successive data bits are multiplexed and output on each LVDS differential pair as shown in Figure 42. So, there are 6 LVDS output pairs for the 11 data bits and 1 LVDS output pair for the output clock. Pins CLKOUTP Output Clock CLKOUTM LOW_D0_P Data Bits Low, D0 LOW_D0_M D1_D2_P Data Bits D1, D2 D1_D2_M D3_D4_P Data Bits D3, D4 D3_D4_M D5_D6_P Data Bits D5, D6 D5_D6_M D7_D8_P Data Bits D7, D8 D7_D8_M D9_D10_P Data Bits D9, D10 D9_D10_M OVR Out-of-Range Indicator Figure 42. DDR LVDS Outputs Even data bits D0, D2, D4, D6, D8, and D10 are output at the rising edge of CLKOUTP and the odd data bits D1, D3, D5, D7, and D9 are output at the falling edge of CLKOUTP. Both the rising and falling edges of CLKOUTP must be used to capture all the 11 data bits (see Figure 43). Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 39 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 CLKOUTP CLKOUTM LOW_D0_P, LOW_D0_M LOW D0 LOW D0 D1_D2_P, D1_D2_M D1 D2 D1 D2 D3_D4_P, D3_D4_M D3 D4 D3 D4 D5_D6_P, D5_D6_M D5 D6 D5 D6 D7_D8_P, D7_D8_M D7 D8 D7 D8 D9_D10_P, D9_D10_M D9 D10 D9 D10 Sample N Sample N+1 Figure 43. DDR LVDS Interface LVDS Buffer Current Programmability The default LVDS buffer output current is 3.5 mA. When terminated by 100 Ω, the results is a 350-mV single-ended voltage swing (700-mVPP differential swing). The LVDS buffer currents can also be programmed to 2.5 mA, 4.5 mA, and 1.75 mA using the register bits <LVDS CURR> (Table 17). In addition, there exists a current double mode, where this current is doubled for the data and output clock buffers (register bits <CURR DOUBLE>, Table 18). LVDS Buffer Internal Termination An internal termination option is available (using the serial interface), by which the LVDS buffers are differentially terminated inside the device. The termination resistences available are – 325, 200, and 170 Ω (nominal with ±20% variation). Any combination of these three terminations can be programmed; the effective termination is the parallel combination of the selected resistences. This results in eight effective terminations from open (no termination) to 75 Ω. The internal termination helps to absorb any reflections coming from the receiver end, improving the signal integrity. With 100-Ω internal and 100-Ω external termination, the voltage swing at the receiver end is halved (compared to no internal termination). The voltage swing can be restored by using the LVDS current double mode. Figure 44 shows the eye diagram of one of the LVDS data outputs with a 10-pF load capacitance (from each pin to ground) and 100-Ω internal termination enabled. The termination can be programmed using register bits <DATA TERM> and <CLKOUT TERM> (Table 17). 40 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 Figure 44. Eye Diagram of LVDS Data Output With Internal Termination Parallel CMOS In this mode, the 11 data outputs and the output clock are available as 3.3-V CMOS voltage levels. Each data bit and the output clock is available on a separate pin in parallel. By default, the data outputs are valid during the rising edge of the output clock. The output clock is CLKOUT (pin 5). CMOS Mode Power Dissipation With CMOS outputs, the DRVDD current scales with the sampling frequency and the load capacitance on every output pin (see Figure 30). The maximum DRVDD current occurs when each output bit toggles between 0 and 1 every clock cycle. In actual applications, this condition is unlikely to occur. The actual DRVDD current is determined by the average number of output bits switching, which is a function of the sampling frequency and the nature of the analog input signal. Digital current due to CMOS output switching = CL x VDRVDD x (N x FAVG) where CL = load capacitance, N x FAVG = average number of output bits switching Figure 30 shows the current with various load capacitances across sampling frequencies at 2MHz analog input frequency. Output Switching Noise and Data Position Programmability (in CMOS mode ONLY) Switching noise (caused by CMOS output data transitions) can couple into the analog inputs during the instant of sampling and degrade the SNR. To minimize this, the device includes programmable options to move the output data transitions with respect to the output clock. This can be used to position the data transitions at the optimum place away from the sampling instant and improve the SNR. Figure 30 shows the variation of SNR for different CMOS output data positions at 200 MSPS. Note that the optimum output data position varies with the sampling frequency. The data position can be programmed using the register bits <DATA POSN> (Table 9). It is recommended to put series resistors (50 to 100 Ω) on each output line placed close to the converter pins. This helps to isolate the outputs from seeing large load capacitances and in turn reduces the amount of switching noise. For example, the data in Figure 30 was taken with 50-Ω resistors on each output line. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 41 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 Output Clock Position Programmability In both the LVDS and CMOS modes, the output clock can be moved around its default position. This can be done using SEN pin 27 (as described in Table 5) or using the serial interface register bits <CLKOUT POSN> (Table 9). Using this allows to trade-off the setup and hold times leading to reliable data capture. There also exists an option to align the output clock edge with the data transition. Note that programming the output clock position also affects the clock propagation delay times. Output Data Format Two output data formats are supported – 2's complement and offset binary. They can be selected using the DFS (pin 6) or the serial interface register bit <DF> (Table 10). Out-of-Range Indicator (OVR) When the input voltage exceeds the full-scale range of the ADC, OVR (pin 3) goes high, and the output code is clamped to the appropriate full-scale level for the duration of the overload. For a positive overdrive, the output code is 0x7FF in offset binary output format, and 0x3FF in 2's complement output format. For a negative input overdrive, the output code is 0x000 in offset binary output format and 0x400 in 2's complement output format. Figure 45 shows the behavior of OVR during the overload. Note that OVR and the output code react to the overload after a latency of 14 clock cycles. POL − Positive overload code 0x7FF for straight binary 0x3FF for 2s complement NOL − Negative overload code 0x000 for straight binary 0x400 for 2s complement Figure 45. OVR During Input Overvoltage Output Timing For the best performance at high sampling frequencies, ADS5517 uses a clock generator circuit to derive internal timing for ADC. This results in optimal setup and hold times of the output data and 50% output clock duty cycle for sampling frequencies from 80 MSPS to 200 MSPS. See Table 20 for timing information above 80 MSPS. 42 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 Table 20. Timing Characteristics (80 MSPS to 200 MSPS) Fs, MSPS tsu DATA SETUP TIME, ns MIN TYP 190 1.2 170 1.3 150 th DATA HOLD TIME, ns MAX MIN TYP 1.7 0.4 1.8 0.5 1.6 2.1 130 2.0 80 (1) tPDI CLOCK PROPAGATION DELAY, ns MAX MIN TYP MAX 0.9 4.0 4.7 5.4 1.0 3.9 4.6 5.3 0.6 1.1 4.3 5.0 5.7 2.5 0.8 1.3 4.5 5.2 5.9 3.6 4.1 1.6 2.1 4.7 5.7 6.7 190 2.2 3.0 0.5 0.9 2.4 3.2 4.0 170 2.5 3.3 0.8 1.2 1.9 2.7 3.5 150 2.8 3.6 1.2 1.6 1.7 2.5 3.3 130 3.3 4.1 1.7 2.1 1.1 1.9 2.7 80 6.0 7.0 3.7 4.1 10.8 12 13.2 DDR LVDS PARALLEL CMOS (1) Timing parameters are specified by design and characterization and not tested in production. Below 80 MSPS, the setup and hold times do not scale with the sampling frequency. The output clock duty cycle also progressively moves away from 50% as the sampling frequency is reduced from 80 MSPS. See Table 21 for timings at sampling frequencies below 80 MSPS. Figure 46 shows the clock duty cycle across sampling frequencies in the DDR LVDS and CMOS modes. Table 21. Timing Characteristics (1 MSPS to 80 MSPS) Fs, MSPS tsu DATA SETUP TIME, ns MIN TYP th DATA HOLD TIME, ns MAX MIN TYP (1) tPDI CLOCK PROPAGATION DELAY, ns MAX MIN TYP MAX DDR LVDS 1 to 80 3.6 1.6 5.7 6 3.7 12 PARALLEL CMOS 1 to 80 Timing parameters are specified by design and characterization and not tested in production. Output Clock Duty Cycle − % (1) 100 90 80 70 60 DDR LVDS 50% Duty Cycle 50 40 CMOS 45% Duty Cycle 30 20 10 0 0 20 40 60 80 100 120 140 160 180 200 Sampling Frequency − MHz Figure 46. Output Clock Duty Cycle (Typical) vs Sampling Frequency The latency of ADS5517 is 14 clock cycles from the sampling instant (input clock rising edge). In the LVDS mode, the latency remains constant across sampling frequencies. In the CMOS mode, the latency is 14 clock cycles above 80 MSPS and 13 clock cycles below 80 MSPS. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 43 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 Board Design Considerations Grounding A single ground plane is sufficient to give good performance, provided the analog, digital and clock sections of the board are cleanly partitioned. See the EVM User Guide (SLWU028) for details on layout and grounding. Supply Decoupling As the ADS5517 already includes internal decoupling, minimal external decoupling can be used without loss in performance. Note that decoupling capacitors can help to filter external power supply noise, so the optimum number of capacitors would depend on the actual application. The decoupling capacitors should be placed close to the converter supply pins. It is recommended to use separate supplies for the analog and digital supply pins to isolate digital switching noise from sensitive analog circuitry. If only a single 3.3V supply is available, it should be routed first to AVDD. It can then be tapped and isolated with a ferrite bead (or inductor) with decoupling capacitor, before being routed to DRVDD. Series Resistors on Data Outputs It is recommended to put series resistors (50 to 100 Ω) on each output line placed close to the converter pins. This helps to isolate the outputs from seeing large load capacitances and in turn reduces the amount of switching noise. Exposed Thermal Pad It is necessary to solder the exposed pad at the bottom of the package to a ground plane for best thermal performance. For detailed information, see application notes QFN Layout Guidelines (SLOA122) and QFN/SON PCB Attachment (SLUA271). 44 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 DEFINITION OF SPECIFICATIONS Analog Bandwidth The analog input frequency at which the power of the fundamental is reduced by 3 dB with respect to the low frequency value. Aperture Delay The delay in time between the rising edge of the input sampling clock and the actual time at which the sampling occurs. Aperture Uncertainty (Jitter) The sample-to-sample variation in aperture delay. Clock Pulse Width/Duty Cycle The duty cycle of a clock signal is the ratio of the time the clock signal remains at a logic high (clock pulse width) to the period of the clock signal. Duty cycle is typically expressed as a percentage. A perfect differential sine-wave clock results in a 50% duty cycle. Maximum Conversion Rate The maximum sampling rate at which certified operation is given. All parametric testing is performed at this sampling rate unless otherwise noted. Minimum Conversion Rate The minimum sampling rate at which the ADC functions. Differential Nonlinearity (DNL) An ideal ADC exhibits code transitions at analog input values spaced exactly 1 LSB apart. The DNL is the deviation of any single step from this ideal value, measured in units of LSBs Integral Nonlinearity (INL) The INL is the deviation of the ADC’s transfer function from a best fit line determined by a least squares curve fit of that transfer function, measured in units of LSBs. Gain Error The gain error is the deviation of the ADC’s actual input full-scale range from its ideal value. The gain error is given as a percentage of the ideal input full-scale range. Offset Error The offset error is the difference, given in number of LSBs, between the ADC’s actual average idle channel output code and the ideal average idle channel output code. This quantity is often mapped into mV. Temperature Drift The temperature drift coefficient (with respect to gain error and offset error) specifies the change per degree Celsius of the parameter from TMIN to TMAX. It is calculated by dividing the maximum deviation of the parameter across the TMIN to TMAX range by the difference TMAX–TMIN. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 45 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 Signal-to-Noise Ratio SNR is the ratio of the power of the fundamental (PS) to the noise floor power (PN), excluding the power at dc and the first nine harmonics. P SNR + 10Log 10 s PN (4) SNR is either given in units of dBc (dB to carrier) when the absolute power of the fundamental is used as the reference, or dBFS (dB to full scale) when the power of the fundamental is extrapolated to the converter’s full-scale range. Signal-to-Noise and Distortion (SINAD) SINAD is the ratio of the power of the fundamental (PS) to the power of all the other spectral components including noise (PN) and distortion (PD), but excluding dc. Ps SINAD + 10Log 10 PN ) PD (5) SINAD is either given in units of dBc (dB to carrier) when the absolute power of the fundamental is used as the reference, or dBFS (dB to full scale) when the power of the fundamental is extrapolated to the converter’s full-scale range. Effective Number of Bits (ENOB) The ENOB is a measure of a converter’s performance as compared to the theoretical limit based on quantization noise. ENOB + SINAD * 1.76 6.02 (6) Total Harmonic Distortion (THD) THD is the ratio of the power of the fundamental (PS) to the power of the first nine harmonics (PD). P THD + 10Log 10 s PN (7) THD is typically given in units of dBc (dB to carrier). Spurious-Free Dynamic Range (SFDR) The ratio of the power of the fundamental to the highest other spectral component (either spur or harmonic). SFDR is typically given in units of dBc (dB to carrier). Two-Tone Intermodulation Distortion IMD3 is the ratio of the power of the fundamental (at frequencies f1 and f2) to the power of the worst spectral component at either frequency 2f1–f2 or 2f2–f1. IMD3 is either given in units of dBc (dB to carrier) when the absolute power of the fundamental is used as the reference, or dBFS (dB to full scale) when the power of the fundamental is extrapolated to the converter’s full-scale range. DC Power Supply Rejection Ratio (DC PSRR) The DC PSSR is the ratio of the change in offset error to a change in analog supply voltage. The DC PSRR is typically given in units of mV/V. 46 Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 ADS5517 www.ti.com SLWS203 – DECEMBER 2007 AC Power Supply Rejection Ratio (AC PSRR) AC PSRR is the measure of rejection of variations in the supply voltage of the ADC. If ΔVSUP is the change in the supply voltage and ΔVOUT is the resultant change in the ADC output code (referred to the input), then DVOUT PSRR = 20Log 10 (Expressed in dBc) DVSUP (8) Common Mode Rejection Ratio (CMRR) CMRR is the measure of rejection of variations in the input common-mode voltage of the ADC. If ΔVcm is the change in the input common-mode voltage and ΔVOUT is the resultant change in the ADC output code (referred to the input), then DVOUT CMRR = 20Log10 (Expressed in dBc) DVCM (9) Voltage Overload Recovery The number of clock cycles taken to recover to less than 1% error for a 6-dB overload on the analog inputs. A 6-dBFS sine wave at Nyquist frequency is used as the test stimulus. Submit Documentation Feedback Copyright © 2007, Texas Instruments Incorporated Product Folder Link(s): ADS5517 47 PACKAGE OPTION ADDENDUM www.ti.com 20-Mar-2008 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty ADS5517IRGZR ACTIVE QFN RGZ 48 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-3-260C-168 HR ADS5517IRGZRG4 ACTIVE QFN RGZ 48 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-3-260C-168 HR ADS5517IRGZT ACTIVE QFN RGZ 48 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-3-260C-168 HR ADS5517IRGZTG4 ACTIVE QFN RGZ 48 250 Green (RoHS & no Sb/Br) CU NIPDAU Level-3-260C-168 HR Lead/Ball Finish MSL Peak Temp (3) (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. 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Addendum-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 19-Mar-2008 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel Diameter Width (mm) W1 (mm) A0 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant ADS5517IRGZR QFN RGZ 48 2500 330.0 16.4 7.3 7.3 1.5 12.0 16.0 Q2 ADS5517IRGZT QFN RGZ 48 250 330.0 16.4 7.3 7.3 1.5 12.0 16.0 Q2 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 19-Mar-2008 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) ADS5517IRGZR QFN RGZ 48 2500 333.2 345.9 28.6 ADS5517IRGZT QFN RGZ 48 250 333.2 345.9 28.6 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. 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