Data Sheet CDK8307 – 23mW/channel at 20MSPS – 35mW/channel at 40MSPS – 41mW/channel at 50MSPS – 51mW/channel at 65MSPS – 59mW/channel at 80MSPS n 72.2dB SNR at 8MHz FIN n 0.5μs startup time from Sleep n 15μs startup time from Power Down n Internal reference circuitry requires no external components n Internal offset correction n Reduced power dissipation modes available – 34mW/channel at 50MSPS – 71.5dB SNR at 8MHz FIN n Coarse and fine gain control n 1.8V supply voltage n Serial LVDS output – 12- and 14-bit output available An integrated PLL multiplies the input sampling clock by a factor of 12 or 14, according to the LVDS output setting. The multiplied clock is used for data serialization and data output. Data and frame synchronization output clocks are supplied for data capture at the receiver. Various modes and configuration settings can be applied to the ADC through the serial control interface (SPI). Each channel can be powered down independently and data format can be selected through this interface. A full chip idle mode can be set by a single external pin. Register settings determines the exact function of this external pin. The CDK8307 is designed to easily interface with field-programmable gate arrays (FPGAs) from several vendors. The very low startup times of the CDK8307 allow significant power reduction in duty-cycled systems, by utilizing the Sleep Mode or Power Down Mode when the receive path is idle. Block Diagram Package alternatives RESETN n The CDK8307 is a high performance low power octal analog-to-digital converter (ADC). The ADC employs internal reference circuitry, a serial control interface and serial LVDS output data, and is based on a proprietary structure. – TQFP-80 – QFN-64 APPLICATIONS n Medical Imaging n Wireless Infrastructure IP1 n Test and Measurement IN1 n Instrumentation IP2 IN2 Exar Corporation 48720 Kato Road, Fremont CA 94538, USA Clock Input PLL LVDS FCLKP FCLKN LCLKP LCLKN ADC Digital Gain LVDS D1N D1P ADC Digital Gain LVDS D2N D2P • • • • • • • • • ADC Digital Gain LVDS D8N D8P www.exar.com Tel. +1 510 668-7000 - Fax. +1 510 668-7001 Rev 1C IP8 IN8 Serial Control Interface AVDD AVSS DVDD DVSS Low Power Dissipation PD n General Description CLKP CLKN 20/40/50/65/80MSPS max sampling rate SCLK SDATA n CSN FEATURES CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS Data Sheet Table of Contents Features................................................................... 1 Table 6. LVDS Output Drive Strength for Table 7. LVDS Internal Termination Applications............................................................. 1 General Description................................................. 1 LCLK, FCLK, and Data................................ 19 Programmability........................................ 20 Table 8. LVDS Output Internal Termination............... 20 Table of Contents.................................................... 2 Table 9. Analog Input Invert.................................... 20 Table 10. LVDS Test Patterns................................... 21 Ordering Information.............................................. 3 Table 11. Programmable Gain.................................. 21 Pin Configurations................................................... 4 Table 12. Gain Setting for Channels 1-8................... 22 Pin Assignments................................................... 5-8 Absolute Maximum Ratings.................................... 9 Reliability Information............................................ 9 Table 13. LVDS Clock Programmability and Data Output Modes.................................. 22 Figure 6. Phase Programmability Modes for LCLK...... 23 ESD Protection......................................................... 9 Figure 7. SDR Interface Modes................................ 23 Recommended Operating Conditions..................... 9 Table 14. Number of Serial Output Bits.................... 23 Electrical Characteristics....................................... 10 Figure 8. LVDS Output Timing Adjustment............... 24 Electrical Characteristics – CDK8307A.............10-11 Table 15. Full Scale Control..................................... 24 Electrical Characteristics – CDK8307B................. 11 Electrical Characteristics – CDK8307C.............11-12 Electrical Characteristics – CDK8307D.............12-13 Table 16. Register Values with Corresponding Charge in Full-Scale Range....................... 25 Table 17. Clock Frequency....................................... 25 Electrical Characteristics – CDK8307E................. 13 Table 18. Clock Frequency Settings.......................... 25 Digital and Timing Electrical Characteristics...13-14 Table 19. Performance Control................................ 25 LVDS Timing Diagrams.......................................... 15 Table 20. Performance Control Settings.................... 26 Figure 1. 12-bit Output, DDR Mode.......................... 15 Table 21. External Common Mode Voltage Figure 2. 14-bit Output, DDR Mode.......................... 15 Buffer Driving Strength............................ 26 Figure 3. 12-bit Output, SDR Mode.......................... 15 Theory of Operation.............................................. 27 Figure 4. Data Timing............................................. 15 Recommended Usage............................................ 27 Serial Interface...................................................... 16 Analog Input.......................................................... 27 Timing Diagram..................................................... 16 Figure 9. Input Configuration Diagram................. 27 Figure 5. Serial Port Interface Timing Diagram...... 16 DC-Coupling........................................................... 27 Table 1. Serial Port Interface Timing Definitions.... 16 Figure 10. DC-Coupled Input............................... 27 Register Initialization.............................................. 16 AC-Coupling........................................................... 28 Serial Register Map...........................................17-18 Figure 11. Transformer Coupled Input.................. 28 Table 2. Summary of Functions Supported Figure 12. AC-Coupled Input............................... 28 Figure 13. Alternative Input Network.................... 28 Description of Serial Registers.........................18-25 Clock Input and Jitter Considerations....................... 29 Table 3. Software Reset.......................................... 18 Mechanical Dimensions ....................................30-31 Table 4. Power-Down Modes................................... 18 QFN-64 Package.................................................... 30 Table 5. LVDS Drive Strength Programmability.......... 19 TQFP-80 Package................................................... 31 ©2009-2013 Exar Corporation 2/31 Rev 1C Rev 1C by Serial Interface.................................17-18 CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS Block Diagram......................................................... 1 Data Sheet Ordering Information Speed Package Pb-Free RoHS Compliant Operating Temperature Range Packaging Method CDK8307AITQ80 20MSPS TQFP-80 Yes Yes -40°C to +85°C Tray CDK8307AILP64 20MSPS QFN-64 Yes Yes -40°C to +85°C Tray CDK8307BITQ80 40MSPS TQFP-80 Yes Yes -40°C to +85°C Tray CDK8307BILP64 40MSPS QFN-64 Yes Yes -40°C to +85°C Tray CDK8307CITQ80 50MSPS TQFP-80 Yes Yes -40°C to +85°C Tray CDK8307CILP64 50MSPS QFN-64 Yes Yes -40°C to +85°C Tray CDK8307DITQ80 65MSPS TQFP-80 Yes Yes -40°C to +85°C Tray CDK8307DILP64 65MSPS QFN-64 Yes Yes -40°C to +85°C Tray CDK8307EITQ80 80MSPS TQFP-80 Yes Yes -40°C to +85°C Tray CDK8307EILP64 80MSPS QFN-64 Yes Yes -40°C to +85°C Tray CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS Part Number Moisture sensitivity level for QFN package is MSL-2A, for TQFP package is MSL-3. Rev 1C ©2009-2013 Exar Corporation 3/31 Rev 1C Data Sheet Pin Configurations NC AVDD NC 54 AVDD NC 55 49 AVDD 56 NC CLKP 57 50 CLKN 58 51 OVDD 59 VCM CSN 60 TP AVSS SDATA 61 52 SCLK 62 53 RESETN 63 IP1 1 48 IN8 IN1 2 47 IP8 AVSS 3 46 AVSS IP2 4 45 IN7 IN2 5 44 IP7 AVSS 6 43 AVSS IP3 7 42 IN6 IN3 8 41 IP6 AVSS 9 40 AVSS IP4 10 39 IN5 IN4 11 38 IP5 DVSS 12 37 AVSS PD 13 36 DVSS DVSS 14 35 DVDD D1P 15 34 D8N D1N 16 33 D8P CDK8307 NC TP AVSS 62 61 32 D7N AVDD 31 63 30 D7P NC 64 D6N VCM 65 29 D6P NC 66 28 NC D5N AVSS 67 27 D5P 68 26 NC LCLKN AVDD 69 25 LCLKP 70 24 CLKP 71 FCLKN CLKN 72 23 FCLKP AVSS 73 22 D4N 74 21 AVSS D4P OVDD 75 20 D3N CSN 76 19 D3P SDATA 77 18 SCLK 78 17 AVSS 79 D2P AVSS 80 D2N QFN-64 AVDD 1 60 AVDD IP1 2 59 IN8 IN1 3 58 IP8 AVSS 4 57 AVSS IP2 5 56 IN7 IN2 6 55 IP7 AVDD 7 54 AVDD AVSS 8 53 AVSS IP3 9 52 IN6 IN3 10 51 IP6 AVSS 11 50 AVSS IP4 12 49 IN5 IN4 13 48 IP5 AVDD 14 47 AVDD DVSS 15 46 DVSS PD 16 45 RESETN DVSS 17 44 DVSS DVSS 18 43 DVSS LCLKP 19 42 FCLKN LCLKN 20 41 FCLKP CDK8307 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 D1P D2P D2N DVDD DVSS D3P D3N D4P D4N D5P D5N D6P D6N DVDD DVSS D7P D7N D8P D8N ©2009-2013 Exar Corporation 4/31 Rev 1C D1N TQFP-80 CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS TQFP-80 64 QFN-64 Rev 1C Data Sheet Pin Assignments - QFN Pin No. Pin Name Description 49, 50, 57 AVDD Analog power supply, 1.8V 3, 6, 9, 37, 40, 43, 46 AVSS Analog ground 1 IP1 Positive differential input signal, channel 1 2 IN1 Negative differential input signal, channel 1 4 IP2 Positive differential input signal, channel 2 5 IN2 Negative differential input signal, channel 2 7 IP3 Positive differential input signal, channel 3 8 IN3 Negative differential input signal, channel 3 10 IP4 Positive differential input signal, channel 4 11 IN4 Negative differential input signal, channel 4 38 IP5 Positive differential input signal, channel 5 39 IN5 Negative differential input signal, channel 5 41 IP6 Positive differential input signal, channel 6 42 IN6 Negative differential input signal, channel 6 44 IP7 Positive differential input signal, channel 7 45 IN7 Negative differential input signal, channel 7 47 IP8 Positive differential input signal, channel 8 48 IN8 Negative differential input signal, channel 8 12, 14, 36 DVSS Digital ground 35 DVDD Digital and I/O power supply, 1.8V 13 PD Power-down input. Activate after applying power in order to initialize the ADC correctly. Alternatively use the SPI power down feature. 15 D1P LVDS channel 1, positive output 16 D1N LVDS channel 1, negative output 17 D2P LVDS channel 2, positive output 18 D2N LVDS channel 2, negative output 19 D3P LVDS channel 3, positive output 20 D3N LVDS channel 3, negative output 21 D4P LVDS channel 4, positive output 22 D4N LVDS channel 4, negative output 27 D5P LVDS channel 5, positive output 28 D5N LVDS channel 5, negative output 29 D6P LVDS channel 6, positive output 30 D6N LVDS channel 6, negative output 31 D7P LVDS channel 7, positive output 32 D7N LVDS channel 7, negative output 33 D8P LVDS channel 8, positive output 34 D8N LVDS channel 8, negative output 23 FCLKP LVDS frame clock (1x), positive output 24 FCLKN LVDS frame clock (1x), negative output 25 LCLKP LVDS bit clock, positive output QFN-64 Rev 1C 5/31 CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS ©2009-2013 Exar Corporation Rev 1C Data Sheet Pin Assignments QFN (Continued) Pin No. Pin Name Description LCLKN NC LVDS bit clock, negative output Not connected 52 TP Test pin. Leave open (un-connected) or connect to GND. 53 VCM Common mode output pin, 0.5 AVDD 58 CLKP Positive differential input clock 59 CLKN Negative differential input clock. 60 OVDD Digital CMOS inputs supply voltage (1.7V to 3.6V) 61 CSN 62 SDATA Serial data input 63 SCLK Serial clock input 64 RESETN CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS 26 51, 54, 55, 56 Chip select enable. Active low. Reset SPI interface Rev 1C ©2009-2013 Exar Corporation 6/31 Rev 1C Data Sheet Pin Assignments - TQFP Pin No. Pin Name Description 1, 7, 14, 47, 54, 60, 63, 70 AVDD Analog power supply, 1.8V 4, 8, 11, 50, 53, 57, 68, 73, 74, 79, 80 AVSS Analog ground 2 IP1 Positive differential input signal, channel 1 3 IN1 Negative differential input signal, channel 1 5 IP2 Positive differential input signal, channel 2 6 IN2 Negative differential input signal, channel 2 9 IP3 Positive differential input signal, channel 3 10 IN3 Negative differential input signal, channel 3 12 IP4 Positive differential input signal, channel 4 13 IN4 Negative differential input signal, channel 4 48 IP5 Positive differential input signal, channel 5 49 IN5 Negative differential input signal, channel 5 51 IP6 Positive differential input signal, channel 6 52 IN6 Negative differential input signal, channel 6 55 IP7 Positive differential input signal, channel 7 56 IN7 Negative differential input signal, channel 7 58 IP8 Positive differential input signal, channel 8 59 IN8 Negative differential input signal, channel 8 TQFP DVSS Digital ground 25, 35 DVDD Digital and I/O power supply, 1.8V 16 PD Power-down input. Activate after applying power in order to initialize the ADC correctly. Alternatively use the SPI power down feature. LCKP LVDS bit clock, positive output 20 LCKN LVDS bit clock, negative output 21 D1P LVDS channel 1, positive output 22 D1N LVDS channel 1, negative output 23 D2P LVDS channel 2, positive output 24 D2N LVDS channel 2, negative output 27 D3P LVDS channel 3, positive output 28 D3N LVDS channel 3, negative output 29 D4P LVDS channel 4, positive output 30 D4N LVDS channel 4, negative output 31 D5P LVDS channel 5, positive output 32 D5N LVDS channel 5, negative output 33 D6P LVDS channel 6, positive output 34 D6N LVDS channel 6, negative output 37 D7P LVDS channel 7, positive output 38 D7N LVDS channel 7, negative output 39 D8P LVDS channel 8, positive output 40 D8N LVDS channel 8, negative output ©2009-2013 Exar Corporation 7/31 Rev 1C 19 CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS 15, 17, 18, 26, 36, 43, 44, 46 Rev 1C Data Sheet Pin Assignments - TQFP (Continued) Pin No. Pin Name Description 41 FCLKP LVDS frame clock (1x), positive output 42 FCLKN LVDS frame clock (1x), negative output 45 RESETN 61 TP Test pin. Leave open (un-connected) or connect to GND. 62, 64, 66, 67, 69 NC Not connected 65 VCM Common mode output pin, 0.5 AVDD 71 CLKP Positive differential input clock 72 CLKN Negative differential input clock. 75 OVDD Digital CMOS inputs supply voltage (1.7V to 3.6V) 76 CSN 77 SDATA Serial data input 78 SCLK Serial clock input CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS Reset SPI interface Chip select enable. Active low. Rev 1C ©2009-2013 Exar Corporation 8/31 Rev 1C Data Sheet Absolute Maximum Ratings The safety of the device is not guaranteed when it is operated above the “Absolute Maximum Ratings”. The device should not be operated at these “absolute” limits. Adhere to the “Recommended Operating Conditions” for proper device function. The information contained in the Electrical Characteristics tables and Typical Performance plots reflect the operating conditions noted on the tables and plots. Reference Pin Min Max Unit AVDD DVDD OVDD AVSS, DVSS Analog inputs and outpts (IPx, INx) CLKx LVDS outputs Digital inputs AVSS DVSS AVSS DVSS / AVSS AVSS AVSS DVSS DVSS -0.3 -0.3 -0.3 -0.3 -0.3 -0.3 -0.3 -0.3 +2.3 +2.3 +3.9 +0.3 +2.3 +3.9 +2.3 +3.9 V V V V V V V V Max Unit TBD +150 °C °C Max Unit +85 °C Reliability Information Parameter Min Junction Temperature Storage Temperature Range Lead Temperature (Soldering, 10s) Typ -60 J-STD-020 ESD Protection Product QFN-64 Human Body Model (HBM) Charged Device Model (CDM) 2kV 500V Recommended Operating Conditions Parameter Min Operating Temperature Range -40 Typ This device can be damaged by ESD. Even though this product is protected with state-of-the-art ESD protection circuitry, damage may occur if the device is not handled with appropriate precautions. ESD damage may range from device failure to performance degradation. Analog circuitry may be more susceptible to damage as vary small parametric changes can result in specification noncompliance. CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS Parameter Rev 1C ©2009-2013 Exar Corporation 9/31 Rev 1C Data Sheet Electrical Characteristics (AVDD = 1.8V, DVDD = 1.8V, OVDD = 1.8V, 50MSPS clock, 50% clock duty cycle, -1dBFS 8MHz input signal, 14-bit output, unless otherwise noted) Symbol Parameter Conditions Min Typ Max Units ±6 %FS DC Accuracy No Missing Codes Offset error after digital offset cancellation 1 Gain Error LSB Gain Matching Gain matching between channels. ±3sigma value at worst case conditions. ±0.5 %FS DNL Differential Non-Linearity 12-bit level ±0.2 LSB INL Integral Non-Linearity 12-bit level ±0.6 LSB VCMO Common Mode Voltage Output VAVDD/2 V Analog Input VCMI VFSR Input Common Mode Analog input common mode voltage Full Scale Range Differential input voltage range Input Capacitance Differential input capacitance Bandwidth Input bandwidth VCM -0.1 VCM +0.2 2.0 V Vpp 2 pF 500 MHz Power Supply AVDD DVDD OVDD Analog Supply Voltage 1.7 1.8 2.0 V Digital Supply Voltage (up to 65MSPS) Digital and output driver supply voltage 1.7 1.8 2.0 V Digital Supply Voltage (above 65MSPS) Digital and output driver supply voltage 1.8 1.9 2.0 V 1.7 1.8 3.6 V Digital CMOS Input Supply Voltage Electrical Characteristics - CDK8307A (AVDD = 1.8V, DVDD = 1.8V, OVDD = 1.8V, 20MSPS clock, 50% clock duty cycle, -1dBFS 8MHz input signal, 14-bit output, unless otherwise noted) Symbol Parameter Conditions Min Typ Max Units FIN = 8MHz 70 72.2 dBFS 71.5 dBFS 71.5 dBFS 70.7 dBFS 82 dBc 77 dBc 95 dBc 95 dBc 82 dBc FIN = 30MHz 77 dBc FIN = 8MHz 11.6 bits FIN = 30MHz 11.5 bits 95 dBc 47 mA Performance SNR SINAD SFDR HD2 HD3 ENOB Signal to Noise Ratio Signal to Noise and Distortion Ratio Spurious Free Dynamic Range Second order Harmonic Distortion Third order Harmonic Distortion Effective number of Bits Crosstalk FIN = 30MHz FIN = 8MHz 69 FIN = 30MHz FIN = 8MHz 75 FIN = 30MHz FIN = 8MHz 85 FIN = 30MHz FIN = 8MHz 75 See note (1) on page 13 Power Supply Analog supply current Digital and output driver supply mA Analog power Dissipation 84 mW Digital power Dissipation 97 mW Total power Dissipation 180 mW Power Down Dissipation Power down mode 10 µW Sleep Mode Dissipation Deep sleep mode 30 mW ©2009-2013 Exar Corporation 10/31 Rev 1C Rev 1C 54 Digital supply current CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS Offset Error Guaranteed Data Sheet Symbol Parameter Conditions Min Typ Max Units Sleep Channel Mode Dissipation All channels. in sleep ch. mode (light sleep) 46 mW Sleep Channel Mode Savings Power dissipation savings per channel off 17 mW Clock Inputs 20 Maximum Conversion Rate MSPS MSPS Electrical Characteristics - CDK8307B (AVDD = 1.8V, DVDD = 1.8V, OVDD = 1.8V, 40MSPS clock, 50% clock duty cycle, -1dBFS 8MHz input signal, 14-bit output, unless otherwise noted) Symbol Parameter Conditions Min Typ Max Units FIN = 8MHz 70 72.2 dBFS 71.5 dBFS 71.5 dBFS 70.7 dBFS 82 dBc 77 dBc 95 dBc 95 dBc Performance SNR Signal to Noise Ratio SINAD Signal to Noise and Distortion Ratio SFDR Spurious Free Dynamic Range HD2 Second order Harmonic Distortion HD3 Third order Harmonic Distortion ENOB FIN = 30MHz FIN = 8MHz 69 FIN = 30MHz FIN = 8MHz 75 FIN = 30MHz FIN = 8MHz 85 FIN = 30MHz 82 dBc FIN = 30MHz 77 dBc FIN = 8MHz 11.6 bits FIN = 30MHz 11.5 bits 95 dBc 90 mA 67 mA Analog power Dissipation 162 mW Digital power Dissipation 120 mW Total power Dissipation 280 mW Effective number of Bits Crosstalk FIN = 8MHz 75 See note (1) on page 13 Power Supply Analog supply current Digital supply current Digital and output driver supply Power Down Dissipation Power down mode 10 µW Sleep Mode Dissipation Deep sleep mode 41 mW Sleep Channel Mode Dissipation All channels. in sleep ch. mode (light sleep) 71 mW Sleep Channel Mode Savings Power dissipation savings per channel off 26 mW Clock Inputs 40 Maximum Conversion Rate MSPS 20 Minimum Conversion Rate MSPS Electrical Characteristics - CDK8307C (AVDD = 1.8V, DVDD = 1.8V, OVDD = 1.8V, 50MSPS clock, 50% clock duty cycle, -1dBFS 8MHz input signal, 14-bit output, unless otherwise noted) Symbol Parameter Min Typ Max Units FIN = 8MHz 70 72.2 dBFS 71.5 dBFS 71.5 dBFS 70.7 dBFS Performance SNR SINAD Signal to Noise Ratio Signal to Noise and Distortion Ratio FIN = 30MHz FIN = 8MHz 69 FIN = 30MHz ©2009-2013 Exar Corporation 11/31 Rev 1C Rev 1C Conditions CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS 15 Minimum Conversion Rate Data Sheet Symbol Parameter SFDR Spurious Free Dynamic Range HD2 Second order Harmonic Distortion ENOB Third order Harmonic Distortion Effective number of Bits Crosstalk Min Typ FIN = 8MHz 75 82 dBc 77 dBc 95 dBc 95 dBc 82 dBc FIN = 30MHz 77 dBc FIN = 8MHz 11.6 bits FIN = 30MHz 11.5 bits 95 dBc 111 mA FIN = 30MHz FIN = 8MHz 85 FIN = 30MHz FIN = 8MHz 75 See note (1) on page 13 Max Units Power Supply Analog supply current 73 mA Analog power Dissipation 200 mW Digital power Dissipation 132 mW Total power Dissipation 331 mW Digital supply current Digital and output driver supply Power Down Dissipation Power down mode 10 µW Sleep Mode Dissipation Deep sleep mode 46 mW Sleep Channel Mode Dissipation All channels. in sleep ch. mode (light sleep) 83 mW Sleep Channel Mode Savings Power dissipation savings per channel off 31 mW Clock Inputs 50 Maximum Conversion Rate MSPS 20 Minimum Conversion Rate MSPS Electrical Characteristics - CDK8307D (AVDD = 1.8V, DVDD = 1.8V, OVDD = 1.8V, 65MSPS clock, 50% clock duty cycle, -1dBFS 8MHz input signal, 14-bit output, unless otherwise noted) Symbol Parameter Conditions Min Typ Max Units FIN = 8MHz 70 72.2 dBFS 71.5 dBFS 71.5 dBFS 70.7 dBFS 82 dBc 77 dBc 95 dBc 95 dBc 82 dBc FIN = 30MHz 77 dBc FIN = 8MHz 11.6 bits FIN = 30MHz 11.5 bits 95 dBc 143 mA Performance SNR Signal to Noise Ratio SINAD Signal to Noise and Distortion Ratio SFDR Spurious Free Dynamic Range HD2 Second order Harmonic Distortion HD3 Third order Harmonic Distortion ENOB Effective number of Bits Crosstalk FIN = 30MHz FIN = 8MHz 69 FIN = 30MHz FIN = 8MHz 75 FIN = 30MHz FIN = 8MHz 85 FIN = 30MHz FIN = 8MHz 75 See note (1) on page 13 Power Supply Analog supply current Digital and output driver supply mA 257 mW Digital power Dissipation 149 mW 405 mW Total power Dissipation Power Down Dissipation Power down mode 10 µW Sleep Mode Dissipation Deep sleep mode 54 mW Sleep Channel Mode Dissipation All channels. in sleep ch. mode (light sleep) 103 mW ©2009-2013 Exar Corporation 12/31 Rev 1C Rev 1C 83 Analog power Dissipation Digital supply current CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS HD3 Conditions Data Sheet Symbol Parameter Sleep Channel Mode Savings Conditions Min Power dissipation savings per channel off Typ Max 38 Units mW Clock Inputs 65 Maximum Conversion Rate MSPS 20 Minimum Conversion Rate MSPS (AVDD = 1.8V, DVDD = 1.8V, OVDD = 1.8V, 80MSPS clock, 50% clock duty cycle, -1dBFS 8MHz input signal, 12-bit output, unless otherwise noted) Symbol Parameter Conditions Min Typ Max Units FIN = 8MHz 68.5 70.1 dBFS 70 dBFS 68 69.6 dBFS 69.5 dBFS 77 dBc 76 dBc 90 dBc 90 dBc 77 dBc FIN = 30MHz 76 dBc FIN = 8MHz 11.3 bits FIN = 30MHz 11.3 bits 95 dBc 173 mA Performance SNR Signal to Noise Ratio SINAD Signal to Noise and Distortion Ratio SFDR Spurious Free Dynamic Range HD2 Second order Harmonic Distortion HD3 Third order Harmonic Distortion ENOB Effective number of Bits Crosstalk FIN = 30MHz FIN = 8MHz FIN = 30MHz FIN = 8MHz 74 FIN = 30MHz FIN = 8MHz 85 FIN = 30MHz FIN = 8MHz 75 See note (1) on page 13 Power Supply Analog supply current 88 mA Analog power Dissipation 312 mW Digital power Dissipation 158 mW Total power Dissipation 470 mW Digital supply current Digital and output driver supply Power Down Dissipation Power down mode 10 µW Sleep Mode Dissipation Deep sleep mode 56 mW Sleep Channel Mode Dissipation All channels. in sleep ch. mode (light sleep) 116 mW Sleep Channel Mode Savings Power dissipation savings per channel off 44 mW Clock Inputs 80 Maximum Conversion Rate MSPS 40 MSPS Max Units 80 %high Minimum Conversion Rate Digital and Timing Electrical Characteristics (AVDD = 1.8V, DVDD = 1.8V, OVDD = 1.8V, unless otherwise noted) Symbol Parameter Conditions Min Typ Clock Inputs Duty Cycle 20 Compliance CMOS, LVDS, LVPECL Differential input swing ±200 Input range, sine Differential input swing, sine wave clock input ±800 Input range, CMOS CLKN connected to ground Input common mode voltage Keep voltages within gnd and voltage of OVDD Input capacitance Differential ©2009-2013 Exar Corporation mVpp mVpp VOVDD 0.3 VOVDD -0.3 2 13/31 mVpp V pF Rev 1C Rev 1C Input range, differential CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS Electrical Characteristics - CDK8307E Data Sheet Symbol Parameter Conditions Min Typ Max Units Logic Inputs (CMOS) High Level Input Voltage VIL Low Level Input Voltage IIH High Level Input Leakage Current IIL Low Level Input Leakage Current CI Input Capacitance VOVDD ≥ 3.0V VOVDD = 1.7V – 3.0V 2 V 0.8 • VOVDD V VOVDD ≥ 3.0V 0 0.8 VOVDD = 1.7V – 3.0V 0 0.2 • VOVDD V ±10 µA ±10 µA 3 V pF Data Outputs (LVDS) Compliance LVDS VOUT Differential Output Voltage 350 mV VCM Output Common Mode Voltage 1.2 V Output Coding Default/Optional Offset Binary/2‘s Complement Timing Characteristics TAP Aperture Delay 0.8 ns εRMS Aperture Jitter <0.5 ps TPD Start up Time from Power Down Start up time from Power Down to Active Mode. References have reached 99% of final value. (See section Clock Frequency) 260 992 clock cycles 15 Start up time from Sleep Mode to Active Mode µs TSLP Startup Time from Sleep 0.5 µs TOVR Out Of Range Recovery Time 1 clk cycles TLAT Pipeline Delay 14 clk cycles LVDS Output Timing Characterisctics tdata tPROP LCLK to Data Delay Time Excluding programmable phase shift 250 7 Clock Propogation Delay LVDS Bit-Clock Duty-Cycle • TLVDS +2.6 7 • TLVDS +3.5 45 Frame clock cycle-to-cycle jitter ps 7 • TLVDS ns +4.2 55 % LCLK cycle 2.5 % LCLK cycle TEDGE Data Rise- and Fall Time Calculated from 20% to 80% 0.4 ns TCLKEDGE Clock Rise- and Fall Time Calculated from 20% to 80% 0.4 ns Note: (1) Signal applied to 7 channels (FIN0). Measurement taken on one channel with full scale at FIN1. FIN1 = 8MHz, FIN0 = 9.9MHz (2) The outputs will be functional with higher loads. However, it is recommended to keep the load on output data bits as low as possible to keep dynamic currents and resulting switching noise at a minimum. CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS VIH Rev 1C ©2009-2013 Exar Corporation 14/31 Rev 1C Data Sheet LVDS Timing Diagrams Analog Input CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS ADC Clock TLVDS LCLKP LCLKN FCLKN FCLKP Dxx<1:0> D10 N-2 D11 N-2 D0 N-1 D1 N-1 D2 N-1 D3 N-1 D4 N-1 D5 N-1 D6 N-1 D7 N-1 D8 N-1 D9 N-1 D10 N-1 D11 N-1 D0 N D1 N D2 N D3 N D4 N D5 N D4 N D5 N D6 N D6 N D7 N D8 N D9 N D10 N TPROP Figure 1. 12-bit Output, DDR Mode Analog Input ADC Clock TLVDS LCLKP LCLKN FCLKN FCLKP Dxx<1:0> D0 N-1 D1 N-1 D2 N-1 D3 N-1 D4 N-1 D5 N-1 D6 N-1 D7 N-1 D8 N-1 D9 D10 D11 D12 D13 N-1 N-1 N-1 N-1 N-1 D0 N D1 N D2 N D3 N D7 N D8 N D9 N D10 D11 D12 D13 N N N N TPROP Figure 2. 14-bit Output, DDR Mode Analog Input ADC Clock TLVDS LCLKP LCLKN FCLKN FCLKP Dxx<1:0> D10 D11 D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 N-2 N-2 N-1 N-1 N-1 N-1 N-1 N-1 N-1 N-1 N-1 N-1 N-1 N-1 D0 N D1 N D2 N D3 N D4 N D5 N D6 N D7 N D8 N D9 N D10 N TPROP Figure 3. 12-bit Output, SDR Mode TLVDS LCLKP LCLKN Rev 1C Dxx<1:0> TLVDS/2 tdata Figure 4. Data Timing ©2009-2013 Exar Corporation 15/31 Rev 1C Data Sheet Serial Interface The CDK8307 configuration registers can be accessed through a serial interface formed by the pins SDATA (serial interface data), SCLK (serial interface clock) and CSN (chip select, active low). The following occurs when CSN is set low: Serial data are shifted into the chip n At every rising edge of SCLK, the value present at SDATA is latched n SDATA is loaded into the register every 24th rising edge of SCLK Multiples of 24-bit words data can be loaded within a single active CSN pulse. If more than 24 bits are loaded into SDATA during one active CSN pulse, only the first 24 bits are kept. The excess bits are ignored. Every 24-bit word is divided into two parts: n The first eight bits form the register address n The remaining 16 bits form the register data Acceptable SCLK frequencies are from 20MHz down to a few hertz. Duty-cycle does not have to be tightly controlled. Timing Diagram Figure 5 shows the timing of the serial port interface. Table 1 explains the timing variables used in the Timing Diagram. tcs tlo CSN SCLK SDATA A7 A6 thi A5 A4 A3 A2 tclk A1 A0 D15 D14 D13 ts th D12 D11 D10 tch chi i tch D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 Figure 5. Serial Port Interface Timing Diagram Table 1. Serial Port Interface Timing Definitions Parameter Minimum Value Unit tcs Setup time between CSN and SCLK Description 8 ns tch Hold time between CSN and SCLK 8 ns thi SCLK high time 20 ns tlo SCLK low time 20 ns tclk SCLK period 50 ns ts Data setup time 5 ns th Data hold time 5 ns Register Initialization Before CDK8307 can be used, the internal registers must be initialized to their default values and power down must be activated. This can be done immediately after applying supply voltage to the circuit. Register initialization can be done in one of two ways: 1. By applying a low-going pulse (minimum 20ns) on the RESETN pin (asynchronous). Power down initialization can be done in one of two ways: 1. By applying a high-going pulse (minimum 20ns) on the PD pin (asynchronous). 2. By cycling the SPI register 0Fhex PD bit to high (reg value '0200'hex) and then low (reg value '0000'hex). ©2009-2013 Exar Corporation 16/31 Rev 1C Rev 1C 2. By using the serial interface to set the RST bit high. Internal registers are reset to default values when this bit is set. The RST bit is self-reset to zero. When using this method, do not apply any low-going pulse on the RESETN pin. CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS n Data Sheet Serial Register Map Table 2. Summary of Functions Supported by the Serial Interface Name Description Default D 1 5 D 1 4 Software reset. This bit is self-clearing Inactive pd_ch<8:1> Channel-specific power-down Inactive sleep Go to sleep-mode Inactive pd Go to power-down Inactive pd_pin_cfg<1:0> Configures the PD pin for sleep-modes PD pin configured for power-down mode ilvds_lclk<2:0> LVDS current drive programmability for LCLKP and LCLKN pins 3.5mA drive ilvds_ frame<2:0> LVDS current drive programmability for FCLKP and FCLKN pins 3.5mA drive ilvds_dat<2:0> LVDS current drive programmability for output data pins 3.5mA drive en_lvds_term Enables internal termination for LVDS buffers Termination disabled X term_lclk<2:0> Programmable termination for LCLKN and LCLKP buffers Termination disabled 1 term_ frame<2:0> Programmable termination for FCLKN and FCLKP buffers Termination disabled 1 term_dat<2:0> Programmable termination for output data buffers Termination disabled 1 invert_ch<8:1> Swaps the polarity of the analog input pins electrically IPx is positive input en_ramp Enables a repeating full-scale ramp pattern on the outputs dual_custom_pat Enable the mode wherein the output toggles between two defined codes D 1 2 D 1 1 D 1 0 D 9 D 8 D 7 X D 6 X D 5 X D 4 X D 3 X D 2 X D 1 X D 0 Address In Hex X 00 X X X X 0F X X X X X X X X 11 X X X X X 12 X X X X X X Inactive X 0 0 Inactive 0 X 0 single_custom_ pat Enables the mode wherein the Inactive output is a constant specified code 0 0 X bits_custom1<13:0> Bits for the single custom pattern and for the first code of the dual Inactive custom pattern. <0> is the LSB X X X X X X X X X X X X X X 26 bits_custom2<13:0> Bits for the second code of the dual custom pattern X X X X X X X X X X X X X X 27 gain_ch1<3:0> Programmable gain for channel 1 0dB gain X X gain_ch2<3:0> Programmable gain for channel 2 0dB gain gain_ch3<3:0> Programmable gain for channel 3 0dB gain gain_ch4<3:0> Programmable gain for channel 4 0dB gain X X X X gain_ch5<3:0> Programmable gain for channel 5 0dB gain X X X X Inactive Programmable gain for channel 6 0dB gain Programmable gain for channel 7 0dB gain gain_ch8<3:0> Programmable gain for channel 8 0dB gain ©2009-2013 Exar Corporation X X X X X X X X X X X X X X X X X X X X X X X 24 25 X X 2A 2B X 17/31 X Rev 1C gain_ch6<3:0> gain_ch7<3:0> CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS rst D 1 3 X X X Rev 1C Data Sheet Table 2. Summary of Functions Supported by the Serial Interface (Continued) Name Description Default D 1 5 D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 9 D 8 D 7 D 6 D 5 X X D 4 D 3 D 2 D 1 D 0 phase_ddr<1:0> Controls the phase of LCLK output relative to data 90 degrees pat_deskew Enable deskew pattern mode Inactive 0 X pat_sync Enable sync pattern mode Inactive X 0 btc_mode Binary two's complement format for ADC output data Straight offset binary msb_first Serialized ADC output data comes out with MSB first LSB-first output en_sdr Enable SDR output mode. LCLK becomes a 12x input clock DDR output mode fall_sdr Rising edge Controls whether the LCLK risof LCLK ing or falling edge comes in the comes in the middle of the data window when middle of the operating in SDR mode data window 42 45 X X X X 46 1 Nominal X ext_vcm_bc<1:0> VCM buffer driving strength control Nominal X X X X lvds_pd_mode Controls LVDS power down mode High z mode lvds_num_bits Sets the number of LVDS output bits 12-bit lvds_advance Advance LVDS data bits and frame clock by one clock cycle Inactive 0 X lvds_delay Delay LVDS data bits and frame clock by one clock cycle Inactive X 0 fs_cntrl<5:0> Fine adjust ADC full scale range 0% change X X clk_freq<1:0> Input clock frequency 65MHz X 50 52 X 53 X X X X 55 X X 56 D 1 D 0 Address In Hex X 00 Address In Hex Description of Serial Registers Table 3. Software Reset Name rst Description Self-clearing software reset Default D 1 5 D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 9 D 8 D 7 D 6 D 5 D 4 D 3 D 2 Inactive Setting the rst register bit to '1', resets all internal registers including the rst register bit itself. Table 4. Power-Down Modes Name Description Default pd_ch<8:1> Channel-specific power-down Inactive sleep Go to sleep-mode Inactive pd Go to power-down Inactive pd_pin_cfg<1:0> Configures the PD pin for sleep-mode PD pin configured for powerdown mode lvds_pd_mode Controls LVDS power down mode High z mode D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 9 D 8 D 7 D 6 D 5 D 4 D 3 D 2 D 1 D 0 X X X X X X X X X X 18/31 X 0F X Rev 1C ©2009-2013 Exar Corporation D 1 5 CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS perfm_cntrl<2:0> ADC performance control Address In Hex X 52 Rev 1C Data Sheet Setting pd_ch<n> = '1', powers down channel <n> of the ADC. Setting sleep = '1', powers down the entire chip, except the band-gap reference circuit. Setting pd = '1' completely powers down the chip, including the band-gap reference circuit. Start-up time from this mode is significantly longer than from the sleep and pd_ch<n> modes. The lvds_pd_mode register configures whether the LVDS data output drivers are powered down or not in sleep and sleep channel modes. LCLK and FCLK drivers are not affected by this register, and are always on in sleep and sleep channel modes. If lvds_pd_mode is set low (default), the LVDS output is put in high Z, and the driver is completely powered down. If lvds_pd_mode is set high, the LVDS output is set to constant 0, and the driver is still on during sleep and sleep channel modes. Table 5. LVDS Drive Strength Programmability Name Description Default ilvds_lclk<2:0> LVDS current drive programmability for LCLKP and LCLKN pins. 3.5mA drive ilvds_ frame<2:0> LVDS current drive programmability for FCLKP and FCLKN pins. 3.5mA drive ilvds_dat<2:0> LVDS current drive programmability for output data pins. 3.5mA drive D 1 5 D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 9 D 8 D 7 D 6 X X X D 5 X D 4 X D 3 D 2 D 1 D 0 X X X Address In Hex 11 X The current delivered by the LVDS output drivers can be configured as shown in Table 6. The default current is 3.5mA, which is what the LVDS standard specifies. Setting the ilvds_lclk<2:0> register controls the current drive strength of the LVDS clock output on the LCLKP and LCLKN pins. Setting the ilvds_frame<2:0> register controls the current drive strength of the frame clock output on the FCLKP and FCLKN pins. Setting the ilvds_dat<2:0> register controls the current drive strength of the data outputs on the D[8:1]P and D[8:1] N pins. Table 6. LVDS Output Drive Strength for LCLK, FCLK, and Data LVDS Drive Strength 000 3.5 mA (default) 001 2.5 mA 010 1.5 mA 011 0.5 mA 100 7.5 mA 101 6.5 mA 110 5.5 mA 111 4.5 mA ©2009-2013 Exar Corporation 19/31 Rev 1C ilvds_*<2:0> CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS Setting pdn_pin_cfg = '1' configures the circuit to enter sleep mode when the PD pin is set high. When pdn_pin_cfg = '0', which is the default, the circuit enters power down mode when the PD pin is set high. Rev 1C Data Sheet Table 7. LVDS Internal Termination Programmability Name Description Default D 1 5 D 1 4 Enables internal termination for LVDS buffers Termination disabled X term_lclk<2:0> Programmable termination for LCLKN and LCLKP buffers Termination disabled 1 term_ frame<2:0> Programmable termination for FCLKN and FCLKP buffers Termination disabled 1 term_dat<2:0> Programmable termination for DxP and DxN buffers Termination disabled 1 D 1 2 D 1 1 D 1 0 D 9 D 8 D 7 D 6 X X X D 5 X D 4 D 3 D 2 D 1 D 0 X X X Address In Hex 12 X X The off-chip load on the LVDS buffers may represent a characteristic impedance that is not perfectly matched with the PCB traces. This may result in reflections back to the LVDS outputs and loss of signal integrity. This effect can be mitigated by enabling an internal termination between the positive and negative outputs of each LVDS buffer. Internal termination mode can be selected by setting the en_lvds_term bit to '1'. Once this bit is set, the internal termination values for the bit clock, frame clock, and data buffers can be independently programmed using sets of three bits. Table 8 shows how the internal termination of the LVDS buffers are programmed. The values are typical values and can vary by up to ±20% from device to device and across temperature. Table 8. LVDS Output INternal Termination for LCLK, FCLK, and Data term_*<2:0> LVDS Internal Termination 000 Termination Disabled 001 280Ω 010 165Ω 011 100Ω 100 125Ω 101 82Ω 110 67Ω 111 56Ω Table 9. Analog Input Invert Name invert_ch<8:1> Description Default Swaps the polarity of the analog input pins electrically IPx is positive input D 1 5 D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 9 D 8 D 7 D 6 D 5 D 4 D 3 D 2 D 1 D 0 Address In Hex X X X X X X X X 24 The IPx pin represents the positive analog input pin, and INx represents the negative (complementary) input. Setting the bits marked invert_ch <8:1> (individual control for each channel) causes the inputs to be swapped. INx would then represent the positive input, and IPx the negative input. CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS en_lvds_term D 1 3 Rev 1C ©2009-2013 Exar Corporation 20/31 Rev 1C Data Sheet Table 10. LVDS Test Patterns Name Description Default D 1 5 D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 9 D 8 D 7 D 6 D 5 D 4 D 3 D 2 D 1 D 0 Address In Hex Enables a repeating full-scale ramp pattern on the outputs Inactive X 0 0 dual_custom_pat Enable the mode wherein the output Inactive toggles between two defined codes 0 X 0 single_custom_ pat Enables the mode wherein the Inactive output is a constant specified code 0 0 X bits_custom1<13:0> Bits for the single custom pattern Inactive and for the first code of the dual custom pattern. <0> is the LSB X X X X X X X X X X X X X X 26 bits_custom2<13:0> Bits for the second code of the dual custom pattern Inactive X X X X X X X X X X X X X X 27 pat_deskew Enable deskew pattern mode Inactive 0 X pat_sync Enable sync pattern mode Inactive X 0 25 45 To ease the LVDS synchronization setup of CDK8307, several test patterns can be set up on the outputs. Normal ADC data are replaced by the test pattern in these modes. Setting en_ramp to '1' sets up a repeating full-scale ramp pattern on all data outputs. The ramp starts at code zero and is increased 1LSB every clock cycle. It returns to zero code and starts the ramp again after reaching the full-scale code. A constant value can be set up on the outputs by setting single_custom_pat to '1', and programming the desired value in bits_custom1<13:0>. In this mode, bits_custom1<13:0> replaces the ADC data at the output, and is controlled by LSB-first and MSB-first modes in the same way as normal ADC data are. The device may also be made to alternate between two codes by programming dual_custom_pat to '1'. The two codes are the contents of bits_custom1<13:0> and bits_custom2<13:0>. Two preset patterns can also be selected: 1. Deskew pattern: Set using pat_deskew, this mode replaces the ADC output with '01010101010101' (two LSBs removed in 12 bit mode). 2. Sync pattern: Set using pat_sync, the normal ADC word is replaced by a fixed 1111110000000 word. Note: Only one of the above patterns should be selected at the same time. Table 11. Programmable Gain Name Description Default D 1 5 D 1 4 D 1 3 D 1 2 gain_ch1<3:0> Programmable gain for channel 1 0dB gain gain_ch2<3:0> Programmable gain for channel 2 0dB gain gain_ch3<3:0> Programmable gain for channel 3 0dB gain gain_ch4<3:0> Programmable gain for channel 4 0dB gain X X X X gain_ch5<3:0> Programmable gain for channel 5 0dB gain X X X X gain_ch6<3:0> Programmable gain for channel 6 0dB gain gain_ch7<3:0> Programmable gain for channel 7 0dB gain gain_ch8<3:0> Programmable gain for channel 8 0dB gain D 1 1 D 1 0 D 9 D 8 X X X X X X X X D 7 D 6 D 5 D 4 X X X X X X X X D 3 D 2 D 1 D 0 X X X X Address In Hex 2A 2B X X X X ©2009-2013 Exar Corporation 21/31 Rev 1C Rev 1C CDK8307 includes a purely digital programmable gain option in addition to the Full-scale Control. The programmable gain of each channel can be individually set using a set of four bits, indicated as gain_chn<3:0> for Channel x. The gain setting is coded in binary from 0dB to 12dB, as shown in Table 12 on the following page. CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS en_ramp Data Sheet Table 12. Gain Setting for Channels 1-8 Channel x Gain Setting 0000 0dB 0001 1dB 0010 2dB 0011 3dB 0100 4dB 0101 5dB 0110 6dB 0111 7dB 1000 8dB 1001 9dB 1010 10dB 1011 11dB 1100 12dB 1101 Do not use 1110 Do not use 1111 Do not use Table 13. LVDS Clock Programmability and Data Output Modes Name Description Default phase_ddr<1:0> Controls the phase of LCLK output relative to data 90 degrees btc_mode Binary two's complement format for ADC output data Straight offset binary msb_first Serialized ADC output data comes out with MSB first LSB-first output en_sdr Enable SDR output mode. LCLK becomes a 12x input clock DDR output mode fall_sdr Rising edge Controls whether the LCLK risof LCLK ing or falling edge comes in the comes in the middle of the data window when middle of the operating in SDR mode data window D 1 5 D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 9 D 8 D 7 D 6 D 5 X X D 4 D 3 D 2 D 1 D 0 Address In Hex 42 X X X X 46 1 The output interface of CDK8307 is normally a DDR interface, with the LCLK rising and falling edge transitions in the middle of alternate data windows. The phase for LCLK can be programmed relative to the output frame clock and data using bits phase_ddr<1:0>. The LCLK phase modes are shown in Figure 6. The default timing is identical to setting phase_ddr<1:0> = '10'. CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS gain_chx<3:0> Rev 1C ©2009-2013 Exar Corporation 22/31 Rev 1C Data Sheet PHASE_DDR<1:0>=’00’ = 270° FCLKN FCLKP LCLKP LCLKN PHASE_DDR<1:0>=’01’ =180° FCLKN FCLKP LCLKN LCLKP Dxx<1:0> PHASE_DDR<1:0>=’10’ = 90° (Default) FCLKN FCLKP LCLKN LCLKP PHASE_DDR<1:0>=’11’ = 0° FCLKN FCLKP LCLKP LCLKN Dxx<1:0> Dxx<1:0> Figure 6. Phase Programmability Modes for LCLK The device can also be made to operate in SDR mode by setting the en_sdr bit to '1'. The bit clock (LCLK) is output at 12x times the input clock in this mode, two times the rate in DDR mode. Depending on the state of fall_sdr, LCLK may be output in either of the two manners shown in Figure 7. As can be seen in Figure 7, only the LCLK rising (or falling) edge is used to capture the output data in SDR mode. The SDR mode is not recommended beyond 40MSPS because the LCLK frequency becomes very high. EN_SDR=’1’, FALL_SDR_’0’ FCLKN FCLKP LCLKP LCLKN EN_SDR=’1’, FALL_SDR_’1’ FCLKN FCLKP LCLKN LCLKP Dxx<1:0> Dxx<1:0> Figure 7. SDR Interface Modes The default data output format is offset binary. Two's complement mode can be selected by setting the btc_mode bit to '1' which inverts the MSB. The first bit of the frame (following the rising edge of FCLKP) is the LSB of the ADC output for default settings. Programming the msb_first mode results in reverse bit order, and the MSB is output as the first bit following the FCLKP rising edge. Table 14. Number of Serial Output Bits Name Description Default D 1 5 D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 9 D 8 D 7 D 6 D 5 D 4 lvds_num_bits Sets the number if LVDS output bits 12-bit lvds_advance Advance LVDS data bits and frame clock by one clock cycle Inactive 0 X lvds_delay Delay LVDS data bits and frame clock by one clock cycle Inactive X 0 D 2 D 1 D 0 Address In Hex X 53 Rev 1C ©2009-2013 Exar Corporation D 3 CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS Dxx<1:0> 23/31 Rev 1C Data Sheet The ADC channels have 13 bits of resolution. There are two options for the serial LVDS outputs, 12 bits or 14 bits, selected by setting lvds_num_bits to '0' or '1', respectively. In 12-bit mode, the LSB bit from the ADCs are removed in the output stream. In 14-bit mode, a '0' is added in the LSB position. Power down mode must be activated after or during a change in the number of output bits. TLVDS LCLKP LCLKN TPROP default: FCLKP FCLKN Dxx<1:0> D3 D4 D5 D6 D7 D8 D9 D10 D11 N-1 N-1 N-1 N-1 N-1 N-1 N-1 N-1 N-1 D0 N TPROP lvds_delay = ‘1’: D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 N-1 N-1 N-1 N-1 N-1 N-1 N-1 N-1 N-1 N-1 TPROP lvds_advance = ‘1’: D3 N D4 N D5 N D6 N D7 N D8 N D9 N D0 N D1 N D2 N D3 N D4 N D5 N D6 N D7 N D8 N D3 N D4 N D5 N D6 N D7 N D8 N D9 N D10 N TLVDS FCLKP FCLKN Dxx<1:0> D2 N TLVDS FCLKP FCLKN Dxx<1:0> D1 N D4 D5 D6 D7 D8 D9 D10 D11 N-1 N-1 N-1 N-1 N-1 N-1 N-1 N-1 D0 N D1 N D2 N *LVDS output timing adjustment Figure 8: LVDS Output Timing Adjustment Table 15. Full Scale Control Name fs_cntrl<5:0> Description Fine adjust ADC full scale range Default D 1 5 D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 9 D 8 0% change D 7 D 6 D 5 D 4 D 3 D 2 D 1 D 0 Address In Hex X X X X X X 55 The full-scale voltage range of CDK8307 can be adjusted using an internal 6-bit DAC controlled by the fs_cntrl register. Changing the value in the register by one step, adjusts the full-scale range approximately 0.3%. This leads to a maximum range of ±10% adjustment. Table 16 shows how the register settings correspond to the full-scale range. Note that the values for full-scale range adjustment are approximate. The DAC is, however, guaranteed to be monotonous. The full-scale control and the programmable gain features differ in two major ways: 2. The programmable gain feature has much coarser gain steps and larger range than the full-scale control. ©2009-2013 Exar Corporation 24/31 Rev 1C Rev 1C 1. The full-scale control feature controls the full-scale voltage range in an analog fashion, whereas the programmable gain is a digital feature. CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS To ease timing in the receiver when using multiple ADC chips, the CDK8307 has the option to adjust the timing of the output data and the frame clock. The propagation delay with respect to the ADC input clock can be moved one LVDS clock cycle forward or backward, by using lvds_advance and lvds_delay, respectively. See figure 8 for details. Note that LCLK is not affected by lvds_delay or lvds_advance settings. Data Sheet Table 16. Register Values with Corresponding Change in Full-Scale Range fs_cntrl <5:0> Full-Scale Range Adjustment 111111 +9.7% ... +0.3% 100000 +0% 011111 -0.3% ... ... 000000 -10% Table 17. Clock Frequency Name clk_freq<1:0> Description Input clock frequency Default D 1 5 D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 9 D 8 D 7 D 6 D 5 D 4 D 3 D 2 50 - 80MHz D 1 D 0 Address In Hex X X 56 To optimize startup time a register is provided where the input clock frequency can be set. Some internal circuitry has startup times that are frequency independent. Default counter values are set to accommodate these startup times at the maximum clock frequency. This will lead to increased startup times at low clock frequency. Setting the value of this register to the nearest higher clock frequency will reduce the count values of the internal counters, to better fit the actual startup time, such that the startup time will be reduced. The start up times from Power Down mode and Deep Sleep mode are changed by this register setting. Table 18. Clock Frequency Settings clk_freq <1:0> Clock Frequency (MHz) Startup Delay (clock cycles) Startup Delay (μs) 00 50 - 80 992 12.4 - 19.8 01 32.5 - 50 640 12.8 - 19.7 10 20 - 32.5 420 12.9 - 21 11 15 - 20 260 13 - 17.3 Table 19. Performance Control Name Description Default perfm_ cntrl<2:0> ADC performance control Nominal ext_vcm_ bc<1:0> VCM buffer driving strength control Nominal D 1 5 D 1 4 D 1 3 D 1 2 D 1 1 D 1 0 D 9 D 8 D 7 D 6 D 5 X D 4 X D 3 D 2 D 1 D 0 X X X Address In Hex 50 There are two registers that impact performance and power dissipation. ©2009-2013 Exar Corporation 25/31 Rev 1C Rev 1C The perfm_cntrl register adjusts the performance level of the ADC core. If full performance is required, the nominal setting must be used. The lowest code can be used in situations where power dissipation is critical and performance is less important. For most conditions the performance at the minimum setting will be similar to nominal setting. However, only 10-bit performance can be expected at worst case conditions. The power dissipation savings shown in Table 20 are only approximate numbers for the ADC current alone. CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS ... 100001 Data Sheet Table 20. Performance Control Settings Power Dissipation 100 -40% (lower performance) 101 -30% 110 -20% 111 -10% 000 (default) Nominal 001 Do not use 010 Do not use 011 Do not use The ext_vcm_bc register controls the driving strength in the buffer supplying the voltage on the VCM pin. If this pin is not in use, the buffer can be switched off. If current is drawn from the VCM pin, the driving strength can be increased to keep the voltage on this pin at the correct level. Table 21. External Common Mode Voltage Buffer Driving Strength ext_vcm_bc <1:0> VCM Buffer Driving Strength 00 Off (VCM floating) 01 (default) Low 10 High 11 Max CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS performance_control <2:0> Rev 1C ©2009-2013 Exar Corporation 26/31 Rev 1C Data Sheet Therory of Operation The ADC employs a pipelined converter architecture. Each stage feeds its output data into the digital error correction logic, ensuring excellent differential linearity and no missing codes at 13-bit level. The CDK8307 operates from two sets of supplies and grounds. The analog supply and ground set is identified as AVDD and AVSS, while the digital set is identified by DVDD and DVSS. Recommended Usage Analog Input The analog input to the CDK8307 is a switched capacitor track-and-hold amplifier optimized for differential operation. Operation at common mode voltages at mid supply is recommended even if performance will be good for the ranges specified. The VCM pin provides a voltage suitable as common mode voltage reference. The internal buffer for the VCM voltage can be switched off, and driving capabilities can be changed programming the ext_vcm_ bc<1:0> register. Figure 9. Input Configuration Diagram DC-Coupling Figure 10 shows a recommended configuration for DCcoupling. Note that the common mode input voltage must be controlled according to specified values. Preferably, the CM_EXT output should be used as a reference to set the common mode voltage. The input amplifier could be inside a companion chip or it could be a dedicated amplifier. Several suitable single ended to differential driver amplifiers exist in the market. The system designer should make sure the specifications of the selected amplifier is adequate for the total system, and that driving capabilities comply with the CDK8307 input specifications. Detailed configuration and usage instructions must be found in the documentation of the selected driver, and the values given in Figure 10 must be varied according to the recommendations for the driver. 43Ω 33pF Figure 9 shows a simplified drawing of the input network. The signal source must have sufficiently low output impedance to charge the sampling capacitors within one clock cycle. A small external resistor (e.g. 22Ω) in series with each input is recommended as it helps reducing transient currents and dampens ringing behavior. A small Rev 1C ©2009-2013 Exar Corporation 43Ω CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS The CDK8307 is an 8-channel, high-speed, CMOS ADC. The 13-bits given out by each channel are serialized to 12, 13 or 14-bits and sent out on a single pair of pins in LVDS format. All eight channels of the CDK8307 operate from a single differential or single ended clock. The sampling clocks for each of the eight channels are generated from the clock input using a carefully matched clock buffer tree. The 12x/13x/14x clock required for the serializer is generated internally from FCLK using a phase-locked loop (PLL). A 6x/6.5x/7x and 1x clock are also output in LVDS format, along with the data to enable easy data capture. The CDK8307 uses internally generated references that can be shorted across several devices to improve gain-matching. The differential reference value is 1V. This results in a differential input of -1V to correspond to the zero code of the ADC, and a differential input of +1V to correspond to the full-scale code (code 8191). differential shunt capacitor at the chip side of the resistors may be used to provide dynamic charging currents and may improve performance. The resistors form a low pass filter with the capacitor, and values must therefore be determined by requirements for the application. Figure 10. DC-Coupled Input 27/31 Rev 1C Data Sheet AC-Coupling 33Ω RT 47Ω 33Ω Ω pF Ω Figure 12. AC-Coupled Input Note that startup time from Sleep Mode and Power Down Mode will be affected by this filter as the time required to charge the series capacitors is dependent on the filter cut-off frequency. If the input signal has a long traveling distance, and the kick-backs from the ADC not are effectively terminated at the signal source, the input network of Figure 13 can be used. The configuration is designed to attenuate the kickback from the ADC and to provide an input impedance that looks as resistive as possible for frequencies below Nyquist. Figure 11. Transformer Coupled Input If the input signal is traveling a long physical distance from the signal source to the transformer (for example a long cable), kick-backs from the ADC will also travel along this distance. If these kick-backs are not terminated properly at the source side, they are reflected and will add to the input signal at the ADC input. This could reduce the ADC performance. To avoid this effect, the source must effectively terminate the ADC kick-backs, or the traveling distance should be very short. If this problem could not be avoided, the circuit in Figure 10 can be used. ©2009-2013 Exar Corporation optional RT 68Ω 220Ω pF 120nH 33Ω Figure 13: Alternative Input Network Values of the series inductor will however depend on board design and conversion rate. In some instances a shunt capacitor in parallel with the termination resistor (e.g. 33pF) may improve ADC performance further. This capacitor attenuate the ADC kick-back even more, and minimize the kicks traveling towards the source. However the impedance match seen into the transformer becomes worse. 28/31 Rev 1C Rev 1C Figure 12 shows AC-coupling using capacitors. Resistors from the CM_EXT output, RCM, should be used to bias the differential input signals to the correct voltage. The series capacitor, CI, form the high-pass pole with these resistors, and the values must therefore be determined based on the requirement to the high-pass cut-off frequency. 120nH 33Ω 1:1 CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS A signal transformer or series capacitors can be used to make an AC-coupled input network. Figure 11 shows a recommended configuration using a transformer. Make sure that a transformer with sufficient linearity is selected, and that the bandwidth of the transformer is appropriate. The bandwidth should exceed the sampling rate of the ADC with at least a factor of 10. It is also important to keep phase mismatch between the differential ADC inputs small for good HD2 performance. This type of transformer coupled input is the preferred configuration for high frequency signals as most differential amplifiers do not have adequate performance at high frequencies. Magnetic coupling between the transformers and PCB traces may impact channel crosstalk, and must hence be taken into account during PCB layout. Data Sheet Clock Input and Jitter Considerations The input clock can be supplied in a variety of formats. The clock pins are AC-coupled internally, and hence a wide common mode voltage range is accepted. Differential clock sources as LVDS, LVPECL or differential sine wave can be connected directly to the input pins. For CMOS inputs, the CLKN pin should be connected to ground, and the CMOS clock signal should be connected to CLKP. For differential sine wave clock input the amplitude must be at least ±0.8Vpp. The quality of the input clock is extremely important for high-speed, high-resolution ADCs. The contribution to SNR from clock jitter with a full scale signal at a given frequency is shown in equation below. SNRjitter = 20 • log (2 • π • FIN • εt) where FIN is the signal frequency, and εt is the total rms jitter measured in seconds. The rms jitter is the total of all jitter sources including the clock generation circuitry, clock distribution and internal ADC circuitry. The jitter performance is improved with reduced rise and fall times of the input clock. Hence, optimum jitter performance is obtained with LVDS or LVPECL clock with fast edges. CMOS and sine wave clock inputs will result in slightly degraded jitter performance. If the clock is generated by other circuitry, it should be retimed with a low jitter master clock as the last operation before it is applied to the ADC clock input. CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS Typically high-speed ADCs use both clock edges to generate internal timing signals. In the CDK8307 only the rising edge of the clock is used. Hence, input clock duty cycles between 20% and 80% is acceptable. For applications where jitter may limit the obtainable performance, it is of utmost importance to limit the clock jitter. This can be obtained by using precise and stable clock references (e.g. crystal oscillators with good jitter specifications) and make sure the clock distribution is well controlled. It might be advantageous to use analog power and ground planes to ensure low noise on the supplies to all circuitry in the clock distribution. It is of utmost importance to avoid crosstalk between the ADC output bits and the clock and between the analog input signal and the clock since such crosstalk often results in harmonic distortion. Rev 1C ©2009-2013 Exar Corporation 29/31 Rev 1C Data Sheet Mechanical Dimensions QFN-64 aaa C A A ccc C A A2 A3 D D1 A1 E F G L e θ1 E1 aaa bbb ccc Pin 1 ID 0.05 Dia. Min – 0.00 – 0.008 0.197 0.197 0.05 0.0096 0.012 0° Inches Millimeters Typ Max Min Typ – 0.035 – – 0.0004 0.002 0.00 0.01 0.026 0.028 – 0.65 0.008 REF 0.2 REF 0.010 0.012 0.2 0.25 0.354 BSC 9.00 BSC 0.354 BSC 8.75 BSC 0.205 0.213 5.0 5.2 0.354 BSC 9.00 BSC 0.344 BSC 8.75 BSC 0.205 0.213 5.0 5.2 – – 1.3 – 0.0168 0.024 0.24 0.42 0.016 0.020 0.3 0.4 0.020 BSC 0.50 BSC – 12° 0° – Tolerance of Form and Position 0.10 0.004 0.10 0.004 0.05 0.002 Max 0.9 0.05 0.7 0.30 5.4 5.4 – 0.6 0.5 12° NOTES: 1. All dimensions are in millimeters. 2. Die thickness allowable is 0.305mm maximum (.012 inches maximum) 3. Dimensioning & tolerances conform to ASME y14.5m. -1994. bbb C B B C bbb C A 1.14 5. The pin #1 identifier must be placed on the top surface of the package by using indentation mark or other feature of package body. 6. Exact shape and size of this feature is optional. 7. Package warpage max 0.08mm. SIDE VIEW 9. Applied only to terminals. 10. Package corners unless otherwise specipied are r0.175±0.025mm. F D2 0.45 4. Dimension applies to plated terminal and is measured between 0.20 and 0.25mm from terminal tip. 8. Applied for exposed pad and terminals. Exclude embedding part of exposed pad from measuring. TOP VIEW Pin 1 ID Dia. 0.20 seating plane θ1 1.14 G E2 L e b 0.10 M C A B L BOTTOM VIEW CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS aaa C B Symbol A A1 A2 A3 b D D1 D2 E E1 E2 Rev 1C ©2009-2013 Exar Corporation 30/31 Rev 1C Data Sheet Mechanical Dimensions (Continued) TQFP-80 Dimensions (mm) 1.20 0.10 ±0.05 1.00 ±0.05 A3 0.25 b 0.22 ±0.05 0.145 +0.055 0.145 -0.045 12.00 ±0.20 12.00 ±0.20 c D E e 0.50 HD HE L Lp L1 x y ZD ZE 14.00 ±0.20 14.00 ±0.20 0.50 0.60 ±0.15 1.00 ±0.20 0.08 0.08 1.25 1.25 3° +5° 3° -3° θ CDK8307 12/13-bit, 20/40/50/65/80MSPS, Eight Channel, Ultra Low Power ADC with LVDS TQFP-80 Symbol A A1 A2 NOTE: Each lead centerline is located within 0.08mm of its true position at maximum material condition. Detail of Lead End For Further Assistance: Rev 1C Exar Corporation Headquarters and Sales Offices 48720 Kato Road Tel.: +1 (510) 668-7000 Fremont, CA 94538 - USA Fax: +1 (510) 668-7001 www.exar.com NOTICE EXAR Corporation reserves the right to make changes to the products contained in this publication in order to improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and makes no representation that the circuits are free of patent infringement. Charts and schedules contained here in are only for illustration purposes and may vary depending upon a user’s specific application. While the information in this publication has been carefully checked; no responsibility, however, is assumed for inaccuracies. EXAR Corporation does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless EXAR Corporation receives, in writing, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized; (b) the user assumes all such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances. Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited. ©2009-2013 Exar Corporation 31/31 Rev 1C