LTC2192 LTC2191/LTC2190 16-Bit, 65Msps/40Msps/ 25Msps Low Power Dual ADCs DESCRIPTION FEATURES n n n n n n n n n n n n 2-Channel Simultaneous Sampling ADC Serial LVDS Outputs: 1, 2 or 4 Bits per Channel 77dB SNR 90dB SFDR Low Power: 198mW/146mW/104mW Total 99mW/73mW/52mW per Channel Single 1.8V Supply Selectable Input Ranges: 1VP-P to 2VP-P 550MHz Full-Power Bandwidth S/H Shutdown and Nap Modes Serial SPI Port for Configuration 52-Pin (7mm x 8mm) QFN Package APPLICATIONS n n n n n n Communications Cellular Base Stations Software-Defined Radios Portable Medical Imaging Multi-Channel Data Acquisition Nondestructive Testing The LTC(R)2192/LTC2191/LTC2190 are 2-channel, simultaneous sampling 16-bit A/D converters designed for digitizing high frequency, wide dynamic range signals. They are perfect for demanding communications applications with AC performance that includes 77dB SNR and 90dB spurious free dynamic range (SFDR). Ultralow jitter of 0.07psRMS allows undersampling of IF frequencies with excellent noise performance. DC specs include 2LSB INL (typ), 0.5LSB DNL (typ) and no missing codes over temperature. The transition noise is 3.3LSBRMS. To minimize the number of data lines the digital outputs are serial LVDS. Each channel outputs one bit, two bits or four bits at a time. The LVDS drivers have optional internal termination and adjustable output levels to ensure clean signal integrity. The ENC+ and ENC- inputs may be driven differentially or single ended with a sine wave, PECL, LVDS, TTL or CMOS inputs. An internal clock duty cycle stabilizer allows high performance at full speed for a wide range of clock duty cycles. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION 2-Tone FFT, fIN = 70MHz and 69MHz VDD CH1 ANALOG INPUT S/H CH2 ANALOG INPUT S/H ENCODE INPUT 1.8V 16-BIT ADC CORE 16-BIT ADC CORE DATA SERIALIZER PLL GND -10 OVDD OGND 219210 TA01a OUT1A OUT1B OUT1C OUT1D OUT2A OUT2B OUT2C OUT2D DATA CLOCK OUT FRAME -20 -30 SERIALIZED LVDS OUTPUTS AMPLITUDE (dBFS) 1.8V 0 -40 -50 -60 -70 -80 -90 -100 -110 -120 0 20 10 FREQUENCY (MHz) 30 219210 G07 219210f 1 LTC2192 LTC2191/LTC2190 OUT1B- OUT1B+ OUT1A- OUT1A+ GND SDO GND VREF GND TOP VIEW SENSE Supply Voltages VDD, OVDD................................................. -0.3V to 2V Analog Input Voltage AIN+, AIN-, PAR/SER, SENSE (Note 3).....................................-0.3V to (VDD + 0.2V) Digital Input Voltage ENC+, ENC-, CS, SDI, SCK (Note 4)....... -0.3V to 3.9V SDO (Note 4)............................................. -0.3V to 3.9V Digital Output Voltage................. -0.3V to (OVDD + 0.3V) Operating Temperature Range LTC2192C, LTC2191C, LTC2190C............. 0C to 70C LTC2192I, LTC2191I, LTC2190I............. -40C to 85C Storage Temperature Range.................... -65C to 150C PIN CONFIGURATION VDD (Notes 1, 2) VDD ABSOLUTE MAXIMUM RATINGS 52 51 50 49 48 47 46 45 44 43 42 41 VCM1 1 40 OUT1C+ GND 2 39 OUT1C- AIN1+ 3 38 OUT1D+ AIN1- 4 37 OUT1D- GND 5 36 DCO+ REFH 6 35 DCO- REFL 7 34 OVDD 53 GND REFH 8 33 OGND REFL 9 32 FR+ PAR/SER 10 31 FR- AIN2+ 11 30 OUT2A+ AIN2- 12 29 OUT2A- GND 13 28 OUT2B+ VCM2 14 27 OUT2B- OUT2C+ OUT2C- OUT2D+ OUT2D- GND SDI SCK CS ENC- ENC+ VDD VDD 15 16 17 18 19 20 21 22 23 24 25 26 UKG PACKAGE 52-LEAD (7mm x 8mm) PLASTIC QFN TJMAX = 150C, JA = 29C/W EXPOSED PAD (PIN 53) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC2192CUKG#PBF LTC2192CUKG#TRPBF LTC2192UKG 52-Lead (7mm x 8mm) Plastic QFN 0C to 70C LTC2192IUKG#PBF LTC2192IUKG#TRPBF LTC2192UKG 52-Lead (7mm x 8mm) Plastic QFN -40C to 85C LTC2191CUKG#PBF LTC2191CUKG#TRPBF LTC2191UKG 52-Lead (7mm x 8mm) Plastic QFN 0C to 70C LTC2191IUKG#PBF LTC2191IUKG#TRPBF LTC2191UKG 52-Lead (7mm x 8mm) Plastic QFN -40C to 85C LTC2190CUKG#PBF LTC2190CUKG#TRPBF LTC2190UKG 52-Lead (7mm x 8mm) Plastic QFN 0C to 70C LTC2190IUKG#PBF LTC2190IUKG#TRPBF LTC2190UKG 52-Lead (7mm x 8mm) Plastic QFN -40C to 85C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ 219210f 2 LTC2192 LTC2191/LTC2190 CONVERTER CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Note 5) PARAMETER CONDITIONS Resolution (No Missing Codes) MIN l 16 LTC2192 TYP MAX MIN LTC2191 TYP MAX 16 MIN LTC2190 TYP MAX UNITS 16 Bits Integral Linearity Error Differential Analog Input (Note 6) l -6 2 6 -6 2 6 -6 2 6 LSB Differential Linearity Error Differential Analog Input l -0.9 0.5 0.9 -0.9 0.5 0.9 -0.9 0.5 0.9 LSB Offset Error (Note 7) l -7 1.5 7 -7 1.5 7 -7 1.5 7 mV Gain Error Internal Reference External Reference l -1.7 1.5 -0.4 0.9 -1.7 1.5 -0.4 0.9 -1.7 1.5 -0.4 0.9 %FS %FS Offset Drift 10 10 10 V/C 30 10 30 10 30 10 ppm/C ppm/C Gain Matching 0.3 0.3 0.3 %FS Offset Matching 1.5 1.5 1.5 mV Transition Noise 3.3 3.3 3.2 LSBRMS Full-Scale Drift Internal Reference External Reference ANALOG INPUT The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Note 5) SYMBOL PARAMETER CONDITIONS VIN Analog Input Range (AIN+ - AIN-) 1.7V < VDD < 1.9V l MIN TYP MAX VIN(CM) Analog Input Common Mode (AIN+ + AIN-)/2 Differential Analog Input (Note 8) l 0.7 VCM 1.25 VSENSE External Voltage Reference Applied to SENSE External Reference Mode l 0.625 1.250 1.300 IINCM Analog Input Common Mode Current Per Pin, 65Msps Per Pin, 40Msps Per Pin, 25Msps IIN1 Analog Input Leakage Current (No Encode) 0 < AIN+, AIN- < VDD l -1 1 A 1 to 2 UNITS VP-P 104 64 40 V V A A A IIN2 PAR/SER Input Leakage Current 0 < PAR/SER < VDD l -3 3 A IIN3 SENSE Input Leakage Current 0.625V < SENSE < 1.3V l -6 6 A tAP Sample-and-Hold Acquisition Delay Time tJITTER Sample-and-Hold Acquisition Delay Jitter CMRR Analog Input Common Mode Rejection Ratio BW-3B Full-Power Bandwidth 0 ns Single-Ended Encode Differential Encode 0.07 0.09 psRMS psRMS 80 dB Figure 6 Test Circuit 550 MHz 219210f 3 LTC2192 LTC2191/LTC2190 DYNAMIC ACCURACY The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. AIN = -1dBFS. (Note 5) SYMBOL PARAMETER CONDITIONS SNR Signal-to-Noise Ratio 5MHz Input 30MHz Input 70MHz Input 140MHz Input SFDR Spurious Free Dynamic Range 5MHz Input 2nd Harmonic 30MHz Input 70MHz Input 140MHz Input Spurious Free Dynamic Range 5MHz Input 3rd Harmonic 30MHz Input 70MHz Input 140MHz Input Spurious Free Dynamic Range 5MHz Input 4th Harmonic or Higher 30MHz Input 70MHz Input 140MHz Input S/(N+D) Signal-to-Noise Plus Distortion Ratio 5MHz Input 30MHz Input 70MHz Input 140MHz Input Crosstalk 10MHz Input MIN l 75.3 l 83 l 84 l 89 l 74.8 LTC2192 TYP MAX 77 76.9 76.8 76.3 90 90 89 84 90 90 89 84 95 95 95 95 76.8 76.7 76.4 76.3 MIN 75.2 LTC2191 TYP MAX 76.9 76.8 76.7 76.2 90 90 89 84 83 84 95 95 95 95 89 74.8 -110 75.6 83 90 90 89 84 84 MIN 89 76.7 76.6 76.3 75.2 75 -110 LTC2190 TYP MAX UNITS 77.1 77 76.9 76.4 dBFS dBFS dBFS dBFS 90 90 89 84 dBFS dBFS dBFS dBFS 90 90 89 84 dBFS dBFS dBFS dBFS 95 95 95 95 dBFS dBFS dBFS dBFS 76.9 76.8 76.5 76.4 dBFS dBFS dBFS dBFS -110 dBc INTERNAL REFERENCE CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Note 5) PARAMETER CONDITIONS VCM Output Voltage IOUT = 0 MIN TYP MAX 0.5 * VDD - 25mV 0.5 * VDD 0.5 * VDD + 25mV VCM Output Temperature Drift UNITS 25 VCM Output Resistance -600A < IOUT < 1mA VREF Output Voltage IOUT = 0 ppm/C 4 1.225 1.250 VREF Output Temperature Drift 1.275 V 25 VREF Output Resistance -400A < IOUT < 1mA VREF Line Regulation 1.7V < VDD < 1.9V V ppm/C 7 0.6 mV/V DIGITAL INPUTS AND OUTPUTS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Note 5) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS ENCODE INPUTS (ENC+, ENC-) Differential Encode Mode (ENC- Not Tied to GND) VID Differential Input Voltage (Note 8) l 0.2 VICM Common Mode Input Voltage Internally Set Externally Set (Note 8) l 1.1 l 0.2 V 1.2 1.6 V V VIN Input Voltage Range ENC+, ENC- to GND (Note 8) RIN Input Resistance See Figure 10 10 k CIN Input Capacitance (Note 8) 3.5 pF 3.6 V 219210f 4 LTC2192 LTC2191/LTC2190 DIGITAL INPUTS AND OUTPUTS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Note 5) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Single-Ended Encode Mode (ENC- Tied to GND) VIH High Level Input Voltage VDD =1.8V l VIL Low Level Input Voltage VDD =1.8V l 1.2 V VIN Input Voltage Range ENC+ to GND l RIN Input Resistance See Figure 11 30 k CIN Input Capacitance (Note 8) 3.5 pF 0 0.6 V 3.6 V DIGITAL INPUTS (CS, SDI, SCK in Serial or Parallel Programming Mode. SDO in Parallel Programming Mode) VIH High Level Input Voltage VDD =1.8V l VIL Low Level Input Voltage VDD =1.8V l IIN Input Current VIN = 0V to 3.6V l CIN Input Capacitance (Note 8) 1.3 V -10 0.6 V 10 A 3 pF SDO OUTPUT (Serial Programming Mode. Open-Drain Output. Requires 2k Pull-Up Resistor if SDO is Used) ROL Logic Low Output Resistance to GND VDD =1.8V, SDO = 0V IOH Logic High Output Leakage Current SDO = 0V to 3.6V COUT Output Capacitance (Note 8) 200 l -10 10 A 3 pF DIGITAL DATA OUTPUTS VOD Differential Output Voltage 100 Differential Load, 3.5mA Mode 100 Differential Load, 1.75mA Mode l l 247 125 350 175 454 250 mV mV VOS Common Mode Output Voltage 100 Differential Load, 3.5mA Mode 100 Differential Load, 1.75mA Mode l l 1.125 1.125 1.250 1.250 1.375 1.375 RTERM On-Chip Termination Resistance Termination Enabled, OVDD = 1.8V 100 V V POWER REQUIREMENTS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Note 9) VDD Analog Supply Voltage (Note 10) l 1.7 1.8 1.9 1.7 1.8 1.9 1.7 1.8 1.9 V OVDD Output Supply Voltage (Note 10) l 1.7 1.8 1.9 1.7 1.8 1.9 1.7 1.8 1.9 V IVDD Analog Supply Current Sine Wave Input l 99 109 72 80 49 56 mA IOVDD Digital Supply Current 1-Lane Mode, 1.75mA Mode 1-Lane Mode, 3.5mA Mode 2-Lane Mode, 1.75mA Mode 2-Lane Mode, 3.5mA Mode 4-Lane Mode, 1.75mA Mode 4-Lane Mode, 3.5mA Mode l l l l 10.2 17.6 13.6 24.7 21.1 39.6 17 30 25 47 9.2 16.6 12.8 23.9 20.3 38.8 16 29 25 47 8.7 16.1 12.3 23.4 19.9 38.4 16 29 25 47 mA mA mA mA mA mA l l l l 198 211 203 223 217 250 227 251 242 281 146 159 152 172 166 199 173 197 189 229 104 118 111 131 124 158 130 153 146 186 mW mW mW mW mW mW 1-Lane Mode, 1.75mA Mode 1-Lane Mode, 3.5mA Mode 2-Lane Mode, 1.75mA Mode 2-Lane Mode, 3.5mA Mode 4-Lane Mode, 1.75mA Mode 4-Lane Mode, 3.5mA Mode MIN LTC2190 TYP MAX CONDITIONS Power Dissipation MIN LTC2191 TYP MAX PARAMETER PDISS MIN LTC2192 TYP MAX SYMBOL UNITS PSLEEP Sleep Mode Power 1 1 1 mW PNAP Nap Mode Power 50 50 50 mW PDIFFCLK Power Increase with Diffential Encode Mode Enabled (No Increase for Sleep Mode) 20 20 20 mW 219210f 5 LTC2192 LTC2191/LTC2190 TIMING CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Note 5) SYMBOL PARAMETER CONDITIONS fS Sampling Frequency (Notes 10, 11) tENCL MIN l 5 ENC Low Time (Note 8) Duty Cycle Stabilizer Off Duty Cycle Stabilizer On l l 7.3 2 tENCH ENC High Time (Note 8) Duty Cycle Stabilizer Off Duty Cycle Stabilizer On l l 7.3 2 tAP Sample-and-Hold Acquistion Delay Time SYMBOL PARAMETER CONDITIONS LTC2192 TYP MAX MIN 65 5 7.69 7.69 100 100 11.88 2 7.69 7.69 100 100 11.88 2 LTC2191 TYP MAX MIN 40 5 12.5 12.5 100 100 19 2 12.5 12.5 100 100 19 2 LTC2190 TYP MAX UNITS 25 MHz 20 20 100 100 ns ns 20 20 100 100 ns ns 0 0 0 MIN TYP MAX ns UNITS Digital Data Outputs (RTERM = 100 Differential, CL = 2pF to GND On Each Output) tSER Serial Data Bit Period 4-Lane Output Mode 2-Lane Output Mode 1-Lane Output Mode 1/(4 * fS) 1/(8 * fS) 1/(16 * fS) tFRAME FR to DCO Delay (Note 8) l tDATA Data to DCO Delay (Note 8) l 0.35 * tSER tPD Propagation Delay (Note 8) l 0.7n + 2 * tSER tr Output Rise Time Data, DCO, FR, 20% to 80% 0.17 ns tf Output Fall Time Data, DCO, FR, 20% to 80% 0.17 ns DCO Cycle-Cycle Jitter tSER = 1ns 0.35 * tSER Pipeline Latency 0.5 * tSER Sec 0.65 * tSER Sec 0.5 * tSER 0.65 * tSER Sec 1.1n + 2 * tSER 1.5n + 2 * tSER Sec 60 psP-P 7 Cycles SPI Port Timing (Note 8) tSCK SCK Period tS Write Mode Readback Mode, CSDO = 20pF, RPULLUP = 2k l l 40 250 ns ns CS-to-SCK Setup Time l 5 ns tH SCK-to-CS Setup Time l 5 ns tDS SDI Setup Time l 5 ns tDH SDI Hold Time l 5 ns tDO SCK Falling to SDO Valid Readback Mode, CSDO = 20pF, RPULLUP = 2k l Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: All voltage values are with respect to GND with GND and OGND shorted (unless otherwise noted). Note 3: When these pin voltages are taken below GND or above VDD, they will be clamped by internal diodes. This product can handle input currents of greater than 100mA below GND or above VDD without latchup. Note 4: When these pin voltages are taken below GND they will be clamped by internal diodes. When these pin voltages are taken above VDD they will not be clamped by internal diodes. This product can handle input currents of greater than 100mA below GND without latchup. Note 5: VDD = OVDD = 1.8V, fSAMPLE = 65MHz (LTC2192), 40MHz (LTC2191), or 25MHz (LTC2190), 2-lane output mode, differential ENC+/ENC- = 2VP-P sine wave, input range = 2VP-P with differential drive, unless otherwise noted. 125 ns Note 6: Integral nonlinearity is defined as the deviation of a code from a best fit straight line to the transfer curve. The deviation is measured from the center of the quantization band. Note 7: Offset error is the offset voltage measured from -0.5LSB when the output code flickers between 0000 0000 0000 0000 and 1111 1111 1111 1111 in 2's complement output mode. Note 8: Guaranteed by design, not subject to test. Note 9: VDD = OVDD=1.8V, fSAMPLE = 65MHz (LTC2192), 40MHz (LTC2191), or 25MHz (LTC2190), 2-lane output mode, ENC+ = singleended 1.8V square wave, ENC- = 0V, input range = 2VP-P with differential drive, unless otherwise noted. The supply current and power dissipation specifications are totals for the entire IC, not per channel. Note 10: Recommended operating conditions. Note 11: The maximum sampling frequency depends on the speed grade of the part and also which serialization mode is used. The maximum serial data rate is 1000Mbps, so tSER must be greater than or equal to 1ns. 219210f 6 LTC2192 LTC2191/LTC2190 TIMING DIAGRAMS 4-Lane Output Mode tAP ANALOG INPUT N N+1 tENCL tENCH ENC- ENC+ tDATA DCO- tSER DCO+ FR- OUT#A- OUT#A+ OUT#B- OUT#B+ OUT#C- OUT#C+ OUT#D- OUT#D+ tSER tFRAME FR+ tPD tSER D15 D13 D11 D9 D15 D13 D11 D9 D15 D14 D12 D10 D8 D14 D12 D10 D8 D14 D7 D5 D3 D1 D7 D5 D3 D1 D7 D6 D4 D2 D0 D6 D4 D2 D0 D6 SAMPLE N-7 SAMPLE N-6 SAMPLE N-5 219210 TD01 2-Lane Output Mode tAP ANALOG INPUT N+1 N tENCL tENCH ENC- ENC+ tSER DCO- DCO+ tFRAME FR- FR+ tSER tPD OUT#A- OUT#A+ tDATA tSER D7 D5 D3 D1 D15 D13 D11 D9 D7 D5 D3 D1 D15 D13 D11 D6 D4 D2 D0 D14 D12 D10 D8 D6 D4 D2 D0 D14 D12 D10 OUT#B- OUT#B+ SAMPLE N-7 SAMPLE N-6 OUT#C+, OUT#C-, OUT#D+, OUT#D- ARE DISABLED SAMPLE N-5 219210 TD02 219210f 7 LTC2192 LTC2191/LTC2190 TIMING DIAGRAMS 1-Lane Output Mode tAP ANALOG INPUT N+1 N tENCH ENC- tENCL ENC+ tSER DCO- DCO+ tFRAME FR- FR+ tSER tPD OUT#A- OUT#A+ tDATA D3 D2 D1 tSER D0 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 D15 D14 D13 D12 219210 TD03 SAMPLE N-7 SAMPLE N-6 SAMPLE N-5 OUT#B+, OUT#B-, OUT#C+, OUT#C-, OUT#D+, OUT#D- ARE DISABLED SPI Port Timing (Readback Mode) tDS tS tDH tSCK tH CS SCK tDO SDI SDO R/W A6 A5 A4 A3 A2 A1 A0 XX D7 HIGH IMPEDANCE XX D6 XX D5 XX D4 XX D3 XX D2 XX XX D1 D0 SPI Port Timing (Write Mode) CS SCK SDI SDO R/W HIGH IMPEDANCE A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0 219210 TD04 219210f 8 LTC2192 LTC2191/LTC2190 TYPICAL PERFORMANCE CHARACTERISTICS LTC2192: Integral Nonlinearity (INL) LTC2192: Differential Nonlinearity (DNL) 4.0 3.0 0 0.8 -10 -20 0.6 1.0 0 -1.0 -2.0 -30 0.4 AMPLITUDE (dBFS) DNL ERROR (LSB) 2.0 INL ERROR (LSB) 1.0 0.2 0 -0.2 -0.4 -0.8 -4.0 -1.0 0 16384 32768 49152 OUTPUT CODE 65536 0 16384 32768 49152 OUTPUT CODE -60 -70 -80 65536 -110 -120 LTC2192: 64k Point FFT, fIN = 30MHz, -1dBFS, 65Msps 0 -10 -20 -20 -20 -30 -30 -30 -70 -80 AMPLITUDE (dBFS) 0 -10 AMPLITUDE (dBFS) 0 -60 -40 -50 -60 -70 -80 -40 -50 -60 -70 -80 -90 -100 -90 -100 -90 -100 -110 -120 -110 -120 -110 -120 0 20 10 FREQUENCY (MHz) 30 0 20 10 FREQUENCY (MHz) 219210 G04 LTC2192: 64k Point 2-Tone FFT, fIN = 69MHz, 70MHz, -7dBFS, 65Msps LTC2192: SNR vs Input Frequency, -1dBFS, 65Msps, 2V Range 78 -20 77 8000 6000 5000 4000 -80 3000 -90 -100 2000 -110 -120 SNR (dBFS) -70 20 10 FREQUENCY (MHz) 30 219210 G07 0 32831 75 74 DIFFERENTIAL ENCODE 73 72 71 1000 0 SINGLE-ENDED ENCODE 76 7000 -60 30 LTC2192: Shorted Input Histogram 9000 -50 20 10 FREQUENCY (MHz) 219210 G06 10000 -40 0 219210 G05 0 COUNT AMPLITUDE (dBFS) 30 -10 -30 30 LTC2192: 64k Point FFT, fIN = 140MHz, -1dBFS, 65Msps -10 -50 20 10 FREQUENCY (MHz) 219210 G03 LTC2192: 64k Point FFT, fIN = 70MHz, -1dBFS, 65Msps -40 0 219210 G02 219210 G01 AMPLITUDE (dBFS) -40 -50 -90 -100 -0.6 -3.0 LTC2192: 64k Point FFT, fIN = 5MHz, -1dBFS, 65Msps 32837 32843 32849 OUTPUT CODE 32855 219210 G08 70 0 50 100 150 200 250 INPUT FREQUENCY (MHz) 300 219210 G09 219210f 9 LTC2192 LTC2191/LTC2190 TYPICAL PERFORMANCE CHARACTERISTICS LTC2192: 2nd, 3rd Harmonic vs Input Frequency, -1dBFS, 65Msps, 1V Range 100 95 95 90 3RD 85 80 2ND 75 70 65 0 50 100 150 200 250 INPUT FREQUENCY (MHz) 120 85 2ND 80 75 100 90 70 60 50 40 30 0 50 100 150 200 250 INPUT FREQUENCY (MHz) 20 -80 -70 -60 -50 -40 -30 -20 -10 INPUT LEVEL (dBFS) 300 219210 G11 219210 G10 LTC2192: SNR vs SENSE, fIN = 5MHz, -1dBFS 45 110 78 4 LANE, 3.5mA 77 35 80 76 SNR (dBFS) 90 IOVDD (mA) IVDD (mA) 100 2 LANE, 3.5mA 25 4 LANE, 1.75mA 1 LANE, 3.5mA 15 70 10 50 20 30 40 SAMPLE RATE (Msps) 5 60 0 75 74 73 72 2 LANE, 1.75mA 1 LANE, 1.75mA 0 0 219210 G12 LTC2192: IOVDD vs Sample Rate, 5MHz, -1dBFS Sine Wave on Each Input LTC2192: IVDD vs Sample Rate, 5MHz, -1dBFS Sine Wave on Each Channel 60 dBc 80 70 300 dBFS 110 3RD 90 65 LTC2192: SFDR vs Input Level, fIN = 70MHz, 65Msps, 2V Range 130 SFDR (dBc AND dBFS) 100 2ND AND 3RD HARMONIC (dBFS) 2ND AND 3RD HARMONIC (dBFS) LTC2192: 2nd, 3rd Harmonic vs Input Frequency, -1dBFS, 65Msps, 2V Range 71 70 20 40 60 SAMPLE RATE (Msps) 0.6 0.7 0.8 0.9 1 1.1 SENSE PIN (V) 1.2 1.3 219210 G15 219210 G13 219210 G14 LTC2191: Integral Nonlinearity (INL) LTC2191: Differential Nonlinearity (DNL) 4.0 1.0 0 3.0 0.8 -10 0 -1.0 -2.0 -30 0.4 AMPLITUDE (dBFS) DNL ERROR (LSB) 1.0 0.2 0 -0.2 -0.4 -0.8 0 16384 32768 49152 OUTPUT CODE 65536 219210 G16 -1.0 -40 -50 -60 -70 -80 -90 -100 -0.6 -3.0 -4.0 -20 0.6 2.0 INL ERROR (LSB) LTC2191: 64k Point FFT, fIN = 5MHz, -1dBFS, 40Msps 0 16384 32768 49152 OUTPUT CODE 65536 219210 G17 -110 -120 0 5 10 15 FREQUENCY (MHz) 20 219210 G18 219210f 10 LTC2192 LTC2191/LTC2190 TYPICAL PERFORMANCE CHARACTERISTICS 0 LTC2191: 64k Point FFT, fIN = 70MHz, -1dBFS, 40Msps -10 -20 -20 -20 -30 -30 -30 -40 -50 -60 -70 -80 AMPLITUDE (dBFS) -10 -40 -50 -60 -70 -80 -50 -60 -70 -80 -90 -100 -90 -100 -110 -120 -110 -120 -110 -120 0 5 10 15 FREQUENCY (MHz) 20 0 5 10 15 FREQUENCY (MHz) LTC2191: 64k Point 2-Tone FFT, fIN = 69MHz, 70MHz, -7dBFS, 40Msps 0 10000 -10 9000 -20 -60 -70 -80 78 76 6000 5000 4000 0 32823 20 32829 32835 32841 OUTPUT CODE 95 95 2ND AND 3RD HARMONIC (dBFS) 100 80 2ND 75 70 65 0 50 100 150 200 250 INPUT FREQUENCY (MHz) 300 219210 G25 50 100 150 200 250 INPUT FREQUENCY (MHz) 120 dBFS 110 3RD 85 2ND 80 75 100 90 80 dBc 70 60 50 40 70 65 LTC2191: SFDR vs Input Level, fIN = 70MHz, 40Msps, 2V Range 130 90 300 219210 G24 LTC2191: 2nd, 3rd Harmonic vs Input Frequency, -1dBFS, 40Msps, 1V Range 100 3RD 0 219210 G23 LTC2191: 2nd, 3rd Harmonic vs Input Frequency, -1dBFS, 40Msps, 2V Range 85 73 70 32847 219210 G22 90 DIFFERENTIAL ENCODE 74 71 SFDR (dBc AND dBFS) 10 15 FREQUENCY (MHz) 75 72 1000 5 SINGLE-ENDED ENCODE 77 2000 0 20 LTC2191: SNR vs Input Frequency, -1dBFS, 40Msps, 2V Range 3000 -90 -100 10 15 FREQUENCY (MHz) LTC2191: Shorted Input Histogram SNR (dBFS) COUNT AMPLITUDE (dBFS) -50 5 219210 G21 7000 -40 0 219210 G20 8000 -30 -110 -120 20 LTC2191: 64k Point FFT, fIN = 140MHz, -1dBFS, 40Msps -40 -90 -100 219210 G19 2ND AND 3RD HARMONIC (dBFS) 0 -10 AMPLITUDE (dBFS) AMPLITUDE (dBFS) 0 LTC2191: 64k Point FFT, fIN = 30MHz, -1dBFS, 40Msps 30 0 50 100 150 200 250 INPUT FREQUENCY (MHz) 300 219210 G26 20 -80 -70 -60 -50 -40 -30 -20 -10 INPUT LEVEL (dBFS) 0 219210 G27 219210f 11 LTC2192 LTC2191/LTC2190 TYPICAL PERFORMANCE CHARACTERISTICS LTC2191: IOVDD vs Sample Rate, 5MHz, -1dBFS Sine Wave on Each Input LTC2191: IVDD vs Sample Rate, 5MHz, -1dBFS Sine Wave Input on Each Channel LTC2191: SNR vs SENSE, fIN = 5MHz, -1dBFS 45 80 78 4 LANE, 3.5mA 75 77 35 76 65 25 2 LANE, 3.5mA 4 LANE, 1.75mA 60 1 LANE, 3.5mA 15 1 LANE, 1.75mA 0 10 20 30 SAMPLE RATE (Msps) 5 40 0 73 20 30 10 SAMPLE RATE (Msps) 70 40 1.0 0 3.0 0.8 -10 0.2 0 -0.2 -0.4 -3.0 -0.8 16384 32768 49152 OUTPUT CODE -1.0 65536 0 16384 32768 49152 OUTPUT CODE 219210 G31 -40 -50 -60 -70 -80 65536 -110 -120 LTC2190: 64k Point FFT, fIN = 70MHz, -1dBFS, 25Msps 0 -10 -20 -20 -20 -30 -30 -30 -70 -80 AMPLITUDE (dBFS) 0 -10 AMPLITUDE (dBFS) 0 -60 -40 -50 -60 -70 -80 -50 -70 -80 -90 -100 -110 -120 -110 -120 -110 -120 10 219210 G34 0 5 FREQUENCY (MHz) 10 219210 G35 LTC2190: 64k Point FFT, fIN = 140MHz, -1dBFS, 25Msps -60 -90 -100 5 FREQUENCY (MHz) 10 -40 -90 -100 0 5 FREQUENCY (MHz) 219210 G33 -10 -50 0 219210 G32 LTC2190: 64k Point FFT, fIN = 30MHz, -1dBFS, 25Msps -40 1.3 -90 -100 -0.6 0 1.2 -30 0.4 AMPLITUDE (dBFS) DNL ERROR (LSB) -2.0 -4.0 0.9 1 1.1 SENSE PIN (V) -20 0.6 2.0 -1.0 0.8 LTC2190: 64k Point FFT, fIN = 5MHz, -1dBFS, 25Msps 4.0 0 0.7 219210 G30 LTC2190: Differential Nonlinearity (DNL) 1.0 0.6 219210 G29 LTC2190: Integral Nonlinearity (INL) INL ERROR (LSB) 74 71 219210 G28 AMPLITUDE (dBFS) 75 72 2 LANE, 1.75mA 55 50 SNR (dBFS) IOVDD (mA) IVDD (mA) 70 0 5 FREQUENCY (MHz) 10 219210 G36 219210f 12 LTC2192 LTC2191/LTC2190 TYPICAL PERFORMANCE CHARACTERISTICS LTC2190: 64k Point, 2-Tone FFT, fIN = 69MHz, 70MHz, -7dBFS, 25Msps 0 10000 -10 9000 -20 77 -60 -70 -80 6000 SNR (dBFS) -50 5000 4000 3000 -90 -100 0 32836 10 32842 32848 32854 OUTPUT CODE 95 2ND 75 70 65 0 50 100 150 200 250 INPUT FREQUENCY (MHz) 120 110 3RD 85 2ND 80 75 0 50 100 150 200 250 INPUT FREQUENCY (MHz) LTC2190: IOVDD vs Sample Rate, 5MHz, -1dBFS Sine Wave on Each Input 78 77 35 SNR (dBFS) 76 2 LANE, 3.5mA 4 LANE, 1.75mA 1 LANE, 3.5mA 20 219210 G43 15 0 5 15 20 10 SAMPLE RATE (Msps) 75 74 73 72 2 LANE, 1.75mA 71 1 LANE, 1.75mA 25 0 LTC2190: SNR vs SENSE, fIN = 5MHz, -1dBFS 40 I0VDD (mA) IVDD (mA) 50 15 20 10 SAMPLE RATE (Msps) 50 219210 G42 4 LANE, 3.5mA 5 60 20 -80 -70 -60 -50 -40 -30 -20 -10 INPUT LEVEL (dBFS) 300 45 0 dBc 70 219210 G41 55 35 90 80 30 219210 G40 40 dBFS 100 40 70 LTC2190: IVDD vs Sample Rate, 5MHz, -1dBFS Sine Wave Input on Each Channel 300 130 90 65 300 45 100 150 200 250 INPUT FREQUENCY (MHz) LTC2190: SFDR vs Input Level, fIN = 70MHz, 25Msps, 2V Range SFDR (dBc AND dBFS) 95 2ND AND 3RD HARMONIC (dBFS) 2ND AND 3RD HARMONIC (dBFS) 100 80 50 219210 G39 LTC2190: 2nd, 3rd Harmonic vs Input Frequency, -1dBFS, 25Msps, 1V Range 100 3RD 0 219210 G38 LTC2190: 2nd, 3rd Harmonic vs Input Frequency, -1dBFS, 25Msps, 2V Range 85 DIFFERENTIAL ENCODE 73 70 32860 219210 G37 90 74 71 1000 5 FREQUENCY (MHz) 75 72 2000 0 SINGLE-ENDED ENCODE 76 7000 -40 COUNT AMPLITUDE (dBFS) 78 8000 -30 -110 -120 LTC2190: SNR vs Input Frequency, -1dBFS, 25Msps, 2V Range LTC2190: Shorted Input Histogram 25 70 0.6 0.7 0.8 0.9 1 1.1 SENSE PIN (V) 1.2 1.3 219210 G45 219210 G44 219210f 13 LTC2192 LTC2191/LTC2190 PIN FUNCTIONS VCM1 (Pin 1): Common Mode Bias Output, Nominally Equal to VDD/2. VCM1 should be used to bias the common mode of the analog inputs of channel 1. Bypass to ground with a 0.1F ceramic capacitor. GND (Pins 2, 5, 13, 22, 45, 47, 49, Exposed Pad Pin 53): ADC Power Ground. The exposed pad must be soldered to the PCB ground. AIN1+ (Pin 3): Channel 1 Positive Differential Analog Input. AIN1- (Pin 4): Channel 1 Negative Differential Analog Input. REFH (Pins 6, 8): ADC High Reference. See the Reference section in the Applications Information for recommended bypassing circuits for REFH and REFL. REFL (Pins 7, 9): ADC Low Reference. See the Reference section in the Applications Information for recommended bypassing circuits for REFH and REFL. PAR/SER (Pin 10): Programming Mode Selection Pin. Connect to ground to enable the serial programming mode. CS, SCK, SDI, SDO become a serial interface that control the A/D operating modes. Connect to VDD to enable the parallel programming mode where CS, SCK, SDI, SDO become parallel logic inputs that control a reduced set of the A/D operating modes. PAR/SER should be connected directly to ground or the VDD of the part and not be driven by a logic signal. AIN2+ (Pin 11): Channel 2 Positive Differential Analog Input. AIN2- (Pin 12): Channel 2 Negative Differential Analog Input. VCM2 (Pin 14): Common Mode Bias Output, Nominally Equal to VDD/2. VCM2 should be used to bias the common mode of the analog inputs of channel 2. Bypass to ground with a 0.1F ceramic capacitor. VDD (Pins 15, 16, 51, 52): Analog Power Supply, 1.7V to 1.9V. Bypass to ground with 0.1F ceramic capacitors. Adjacent pins can share a bypass capacitor. ENC+ (Pin 17): Encode Input. Conversion starts on the rising edge. ENC- (Pin 18): Encode Complement Input. Conversion starts on the falling edge. Tie to GND for single-ended encode mode. CS (Pin 19): In serial programming mode, (PAR/SER = 0V), CS is the serial interface chip select input. When CS is low, SCK is enabled for shifting data on SDI into the mode control registers. In the parallel programming mode (PAR/SER = VDD), CS along with SCK selects 1-, 2- or 4-lane output mode (see Table 3). CS can be driven with 1.8V to 3.3V logic. SCK (Pin 20): In serial programming mode, (PAR/SER = 0V), SCK is the serial interface clock input. In the parallel programming mode (PAR/SER = VDD), SCK along with CS selects 1-, 2- or 4-lane output mode (see Table 3). SCK can be driven with 1.8V to 3.3V logic. SDI (Pin 21): In Serial Programming Mode, (PAR/SER = 0V), SDI is the Serial Interface Data Input. Data on SDI is clocked into the mode control registers on the rising edge of SCK. In the parallel programming pode (PAR/SER = VDD), SDI can be used to power down the part. SDI can be driven with 1.8V to 3.3V logic. OGND (Pin 33): Output Driver Ground. This pin must be shorted to the ground plane by a very low inductance path. Use multiple vias close to the pin. OVDD (Pin 34): Output Driver Supply. Bypass to ground with a 0.1F ceramic capacitor. SDO (Pin 46): In serial programming mode, (PAR/SER = 0V), SDO is the optional serial interface data output. Data on SDO is read back from the mode control registers and can be latched on the falling edge of SCK. SDO is an open-drain NMOS output that requires an external 2k pull-up resistor to 1.8V to 3.3V. If read back from the mode control registers is not needed, the pull-up resistor is not necessary and SDO can be left unconnected. In the parallel programming mode (PAR/SER = VDD), SDO selects 3.5mA or 1.75mA LVDS output currents. When used as an input, SDO can be driven with 1.8V to 3.3V logic through a 1k series resistor. 219210f 14 LTC2192 LTC2191/LTC2190 PIN FUNCTIONS VREF (Pin 48): Reference Voltage Output. Bypass to ground with a 2.2F ceramic capacitor. The reference output is nominally 1.25V. SENSE (Pin 50): Reference Programming Pin. Connecting SENSE to VDD selects the internal reference and a 1V input range. Connecting SENSE to ground selects the internal reference and a 0.5V input range. An external reference between 0.625V and 1.3V applied to SENSE selects an input range of 0.8 * VSENSE. LVDS Outputs The following pins are differential LVDS outputs. The output current level is programmable. There is an optional internal 100 termination resistor between the pins of each LVDS output pair. OUT2D-/OUT2D+, OUT2C-/OUT2C+, OUT2B-/OUT2B+, OUT2A-/OUT2A+ (Pins 23/24, 25/26, 27/28, 29/30): Serial Data Outputs for Channel 2. In 1-lane output mode only OUT2A-/OUT2A+ are used. In 2-Lane output mode only OUT2A-/OUT2A+ and OUT2B-/OUT2B+ are used. FR-/FR+ (Pins 31/32): Frame Start Outputs. DCO-/DCO+ (Pins 35/36): Data Clock Outputs. OUT1D-/OUT1D+, OUT1C-/OUT1C+, OUT1B-/OUT1B+, OUT1A-/OUT1A+ (Pins 37/38, 39/40, 41/42, 43/44): Serial Data Outputs for Channel 1. In 1-lane output mode only OUT1A-/OUT1A+ are used. In 2-lane output mode only OUT1A-/OUT1A+ and OUT1B-/OUT1B+ are used. 219210f 15 LTC2192 LTC2191/LTC2190 FUNCTIONAL BLOCK DIAGRAM 1.8V ENC+ ENC- 1.8V VDD CH1 ANALOG INPUT OVDD PLL 16-BIT ADC CORE S/H DATA SERIALIZER CH2 ANALOG INPUT 16-BIT ADC CORE S/H OUT1A OUT1B OUT1C OUT1D OUT2A OUT2B OUT2C OUT2D DATA CLOCK OUT FRAME OGND VREF 2.2F 1.25V REFERENCE RANGE SELECT REF BUF REFH REFL SENSE VDD/2 DIFF REF AMP MODE CONTROL REGISTERS 219210 F01 REFH 2.2F 0.1F REFL VCM1 VCM2 0.1F 0.1F PAR/SER CS SCK SDI SDO 0.1F Figure 1. Functional Block Diagram 219210f 16 LTC2192 LTC2191/LTC2190 APPLICATIONS INFORMATION CONVERTER OPERATION Single-Ended Input The LTC2192/LTC2191/LTC2190 are low power, 2-channel, 16-bit, 65/40/25Msps A/D converters that are powered by a single 1.8V supply. The analog inputs should be driven differentially. The encode input can be driven differentially or single ended for lower power consumption. To minimize the number of data lines the digital outputs are serial LVDS. Each channel outputs one bit at a time (1-lane mode), two bits at a time (2-lane mode) or four bits at a time (4lane mode). Many additional features can be chosen by programming the mode control registers through a serial SPI port. For applications less sensitive to harmonic distortion, the AIN+ input can be driven singled ended with a 1VP-P signal centered around VCM. The AIN- input should be connected to VCM and the VCM bypass capacitor should be increased to 2.2F. With a singled-ended input the harmonic distortion and INL will degrade, but the noise and DNL will remain unchanged. ANALOG INPUT The analog inputs are differential CMOS sample-andhold circuits (Figure 2). The inputs should be driven differentially around a common mode voltage set by the VCM1 or VCM2 output pins, which are nominally VDD/2. For the 2V input range, the inputs should swing from VCM - 0.5V to VCM + 0.5V. There should be 180 phase difference between the inputs. The two channels are simultaneously sampled by a shared encode circuit (Figure 2). INPUT DRIVE CIRCUITS Input Filtering If possible, there should be an RC lowpass filter right at the analog inputs. This lowpass filter isolates the drive circuitry from the A/D sample-and-hold switching, and also limits wideband noise from the drive circuitry. Figure 3 shows an example of an input RC filter. The RC component values should be chosen based on the application's input frequency. Transformer Coupled Circuits Figure 3 shows the analog input being driven by an RF transformer with a center-tapped secondary. The center LTC2192 VDD AIN+ RON 15 10 CPARASITIC 1.8pF VDD AIN- CSAMPLE 5pF RON 15 10 CSAMPLE 5pF CPARASITIC 1.8pF VDD 1.2V 10k ENC+ ENC- 10k 1.2V 219210 F02 Figure 2. Equivalent Input Circuit. Only One of Two Analog Channels Is Shown 219210f 17 LTC2192 LTC2191/LTC2190 APPLICATIONS INFORMATION 50 50 VCM 0.1F 0.1F 0.1F ANALOG INPUT T1 1:1 25 25 0.1F AIN+ ANALOG INPUT LTC2192 0.1F AIN+ T2 T1 25 1.8pF 0.1F AIN- T1: MA/COM MABAES0060 RESISTORS, CAPACITORS ARE 0402 PACKAGE SIZE Figure 3. Analog Input Circuit Using a Transformer. Recommended for Input Frequencies from 5MHz to 70MHz 25 AIN- T1: MA/COM MABA-007159-000000 T2: COILCRAFT WBC1-1TL RESISTORS, CAPACITORS ARE 0402 PACKAGE SIZE 219210 F03 50 ANALOG INPUT 12 T1 T2 25 50 VCM VCM 0.1F 0.1F AIN+ LTC2192 0.1F 219210 F05 Figure 5. Recommended Front-End Circuit for Input Frequencies from 150MHz to 250MHz 0.1F 0.1F LTC2192 0.1F 25 12pF 25 VCM ANALOG INPUT 4.7nH T1 AIN+ LTC2192 0.1F 25 8.2pF 0.1F 25 12 0.1F 25 AIN- T1: MA/COM MABA-007159-000000 T2: COILCRAFT WBC1-1TL RESISTORS, CAPACITORS ARE 0402 PACKAGE SIZE tap is biased with VCM, setting the A/D input at its optimal DC level. At higher input frequencies a transmission line balun transformer (Figures 4 to 6) has better balance, resulting in lower A/D distortion. Amplifier Circuits Figure 7 shows the analog input being driven by a high speed differential amplifier. The output of the amplifier is AC coupled to the A/D so the amplifier's output common mode voltage can be optimally set to minimize distortion. At very high frequencies an RF gain block will often have lower distortion than a differential amplifier. If the gain block is single ended, then a transformer circuit (Figures 4 to 6) should convert the signal to differential before driving the A/D. AIN- T1: MA/COM ETC1-1-13 RESISTORS, CAPACITORS ARE 0402 PACKAGE SIZE 219210 F04 Figure 4. Recommended Front-End Circuit for Input Frequencies from 5MHz to 150MHz 4.7nH 219210 F06 Figure 6. Recommended Front-End Circuit for Input Frequencies Above 250MHz VCM HIGH SPEED DIFFERENTIAL 0.1F AMPLIFIER ANALOG INPUT 200 200 25 + - 0.1F AIN+ 12pF 0.1F 25 LTC2192 AIN- 12pF 219210 F07 Figure 7. Front-End Circuit Using a High Speed Differential Amplifier 219210f 18 LTC2192 LTC2191/LTC2190 APPLICATIONS INFORMATION Reference The LTC2192/LTC2191/LTC2190 have an internal 1.25V voltage reference. For a 2V input range using the internal reference, connect SENSE to VDD. For a 1V input range using the internal reference, connect SENSE to ground. For a 2V input range with an external reference, apply a 1.25V reference voltage to SENSE (Figure 9). The input range can be adjusted by applying a voltage to SENSE that is between 0.625V and 1.30V. The input range will then be 1.6 * VSENSE. The VREF, REFH and REFL pins should be bypassed as shown in Figure 8. A low inductance 2.2F interdigitated capacitor is recommended for the bypass between REFH and REFL. This type of capacitor is available at a low cost from multiple suppliers. Alternatively, C1 can be replaced by a standard 2.2F capacitor between REFH and REFL. The capacitors should be as close to the pins as possible (not on the back side of the circuit board). Figure 8c and 8d show the recommended circuit board layout for the REFH/REFL bypass capacitors. Note that in Figure 8c, every pin of the interdigitated capacitor (C1) is connected since the pins are not internally connected in some vendors' capacitors. In Figure 8d the REFH and REFL pins are connected by short jumpers in an internal layer. To minimize the inductance of these jumpers they can be placed in a small hole in the GND plane on the second board layer. REFH C3 0.1F LTC2192 REFL C1 2.2F REFH C2 0.1F REFL CAPACITORS ARE 0402 PACKAGE SIZE 219210 F08b Figure 8b. Alternative REFH/REFL Bypass Circuit LTC2192 VREF 1.25V 5 2.2F 1.25V BANDGAP REFERENCE 0.625V TIE TO VDD FOR 2V RANGE; TIE TO GND FOR 1V RANGE; RANGE = 1.6 * VSENSE FOR 0.625V < VSENSE < 1.300V 219210 F08c Figure 8c. Recommended Layout for the REFH/REFL Bypass Circuit in Figure 8a RANGE DETECT AND CONTROL SENSE BUFFER INTERNAL ADC HIGH REFERENCE C2 0.1F + REFH - REFL - + REFH + - REFL - + C1 C3 0.1F C1: 2.2F LOW INDUCTANCE INTERDIGITATED CAPACITOR TDK CLLE1AX7S0G225M MURATA LLA219C70G225M AVX W2L14Z225M OR EQUIVALENT 219210 F08d Figure 8d. Recommended Layout for the REFH/REFL Bypass Circuit in Figure 8b 0.8x DIFF AMP VREF INTERNAL ADC LOW REFERENCE Figure 8a. Reference Circuit 2.2F 219210 F08a 1.25V EXTERNAL REFERENCE LTC2192 SENSE 1F 219210 F09 Figure 9. Using an External 1.25V Reference 219210f 19 LTC2192 LTC2191/LTC2190 APPLICATIONS INFORMATION Encode Input The signal quality of the encode inputs strongly affects the A/D noise performance. The encode inputs should be treated as analog signals--do not route them next to digital traces on the circuit board. There are two modes of operation for the encode inputs: the differential encode mode (Figure 10), and the single-ended encode mode (Figure 11). The differential encode mode is recommended for sinusoidal, PECL, or LVDS encode inputs (Figures 12, 13). The encode inputs are internally biased to 1.2V through 10k equivalent resistance. The encode inputs can be taken above VDD (up to 3.6V), and the common mode range is from 1.1V to 1.6V. In the differential encode mode, ENC- should stay at least 200mV above ground to avoid falsely triggering the single-ended encode mode. For good jitter performance ENC+ should have fast rise and fall times. The single-ended encode mode should be used with CMOS encode inputs. To select this mode, ENC- is connected to ground and ENC+ is driven with a square wave LTC2192 VDD encode input. ENC+ can be taken above VDD (up to 3.6V) so 1.8V to 3.3V CMOS logic levels can be used. The ENC+ threshold is 0.9V. For good jitter performance ENC+ should have fast rise and fall times. If the encode signal is turned off or drops below approximately 500kHz, the A/D enters nap mode. 0.1F ENC+ T1 50 100 0.1F 50 ENC- 0.1F T1 = MA/COM ETC1-1-13 RESISTORS AND CAPACITORS ARE 0402 PACKAGE SIZE 219210 F12 Figure 12. Sinusoidal Encode Drive 0.1F PECL OR LVDS CLOCK ENC+ LTC2192 0.1F ENC- DIFFERENTIAL COMPARATOR VDD LTC2192 219210 F13 Figure 13. PECL or LVDS Encode Drive 15k ENC+ Clock PLL and Duty Cycle Stabilizer ENC- 30k 219210 F10 Figure 10. Equivalent Encode Input Circuit for Differential Encode Mode LTC2192 1.8V TO 3.3V 0V ENC+ ENC- 30k The encode clock is multiplied by an internal phase-locked loop (PLL) to generate the serial digital output data. If the encode signal changes frequency or is turned off, the PLL requires 25s to lock onto the input clock. A clock duty cycle stabilizer circuit allows the duty cycle of the applied encode signal to vary from 30% to 70%. In the serial programming mode it is possible to disable the duty cycle stabilizer, but this is not recommended. In the parallel programming mode the duty cycle stabilizer is always enabled. CMOS LOGIC BUFFER 219210 F11 Figure 11. Equivalent Encode Input Circuit for Single-Ended Encode Mode 20 219210f LTC2192 LTC2191/LTC2190 APPLICATIONS INFORMATION DIGITAL OUTPUTS Optional LVDS Driver Internal Termination The digital outputs of the LTC2192/LTC2191/LTC2190 are serialized LVDS signals. Each channel outputs one bit at a time (1-lane mode), two bits at a time (2-lane mode) or four bits at a time (4-lane mode). Please refer to the Timing Diagrams for details. In 4-lane mode the clock duty cycle stabilizer must be enabled. In most cases using just an external 100 termination resistor will give excellent LVDS signal integrity. In addition, an optional internal 100 termination resistor can be enabled by serially programming mode control register A2. The internal termination helps absorb any reflections caused by imperfect termination at the receiver. When the internal termination is enabled, the output driver current is doubled to maintain the same output voltage swing. Internal termination can only be selected in serial programming mode. The output data should be latched on the rising and falling edges of the data clock out (DCO). A data frame output (FR) can be used to determine when the data from a new conversion result begins. The maximum serial data rate for the data outputs is 1Gbps, so the maximum sample rate of the ADC will depend on the serialization mode as well as the speed grade of the ADC (See Table 1). The minimum sample rate for all serialization modes is 5Msps. By default the outputs are standard LVDS levels: 3.5mA output current and a 1.25V output common mode voltage. An external 100 differential termination resistor is required for each LVDS output pair. The termination resistors should be located as close as possible to the LVDS receiver. The outputs are powered by OVDD and OGND which are isolated from the A/D core power and ground. Table 1. Maximum Sampling Frequency for All Serialization Modes. Note That These Limits are for the LTC2192. The Sampling Frequency for the Slower Speed Grades Cannot Exceed 40MHz (LTC2191) or 25MHz (LTC2190) MAXIMUM SAMPLING SERIALIZATION FREQUENCY, DCO FR SERIAL MODE fS (MHz) FREQUENCY FREQUENCY DATA RATE 4-Lane 65 2 * fS fS 4 * fS 2-Lane 65 4 * fS fS 8 * fS 1-Lane 62.5 8 * fS fS 16 * fS Programmable LVDS Output Current In LVDS mode, the default output driver current is 3.5mA. This current can be adjusted by control register A2 in the serial programming mode. Available current levels are 1.75mA, 2.1mA, 2.5mA, 3mA, 3.5mA, 4mA and 4.5mA. In the parallel programming mode the SDO pin can select either 3.5mA or 1.75mA. DATA FORMAT Table 2 shows the relationship between the analog input voltage and the digital data output bits. By default the output data format is offset binary. The 2's complement format can be selected by serially programming mode control register A1. Table 2. Output Codes vs Input Voltage AIN+-AIN- (2V RANGE) D15-D0 (OFFSET BINARY) D15-D0 (2' s COMPLEMENT) >1.000000V +0.999970V +0.999939V 1111 1111 1111 1111 1111 1111 1111 1111 1111 1111 1111 1110 0111 1111 1111 1111 0111 1111 1111 1111 0111 1111 1111 1110 +0.000030V +0.000000V -0.000030V -0.000061V 1000 0000 0000 0001 1000 0000 0000 0000 0111 1111 1111 1111 0111 1111 1111 1110 0000 0000 0000 0001 0000 0000 0000 0000 1111 1111 1111 1111 1111 1111 1111 1110 -0.999939V -1.000000V <-1.000000V 0000 0000 0000 0001 0000 0000 0000 0000 0000 0000 0000 0000 1000 0000 0000 0001 1000 0000 0000 0000 1000 0000 0000 0000 Digital Output Randomizer Interference from the A/D digital outputs is sometimes unavoidable. Digital interference may be from capacitive or inductive coupling or coupling through the ground plane. Even a tiny coupling factor can cause unwanted tones in the ADC output spectrum. By randomizing the digital output before it is transmitted off-chip, these unwanted tones can be randomized which reduces the unwanted tone amplitude. 219210f 21 LTC2192 LTC2191/LTC2190 APPLICATIONS INFORMATION The digital output is randomized by applying an exclusive OR logic operation between the LSB and all other data output bits. To decode, the reverse operation is applied--an exclusive OR operation is applied between the LSB and all other bits. The FR and DCO outputs are not affected. The output randomizer is enabled by serially programming mode control register A1. Digital Output Test Pattern To allow in-circuit testing of the digital interface to the A/D, there is a test mode that forces the A/D data outputs (D15-D0) of both channels to known values. The digital output test patterns are enabled by serially programming mode control registers A2, A3 and A4. When enabled, the test patterns override all other formatting modes: 2's complement and randomizer. Output Disable The digital outputs may be disabled by serially programming mode control register A2. The current drive for all digital outputs including DCO and FR are disabled to save power or enable in-circuit testing. When disabled the common mode of each output pair becomes high impedance, but the differential impedance may remain low. leaves nap mode. Nap mode is enabled by mode control register A1 in the serial programming mode. DEVICE PROGRAMMING MODES The operating modes of the LTC2192/LTC2191/LTC2190 can be programmed by either a parallel interface or a simple serial interface. The serial interface has more flexibility and can program all available modes. The parallel interface is more limited and can only program some of the more commonly used modes. Parallel Programming Mode To use the parallel programming mode, PAR/SER should be tied to VDD. The CS, SCK, SDI and SDO pins are binary logic inputs that set certain operating modes. These pins can be tied to VDD or ground, or driven by 1.8V, 2.5V or 3.3V CMOS logic. When used as an input, SDO should be driven through a 1k series resistor. Table 3 shows the modes set by CS, SCK, SDI and SDO. Table 3. Parallel Programming Mode Control Bits (PAR/SER = VDD) PIN CS/SCK Sleep and Nap Modes The A/D may be placed in sleep or nap modes to conserve power. In sleep mode the entire device is powered down, resulting in 1mW power consumption. Sleep mode is enabled by mode control register A1 (serial programming mode), or by SDI (parallel programming mode). The amount of time required to recover from sleep mode depends on the size of the bypass capacitors on VREF , REFH and REFL. For the suggested values in Figure 8, the A/D will stabilize after 2ms. In nap mode any combination of A/D channels can be powered down while the internal reference circuits and the PLL stay active, allowing faster wake up than from sleep mode. Recovering from nap mode requires at least 100 clock cycles. If the application demands very accurate DC settling then an additional 50s should be allowed so the on-chip references can settle from the slight temperature shift caused by the change in supply current as the A/D DESCRIPTION 2-Lane/4-Lane/1-Lane Selection Bits 00 = 2-Lane Output Mode 01 = 4-Lane Output Mode 10 = 1-Lane Output Mode 11 = Not Used SDI Power Down Control Bit 0 = Normal Operation 1 = Sleep Mode SDO LVDS Current Selection Bit 0 = 3.5mA LVDS Current Mode 1 = 1.75mA LVDS Current Mode Serial Programming Mode To use the serial programming mode, PAR/SER should be tied to ground. The CS, SCK, SDI and SDO pins become a serial interface that program the A/D mode control registers. Data is written to a register with a 16-bit serial word. Data can also be read back from a register to verify its contents. Serial data transfer starts when CS is taken low. The data on the SDI pin is latched at the first 16 rising edges of SCK. Any SCK rising edges after the first 16 are ignored. The data transfer ends when CS is taken high again. 219210f 22 LTC2192 LTC2191/LTC2190 APPLICATIONS INFORMATION The first bit of the 16-bit input word is the R/W bit. The next seven bits are the address of the register (A6:A0). The final eight bits are the register data (D7:D0). If the R/W bit is low, the serial data (D7:D0) will be written to the register set by the address bits (A6:A0). If the R/W bit is high, data in the register set by the address bits (A6:A0) will be read back on the SDO pin (see the Timing Diagrams). During a read back command the register is not updated and data on SDI is ignored. The SDO pin is an open-drain output that pulls to ground with a 200 impedance. If register data is read back through SDO, an external 2k pull-up resistor is required. If serial data is only written and read back is not needed, then SDO can be left floating and no pull-up resistor is needed. Table 4 shows a map of the mode control registers. Software Reset If serial programming is used, the mode control registers should be programmed as soon as possible after the power supplies turn on and are stable. The first serial command must be a software reset which will reset all register data bits to logic 0. To perform a software reset, bit D7 in the reset register is written with a logic 1. After the reset SPI write command is complete, bit D7 is automatically set back to zero. Table 4. Serial Programming Mode Register Map (PAR/SER = GND) REGISTER A0: RESET REGISTER (ADDRESS 00h) D7 D6 RESET X RESET Bit 7 D5 D4 D3 D2 D1 D0 X X X X X X Software Reset Bit 0 = Not Used 1 = Software Reset. All Mode Control Registers are Reset to 00h. The ADC is Momentarily Placed in Sleep Mode. This Bit is Automatically Set Back to Zero at the end of the SPI write command. The Reset register is write-only. Data read back from the Reset register will be random. Bits 6-0 Unused, Don't Care Bits. REGISTER A1: FORMAT AND POWER-DOWN REGISTER (ADDRESS 01h) D7 D6 D5 D4 D3 D2 D1 D0 DCSOFF RAND TWOSCOMP SLEEP NAP_2 X X NAP_1 Bit 7 Clock Duty Cycle Stabilizer Bit DCSOFF 0 = Clock Duty Cycle Stabilizer On 1 = Clock Duty Cycle Stabilizer Off. This is not recommended. Bit 6 RAND Data Output Randomizer Mode Control Bit 0 = Data Output Randomizer Mode Off 1 = Data Output Randomizer Mode On Bit 5 TWOSCOMP Two's Complement Mode Control Bit 0 = Offset Binary Data Format 1 = Two's Complement Data Format Bits 4, 3, 0 SLEEP:NAP_2:NAP_1 Sleep/Nap Mode Control Bits 000 = Normal Operation 0X1 = Channel 1 in Nap Mode 01X = Channel 2 in Nap Mode 1XX = Sleep Mode. Both Channels are Disabled. Note: Any Combination of Channels Can Be Placed in Nap Mode Bits 1, 2 Unused, Don't Care Bits 219210f 23 LTC2192 LTC2191/LTC2190 APPLICATIONS INFORMATION REGISTER A2: OUTPUT MODE REGISTER (ADDRESS 02h) D7 ILVDS2 D6 D5 D4 D3 D2 D1 D0 ILVDS1 ILVDS0 TERMON OUTOFF OUTTEST OUTMODE1 OUTMODE0 Bits 7-5 ILVDS2:ILVDS0 LVDS Output Current Bits 000 = 3.5mA LVDS Output Driver Current 001 = 4.0mA LVDS Output Driver Current 010 = 4.5mA LVDS Output Driver Current 011 = Not Used 100 = 3.0mA LVDS Output Driver Current 101 = 2.5mA LVDS Output Driver Current 110 = 2.1mA LVDS Output Driver Current 111 = 1.75mA LVDS Output Driver Current Bit 4 TERMON LVDS Internal Termination Bit 0 = Internal Termination Off 1 = Internal Termination On. LVDS Output Driver Current is 2x the Current Set by ILVDS2:ILVDS0 Bit 3 OUTOFF Output Disable Bit 0 = Digital Outputs are Enabled 1 = Digital Outputs are Disabled Bit 2 OUTTEST Digital Output Test Pattern Control Bit 0 = Digital Output Test Pattern Off 1 = Digital Output Test Pattern On Bits 1-0 OUTMODE1:OUTMODE0 00 = 2-Lane Output Mode 01 = 4-Lane Output Mode 10 = 1-Lane Output Mode 11 = Not Used Digital Output Mode Control Bits REGISTER A3: TEST PATTERN MSB REGISTER (ADDRESS 03h) D7 D6 D5 D4 D3 D2 D1 D0 TP15 TP14 TP13 TP12 TP11 TP10 TP9 TP8 Bits 7-0 TP15:TP8 Test Pattern Data Bits (MSB) TP15:TP8 Set the Test Pattern for Data Bit 15 (MSB) Through Data Bit 8. REGISTER A4: TEST PATTERN LSB REGISTER (ADDRESS 04h) D7 D6 D5 D4 D3 D2 D1 D0 TP7 TP6 TP5 TP4 TP3 TP2 TP1 TP0 Bits 7-0 TP7:TP0 Test Pattern Data Bits (LSB) TP7:TP0 Set the Test Pattern for Data Bit 7 Through Data Bit 0 (LSB). 219210f 24 LTC2192 LTC2191/LTC2190 APPLICATIONS INFORMATION GROUNDING AND BYPASSING The analog inputs, encode signals, and digital outputs should not be routed next to each other. Ground fill and grounded vias should be used as barriers to isolate these signals from each other. The LTC2192/LTC2191/LTC2190 require a printed circuit board with a clean unbroken ground plane. A multilayer board with an internal ground plane in the first layer beneath the ADC is recommended. Layout for the printed circuit board should ensure that digital and analog signal lines are separated as much as possible. In particular, care should be taken not to run any digital track alongside an analog signal track or underneath the ADC. HEAT TRANSFER Most of the heat generated by the LTC2192/LTC2191/ LTC2190 is transferred from the die through the bottomside exposed pad and package leads onto the printed circuit board. For good electrical and thermal performance, the exposed pad must be soldered to a large grounded pad on the PC board. This pad should be connected to the internal ground planes by an array of vias. High quality ceramic bypass capacitors should be used at the VDD, OVDD, VCM, VREF, REFH and REFL pins. Bypass capacitors must be located as close to the pins as possible. Size 0402 ceramic capacitors are recommended. The traces connecting the pins and bypass capacitors must be kept short and should be made as wide as possible. Of particular importance is the capacitor between REFH and REFL. This capacitor should be on the same side of the circuit board as the A/D, and as close to the device as possible. TYPICAL APPLICATIONS C4 2.2F SDO 42 43 41 OUT1B- OUT1B + OUT1A- 44 OUT1A+ 45 GND 46 SDO 47 GND 48 VREF 49 GND 50 SENSE VDD VDD FR- AIN2+ OUT2A+ AIN2- OUT2A- C7 0.1F ENCODE INPUT SPI PORT OUT2C+ OUT2B OUT2B- 34 OVDD 33 32 31 DIGITAL OUTPUTS C16 0.1F 30 29 28 27 26 OUT2C- 25 OUT2D + 24 VDD 23 VCM2 GND GND OUT2D- + SDI C37 0.1F PAR/SER 22 14 FR+ SCK 13 OGND REFL 21 12 REFH CS AIN2- 11 35 OVDD LTC2192 20 PAR/SER AIN2+ REFL ENC 9 10 36 - DCO REFH 37 + DCO 19 8 GND - 7 38 OUT1D- ENC 6 39 + OUT1C AIN1- 18 C2 0.1F + - - + CN1 + - - + 40 - OUT1D + C3 0.1F 5 OUT1C+ AIN1+ VDD AIN1- 4 GND 17 AIN1+ 3 VCM1 VDD 2 16 1 52 C5 0.1F 15 C29 0.1F 51 SENSE VDD 219210 TA02 219210f 25 LTC2192 LTC2191/LTC2190 TYPICAL APPLICATIONS Top Side Inner Layer 2 Inner Layer 3 Inner Layer 4 Inner Layer 5 Bottom Side 219210f 26 LTC2192 LTC2191/LTC2190 PACKAGE DESCRIPTION UKG Package 52-Lead Plastic QFN (7mm x 8mm) (Reference LTC DWG # 05-08-1729 Rev O) 7.50 0.05 6.10 0.05 5.50 REF (2 SIDES) 0.70 0.05 6.45 0.05 6.50 REF 7.10 0.05 8.50 0.05 (2 SIDES) 5.41 0.05 PACKAGE OUTLINE 0.25 0.05 0.50 BSC RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 7.00 0.10 (2 SIDES) 0.75 0.05 0.00 - 0.05 R = 0.115 TYP 5.50 REF (2 SIDES) 51 52 0.40 0.10 PIN 1 TOP MARK (SEE NOTE 6) 1 2 PIN 1 NOTCH R = 0.30 TYP OR 0.35 x 45C CHAMFER 8.00 0.10 (2 SIDES) 6.50 REF (2 SIDES) 6.45 0.10 5.41 0.10 R = 0.10 TYP TOP VIEW 0.200 REF 0.00 - 0.05 0.75 0.05 (UKG52) QFN REV O 0306 0.25 0.05 0.50 BSC BOTTOM VIEW--EXPOSED PAD SIDE VIEW NOTE: 1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.20mm ON ANY SIDE, IF PRESENT 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE 219210f Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 27 LTC2192 LTC2191/LTC2190 TYPICAL APPLICATION 1.8V OVDD S/H CH2 ANALOG INPUT S/H 16-BIT ADC CORE 16-BIT ADC CORE ENCODE INPUT DATA SERIALIZER PLL 0 OUT1A OUT1B OUT1C OUT1D OUT2A OUT2B OUT2C OUT2D DATA CLOCK OUT FRAME -10 -20 -30 SERIALIZED LVDS OUTPUTS OGND GND AMPLITUDE (dBFS) CH1 ANALOG INPUT 2-Tone FFT, fIN = 70MHz and 69MHz 1.8V VDD -40 -50 -60 -70 -80 -90 -100 -110 -120 219210 TA01a 0 20 10 FREQUENCY (MHz) 30 219210 G07 RELATED PARTS PART NUMBER ADCs LTC2259-14/LTC2260-14/ LTC2261-14 LTC2262-14 DESCRIPTION COMMENTS 14-Bit, 80Msps/105Msps/125Msps 1.8V ADCs, Ultralow Power 14-Bit, 150Msps 1.8V ADC, Ultralow Power LTC2266-14/LTC2267-14/ 14-Bit, 80Msps/105Msps/125Msps LTC2268-14 1.8V Dual ADCs, Ultralow Power LTC2266-12/LTC2267-12/ 12-Bit, 80Msps/105Msps/125Msps LTC2268-12 1.8V Dual ADCs, Ultralow Power LTC2208 16-Bit, 130Msps 3.3V ADC 89mW/106mW/127mW, 73.4dB SNR, 85dB SFDR, DDR LVDS/DDR CMOS/CMOS Outputs, 6mm x 6mm QFN-40 149mW, 72.8dB SNR, 88dB SFDR, DDR LVDS/DDR CMOS/CMOS Outputs, 6mm x 6mm QFN-40 216mW/250mW/293mW, 73.4dB SNR, 85dB SFDR, Serial LVDS Outputs, 6mm x 6mm QFN-40 216mW/250mW/293mW, 70.5dB SNR, 85dB SFDR, Serial LVDS Outputs, 6mm x 6mm QFN-40 LTC2207/LTC2206 16-Bit, 105Msps/80Msps 3.3V ADCs LTC2217/LTC2216 16-Bit, 105Msps/80Msps 3.3V ADCs 900mW/725mW, 77.9dB SNR, 100dB SFDR, CMOS Outputs, 7mm x 7mm QFN-48 1190mW/970mW, 81.2dB SNR, 100dB SFDR, CMOS/LVDS Outputs, 9mm x 9mm QFN-64 RF Mixers/Demodulators LTC5517 40MHz to 900MHz Direct Conversion Quadrature Demodulator LTC5527 400MHz to 3.7GHz High Linearity Downconverting Mixer LTC5557 400MHz to 3.8GHz High Linearity Downconverting Mixer LTC5575 800MHz to 2.7GHz Direct Conversion Quadrature Demodulator Amplifiers/Filters LTC6412 800MHz, 31dB Range, Analog-Controlled Variable Gain Amplifier LTC6420-20 1.8GHz Dual Low Noise, Low Distortion Differential ADC Drivers for 300MHz IF LTC6421-20 1.3GHz Dual Low Noise, Low Distortion Differential ADC Drivers LTC6605-7/LTC6605-10/ Dual Matched 7MHz/10MHz/14MHz LTC6605-14 Filters with ADC Drivers Signal Chain Receivers LTM9002 14-Bit Dual Channel IF/Baseband Receiver Subsystem 1250mW, 77.7dB SNR, 100dB SFDR, CMOS/LVDS Outputs, 9mm x 9mm QFN-64 High IIP3: 21dBm at 800MHz, Integrated LO Quadrature Generator 24.5dBm IIP3 at 900MHz, 23.5dBm IIP3 at 3.5GHz, NF = 12.5dB, 50 Single-Ended RF and LO Ports 23.7dBm IIP3 at 2.6GHz, 23.5dBm IIP3 at 3.5GHz, NF = 13.2dB, 3.3V Supply Operation, Integrated Transformer High IIP3: 28dBm at 900MHz, Integrated LO Quadrature Generator, Integrated RF and LO Transformer Continuously Adjustable Gain Control, 35dBm OIP3 at 240MHz, 10dB Noise Figure, 4mm x 4mm QFN-24 Fixed Gain 10V/V, 1nV/Hz Total Input Noise, 80mA Supply Current per Amplifier, 3mm x 4mm QFN-20 Fixed Gain 10V/V, 1nV/Hz Total Input Noise, 40mA Supply Current per Amplifier, 3mm x 4mm QFN-20 Dual Matched 2nd Order Lowpass Filters with Differential Drivers, Pin-Programmable Gain, 6mm x 3mm DFN-22 Integrated High Speed ADC, Passive Filters and Fixed Gain Differential Amplifiers 219210f 28 Linear Technology Corporation LT 0611 * PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 www.linear.com LINEAR TECHNOLOGY CORPORATION 2011