MAX1067CEEE

19-2955; Rev 1; 8/07 Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters General Description The MAX1067/MAX1068 low-power, multichannel, 14bit analog-to-digital converters (ADCs) feature a successive-approximation ADC, integrated +4.096V reference, a reference buffer, an internal oscillator, automatic power-down, and a high-speed SPI™/ QSPI™/MICROWIRE™-compatible interface. The MAX1067/MAX1068 operate with a single +5V analog supply and feature a separate digital supply, allowing direct interfacing with +2.7V to +5.5V digital logic. The MAX1067/MAX1068 consume only 3.6mA (AVDD = DVDD = +5V) at 200ksps when using an external reference. AutoShutdown™ reduces the supply current to 185µA at 10ksps and to less than 10µA at reduced sampling rates. The MAX1067 includes a 4-channel input multiplexer, and the MAX1068 accepts up to eight analog inputs. In addition, digital signal processor (DSP)-initiated conversions are simplified with the DSP frame-sync input and output featured in the MAX1068. The MAX1068 includes a data-bit transfer input to select between 8-bit-wide or 16bit-wide data-transfer modes. Both devices feature a scan mode that converts each channel sequentially or one channel continuously. Excellent dynamic performance and low power, combined with ease of use and an integrated reference, make the MAX1067/MAX1068 ideal for control and dataacquisition operations or for other applications with demanding power consumption and space requirements. The MAX1067 is available in a 16-pin QSOP package, and the MAX1068 is available in a 24-pin QSOP package. Both devices are guaranteed over the commercial (0°C to +70°C) and extended (-40°C to +85°C) temperature ranges. Use the MAX1168 evaluation kit to evaluate the MAX1068. ♦ 14-Bit Resolution, ±0.5 LSB INL and ±1 LSB DNL (max) ♦ +5V Single-Supply Operation ♦ Adjustable Logic Level (+2.7V to +5.25V) ♦ Input Voltage Range: 0 to VREF ♦ Internal (+4.096V) or External (+3.8V to AVDD) Reference ♦ Internal Track/Hold, 4MHz Input Bandwidth ♦ Internal or External Clock ♦ SPI/QSPI/MICROWIRE-Compatible Serial Interface, MAX1068 Performs DSP-Initiated Conversions ♦ 8-Bit-Wide or 16-Bit-Wide Data-Transfer Mode (MAX1068 Only) ♦ 4-Channel (MAX1067) or 8-Channel (MAX1068) Input Mux Scan Mode Sequentially Converts Multiple Channels or One Channel Continuously ♦ Low Power 3.6mA at 200ksps 1.85mA at 100ksps 185µA at 10ksps 0.6µA in Full Power-Down Mode ♦ Small Package Size 16-Pin QSOP (MAX1067) 24-Pin QSOP (MAX1068) Features MAX1067/MAX1068 Applications Motor Control Industrial Process Control Industrial I/O Modules Data-Acquisition Systems Thermocouple Measurements Accelerometer Measurements PART MAX1067ACEE MAX1067BCEE MAX1067CCEE MAX1067AEEE MAX1067BEEE MAX1067CEEE Ordering Information TEMP RANGE 0°C to +70°C 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C -40°C to +85°C PINPACKAGE 16 QSOP 16 QSOP 16 QSOP 16 QSOP 16 QSOP 16 QSOP INL (LSB) ±0.5 ±1 ±2 ±0.5 ±1 ±2 Ordering Information continued at end of data sheet. SPI/QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp. AutoShutdown is a trademark of Maxim Integrated Products, Inc. ________________________________________________________________ Maxim Integrated Products 1 Pin Configurations appear at end of data sheet. For pricing delivery, and ordering information please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters MAX1067/MAX1068 ABSOLUTE MAXIMUM RATINGS AVDD to AGND .........................................................-0.3V to +6V DVDD to DGND.........................................................-0.3V to +6V DGND to AGND.....................................................-0.3V to +0.3V AIN_, REF, REFCAP to AGND..................-0.3V to (AVDD + 0.3V) SCLK, CS, DSEL, DSPR, DIN to DGND ...................-0.3V to +6V DOUT, DSPX, EOC to DGND...................-0.3V to (DVDD + 0.3V) Maximum Current into Any Pin............................................50mA Continuous Power Dissipation (TA = +70°C) 16-Pin QSOP (derate 8.3mW/°C above +70°C)...........667mW 24-Pin QSOP (derate 9.5mW/°C above +70°C)...........762mW Operating Temperature Ranges MAX106_ _ CE_ ..................................................0°C to +70°C MAX106_ _ EE_ ...............................................-40°C to +85°C Maximum Junction Temperature .....................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (AVDD = DVDD = +4.75V to +5.25V, fSCLK = 4.8MHz external clock (50% duty cycle), 24 clocks/conversion (200ksps), external VREF = +4.096V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER DC ACCURACY (Note 1) Resolution MAX106_A Relative Accuracy (Note 2) INL MAX106_B MAX106_C MAX106_A Differential Nonlinearity DNL No missing codes over temperature MAX106_B MAX106_C Transition Noise Offset Error Gain Error Offset Drift Gain Drift Signal-to-Noise Plus Distortion Signal-to-Noise Ratio Total Harmonic Distortion Spurious-Free Dynamic Range Full-Power Bandwidth Full-Linear Bandwidth Channel-to-Channel Isolation CONVERSION RATE Conversion Time tCONV Internal clock, no data transfer, single conversion (Note 5) External clock 5.52 3.75 7.07 µs SINAD SNR THD SFDR -3dB point SINAD > 81dB (Note 4) 86 (Note 3) 81 82 DYNAMIC SPECIFICATIONS (1kHz sine wave, 4.096VP-P) (Note 1) 84 84 -98 99 4 10 85 -86 dB dB dB dB MHz kHz dB (Note 3) RMS noise External reference Internal reference 0.33 0.35 ±0.1 ±0.01 1 ±1.2 ±10 ±0.2 14 ±0.5 ±1.0 ±1.5 ±1 ±2 ±3 ±1 +1.5 -1.0 +1.5 -1.0 LSBRMS mV %FSR ppm/°C ppm/°C LSB LSB Bits SYMBOL CONDITIONS MIN TYP MAX UNITS 2 _______________________________________________________________________________________ Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters ELECTRICAL CHARACTERISTICS (continued) (AVDD = DVDD = +4.75V to +5.25V, fSCLK = 4.8MHz external clock (50% duty cycle), 24 clocks/conversion (200ksps), external VREF = +4.096V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER Acquisition Time Serial Clock Frequency Internal Clock Frequency Aperture Delay Aperture Jitter SYMBOL tACQ fSCLK fINTCLK tAD tAJ 8-bit-wide data-transfer mode 16-bit-wide data-transfer mode Internal clock, single conversion, 8-bit-wide data-transfer mode Sample Rate (Note 7) fS Internal clock, single conversion, 16-bitwide data-transfer mode Internal clock, scan mode, 8-bit-wide datatransfer mode (four conversions) External clock, scan mode, 16-bit-wide data-transfer mode (four conversions) Duty Cycle ANALOG INPUT (AIN_) Input Range Input Capacitance EXTERNAL REFERENCE Input Voltage Range Input Current INTERNAL REFERENCE Reference Voltage Reference Short-Circuit Current Reference Temperature Coefficient Reference Wake-Up Time tRWAKE VREF = 0 VREFIN IREFSC 4.042 4.096 13 ±25 5 4.136 V mA ppm/°C ms VREF IREF (Note 8) VAIN_ = 0 SCLK idle CS = DVDD, SCLK idle 3.8 34 0.1 0.1 µA AVDD – 0.2 V VAIN_ CAIN_ 0 45 VREF V pF 45 4.17 3.125 89 68 103 82 55 % ksps (Note 6) External clock, data transfer and conversion External clock, data transfer only Internal clock 3.2 4.0 15 10MHz) that can drive the ADC’s input capacitance and settle quickly. Input Bandwidth The ADC’s input-tracking circuitry has a 4MHz smallsignal bandwidth, making possible the digitization of high-speed transient events and the measurement of periodic signals with bandwidths exceeding the ADC’s sampling rate by using undersampling techniques. To avoid aliasing of unwanted, high-frequency signals into the frequency band of interest, use anti-alias filtering. Analog Input Protection Internal protection diodes, which clamp the analog input to AVDD or AGND, allow the input to swing from (AGND - 0.3V) to (AVDD + 0.3V) without damaging the device. If the analog input exceeds 300mV beyond the supplies, limit the input current to 10mA. ______________________________________________________________________________________ 13 Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters MAX1067/MAX1068 AIN0 AIN1 AIN2 AIN3 DIN REF 1µF +5V 0.1µF +5V 0.1µF GND GND CS SCLK DOUT EOC MAX1067 AGND AGND DGND REFCAP CS SCLK DOUT EOC ANALOG INPUTS ANALOG INPUTS DIN AIN0 AIN1 AIN2 AIN3 AIN4 AIN5 AIN6 AIN7 DIN DSEL DSPR REF AVDD 0.1µF MAX1068 CS SCLK DSPX DOUT EOC CS SCLK DSPX DOUT EOC DIN 16 8 1µF +5V AVDD DVDD 0.1µF AGND AGND DGND REFCAP 0.1µF +5V 0.1µF DVDD Figure 5. MAX1067 Typical Operating Circuit Figure 6. MAX1068 Typical Operating Circuit MUX RDSON AIN_ CMUX HOLD CSWITCH TRACK REF CAPACITIVE DAC ZERO CDAC AGND HOLD TRACK RIN In addition to the standard 3-wire serial interface modes, the MAX1068 includes a DSPR input and a DSPX output for communicating with DSPs in external clock mode and a DSEL input to determine 8-bit-wide or 16-bit-wide data-transfer mode. When not using the MAX1068 in the DSP interface mode, connect DSPR to DVDD and leave DSPX unconnected. Command/Configuration/Control Register AUTO-ZERO RAIL Figure 7. Equivalent Input Circuit Digital Interface The MAX1067/MAX1068 feature an SPI/QSPI/ MICROWIRE-compatible 3-wire serial interface. The MAX1067 digital interface consists of digital inputs CS, SCLK, and DIN; and outputs DOUT and E OC . The MAX1067 operates in the following modes: • SPI interface with external clock • SPI interface with internal clock • SPI interface with internal clock and scan mode Table 1 shows the contents of the command/configuration/control register and the state of each bit after initial power-up. Tables 2–6 define the control and configuration of the device for each bit. Cycling the power supplies resets the command/configuration/control register to the power-on-reset default state. Initialization After Power-Up A logic high on CS places the MAX1067/MAX1068 in the shutdown mode chosen by the power-down bits, and places DOUT in a high-impedance state. Drive CS low to power-up and enable the MAX1067/MAX1068 before starting a conversion. In internal reference mode, allow 5ms for the shutdown internal reference and/or buffer to wake and stabilize before starting a conversion. In external reference mode (or if the internal reference is already on), no reference settling time is needed after power-up. Table 1. Command/Configuration/Control Register COMMAND POWER-UP STATE BIT7 (MSB) CH SEL2 0 BIT6 CH SEL1 0 BIT5 CH SEL0 0 BIT4 SCAN1 0 BIT3 SCAN0 0 BIT2 REF/PD_SEL1 1 BIT1 REF/PD SEL0 1 BIT0 (LSB) INT/EXT CLK 0 14 ______________________________________________________________________________________ Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters MAX1067/MAX1068 Table 2. Channel Select BIT7 CH SEL2 0 0 0 0 1 1 1 1 BIT6 CH SEL1 0 0 1 1 0 0 1 1 BIT5 CH SEL0 0 1 0 1 0 1 0 1 CHANNEL AIN_ 0 1 2 3 4 5 6 7 Table 3. MAX1067 Scan Mode, Internal Clock Only ACTION Single channel, no scan Sequentially scan channels 0 through N (N ≤ 3) Sequentially scan channels 2 through N (2 ≤ N ≤ 3) Scan channel N 4 times BIT4 SCAN1 0 0 1 1 BIT3 SCAN0 0 1 0 1 Table 4. MAX1068 Scan Mode, Internal Clock Only (Not for DSP Mode) ACTION Single channel, no scan Sequentially scan channels 0 through N (N ≤ 7) Sequentially scan channels 4 through N (4 ≤ N ≤ 7) Scan channel N 8 times BIT4 SCAN1 0 0 1 1 BIT3 SCAN0 0 1 0 1 Table 5. Power-Down Modes BIT2 REF/PD_ SEL1 0 0 1 1 BIT1 REF/PD SEL0 0 1 0 1 REFERENCE REFERENCE MODE (INTERNAL REFERENCE) Internal reference and reference buffer stay on between conversions Internal reference and reference buffer off between conversions Internal reference on, reference buffer off between conversions Internal reference and buffer always off TYPICAL SUPPLY CURRENT 1mA 0.6µA 0.43mA 0.6µA TYPICAL WAKEUP TIME (CREF = 1µF) NA 5ms 5ms NA Internal Internal Internal External Table 6. Clock Modes BIT0 INT/EXT CLK 0 1 CLOCK MODE External clock Internal clock ______________________________________________________________________________________ 15 Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters MAX1067/MAX1068 tCSW CS tCSS tCL SCLK tDS tDH DIN ••• tCH ••• ••• tCP tCSH tDO tDV DOUT ••• tTR Figure 8. Detailed SPI Interface Timing CS COMPLETE CONVERSION SEQUENCE DOUT CONVERSION 0 POWERED UP POWERED DOWN CONVERSION 1 POWERED UP ence and buffer wake up on the falling edge of CS when in SPI/QSPI/MICROWIRE mode and on the falling edge of DSPR when in DSP mode. Allow 5ms for the internal reference to rise and settle when powering up from a complete shutdown (VREF = 0, CREF = 1µF). The internal reference stays on and the buffer is shut off on the rising edge of CS when bit 2 = 1 and bit 1 = 0. The MAX1067/MAX1068 enter this mode on the rising edge of CS. The buffer wakes up on the falling edge of CS when in SPI/QSPI/MICROWIRE mode and on the falling edge of DSPR when in DSP mode. Allow 5ms for VREF to settle when powering up from a complete shutdown (VREF = 0, CREF = 1µF). VREFCAP is always equal to +4.096V in this mode. Set both bit 2 and bit 1 to 1 to turn off the reference and reference buffer to allow connection of an external reference. Using an external reference requires no extra wake-up time. Figure 9. Shutdown Sequence Power-Down Modes Table 5 shows the MAX1067/MAX1068 power-down modes. Three internal reference modes and one external reference mode are available. Select power-down modes by writing to bits 2 and 1 in the command/configuration/control register. The MAX1067/MAX1068 enter the selected power-down mode on the rising edge of CS. The internal reference stays on when CS is pulled high, if bits 2 and 1 are set to zero. This mode allows for the fastest turn-on time. Setting bit 2 = 0 and bit 1 = 1 turns both the reference and reference buffer off when CS is brought high. This mode achieves the lowest supply current. The refer- Operating Modes External Clock 8-Bit-Wide Data-Transfer Mode (MAX1067 and MAX1068) Force DSPR high and DSEL low (MAX1068) for SPI/ QSPI/MICROWIRE-interface mode. The falling edge of CS wakes the analog circuitry and allows SCLK to clock in data. Ensure the duty cycle on SCLK is between 45% and 55% when operating at 4.8MHz (the maximum clock frequency). For lower clock frequencies, ensure the 16 ______________________________________________________________________________________ Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters MAX1067/MAX1068 CS 1 SCLK MSB LSB 0 MSB LSB S1 S0 8 16 24 DIN DOUT DSPR* DSEL* ADC STATE *MAX1068 ONLY tACQ tCONV IDLE Figure 10. SPI External Clock Mode, 8-Bit Data-Transfer Mode, Conversion Timing minimum high and low times are at least 93ns. External clock-mode conversions with SCLK rates less than 125kHz can reduce accuracy due to leakage of the sampling capacitor. DOUT changes from high-Z to logic low after CS is brought low. Input data latches on the rising edge of SCLK. The first SCLK rising edge begins loading data into the command/configuration/control register from DIN. The devices select the proper channel for conversion on the rising edge of the 3rd SCLK cycle. Acquisition begins immediately thereafter and ends on the falling edge of the 6th clock cycle. The MAX1067/MAX1068 sample the input and begin conversion on the falling edge of the 6th clock cycle. Setup and configuration of the MAX1067/MAX1068 complete on the rising edge of the 8th clock cycle. The conversion result is available (MSB first) at DOUT on the falling edge of the 8th SCLK cycle. To read the entire conversion result, 16 SCLK cycles are needed. Extra clock pulses, occurring after the conversion result has been clocked out and prior to the rising edge of CS, cause zeros to be clocked out of DOUT. The MAX1067/MAX1068 external clock 8-bit-wide data-transfer mode requires 24 SCLK cycles for completion (Figure 10). Force CS high after the conversion result is read. For maximum throughput, force CS low again to initiate the next conversion immediately after the specified minimum time (tCSW). Forcing CS high in the middle of a conversion immediately aborts the conversion and places the MAX1067/MAX1068 in shutdown. External Clock 16-Bit-Wide Data-Transfer Mode (MAX1068 Only) Force DSPR high and DSEL high for SPI/QSPI/ MICROWIRE-interface mode. Logic high at DSEL allows the MAX1068 to transfer data in 16-bit-wide words. The acquisition time is extended an extra eight SCLK cycles in the 16-bit-wide data-transfer mode. The falling edge of CS wakes the analog circuitry and allows SCLK to clock in data. Ensure the duty cycle on SCLK is between 45% and 55% when operating at 4.8MHz (the maximum clock frequency). For lower clock frequencies, ensure that the minimum high and low times are at least 93ns. External-clock-mode conversions with SCLK rates less than 125kHz can reduce accuracy due to leakage of the sampling capacitor. DOUT changes from high-Z to logic low after CS is brought low. Input data latches on the rising edge of SCLK. The first SCLK rising edge begins loading data into the command/configuration/control register from DIN. The devices select the proper channel for conversion and begin acquisition on the rising edge of the 3rd SCLK cycle. Setup and configuration of the MAX1068 completes on the rising edge of the 8th clock cycle. Acquisition ends on the falling edge of the 14th SCLK cycle. The MAX1068 samples the input and begins conversion on the falling edge of the 14th clock cycle. The conversion result is available (MSB first) at DOUT on the falling edge of the 16th SCLK cycle. To read the entire conversion result, 16 SCLK cycles are needed. Extra clock pulses, occurring after the conversion result has been clocked out and 17 ______________________________________________________________________________________ Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters MAX1067/MAX1068 CS 1 SCLK MSB DIN DOUT DSPR DSEL ADC STATE tACQ tCONV IDLE LSB 0X X X X X X X X MSB LSB S1 S0 8 16 24 32 , X = DON T CARE Figure 11. SPI External Clock Mode, 16-Bit Data-Transfer Mode, Conversion Timing (MAX1068 Only) CS 1 SCLK INTERNAL CLK MSB LSB 1 MSB LSB S1 S0 X 8 2 6 ••• 9 16 24 25 DIN DOUT EOC ADC STATE , X = DON T CARE DSPR = DVDD, DSEL = GND (MAX1068 ONLY) tACQ tCONV IDLE POWER-DOWN Figure 12. SPI Internal Clock Mode, 8-Bit Data-Transfer Mode, Conversion Timing prior to the rising edge of C S , cause zeros to be clocked out of DOUT. The MAX1068 external clock 16bit-wide data-transfer mode requires 32 SCLK cycles for completion (Figure 11). Force CS high after the conversion result is read. For maximum throughput, force CS low again to initiate the next conversion immediately after the specified minimum time (tCSW). Forcing CS high in the middle of a conversion immediately aborts the conversion and places the MAX1068 in shutdown. Internal Clock 8-Bit-Wide Data-Transfer and Scan Mode (MAX1067 and MAX1068) Force DSPR high and DSEL low (MAX1068) for the SPI/ QSPI/MICROWIRE-interface mode. The falling edge of CS wakes the analog circuitry and allows SCLK to clock in data (Figure 12). DOUT changes from high-Z 18 to logic low after CS is brought low. Input data latches on the rising edge of SCLK. The command/configuration/control register begins reading DIN on the first SCLK rising edge and ends on the rising edge of the 8th SCLK cycle. The MAX1067/MAX1068 select the proper channel for conversion on the rising edge of the 3rd SCLK cycle. The internal oscillator activates 125ns after the rising edge of the 8th SCLK cycle. Turn off the external clock while the internal clock is on. Turning off SCLK ensures the lowest noise performance during acquisition. Acquisition begins on the 2nd rising edge of the internal clock and ends on the falling edge of the 6th internal clock cycle. Each bit of the conversion result shifts into memory as it becomes available. The conversion result is available (MSB first) at DOUT on the falling edge of EOC. The internal oscillator and analog circuitry are shut down on the high-to-low EOC tran- ______________________________________________________________________________________ Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters MAX1067/MAX1068 CS 1 SCLK INTERNAL CLK DIN DOUT EOC ADC STATE DATA XXXXXXXX MSB LSB S1 S0 X ••• 8 9 ••• 16 2 ••• 17 13 ••• 24 32 32 CONFIGURATION , X = DON T CARE DSPR = DSEL = DVDD tACQ tCONV POWER-DOWN Figure 13. SPI Internal Clock Mode,16-Bit Data-Transfer Mode, Conversion Timing (MAX1068 Only) CS 1 SCLK INTERNAL CLK MSB LSB 1 MSB LSB ••• S1 S0 X 8 2 6 ••• 9 ••• 40 24 26 30 ••• 48 DIN DOUT EOC ADC STATE CONFIGURATION , X = DON T CARE DSPR = DVDD, DSEL = GND (MAX1068 ONLY) tACQ tCONV tACQ tCONV POWER-DOWN Figure 14. SPI Internal Clock Mode, 8-Bit Data-Transfer Mode, Scan Mode for Two Conversions, Conversion Timing sition. Use the EOC high-to-low transition as the signal to restart the external clock (SCLK). To read the entire conversion result, 16 SCLK cycles are needed. Extra clock pulses, occurring after the conversion result has been clocked out and prior to the rising edge of CS, cause the conversion result to be shifted out again. The MAX1067/MAX1068 internal clock 8-bit-wide datatransfer mode requires 24 external clock cycles and 25 internal clock cycles for completion. Force CS high after the conversion result is read. For maximum throughput, force CS low again to initiate the next conversion immediately after the specified minimum time (tCSW). Forcing CS high in the middle of a conversion immediately aborts the conversion and places the MAX1067/MAX1068 in shutdown. Scan mode allows multiple channels to be scanned consecutively or one channel to be scanned eight times. Scan mode can only be enabled when using the MAX1067/MAX1068 in the internal clock mode. Enable scanning by setting bits 4 and 3 in the command/configuration/control register (see Tables 3 and 4). In scan mode, conversion results are stored in memory until the completion of the last conversion in the sequence. Upon completion of the last conversion in the sequence, EOC transitions from high to low to indicate the end of the conversion and shuts down the internal oscillator. Use the EOC high-to-low transition as the signal to restart the external clock (SCLK). DOUT provides the conversion results in the same order as the channel conversion process. The MSB of the first conversion is available at DOUT on the falling edge of EOC (Figure 14). 19 ______________________________________________________________________________________ Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters Internal Clock 16-Bit-Wide Data-Transfer and Scan Mode (MAX1068 Only) Force DSPR high and DSEL low for the SPI/QSPI/ MICROWIRE-interface mode. The falling edge of CS wakes the analog circuitry and allows SCLK to clock in data (see Figure 13). DOUT changes from high-Z to logic low after CS is brought low. Input data latches on the rising edge of SCLK. The command/configuration/control register begins reading DIN on the first SCLK rising edge and ends on the rising edge of the 8th SCLK cycle. The MAX1068 selects the proper channel for conversion on the rising edge of the 3rd SCLK cycle. The internal oscillator activates 125ns after the rising edge of the 16th SCLK cycle. Turn off the external clock while the internal clock is on. Turning off SCLK ensures lowest noise performance during acquisition. Acquisition begins on the 2nd rising edge of the internal clock and ends on the falling edge of the 18th internal clock cycle. Each bit of the conversion result shifts into memory as it becomes available. The conversion result is available (MSB first) at DOUT on the falling edge of EOC. The internal oscillator and analog circuitry are shut down on the EOC high-to-low transition. Use the EOC high-to-low transition as the signal to restart the external clock (SCLK). To read the entire conversion result, 16 SCLK cycles are needed. Extra clock pulses, occurring after the conversion result has been clocked out and prior to the rising edge of CS, cause MAX1067/MAX1068 the conversion result to be shifted out again. The MAX1068 internal-clock 16-bit-wide data-transfer mode requires 32 external clock cycles and 32 internal clock cycles for completion. Force CS high after the conversion result is read. For maximum throughput, force CS low again to initiate the next conversion immediately after the specified minimum time (tCSW). Forcing CS high in the middle of a conversion immediately aborts the conversion and places the MAX1068 in shutdown. Scan mode allows multiple channels to be scanned consecutively or one channel to be scanned eight times. Scan mode can only be enabled when using the MAX1068 in internal clock mode. Enable scanning by setting bits 4 and 3 in the command/configuration/control register (see Tables 3 and 4). In scan mode, conversion results are stored in memory until the completion of the last conversion in the sequence. Upon completion of the last conversion in the sequence, EOC transitions from high to low to indicate the end of the conversion and shuts down the internal oscillator. Use the EOC high-to-low transition as the signal to restart the external clock (SCLK). DOUT provides the conversion results in the same order as the channel conversion process. The MSB of the first conversion is available at DOUT on the falling edge of EOC. Figure 15 shows the timing diagram for 16-bit-wide data transfer in scan mode. CS 1 SCLK INTERNAL CLK DIN DOUT DATA XXXXXXXX MSB ••• LSB S1 S0 X ••• 8 9 ••• 16 2 ••• 17 ••• 48 13 ••• 32 34 ••• 45 ••• 64 EOC ADC STATE , X = DON T CARE tACQ tCONV tACQ tCONV POWER-DOWN Figure 15. SPI Internal Clock Mode, 16-Bit Data-Transfer Mode, Scan Mode for Two Conversions, Conversion Timing (MAX1068 Only) 20 ______________________________________________________________________________________ Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters DSP 8-Bit-Wide Data-Transfer Mode (External Clock Mode, MAX1068 Only) Figure 16 shows the DSP-interface timing diagram. Logic low at DSPR on the falling edge of CS enables DSP interface mode. After the MAX1068 enters DSP mode, CS can remain low for the duration of the conversion process and each subsequent conversion. Drive DSEL low to select the 8-bit data-transfer mode. A sync pulse from the DSP at DSPR wakes the analog circuitry and allows SCLK to clock in data (Figure 17). The frame sync pulse alerts the MAX1068 that incoming data is about to be sent to DIN. Ensure the duty cycle on SCLK is between 45% and 55% when operating at 4.8MHz (the maximum clock frequency). For lower clock frequencies, ensure the minimum high and low times are at least 93ns. External clock mode conversions with SCLK rates less than 125kHz can reduce accuracy due to leakage of the sampling capacitor. The input data latches on the falling edge of SCLK. The command/configuration/control register starts reading data in on the falling edge of the first SCLK cycle immediately following the falling edge of the frame sync pulse and ends on the falling edge of the 8th SCLK cycle. The MAX1068 selects the proper channel for conversion on the falling edge of the 3rd clock cycle and begins acquisition. Acquisition continues until the rising edge of the 7th clock cycle. The MAX1068 samples the input on the rising edge of the 7th clock cycle. On the rising edge of the 8th clock cycle, the MAX1068 outputs a frame sync pulse at DSPX. The frame sync pulse alerts the DSP that the conversion results are about to be output at DOUT (MSB first) starting on the rising edge of the 9th clock pulse. To read the entire conversion results, 16 SCLK cycles are needed. Extra clock pulses, occuring after the conversion result has been clocked out, and prior to the next rising edge of DSPR, cause zeros to be clocked out of DOUT. The MAX1068 external-clock, DSP 8-bit-wide data-transfer mode requires 24 clock cycles to complete. Begin a new conversion by sending a new frame sync pulse to DSPR followed by new configuration data. Send the new DSPR pulse immediately after reading the conversion result to realize maximum throughput. Sending a new frame sync pulse in the middle of a conversion immediately aborts the current conversion and begins a new one. A rising edge on CS in the middle of a conversion aborts the current conversion and places the MAX1068 in shutdown. DSP 16-Bit-Wide Data-Transfer Mode (External Clock Mode, MAX1068 Only) Figure 16 shows the DSP-interface timing diagram. Logic low at DSPR on the falling edge of CS enables DSP interface mode. After the MAX1068 enters DSP mode, CS can remain low for the duration of the conversion process and each subsequent conversion. The acquisition time is extended an extra eight SCLK cycles in the 16-bit-wide data-transfer mode. Drive DSEL high to select the 16-bit-wide data-transfer mode. A sync pulse from the DSP at DSPR wakes the analog circuitry and allows SCLK to clock in data (Figure 18). The frame sync pulse also alerts the MAX1068 that incoming data is about to be sent to DIN. Ensure the duty cycle on SCLK is between 45% and 55% when operating at MAX1067/MAX1068 tCSW CS tDF tFSS DSPR tFSH tCSS tCL SCLK tCP tDS tDH DIN tCH tCSH ... ... ... ... tDV tDO tTR DOUT ... Figure 16. Detailed DSP-Interface Timing (MAX1068 Only) ______________________________________________________________________________________ 21 Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters MAX1067/MAX1068 4.8MHz (the maximum clock frequency). For lower clock frequencies, ensure the minimum high and low times are at least 93ns. External-clock-mode conversions with SCLK rates less than 125kHz can reduce accuracy due to leakage of the sampling capacitor. The input data latches on the falling edge of SCLK. The command/configuration/control register starts reading data in on the falling edge of the first SCLK cycle immediately following the falling edge of the frame sync pulse and ends on the falling edge of the 16th SCLK cycle. The MAX1068 selects the proper channel for conversion on the falling edge of the 3rd clock cycle and begins acquisition. Acquisition continues until the rising edge of the 15th clock cycle. The MAX1068 samples the input on the rising edge of the 15th clock cycle. On the rising edge of the 16th clock cycle, the MAX1068 outputs a frame sync pulse at DSPX. The frame sync pulse alerts the DSP that the conversion results are about to be output at DOUT (MSB first) starting on the rising edge of the 17th clock pulse. To read the entire conversion result, 16 SCLK cycles are needed. Extra clock pulses, occuring after the conversion result has been clocked out and prior to the next rising edge of DSPR, cause zeros to be clocked out of DOUT. The MAX1068 external clock, DSP 16-bit-wide data-transfer mode requires 32 clock cycles to complete. Begin a new conversion by sending a new frame sync pulse to DSPR followed by new configuration data. Send the new DSPR pulse immediately after reading the conversion result to realize maximum throughput. Sending a new frame sync pulse in the middle of a conversion immediately aborts the current conversion and begins a new one. A rising edge on CS in the middle of a conversion aborts the current conversion and places the MAX1068 in shutdown. CS DSPR 1 SCLK MSB LSB 0 MSB LSB S1 S0 8 16 24 DIN DOUT DSPX ADC STATE tACQ tCONV IDLE Figure 17. DSP External Clock Mode, 8-Bit Data-Transfer Mode, Conversion Timing (MAX1068 Only) CS DSPR 1 SCLK MSB DIN DOUT DSPX ADC STATE LSB 0X X X X X X X X MSB LSB S1 S0 8 16 24 32 , X = DON T CARE tACQ tCONV IDLE Figure 18. DSP External Clock Mode, 16-Bit Data-Transfer Mode, Conversion Timing (MAX1068 Only) 22 ______________________________________________________________________________________ Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters Output Coding and Transfer Function The data output from the MAX1067/MAX1068 is straight binary. Figure 19 shows the nominal transfer function. Code transitions occur halfway between successive integer LSB values (V REF = +4.096V, and 1 LSB = +250µV or 4.096V / 16,384V). OUTPUT CODE 11...111 11...110 11...101 FULL-SCALE TRANSITION MAX1067/MAX1068 Applications Information Internal Reference The internal bandgap reference provides a buffered +4.096V. Bypass REFCAP with a 0.1µF capacitor to AGND and REF with a 1µF capacitor to AGND. For best results, use low-ESR, X5R/X7R ceramic capacitors. Allow 5ms for the reference and buffer to wake up from full power-down (see Table 5). 00...011 00...010 00...001 00...000 0 1 2 3 FS = VREF V 1 LSB = REF 16,384 External Reference The MAX1067/MAX1068 accept an external reference with a voltage range between +3.8V and AV DD . Connect the external reference directly to REF. Bypass REF to AGND with a 10µF capacitor. When not using a low-ESR bypass capacitor, use a 0.1µF ceramic capacitor in parallel with the 10µF capacitor. Noise on the reference degrades conversion accuracy. The input impedance at REF is 37kΩ for DC currents. During a conversion, the external reference at REF must deliver 118µA of DC load current and have an output impedance of 10Ω or less. For optimal performance, buffer the reference through an op amp and bypass the REF input. Consider the equivalent input noise (82µV RMS ) of the MAX1067/ MAX1068 when choosing a reference. FS FS - 3/2 LSB INPUT VOLTAGE (LSB) Figure 19. Unipolar Transfer Function, Full Scale (FS) = VREF, Zero Scale (ZS) = GND Input Buffer Most applications require an input-buffer amplifier to achieve 14-bit accuracy. The input amplifier must have a slew rate of at least 2V/µs and a unity-gain bandwidth of at least 10MHz to complete the required output-voltage change before the end of the acquisition time. At the beginning of the acquisition, the internal sampling capacitor array connects to AIN_ (the amplifier input), causing some disturbance on the output of the buffer. Ensure the sampled voltage has settled before the end of the acquisition time. Digital Noise Digital noise can couple to AIN_ and REF. The conversion clock (SCLK) and other digital signals active during input acquisition contribute noise to the conversion result. Noise signals, synchronous with the sampling interval, result in an effective input offset. Asynchronous signals produce random noise on the input, whose highfrequency components can be aliased into the frequency band of interest. Minimize noise by presenting a low impedance (at the frequencies contained in the noise signal) at the inputs. This requires bypassing AIN_ to AGND, or buffering the input with an amplifier that has a small-signal bandwidth of several megahertz (doing both is preferable). AIN has a typical bandwidth of 4MHz. Internal/External Oscillator Select either an external (0.1MHz to 4.8MHz) or the internal 4MHz (typ) clock to perform conversions (Table 6). The external clock shifts data in and out of the MAX1067/MAX1068 in either clock mode. When using the internal clock mode, the internal oscillator controls the acquisition and conversion processes, while the external oscillator shifts data in and out of the MAX1067/MAX1068. Turn off the external clock (SCLK) when the internal clock is on to realize lowest noise performance. The internal clock remains off in external clock mode. ______________________________________________________________________________________ 23 Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters MAX1067/MAX1068 Distortion Avoid degrading dynamic performance by choosing an amplifier with distortion much less than the total harmonic distortion of the MAX1067/MAX1068 at the frequencies of interest (THD = -98db at 1kHz). If the chosen amplifier has insufficient common-mode rejection, which results in degraded THD performance, use the inverting configuration (positive input grounded) to eliminate errors from this source. Low-temperature-coefficient, gain-setting resistors reduce linearity errors caused by resistance changes due to self-heating. To reduce linearity errors due to finite amplifier gain, use amplifier circuits with sufficient loop gain at the frequencies of interest.. DC Accuracy To improve DC accuracy, choose a buffer with an offset much less than the MAX1067/MAX1068s’ offset (±10mV max for +5V supply), or whose offset can be trimmed while maintaining stability over the required temperature range. Serial Interfaces SPI and MICROWIRE Interfaces When using the SPI (Figure 20a) or MICROWIRE (Figure 20b) interfaces, set CPOL = 0 and CPHA = 0. Drive CS low to power on the MAX1067/MAX1068 before starting a conversion (Figure 20c). Three consecutive 8-bit-wide readings are necessary to obtain the entire 14-bit result from the ADC. DOUT data transitions on the serial clock’s falling edge. The first 8-bit-wide data stream contains all leading zeros. The 2nd 8-bit-wide data stream contains the MSB through D6. The 3rd 8-bit-wide data stream contains D5 through D0 followed by S1 and S0. I/O SCK MISO SPI VDD CS SCLK DOUT MICROWIRE I/O SK SI CS SCLK DOUT SS MAX1067 MAX1068 MAX1067 MAX1068 Figure 20a. SPI Connections Figure 20b. MICROWIRE Connections 1ST BYTE READ SCLK CS 1 4 6 8 2ND BYTE READ 12 16 DOUT* 0 0 0 0 0 0 0 0 D13 MSB D12 D11 D10 D9 D8 D7 D6 D5 *WHEN CS IS HIGH, DOUT = HIGH-Z 3RD BYTE READ 20 24 HIGH-Z D5 D4 D3 D2 D1 D0 LSB S1 S0 Figure 20c. SPI/MICROWIRE Interface Timing Sequence (CPOL = CPHA = 0) 24 ______________________________________________________________________________________ Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters QSPI Interface Using the high-speed QSPI interface with CPOL = 0 and CPHA = 0, the MAX1067/MAX1068 support a maximum f SCLK of 4.8MHz. Figure 21a shows the MAX1067/MAX1068 connected to a QSPI master and Figure 21b shows the associated interface timing. PIC16 with SSP Module and PIC17 Interface The MAX1067/MAX1068 are compatible with a PIC16/ PIC17 controller (µC), using the synchronous serial-port (SSP) module. To establish SPI communication, connect the controller as shown in Figure 22a and configure the PIC16/PIC17 as system master by initializing its synchronous serialport control register (SSPCON) and synchronous serialport status register (SSPSTAT) to the bit patterns shown in Tables 7 and 8. In SPI mode, the PIC16/PIC17 µCs allow 8 bits of data to be synchronously transmitted and received simultaneously. Three consecutive 8-bit-wide readings (Figure 22b) are necessary to obtain the entire 14-bit result from the ADC. DOUT data transitions on the serial clock’s falling edge and is clocked into the µC on SCLK’s rising edge. The first 8-bit-wide data stream contains all zeros. The 2nd 8-bit-wide data stream contains the MSB through D6. The 3rd 8-bit-wide data stream contains bits D5 through D0 followed by S1 and S0. MAX1067/MAX1068 CS SCK MISO QSPI VDD CS SCLK DOUT MAX1067 MAX1068 SS Figure 21a. QSPI Connections SCLK CS DOUT* 1 4 6 8 12 16 20 24 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 S1 S0 HIGH-Z SAMPLING INSTANT *WHEN CS IS HIGH, DOUT = HIGH-Z MSB LSB Figure 21b. QSPI Interface Timing Sequence (External Clock, 8-Bit Data Transfer, CPOL = CPHA = 0) Table 7. Detailed SSPCON Register Contents CONTROL BIT WCOL SSPOV BIT7 BIT6 SETTINGS X X SYNCHRONOUS SERIAL-PORT CONTROL REGISTER (SSPCON) Write Collision Detection Bit Receive Overflow Detection Bit Synchronous Serial-Port Enable Bit: 0: Disables serial port and configures these pins as I/O port pins. 1: Enables serial port and configures SCK, SDO, and SCI pins as serial port pins. Clock Polarity Select Bit. CKP = 0 for SPI master-mode selection. Synchronous Serial-Port Mode Select Bit. Sets SPI master-mode and selects fCLK = fOSC / 16. SSPEN BIT5 1 CKP SSPM3 SSPM2 SSPM1 SSPM0 BIT4 BIT3 BIT2 BIT1 BIT0 0 0 0 0 1 X = Don’t care. ______________________________________________________________________________________ 25 Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters MAX1067/MAX1068 Table 8. Detailed SSPSTAT Register Contents CONTROL BIT SMP CKE D/A P S R/W UA BF BIT7 BIT6 BIT5 BIT4 BIT3 BIT2 BIT1 BIT0 SETTINGS 0 1 X X X X X X SYNCHRONOUS SERIAL-PORT STATUS REGISTER (SSPSTAT) SPI Data-Input Sample Phase. Input data is sampled at the middle of the data output time. SPI Clock Edge-Select Bit. Data is transmitted on the rising edge of the serial clock. Data Address Bit Stop Bit Start Bit Read/Write Bit Information Update Address Buffer-Full Status Bit X = Don’t care. DSP Interface VDD VDD SCLK DOUT CS SCK SDI I/O PIC16/17 MAX1067 MAX1068 GND Figure 22a. SPI Interface Connection for a PIC16/PIC17 The DSP mode of the MAX1068 only operates in external clock mode. Figure 23 shows a typical DSP interface connection to the MAX1068. Use the same oscillator as the DSP to provide the clock signal for the MAX1068. The DSP provides the falling edge at CS to wake the MAX1068. The MAX1068 detects the state of DSPR on the falling edge of CS (Figure 17). Logic low at DSPR places the MAX1068 in DSP mode. After the MAX1068 enters DSP mode, CS can be left low. A frame sync pulse from the DSP to DSPR initiates a conversion. The MAX1068 sends a frame sync pulse from DSPX to the DSP signaling that the MSB is available at DOUT. Send another frame sync pulse from the DSP to DSPR to begin the next conversion. The MAX1068 does not operate in scan mode when using DSP mode. 1ST BYTE READ SCLK CS 1 4 6 8 2ND BYTE READ 12 16 DOUT* 0 0 0 0 0 0 0 0 D13 MSB 3RD BYTE READ 20 D12 D11 D10 D9 D8 D7 D6 *WHEN CS IS HIGH, DOUT = HIGH-Z 24 HIGH-Z D5 D4 D3 D2 D1 D0 LSB S1 S0 Figure 22b. SPI Interface Timing with PIC16/PIC17 in Master Mode (CKE = 1, CKP = 0, SMP = 0, SSPM3 - SSPM0 = 0001) 26 ______________________________________________________________________________________ Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters MAX1067/MAX1068 EFFECTIVE NUMBER OF BITS (ENOB) EXTERNAL CLOCK 16 14 12 SCLK TFS RFS DSP DT DR FL1 SCLK DSPR DSPX DIN DOUT CS EFFECTIVE BITS MAX1068 10 8 6 4 2 0 0.1 1 10 100 FREQUENCY (kHz) fSAMPLE = 200ksps Figure 23. DSP Interface Connection Figure 24. Effective Bits vs. Frequency Definitions Integral Nonlinearity Integral nonlinearity (INL) is the deviation of the values on an actual transfer function from a straight line. This straight line can be either a best-straight-line fit or a line drawn between the end points of the transfer function, once offset and gain errors have been nullified. The static linearity parameters for the MAX1067/MAX1068 are measured using the end-point method. noise error only and results directly from the ADC’s resolution (N bits): SNR = (6.02 ✕ N + 1.76)dB In reality, there are other noise sources besides quantization noise: thermal noise, reference noise, clock jitter, etc. SNR is computed by taking the ratio of the RMS signal to the RMS noise, which includes all spectral components minus the fundamental, the first five harmonics, and the DC offset. Differential Nonlinearity Differential nonlinearity (DNL) is the difference between an actual step-width and the ideal value of ±1 LSB. A DNL error specification of ±1 LSB guarantees no missing codes and a monotonic transfer function. Signal-to-Noise Plus Distortion Signal-to-noise plus distortion (SINAD) is the ratio of the fundamental input frequency’s RMS amplitude to the RMS equivalent of all the other ADC output signals: SINAD (dB) = 20 ✕ log [SignalRMS / (Noise + Distortion)RMS] Aperture Definitions Aperture jitter (tAJ) is the sample-to-sample variation in the time between samples. Aperture delay (tAD) is the time between the falling edge of the sampling clock and the instant when the actual sample is taken. Effective Number of Bits Effective number of bits (ENOB) indicates the global accuracy of an ADC at a specific input frequency and sampling rate. An ideal ADC’s error consists of quantization noise only. With an input range equal to the fullscale range of the ADC, calculate the ENOB as follows: ENOB = (SINAD - 1.76) / 6.02 Figure 24 shows the ENOB as a function of the MAX1067/ MAX1068s’ input frequency. Signal-to-Noise Ratio For a waveform perfectly reconstructed from digital samples, signal-to-noise ratio (SNR) is the ratio of the full-scale analog input (RMS value) to the RMS quantization error (residual error). The ideal, theoretical minimum analog-to-digital noise is caused by quantization ______________________________________________________________________________________ 27 Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters MAX1067/MAX1068 Total Harmonic Distortion Total harmonic distortion (THD) is the ratio of the RMS sum of the first five harmonics of the input signal to the fundamental itself. This is expressed as: ⎡⎛ 2 2 2 2 ⎢ ⎝ V2 + V3 + V4 + V5 ⎞ ⎠ ⎢ THD = 20 × log V1 ⎢ ⎢ ⎣ ⎤ ⎥ ⎥ ⎥ ⎥ ⎦ AIN_ 1µF +5V 0.1µF 10Ω DVDD 0.1µF AGND AGND DGND AVDD MAX1067 MAX1068 AIN_ REF CS SCLK DOUT CS SCLK DOUT where V1 is the fundamental amplitude and V2 through V5 are the 2nd- through 5th-order harmonics. Spurious-Free Dynamic Range Spurious-free dynamic range (SFDR) is the ratio of the RMS amplitude of the fundamental (maximum signal component) to the RMS value of the next-largest frequency component. GND Supplies, Layout, Grounding, and Bypassing Use printed circuit (PC) boards with separate analog and digital ground planes. Do not use wire-wrap boards. Connect the two ground planes together at the MAX1067/MAX1068 AGND terminal. Isolate the digital supply from the analog with a low-value resistor (10Ω) or ferrite bead when the analog and digital supplies come from the same source (Figure 25). Constraints on sequencing the power supplies and inputs are as follows: • Apply AGND before DGND. • Apply AIN_ and REF after AV DD and AGND are present. • DVDD is independent of the supply sequencing. Ensure that digital return currents do not pass through the analog ground and that return-current paths are low Figure 25. Powering AVDD and DVDD from a Single Supply impedance. A 5mA current flowing through a PC board ground trace impedance of only 0.05Ω creates an error voltage of about 250µV and a 1 LSB error with a +4.096V full-scale system. The board layout should ensure that digital and analog signal lines are kept separate. Do not run analog and digital lines (especially the SCLK and DOUT) parallel to one another. If one must cross another, do so at right angles. The ADC’s high-speed comparator is sensitive to highfrequency noise on the AVDD power supply. Bypass an excessively noisy supply to the analog ground plane with a 0.1µF capacitor in parallel with a 1µF to 10µF low-ESR capacitor. Keep capacitor leads short for best supply-noise rejection. 28 ______________________________________________________________________________________ Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters Ordering Information (continued) PART MAX1068ACEG MAX1068BCEG MAX1068CCEG MAX1068AEEG* MAX1068BEEG* TEMP RANGE 0°C to +70°C 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C PINPACKAGE 24 QSOP 24 QSOP 24 QSOP 24 QSOP 24 QSOP INL (LSB) ±0.5 ±1 ±2 ±0.5 ±1 ±2 MAX1067/MAX1068 Chip Information TRANSISTOR COUNT: 20,760 PROCESS: BiCMOS MAX1068CEEG* -40°C to +85°C 24 QSOP *Future product—contact factory for availability. Pin Configurations TOP VIEW DOUT 1 SCLK 2 DIN 3 EOC 4 AIN0 5 AIN1 6 AIN2 7 AIN3 8 16 DVDD 15 DGND 14 CS DSPR 1 DSEL 2 DOUT 3 SCLK 4 DIN 5 EOC 6 AIN0 7 AIN1 8 AIN2 9 AIN3 10 AIN4 11 AIN5 12 24 N.C. 23 DSPX 22 DVDD 21 DGND MAX1067 13 AVDD 12 AGND 11 AGND 10 REFCAP 9 REF MAX1068 20 CS 19 AVDD 18 AGND 17 AGND 16 REFCAP 15 REF 14 AIN7 13 AIN6 QSOP QSOP ______________________________________________________________________________________ 29 Multichannel, 14-Bit, 200ksps Analog-to-Digital Converters MAX1067/MAX1068 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) QSOP.EPS PACKAGE OUTLINE, QSOP .150", .025" LEAD PITCH 21-0055 F 1 1 Revision History Pages changed at Rev 1: 1–6, 30 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 30 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.