MAX1108

19-1399; Rev 0; 10/98 Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs General Description The MAX1108/MAX1109 low-power, 8-bit, dual-channel, analog-to-digital converters (ADCs) feature an internal track/hold (T/H) voltage reference, clock, and serial interface. The MAX1108 is specified from +2.7V to +3.6V and consumes only 105µA. The MAX1109 is specified from +4.5V to +5.5V and consumes only 130µA. The analog inputs are software configurable, allowing unipolar/bipolar and single-ended/differential operation; battery monitoring capability is also included. The full-scale analog input range is determined by the internal reference of +2.048V (MAX1108) or +4.096V (MAX1109), or by an externally applied reference ranging from 1V to VDD. The MAX1108/MAX1109 also feature a software power-down mode that reduces power consumption to 0.5µA when the device is not in use. The 4-wire serial interface directly connects to SPI™, QSPI™, and MICROWIRE™ devices without external logic. Conversions up to 50ksps are performed using either the internal clock or an external serial-interface clock. The MAX1108 and MAX1109 are available in a 10-pin µMAX package with a footprint that is just 20% of an 8-pin plastic DIP. Features o Single Supply: +2.7V to +3.6V (MAX1108) +4.5V to +5.5V (MAX1109) o Low Power: 105µA at +3V and 50ksps 0.5µA in Power-Down Mode o Software-Configurable Unipolar or Bipolar Inputs o Input Voltage Range: 0 to VDD o Internal Track/Hold o Internal Reference: +2.048V (MAX1108) +4.096V (MAX1109) o Reference Input Range: 1V to VDD o SPI/QSPI/MICROWIRE-Compatible Serial Interface o VDD Monitoring Mode o Small 10-Pin µMAX Package MAX1108/MAX1109 Ordering Information PART MAX1108CUB MAX1108EUB MAX1109CUB MAX1109EUB TEMP. RANGE 0°C to +70°C -40°C to +85°C 0°C to +70°C -40°C to +85°C PIN-PACKAGE 10 µMAX 10 µMAX 10 µMAX 10 µMAX Applications Portable Data Logging Hand-Held Measurement Devices Medical Instruments System Diagnostics Solar-Powered Remote Systems 4–20mA-Powered Remote Systems Receive-Signal Strength Indicators Functional Diagram VDD CS SCLK INPUT SHIFT REGISTER OUTPUT SHIFT REGISTER Pin Configuration DIN DOUT TOP VIEW VDD 1 CH0 CH1 GND REF 2 3 4 5 10 SCLK 9 DOUT DIN CS COM REF MAX1108 MAX1109 CONTROL LOGIC CH0 CH1 COM ANALOG INPUT MUX INTERNAL REFERENCE T/H INTERNAL OSCILLATOR SAR MAX1108 MAX1109 8 7 6 CHARGE REDISTRIBUTION DAC µMAX GND SPI and QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp. ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs MAX1108/MAX1109 ABSOLUTE MAXIMUM RATINGS VDD to GND ..............................................................-0.3V to +6V CH0, CH1, COM, REF, DOUT to GND .......-0.3V to (VDD + 0.3V) DIN, SCLK, CS to GND ............................................-0.3V to +6V Continuous Power Dissipation (TA = +70°C) 10-pin µMAX (derate 5.6mW/°C above +70°C) ............444mW Operating Temperature Ranges MAX110_CUB ......................................................0°C to +70°C MAX110_EUB ...................................................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10sec) .............................+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—MAX1108 (VDD = +2.7V to +3.6V; unipolar input mode; COM = GND, fSCLK = 500kHz, external clock mode (50% duty cycle); 10 clocks/conversion cycle (50ksps); 1µF capacitor at REF, external +2.048V reference at REF; TA = TMIN to TMAX; unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER DC ACCURACY Resolution Relative Accuracy (Note 1) Differential Nonlinearity Offset Error Gain Error (Note 3) Gain Temperature Coefficient Total Unadjusted Error Channel-to-Channel Offset Matching VDD / 2 Sampling Accuracy DYNAMIC PERFORMANCE (10kHz sine-wave input, 2.048Vp-p, 50ksps, 500kHz external clock) Signal-to-Noise Plus Distortion Total Harmonic Distortion (up to the 5th harmonic) Spurious-Free Dynamic Range Small-Signal Bandwidth Full-Power Bandwidth ANALOG INPUTS Unipolar input, VCOM = 0 Input Voltage Range (Note 4) VCH_ Bipolar input, VCOM or VCH1 = VREF / 2, referenced to COM or CH1 On/off-leakage current, VCOM or VCH = 0 or VDD CIN ±0.01 18 0 VREF ±VREF / 2 ±1 V SINAD THD SFDR BW-3dB -3dB rolloff 49 -70 68 1.5 0.8 dB dB dB MHz MHz TUE TA = +25°C TA = TMIN to TMAX ±0.5 ±0.1 50 ±0.8 ±1 INL DNL VDD = 2.7V to 3.6V VDD = 5.5V (Note 2) No missing codes over temperature VDD = 2.7V to 3.6V VDD = 5.5V (Note 2) ±0.2 ±0.5 ±1 8 ±0.15 ±0.2 ±1 ±1 ±0.5 bits LSB LSB LSB LSB ppm/°C LSB LSB mV SYMBOL CONDITIONS MIN TYP MAX UNITS Multiplexer Leakage Current Input Capacitance µA pF 2 _______________________________________________________________________________________ Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs ELECTRICAL CHARACTERISTICS—MAX1108 (continued) (VDD = +2.7V to +3.6V; unipolar input mode; COM = GND, fSCLK = 500kHz, external clock mode (50% duty cycle); 10 clocks/conversion cycle (50ksps); 1µF capacitor at REF, external +2.048V reference at REF; TA = TMIN to TMAX; unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER TRACK/HOLD Conversion Time (Note 5) Track/Hold Acquisition Time Aperture Delay Aperture Jitter Internal Clock Frequency External Clock Frequency Range INTERNAL REFERENCE Output Voltage REF Short-Circuit Current REF Tempco Load Regulation Capacitive Bypass at REF EXTERNAL REFERENCE Input Voltage Range Input Current POWER REQUIREMENTS Supply Voltage VDD VDD = 2.7V to 3.6V, CL = 10pF Supply Current (Notes 2, 8) IDD VDD = 5.5V, CL = 10pF Internal reference External reference Internal reference External reference 2.7 3 105 70 130 95 0.5 ±0.4 2.5 ±4 2 3 0.8 0.2 ±1 ±1 15 mV V V V V µA µA pF 5.5 250 µA µA V +2.048V at REF, full scale, 500kHz external clock 1.0 1 VDD + 0.05 20 V µA 0 to 0.5mA (Note 7) 1 VREF IREFSC (Note 6) 1.968 2.048 150 ±50 2.5 2.128 V µA ppm/°C mV µF 50 For data transfer only tCONV tACQ Internal clock External clock, 500kHz, 10 sclks/conv External clock, 2MHz 20 1 10 3.6V DIGITAL INPUTS (DIN, SCLK, and CS) Threshold Voltage High Threshold Voltage Low Input Hysteresis Input Current High Input Current Low Input Capacitance VIH VIL VHYST IIH IIL CIN _______________________________________________________________________________________ 3 Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs MAX1108/MAX1109 ELECTRICAL CHARACTERISTICS—MAX1108 (continued) (VDD = +2.7V to +3.6V; unipolar input mode; COM = GND, fSCLK = 500kHz, external clock mode (50% duty cycle); 10 clocks/conversion cycle (50ksps); 1µF capacitor at REF, external +2.048V reference at REF; TA = TMIN to TMAX; unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER DIGITAL OUTPUT (DOUT) Output High Voltage Output Low Voltage Three-State Leakage Current Three-State Output Capacitance Acquisition Time DIN to SCLK Setup Time DIN to SCLK Hold Time SCLK Fall to Output Data Valid CS Fall to Output Enable CS Rise to Output Disable CS to SCLK Rise Setup CS to SCLK Rise Hold SCLK Pulse Width High SCLK Pulse Width Low Wake-Up Time Wake-Up Time VOH VOL IL COUT tACQ tDS tDH tDO tDV tTR tCSS tCSH tCH tCL tWAKE External reference Internal reference (Note 10) Figure 1, CLOAD = 100pF Figure 1, CLOAD = 100pF Figure 2, CLOAD = 100pF 100 0 200 200 20 12 ISOURCE = 0.5mA ISINK = 5mA ISINK = 16mA CS = VDD CS = VDD 1.0 100 0 20 200 240 240 0.8 ±0.01 15 ±10 VDD - 0.5 0.4 V V V µA pF µs ns ns ns ns ns ns ns ns ns µs ms SYMBOL CONDITIONS MIN TYP MAX UNITS TIMING CHARACTERISTICS (Figures 8, 9, and 10) ELECTRICAL CHARACTERISTICS—MAX1109 (VDD = +4.5V to +5.5V; unipolar input mode; COM = GND, fSCLK = 500kHz, external clock (50% duty cycle); 10 clocks/conversion cycle (50ksps); 1µF capacitor at REF, external +4.096V reference at REF; TA = TMIN to TMAX; unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER DC ACCURACY Resolution Relative Accuracy (Note 1) Differential Nonlinearity Offset Error Gain Error (Note 3) Gain Temperature Coefficient Total Unadjusted Error Channel-to-Channel Offset Matching VDD / 2 Sampling Accuracy TUE TA = +25°C TA = TMIN to TMAX ±0.5 ±0.1 50 ±0.8 ±1 INL DNL VDD = 4.5V to 5.5V No missing codes over temperature VDD = 4.5V to 5.5V ±0.2 8 ±0.15 ±0.5 ±1 ±1 ±1 bits LSB LSB LSB LSB ppm/°C LSB LSB mV SYMBOL CONDITIONS MIN TYP MAX UNITS 4 _______________________________________________________________________________________ Single-Supply, Low-Power, 2-Channel, Serial 8-Bit ADCs ELECTRICAL CHARACTERISTICS—MAX1109 (continued) (VDD = +4.5V to +5.5V; unipolar input mode; COM = GND, fSCLK = 500kHz, external clock (50% duty cycle); 10 clocks/conversion cycle (50ksps); 1µF capacitor at REF, external +4.096V reference at REF; TA = TMIN to TMAX; unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER Signal-to-Noise Plus Distortion Total Harmonic Distortion (up to the 5th harmonic) Spurious Free Dynamic Range Small-Signal Bandwidth Full-Power Bandwidth ANALOG INPUTS Unipolar input, VCOM = 0 Input Voltage Range (Note 4) VCH_ Bipolar input, VCOM or VCH1 = VREF / 2, referenced to COM or CH1 On/off-leakage current, VCH = 0 or VDD CIN Internal clock External clock, 500kHz, 10 sclks/conv External clock, 2MHz 20 1 10