ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 14-BIT, 210 MSPS ADC WITH DDR LVDS/CMOS OUTPUTS FEATURES • • • • • • • • • • • • • • • • • • Maximum Sample Rate: 210 MSPS 14-Bit Resolution No Missing Codes Total Power Dissipation 1.23 W Internal Sample and Hold 73.3-dBFS SNR at 70-MHz IF 85-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 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) DESCRIPTION ADS5547 is a high performance 14-bit, 210-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. 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 ADS5547 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 ADS5547 PRODUCT FAMILY 210 MSPS 190 MSPS 170 MSPS 14 bit ADS5547 ADS5546 ADS5545 12 bit ADS5527 - ADS5525 APPLICATIONS • • • • • • • • Wireless Communications Infrastructure Software Defined Radio Power Amplifier Linearization 802.16d/e Test and Measurement Instrumentation High Definition Video Medical Imaging Radar Systems 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 © 2006, Texas Instruments Incorporated ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 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 D0_D1_P D0_D1_M D2_D3_P D2_D3_M D4_D5_P D4_D5_M Digital Encoder and Serializer INP 14-Bit ADC SHA INM D6_D7_P D6_D7_M D8_D9_P D8_D9_M D10_D11_P D10_D11_M VCM Control Interface Reference D12_D13_P D12_D13_M OVR MODE OE DFS RESET SEN SDATA SCLK IREF ADS5547 LVDS MODE PACKAGE/ORDERING INFORMATION (1) PRODUCT PACKAGELEAD ADS5547 QFN-48 (2) (1) (2) 2 PACKAGE DESIGNATOR RGZ SPECIFIED TEMPERATURE RANGE –40°C to 85°C PACKAGE MARKING ORDERING NUMBER TRANSPORT MEDIA, QUANTITY ADS5547IRGZT Tape and Reel, 250 ADS5547IRGZR Tape and Reel, 2500 AZ5547 For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI Web site 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 PCB. Submit Documentation Feedback ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 ABSOLUTE MAXIMUM RATINGS (1) over operating free-air temperature range (unless otherwise noted) VALUE UNIT Supply voltage range, AVDD –0.3 V to 3.9 V Supply voltage range, DRVDD –0.3 V 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 V to minimum (3.6, AVDD + 0.3 V) 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 V to AVDD + 0.3 V 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 VPP 1.5 ±0.1 Input common-mode voltage 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 50 210 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 31) 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) –40 5 pF 10 pF 100 Ω 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 3 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 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 = 210 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 14 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 REFERENCE VOLTAGES V(REFB) Internal reference bottom voltage Internal reference mode 0.5 V V(REFT) Internal reference top voltage Internal reference mode 2.5 V VCM Common mode output voltage Internal reference mode 1.5 V VCM output current capability Internal reference mode ±4 mA DC ACCURACY No Missing Codes DNL Differential non-linearity INL Integral non-linearity Assured Offset error 0.5 2.5 LSB -5 3.5 5 LSB 5 Offset temperature coefficient mV 0.002 Gain error Gain temperature coefficient PSRR -0.95 DC Power supply rejection ratio ppm/°C ±1 %FS 0.01 ∆%/°C 0.6 mV/V POWER SUPPLY I(AVDD) I(DRVDD) ICC 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 1.375 Standby power In STANDBY mode with clock stopped 100 150 mW Clock stop power With input clock stopped 100 150 mW Submit Documentation Feedback W ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 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 = 210 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 73.6 FIN = 70 MHz 71 FIN = 100 MHz 72.9 FIN = 170 MHz SNR Signal to noise ratio FIN = 230 MHz FIN = 300 MHz FIN = 400 MHz RMS output noise 71.7 0 dB gain, 2 VPP FS (1) 71 3 dB gain, 1.4 VPP FS 69.1 0 dB gain, 2 VPP FS 3 dB gain, 1.4 VPP FS 68.6 0 dB gain, 2 VPP FS 68.5 3 dB gain, 1.4 VPP FS 67.7 Inputs tied to common-mode 1.18 76 FIN = 100 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 70 FIN = 100 MHz Signal to noise and distortion ratio FIN = 300 MHz FIN = 400 MHz 70.7 0 dB gain, 2 VPP FS 69 3 dB gain, 1.4 VPP FS 68.7 0 dB gain, 2 VPP FS 67.8 3 dB gain, 1.4 VPP FS 67.6 0 dB gain, 2 VPP FS 63.5 3 dB gain, 1.4 VPP FS 64.3 FIN = 20 MHz 76 FIN = 100 MHz Second harmonic FIN = 300 MHz FIN = 400 MHz (1) 90 90 FIN = 170 MHz HD2 dBFS 92 FIN = 70 MHz FIN = 230 MHz 72.6 71.1 FIN = 170 MHz SINAD dBc 73 FIN = 70 MHz FIN = 230 MHz 85 78 FIN = 170 MHz FIN = 230 MHz LSB 87 FIN = 70 MHz Spurious free dynamic range dBFS 70 FIN = 20 MHz SFDR 73.3 88 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 5 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 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 = 210 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 76 FIN = 100 MHz FIN = 230 MHz FIN = 300 MHz FIN = 400 MHz Worst harmonic (other than HD2, HD3) Total harmonic distortion 79 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 74 IMD PSRR 6 Effective number of bits 77 FIN = 170 MHz 77 FIN = 230 MHz 74 FIN = 300 MHz 72 Two-tone intermodulation distortion FIN = 70 MHz FIN1 = 50.03 MHz, FIN2 = 46.03 MHz, -7 dBFS each tone FIN1 = 190.1 MHz, FIN2 = 185.02 MHz, -7 dBFS each tone AC power supply rejection ratio 30 MHz, 200 mVPP signal on 3.3-V supply Voltage overload recovery time Recovery to 1% (of final value) for 6-dB overload with sine-wave input at Nyquist frequency Submit Documentation Feedback dBc dBc 82 FIN = 100 MHz FIN = 400 MHz ENOB 85 0 dB gain, 2 VPP FS FIN = 70 MHz THD UNIT 78 FIN = 170 MHz Third harmonic MAX 87 FIN = 70 MHz HD3 TYP dBc 65 11.3 11.8 bits 91.1 dBFS 86.5 35 dBc 1 Clock cycles ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 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 = 210 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 valid (6) Data hold time (5) Zero-cross of CLKOUTP to data becoming invalid (6) to zero-cross of CLKOUTP 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 7 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 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 3.7 4.4 5.1 45% 50% 55% UNIT Clock propagation delay (7) Input clock rising edge zero-cross to output clock rising edge zero-cross LVDS bit clock duty cycle Duty cycle of differential clock, (CLKOUTP-CLKOUTM) 80 ≤ Fs ≤ 210 MSPS 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 ≤ 210 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 ≤ 210 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 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 (10) 0.4 0.8 Clock propagation delay (11) 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 ≤ 210 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 ≤ 210 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 ≤ 210 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 (5) (9) (7) 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 (8) Data valid refers to logic high of 2 V and logic low of 0.8 V (9) 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. (10) Data valid refers to logic high of 2 V and logic low of 0.8 V (11) 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 8 Submit Documentation Feedback ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 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 E O E – Even Bits D0,D2,D4,D6,D8,D10,D12 O – Odd Bits D1,D3,D5,D7,D9,D11,D13 E O N–14 E O N–13 E O N–12 E tPDI th 14 Clock Cycles DDR LVDS O N–11 E N–10 O E O E O N N–1 E E O O N+2 N+1 tPDI CLKOUT tsu Parallel CMOS 14 Clock Cycles Output Data D0–D13 N–14 N–13 N–12 N–11 th N–10 N–1 N N+1 N+2 Figure 1. Latency Submit Documentation Feedback 9 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 CLKM Input Clock CLKP tPDI Output Clock CLKOUTP CLKOUTM tsu th tsu Output Data Pair (1) (2) Dn Dn_Dn+1_P, Dn_Dn+1_M th Dn (1) Dn+1 – Bits D0, D2, D4, D6, D8, D10, D12 Dn+1 – Bits D1, D3, D5, D7, D9, D11, D13 Figure 2. LVDS Mode Timing CLKM Input Clock CLKP tPDI Output Clock CLKOUT th tsu Output Data Dn Dn (1) (1) Dn – Bits D0–D13 Figure 3. CMOS Mode Timing 10 Submit Documentation Feedback (2) ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 DEVICE PROGRAMMING MODES ADS5547 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 four 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 11 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 Table 2. Priority Between Parallel Pins and Serial Registers PIN MODE FUNCTIONS SUPPORTED 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 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 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. Submit Documentation Feedback 13 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 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 tSCLK SCLK period TYP 50 SCLK duty cycle MAX UNIT ns 50% 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 Submit Documentation Feedback ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 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 15 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 DESCRIPTION OF SERIAL REGISTERS Table 8 gives a summary of all the modes that can be programmed through the serial interface. Table 8. Serial Interface Register Map REGISTER ADDRESS A7 A6 A5 A4 A3 A2 REGISTER DATA A1 A0 D7 D6 D5 D4 D3 D2 D1 DESCRIPTION D0 <STBY> – Global Power Down 0 1 1 0 0 0 1 1 0 0 0 1 1 0 0 0 1 1 1 0 0 0 0 0 0 0 NORMAL converter operation (Default after reset) 0 0 0 0 0 0 STANDBY 1 0 Resets all registers to default values <RST> – Software Reset 0 1 1 0 1 1 0 0 0 0 0 0 0 0 <DF> – Output Data Format 0 1 1 0 0 0 1 1 0 0 0 0 0 0 0 0 2's complement output format (Default after reset) 0 1 1 0 0 0 1 1 0 0 0 0 1 0 0 0 Straight binary output format <ODI> – Output Data Interface 0 1 1 0 1 1 0 0 0 0 0 0 1 0 0 0 DDR LVDS outputs (D4:D3 defaults to 00 after reset) 0 1 1 0 1 1 0 0 0 0 0 1 1 0 0 0 Parallel CMOS outputs <REF> –Internal/External reference mode 0 1 1 0 1 1 0 1 0 0 0 0 0 0 0 0 Internal reference (Default after reset) 0 1 1 0 1 1 0 1 0 0 0 1 0 0 0 0 External reference – Force voltage on VCM pin 0 1 1 0 0 1 0 1 0 0 0 0 0 0 0 0 Normal operation (Default after reset) 0 1 1 0 0 1 0 1 0 0 1 0 0 0 0 0 All zeros 0 1 1 0 0 1 0 1 0 1 0 0 0 0 0 0 All ones 0 1 1 0 0 1 0 1 0 1 1 0 0 0 0 0 Toggle pattern Alternate 1s and 0s on each data output and across the data outputs. 0 1 1 0 0 1 0 1 1 0 0 0 0 0 0 0 Ramp pattern – Output data ramps from 0x0000 to 0x3FFF every clock cycle 0 1 1 0 0 1 0 1 1 0 1 0 0 0 0 0 Custom pattern. Write the custom pattern in CUSTOM PATTERN registers A and B. 0 1 1 0 0 1 0 1 X X X 0 0 0 0 0 NOT USED <TEST PATTERN> – Output test pattern on data outputs <CUSTOM PATTERN> – Output custom pattern on data outputs 0 1 1 0 1 0 0 1 D7 D6 D5 D4 D3 D2 D1 D0 CUSTOM PATTERN D7-D0 0 1 1 0 1 0 1 0 0 0 D13 D12 D11 D10 D9 D8 CUSTOM PATTERN D13-D8 <CLK GAIN> – Clock Buffer gain programmability, Gain decreases monotonically from Gain 4 to Gain 0 0 1 1 0 1 0 1 1 0 0 1 1 0 0 1 0 Gain 4 0 1 1 0 1 0 1 1 0 0 1 0 1 0 1 0 Gain 3 0 1 1 0 1 0 1 1 0 0 1 0 0 1 1 0 Gain 2 0 1 1 0 1 0 1 1 0 0 1 0 0 0 0 0 Gain 1 (Default after reset) 0 1 1 0 1 0 1 1 0 0 1 0 0 0 1 1 Gain 0 Minimum gain <POWER SCALING> Power scaling vs sampling frequency. The ADC can be operated at reduced power at lower sampling rates with no loss in performance. 16 0 1 1 0 1 1 0 1 0 0 1 0 0 0 0 0 Default Fs > 150 MSPS (Default after reset) 0 1 1 0 1 1 0 1 1 0 1 0 0 0 0 0 Power Mode 1 – 105 < Fs ≤ 150 MSPS 0 1 1 0 1 1 0 1 0 1 1 0 0 0 0 0 Power Mode 2 – 50 < Fs ≤ 105 MSPS 0 1 1 0 1 1 0 1 1 1 1 0 0 0 0 0 Power Mode 3 – Fs ≤ 50 MSPS Submit Documentation Feedback ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 Table 8. Serial Interface Register Map (continued) REGISTER ADDRESS A7 A6 A5 A4 A3 A2 REGISTER DATA A1 A0 D7 D6 D5 D4 D3 D2 D1 DESCRIPTION D0 <GAIN> Gain programming - Channel gain can be programmed from 0 to 6 dB for SFDR/SNR trade-off. For each gain setting, the input full-scale range has to be proportionally scaled. For 6 dB gain, the full-scale range is 1 VPP compared to 2 VPP at 0 dB gain. 0 1 1 0 1 0 0 0 0 0 0 0 1 0 0 0 0 dB (Default after reset) 0 1 1 0 1 0 0 0 0 0 0 0 1 0 0 1 1 dB 0 1 1 0 1 0 0 0 0 0 0 0 1 0 1 0 2 dB 0 1 1 0 1 0 0 0 0 0 0 0 1 0 1 1 3 dB 0 1 1 0 1 0 0 0 0 0 0 0 1 1 0 0 4 dB 0 1 1 0 1 0 0 0 0 0 0 0 1 1 0 1 5 dB 0 1 1 0 1 0 0 0 0 0 0 0 1 1 1 0 6 dB 0 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 3.5 mA (Default after reset) 0 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 2.5 mA 0 1 1 1 1 1 1 0 0 0 0 0 0 0 1 0 4.5 mA 0 1 1 1 1 1 1 0 0 0 0 0 0 0 1 1 1.75 mA <LVDS CURRENT> – LVDS Output data and clock buffers nominal current programmability <CURRENT DOUBLE> – The output data and clock buffer currents are doubled from the value selected by the <LVDS CURRENT> register. 0 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 value specified by <LVDS CURRENT> (Default after reset) 0 1 1 1 1 1 1 1 0 1 0 0 0 0 0 0 2x data, 2x clock currents 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 1x data, 2x clock currents 0 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 2x data, 4x clock currents <DATA TERM> Internal termination - Option to terminate the LVDS DATA buffers inside the ADC to improve signal integrity. By default, internal termination is disabled. 0 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 No termination (Default after reset) 0 1 1 1 1 1 1 0 0 0 1 0 0 0 0 0 325 Ω 0 1 1 1 1 1 1 0 0 1 0 0 0 0 0 0 200 Ω 0 1 1 1 1 1 1 0 0 1 1 0 0 0 0 0 125 Ω 0 1 1 1 1 1 1 0 1 0 0 0 0 0 0 0 170 Ω 0 1 1 1 1 1 1 0 1 0 1 0 0 0 0 0 120 Ω 0 1 1 1 1 1 1 0 1 1 0 0 0 0 0 0 100 Ω 0 1 1 1 1 1 1 0 1 1 1 0 0 0 0 0 75 Ω <CLK TERM> Internal termination - Option to terminate the LVDS CLK buffers inside the ADC to improve signal integrity. By default, internal termination is disabled. 0 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 No termination (Default after reset) 0 1 1 1 1 1 1 0 0 0 0 0 0 1 0 0 325 Ω 0 1 1 1 1 1 1 0 0 0 0 0 1 0 0 0 200 Ω 0 1 1 1 1 1 1 0 0 0 0 0 1 1 0 0 125 Ω 0 1 1 1 1 1 1 0 0 0 0 1 0 0 0 0 170 Ω 0 1 1 1 1 1 1 0 0 0 0 1 0 1 0 0 120 Ω 0 1 1 1 1 1 1 0 0 0 0 1 1 0 0 0 100 Ω 0 1 1 1 1 1 1 0 0 0 0 1 1 1 0 0 75 Ω <CLKOUT POSN CMOS> – Output clock rising edge programmability in CMOS mode (1) (1) 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0 1 Default position 0 1 1 0 0 0 1 0 0 0 0 0 0 0 1 1 CLKOUT rising edge later by (1/12)Ts 0 1 1 0 0 0 1 0 0 0 0 0 0 1 0 1 CLKOUT rising edge later by (3/12)Ts 0 1 1 0 0 0 1 0 0 0 0 0 0 1 1 1 CLKOUT rising edge later by (2/12)Ts Ts = 1/Sampling Frequency Submit Documentation Feedback 17 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 Table 8. Serial Interface Register Map (continued) REGISTER ADDRESS A7 A6 A5 A4 A3 A2 REGISTER DATA A1 A0 D7 D6 D5 D4 D3 D2 D1 DESCRIPTION D0 <CLKOUT POSN CMOS> – Output clock falling edge programmability in CMOS mode (2) 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0 1 Default position 0 1 1 0 0 0 1 0 0 0 0 0 1 0 0 1 CLKOUT falling edge later by (1/12)Ts 0 1 1 0 0 0 1 0 0 0 0 1 0 0 0 1 CLKOUT falling edge later by (3/12)Ts 0 1 1 0 0 0 1 0 0 0 0 1 1 0 0 1 CLKOUT falling edge later by (2/12)Ts <CLKOUT POSN LVDS> – Output clock rising edge programmability in LVDS mode (2) 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0 1 Default position 0 1 1 0 0 0 1 0 0 0 0 0 0 0 1 1 CLKOUT rising edge earlier by (1/12)Ts 0 1 1 0 0 0 1 0 0 0 0 0 0 1 0 1 CLKOUT rising edge aligned with data transition 0 1 1 0 0 0 1 0 0 0 0 0 0 1 1 1 CLKOUT rising edge aligned with data transition <CLKOUT POSN LVDS> – Output clock falling edge programmability in LVDS mode (2) 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0 1 Default position 0 1 1 0 0 0 1 0 0 0 0 0 1 0 0 1 CLKOUT falling edge earlier by (1/12)Ts 0 1 1 0 0 0 1 0 0 0 0 1 0 0 0 1 CLKOUT falling edge aligned with data transition 0 1 1 0 0 0 1 0 0 0 0 1 1 0 0 1 CLKOUT falling edge aligned with data transition <LOW SPEED> – For low sampling frequency operation (2) 18 0 1 1 0 0 0 1 1 0 0 0 0 0 0 0 0 DEFAULT SPEED mode - for 50 < Fs ≤ 210 MSPS 0 1 1 0 0 0 1 1 0 0 0 1 0 0 0 0 LOW SPEED mode - for 1 < Fs ≤ 50 MSPS Ts = 1/Sampling Frequency Submit Documentation Feedback ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 PIN CONFIGURATION (LVDS MODE) 37 D2_D3_M 38 D2_D3_P 39 D4_D5_M 40 D4_D5_P 41 D6_D7_M 42 D6_D7_P 43 D8_D9_M 44 D8_D9_P 45 D10_D11_M 46 D10_D11_P 47 D12_D13_M 48 D12_D13_P RGZ PACKAGE (TOP VIEW) DRGND 1 36 DRGND DRVDD 2 35 DRVDD OVR 3 34 D0_D1_P CLKOUTM 4 33 D0_D1_M CLKOUTP 5 32 NC DFS 6 31 NC OE 7 30 RESET AVDD 8 29 SCLK AGND 9 28 SDATA AVDD 24 MODE 23 AVDD 22 IREF 21 AVDD 20 AGND 19 AVDD 18 25 AGND AGND 17 AGND 12 INM 16 26 AVDD INP 15 CLKM 11 AGND 14 27 SEN VCM 13 CLKP 10 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 Submit Documentation Feedback 19 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 PIN CONFIGURATION (LVDS MODE) (continued) 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 D0_D1_P Differential output data D0 and D1 multiplexed, true O 34 1 D0_D1_M Differential output data D0 and D1 multiplexed, complement. O 33 1 D2_D3_P Differential output data D2 and D3 multiplexed, true O 38 1 D2_D3_M Differential output data D2 and D3 multiplexed, complement O 37 1 D4_D5_P Differential output data D4 and D5 multiplexed, true O 40 1 D4_D5_M Differential output data D4 and D5 multiplexed, complement O 39 1 D6_D7_P Differential output data D6 and D7 multiplexed, true O 42 1 D6_D7_M Differential output data D6 and D7 multiplexed, complement O 41 1 D8_D9_P Differential output data D8 and D9 multiplexed, true O 44 1 D8_D9_M Differential output data D8 and D9 multiplexed, complement O 43 1 D10_D11_P Differential output data D10 and D11 multiplexed, true O 46 1 D10_D11_M Differential output data D10 and D11 multiplexed, complement O 45 1 D12_D13_P Differential output data D12 and D13 multiplexed, true O 48 1 D12_D13_M Differential output data D12 and D13 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 NC Do not connect 31, 32 2 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. 20 Submit Documentation Feedback ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 PIN CONFIGURATION (CMOS MODE) 37 D2 38 D3 39 D4 40 D5 41 D6 42 D7 43 D8 44 D9 45 D10 46 D11 47 D12 48 D13 RGZ PACKAGE (TOP VIEW) DRGND 1 36 DRGND DRVDD 2 35 DRVDD OVR 3 34 D1 UNUSED 4 33 D0 CLKOUT 5 32 NC DFS 6 31 NC OE 7 30 RESET AVDD 8 29 SCLK AGND 9 28 SDATA AVDD 24 MODE 23 AVDD 22 IREF 21 AVDD 20 AGND 19 AVDD 18 25 AGND AGND 17 AGND 12 INM 16 26 AVDD INP 15 CLKM 11 AGND 14 27 SEN VCM 13 CLKP 10 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 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 21 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 PIN CONFIGURATION (CMOS MODE) (continued) 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 O 33 1 D0 CMOS output data D1 O 34 1 D2 CMOS output data D2 O 37 1 D2 CMOS output data D3 O 38 1 D4 CMOS output data D4 O 39 1 D4 CMOS output data D5 O 40 1 D6 CMOS output data D6 O 41 1 D7 CMOS output data D7 O 42 1 D8 CMOS output data D8 O 43 1 D9 CMOS output data D9 O 44 1 D10 CMOS output data D10 O 45 1 D11 CMOS output data D11 O 46 1 D12 CMOS output data D12 O 47 1 D13 CMOS output data D13 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 4 1 NC Do not connect 31, 32 2 22 Submit Documentation Feedback ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 TYPICAL CHARACTERISTICS All plots are at 25°C, AVDD = DRVDD = 3.3 V, sampling frequency = 210 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 Figure 9. Figure 10. FFT for 100 MHz INPUT SIGNAL FFT for 170 MHz INPUT SIGNAL 0 0 SFDR = 81.74 dBc, SNR = 72.46 dBFS, SINAD = 71.37 dBFS -40 SFDR = 82.82 dBc, SNR = 71.6 dBFS, SINAD = 70.83 dBFS -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 50 60 70 80 90 100 90 100 f - Frequency - MHz Figure 11. Figure 12. FFT for 220 MHz INPUT SIGNAL FFT for 300 MHz INPUT SIGNAL 0 0 SFDR = 80.98 dBc, SNR = 70.86 dBFS, SINAD = 70.16 dBFS -20 -40 -60 -80 -100 -120 SFDR = 74.68 dBc, SNR = 69.48 dBFS, SINAD = 67.47 dBFS -20 Amplitude - dB Amplitude - dB 40 -40 -60 -80 -100 -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 f - Frequency - MHz Figure 13. Figure 14. Submit Documentation Feedback 23 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 TYPICAL CHARACTERISTICS (continued) All plots are at 25°C, AVDD = DRVDD = 3.3 V, sampling frequency = 210 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 400 MHz INPUT SIGNAL FFT for 600 MHz INPUT SIGNAL 0 0 SFDR = 70.92 dBc, SNR = 68.19 dBFS, SINAD = 64.82 dBFS SFDR = 65.5 dBc, SNR = 65.29 dBFS, SINAD = 61 dBFS -20 -40 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 70 80 100 90 Figure 16. INTERMODULATION DISTORTION (IMD) vs FREQUENCY INTERMODULATION DISTORTION (IMD) vs FREQUENCY 0 fIN1 = 50.03 MHz, -7 dBFS, fIN2 = 46.03 MHz, -7 dBFS, SFDR = 88.5 dBc, 2-Tone IMD, 91.1 dBFS -40 fIN1 = 190.1 MHz, -7 dBFS, fIN2 = 185.02 MHz, -7 dBFS, SFDR = 87.1 dBc, 2-Tone IMD, 86.5 dBFS -20 Amplitude - dB Amplitude - dB 60 Figure 15. -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 40 50 60 70 80 90 100 f - Frequency - MHz Figure 17. Figure 18. SFDR vs INPUT FREQUENCY SNR vs INPUT FREQUENCY 75 90 74 SNR − dBFS 86 82 SFDR - dBc 50 f - Frequency - MHz 0 78 74 LVDS Mode 73 72 71 70 69 70 68 66 67 62 66 0 50 100 150 200 250 300 350 400 0 fIN - Input Frequency - MHz Figure 19. 24 40 50 100 150 200 250 Figure 20. Submit Documentation Feedback 300 fIN − Input Frequency − MHz 350 400 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 TYPICAL CHARACTERISTICS (continued) All plots are at 25°C, AVDD = DRVDD = 3.3 V, sampling frequency = 210 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 INPUT FREQUENCY SFDR vs GAIN 75 96 74 CMOS Mode 1 dB 2 dB 3 dB 92 88 72 SFDR − dBc SNR - dBFS 73 71 70 69 84 80 68 76 67 72 6 dB 5 dB 4 dB 0 dB 66 0 50 100 150 200 250 68 300 0 50 fIN - Input Frequency - MHz 100 150 200 250 300 350 400 fIN − Input Frequency − MHz Figure 21. Figure 22. SNR vs GAIN PERFORMANCE vs AVDD 76 92 75 90 74.5 1 dB 2 dB 3 dB SFDR - dBc SNR − dBFS 74 72 70 68 74 FIN = 70 MHz DRVDD = 3.3 V 73.5 86 SNR 73 84 5 dB 66 4 dB 82 3 6 dB 64 SFDR 88 0 50 100 SNR - dBFS 0 dB 150 200 250 300 350 72.5 3.1 3.2 3.3 3.4 3.5 3.6 AVDD - Supply Voltage - V 400 fIN − Input Frequency − MHz Figure 23. Figure 24. PERFORMANCE vs DRVDD PERFORMANCE vs TEMPERATURE 75 92 75.0 fIN = 70 MHz 74.5 73.5 86 SNR 73 84 SFDR − dBc 74 SNR − dBFS fIN = 70 MHz AVDD = 3.3 V 88 74.5 90 SFDR 88 74.0 86 73.5 84 SNR − dBFS SFDR 90 SFDR − dBc 92 73.0 SNR 72.5 82 3.0 3.1 3.2 3.3 3.4 3.5 3.6 82 −40 −15 10 50 35 72.5 85 o TA − Free-Air Temperature − C DRVDD − Supply Voltage − V Figure 25. Figure 26. Submit Documentation Feedback 25 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 TYPICAL CHARACTERISTICS (continued) All plots are at 25°C, AVDD = DRVDD = 3.3 V, sampling frequency = 210 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 75 POWER DISSIPATION vs SAMPLING FREQUENCY 1.24 PD − Power Dissipation − W fIN = 70 MHz 74 72 Default 71 Power Mode 1 70 Power Mode 3 69 68 Power Mode 2 67 66 40 60 80 100 120 140 160 180 1.12 1.00 0.94 0.88 Power Mode 1 0.82 0.76 0.70 0.64 220 200 Default 1.06 Power Mode 2 Power Mode 3 0 20 40 60 80 100 120 140 160 180 200 220 FS − Sampling Frequency − MSPS FS − Sampling Frequency − MSPS Figure 27. Figure 28. PERFORMANCE vs INPUT AMPLITUDE PERFORMANCE vs CLOCK AMPLITUDE 105 95 76 75 74 SNR (dBFS) 65 73.5 55 73 SFDR (dBc) SFDR 84 74 SNR 73 82 72.5 80 71.5 −40 −30 −20 −10 78 0.3 0 0.5 0.8 1.5 1.8 2.1 2.5 Figure 30. PERFORMANCE vs INPUT CLOCK DUTY CYCLE OUTPUT NOISE HISTOGRAM WITH INPUTS TIED TO COMMON-MODE 35 78 72 45 50 55 Input Clock Duty Cycle − % 60 65 15 10 5 0 Output Code Figure 31. Figure 32. Submit Documentation Feedback 8250 73 8249 80 8248 SNR 20 8246 74 25 8245 82 30 8243 75 8242 84 Occurence − % SFDR SNR − dBFS 76 86 40 71 2.8 40 77 fIN = 10 MHz 26 2.3 Figure 29. 88 SFDR − dBc 1.3 Clock Amplitude - VPP Input Amplitude − dBFS 35 1.1 8252 −50 8244 25 −60 fIN = 70 MHz 72 fIN = 70 MHz Sine Wave Input Clock 72 35 8251 45 SFDR - dBc 75 75 86 74.5 SNR - dBFS SFDR (dBFS) 85 SNR − dBFS SFDR − dBc, dBFS 88 75.5 8247 SNR − dBFS 73 LVDS Mode 1.18 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 TYPICAL CHARACTERISTICS (continued) All plots are at 25°C, AVDD = DRVDD = 3.3 V, sampling frequency = 210 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) PERFORMANCE IN EXTERNAL REFERENCE MODE 88 -35 76 -40 84 74 82 73 SNR 80 72 CMRR − dBc SFDR SNR − dBFS 75 86 SFDR − dBc COMMON-MODE REJECTION RATIO vs FREQUENCY -45 -50 -55 -60 -65 78 1.4 71 1.45 1.5 1.55 Voltage Forced on the CM Pin − V 1.6 -70 0 20 40 60 80 100 f - Frequency of AC Common-Mode Voltage - MHz Figure 33. Figure 34. Submit Documentation Feedback 27 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 TYPICAL CHARACTERISTICS (continued) All plots are at 25°C, AVDD = DRVDD = 3.3 V, sampling frequency = 210 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) fS - Sampling Frequency - MSPS 210 200 180 160 140 120 100 80 65 100 200 300 400 500 600 700 fIN - Input Frequency - MHz 62 63 64 65 66 67 68 69 70 71 72 73 SNR - dBFS Figure 35. SNR Contour in dBFS fS - Sampling Frequency - MSPS 210 200 180 160 140 120 100 80 65 100 200 300 400 500 600 700 80 85 90 fIN - Input Frequency - MHz 55 60 65 70 75 SFDR - dBc Figure 36. SFDR Contour in dBc 28 Submit Documentation Feedback ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 APPLICATION INFORMATION THEORY OF OPERATION ADS5547 is a low power 14-bit 210 MSPS pipeline ADC in a CMOS process. ADS5547 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 14-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 37. 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 37. 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 ADS5547 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 38). 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 parasitics. 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). 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, as shown in Figure 39. Submit Documentation Feedback 29 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 APPLICATION INFORMATION (continued) 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 40). Example Drive Circuits A suitable configuration using RF transformers and including the R-C-R filter is shown in Figure 38. Note the 15-Ω series resistors and the low common-mode impedance (using 33-Ω resistors terminated to VCM). ADS5547 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 38. Example Drive Circuit With RF Transformers 2 Magnitude − dB 1 0 -1 -2 -3 -4 -5 -6 0 100 200 300 400 500 600 700 800 900 1000 f − Frequency − MHz Figure 39. Analog Input Bandwidth, TFADC (Actual Silicon Data) 30 Submit Documentation Feedback ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 APPLICATION INFORMATION (continued) 500 450 Magnitude − dB 400 350 300 250 200 150 100 50 0 0 100 200 300 400 500 600 700 800 900 1000 f − Frequency − MHz Figure 40. Input Impedance, ZI 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 38) 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). Submit Documentation Feedback 31 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 APPLICATION INFORMATION (continued) 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 210 MSPS). Equation 1 describes the dependency of the common-mode current and the sampling frequency. (342 mA) x Fs 210 MSPS (1) This equation helps to design the output capability and impedance of the CM driving circuit accordingly. Reference ADS5547 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>. INTREF Internal Reference VCM INTREF EXTREF REFM REFP ADS5547 Figure 41. 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. 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. 32 Submit Documentation Feedback ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 APPLICATION INFORMATION (continued) 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, ADS5547 uses a clock generator circuit to derive internal timing for the ADC. The clock generator operates from 210 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 ADS5547 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 42. This allows the use of transformer-coupled drive circuits for sine wave clock, or ac-coupling for LVPECL, LVDS clock sources (Figure 43 and Figure 44) VCM VCM 5 kW 5 kW CLKP CLKM ADS5547 Figure 42. Internal Clock Buffer 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 43. Submit Documentation Feedback 33 ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 APPLICATION INFORMATION (continued) 0.1 mF CLKP Differential Sine-Wave or PECL or LVDS Clock Input 0.1 mF CLKM ADS5547 Figure 43. 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 44. 0.1 mF CMOS Clock Input CLKP 0.1 mF CLKM ADS5547 Figure 44. 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 very 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 31 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 <CLK GAIN>. The clock buffer gain decreases monotonically from Gain 4 to Gain 0 settings. 34 Submit Documentation Feedback ADS5547 www.ti.com SLWS192 – NOVEMBER 2006 APPLICATION INFORMATION (continued) Table 9. Clock Buffer Gain Programming REGISTER ADDRESS A7 A6 A5 A4 A3 A2 REGISTER DATA A1 A0 D7 D6 D5 D4 D3 DESCRIPTION D2 D1 D0 <CLK GAIN> – Clock buffer gain programmability, Gain decreases monotonically from Gain 4 to Gain 0 0 1 1 0 1 0 1 1 0 0 1 1 0 0 1 0 Gain 4 0 1 1 0 1 0 1 1 0 0 1 0 1 0 1 0 Gain 3 0 1 1 0 1 0 1 1 0 0 1 0 0 1 1 0 Gain 2 0 1 1 0 1 0 1 1 0 0 1 0 0 0 0 0 Gain 1 Default gain 0 1 1 0 1 0 1 1 0 0 1 0 0 0 1 1 Gain 0 Minimum gain Programmable Gain ADS5547 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). Table 10. Programmable Gain REGISTER ADDRESS A7 A6 A5 A4 A3 A2 REGISTER DATA A1 A0 D7 D6 D5 D4 D3 DESCRIPTION D2 D1 D0 <GAIN> Gain programming - Channel gain can be programmed from 0 to 6 dB for SFDR/SNR trade-off. For each gain setting, the input full-scale range has to be proportionally scaled. For 6 dB gain, the full-scale range is 1 VPP compared to 2 VPP at 0 dB gain. 0 1 1 0 1 0 0 0 0 0 0 0 1 0 0 0 0 dB Default after reset 0 1 1 0 1 0 0 0 0 0 0 0 1 0 0 1 1 dB 0 1 1 0 1 0 0 0 0 0 0 0 1 0 1 0 2 dB 0 1 1 0 1 0 0 0 0 0 0 0 1 0 1 1 3 dB 0 1 1 0 1 0 0 0 0 0 0 0 1 1 0 0 4 dB 0 1 1 0 1 0 0 0 0 0 0 0 1 1 0 1 5 dB 0 1 1 0 1 0 0 0 0 0 0 0 1 1 1 0 6 dB Power Down ADS5547 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> 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 wa