EVALUATION KIT AVAILABLE MAX35101 Time-to-Digital Converter with Analog Front-End General Description Benefits and Features The MAX35101 is a time-to-digital converter with built-in High Accuracy Flow Measurement for Billing amplifier and comparator targeted as a complete analog and Leak Detection front-end (AFE) solution for the ultrasonic heat meter and Time-to-Digital Accuracy Down to 20ps flow meter markets. Measurement Range Up to 8ms Two Channels: Single-Stop Channel With a time measurement accuracy of 20ps and auto- matic differential time-of-flight (TOF) measurement, this High Accuracy Temperature Measurement for device makes for simplified computation of liquid flow. Precise Heat and Flow Calculations Early edge detection ensures measurements are made Up to Four (4) 2-Wire Sensors PT1000 and PT500 RTD Support with consistent wave patterns to greatly improve accuracy and eliminate erroneous measurements. Maximizes Battery Life with Low Device and Multihit capability with stop-enable windowing allows Overall System Power Low 10A ToF measurement and < 125nA the device to be fine-tuned for the application. Internal analog switches, an autozero amplifier/comparator, real- Duty-Cycled Temperature Measurement Event Timing Mode Reduces Host C time clock (RTC), and programmable receiver sensitivity provide the analog interface and control for a minimal Overhead to Minimize System Power Consumption electrical bill of material solution. The RTC provides an 2.3V to 3.6V Single-Supply Operation event timing mode that is configurable and runs cyclic High-Integration Solution Minimizes Parts Count algorithms to minimize microprocessor interactivity and and Reduces BOM Cost increase battery life. 8KB of Nonvolatile Flash Memory for Data Logging Built-in arithmetic logic unit provides TOF difference mea- Built-in Real Time Clock surements. A programmable receiver hit accumulator can Small, 5mm x 5mm, 32-Pin TQFP Package be utilized to minimize the host microprocessor access -40C to +85C Operation and thus minimize current consumption. Applications For temperature measurement, the MAX35101 supports Ultrasonic Heat Meters up to four (4) 2-wire PT1000/500 platinum resistive tem- Ultrasonic Water Meters perature detectors (RTD). Ultrasonic Gas Meters A simple 4-wire SPI interface allows any microcon- troller to effectively configure the device for its intended measurement. On-board 8KB user flash allows the MAX35101 to be nonvolatile-configurable and provide nonvolatile energy use data to be logged. Configuration can be recalled any- time with a SPI command. Ordering Information appears at end of data sheet. 19-6830 Rev 1 1/15MAX35101 Time-to-Digital Converter with Analog Front-End Absolute Maximum Ratings (Voltages relative to ground.) Operating Temperature Range ........................... -40C to +85C Voltage Range on V Pins.................................-0.5V to +4.0V Junction Temperature ......................................................+150C CC Voltage Range on All Other Pins Storage Temperature Range ............................ -55C to +125C (not to exceed 4.0V) ............................. -0.5V to (V + 0.5V) Lead Temperature (soldering, 10s) .................................+300C CC Continuous Power Dissipation (T = +70C) Soldering Temperature (reflow) .......................................+260C A TQFP (derate 27.80mW/C above +70C) ...........2222.20mW ESD Protection (All Pins, Human Body Model) ..................2kV 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. Package Thermal Characteristics (Note 1) TQFP Junction-to-Ambient Thermal Resistance ( ) ..........36C/W Junction-to-Case Thermal Resistance ( ) .....................4C/W JA JC Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. Recommended Operating Conditions (T = -40C to +85C, unless otherwise noted.) (Notes 2, 3) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage V 2.3 3.0 3.6 V CC Input Logic 1 V V x 0.7 V + 0.3 V CC CC IH (RST, CSW, SCK, DIN, CE) Input Logic 0 V -0.3 V x 0.3 V CC IL (RST, CSW, SCK, DIN, CE) Input Logic 1 (32KX1) V V x 0.85 V + 0.3 V CC CC IH32KX1 Input Logic 0 (32KX1) V -0.3 V x 0.15 V IL32KX1 CC Electrical Characteristics (V = 2.3V to 3.6V, T = -40C to +85C, unless otherwise noted. Typical values are at V = 3.0V and T = +25C.) (Notes 2, 3) CC A CC A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Input Leakage I -0.1 +0.1 A L (CSW, RST, SCK, DIN, CE) Output Leakage -0.1 +0.1 A (INT, WDO, T1,T2,T3,T4) Output Voltage Low (32KOUT) V 2mA 0.2 x V V OL32K CC Output Voltage High (32KOUT) V -1mA 0.8 x V V OH32K CC Output Voltage High V -4mA 0.8 x V V OH CC (DOUT, CMP OUT/UP DN) Output Voltage High (TC) V V = 3.3V, I = -4mA 2.9 3.1 V OHTC CC OUT Maxim Integrated 2 www.maximintegrated.com