Microchip Technology

The TC652/653 are integrated temperature sensors and brushless DC fan speed controllers with FanSense™ technology. The TC652/653 measure their junction temperature and control the speed of the fan based on that temperature, making them especially suited for applications in modern electronic equipment. The FanSense™ fan fault detect circuitry eliminates the need for a more expensive 3 wire fan. Temperature data is converted from the on-chip thermal sensing element and translated into a fractional fan speed from 40% to 100%. A temperature selection guide in the data sheet is used to choose the low and high temperature limits to control the fan. The TC652/653 also include a single trip point over temperature alert (Tover) that eliminates the need for additional temperature sensors. In addition the TC653 includes an auto fan shutdown function for additional power savings. The TC652/653 are easy to use, require no software overhead, and are therefore the ideal choice for implementing thermal management in a variety of systems. FanSense™ is a trademark of Microchip Technology Inc.

The TC654 is a dual PWM mode fan speed controller with FanSense™ TM technology for use with brush-less DC motors. The device allows temperature proportional speed control and therefore accomplishes lower acoustic fan noise and longer fan life. The TC654 reads the voltage provided by an external ther-mistor (or voltage output temperature sensor) and adjusts a 30% to 100% PWM duty cycle output to the fan with respect to the input temperature voltage. The PWM duty cycle can also be programmed via SMBus to allow fan speed control without the need of an external thermistor. In normal fan operation, pulse trains are present at the SENSE pin. These pulses are used to calculate the fan RPM. The fan RPM data is used to detect a worn out, stalled, open or unconnected fan. An RPM level below the user-programmable threshold causes the TC654 to assert a logic low alert signal (FAULT). Thedefault value is 500RPM. The TC654 consumes only 0.3mA during operation and can also enter a low-power shutdown mode by setting the appropriate bit in the configuration register.

The TC655 is a dual PWM mode fan speed controller with FanSense™ TM technology for use with brush-less DC motors. The device allows temperature proportional speed control and therefore accomplishes lower acoustic fan noise and longer fan life. The TC655 reads the voltage provided by an external ther-mistor (or voltage output temperature sensor) and adjusts a 30% to 100% PWM duty cycle output to the fan with respect to the input temperature voltage. The PWM duty cycle can also be programmed via SMBus to allow fan speed control without the need of an external thermistor. In normal fan operation, pulse trains are present at the SENSE pin. These pulses are used to calculate the fan RPM. The fan RPM data is used to detect a worn out, stalled, open or unconnected fan. An RPM level below the user-programmable threshold causes the TC655 to assert a logic low alert signal (FAULT). Thedefault value is 500RPM. The TC655 consumes only 0.3mA during operation and can also enter a low-power shutdown mode by setting the appropriate bit in the configuration register.

The TC682 is a CMOS charge pump converter that provides an inverted doubled output from a single positive supply. An on-board 12kHz (typical) oscillator provides the clock and only 3 external capacitors are required for full circuit implementation.Low output source impedance (typically 140Ohms), provides output current up to 10mA. The TC682 features low quiescent current and high efficiency, making it the ideal choice for a wide variety of applications that require a negative voltage derived from a single positive supply (for example: generation of -6V from a 3V lithium cell or -10V generated from a +5V logic supply).The minimum external parts count and small physical size of the TC682 make it useful in many medium-current, dual voltage analog power supplies.

The TC7106A 3½ digit LCD direct-display drive analog-to-digital converters allow existing TC7106 based systems to be upgraded. Each device has a precision reference with a 20ppm/°C max temperature coefficient. This represents a 4-7 times improvement over similar 3½ digit converters. Existing TC7106 based systems may be upgraded without changing external passive component values. The TC7106A low power drain and 9V battery operation make it suitable for portable applications. The TC7106A reduces linearity error to less than 1 count. Rollover error (the difference in readings for equal magnitude but opposite polarity input signals) is below ±1 count. High impedance differential inputs offer 1pA leakage current and a 1012 Ohm input impedance. The differential reference input allows ratiometric measurements for ohms or bridge transducer measurements. The 15µVp-p noise performance guarantees a great reading. The auto-zero cycle guarantees a zero display reading with a zero-volts input.

The TC7107A 3½ digit LED direct-display drive analog-to-digital converters allow existing TC7107 based systems to be upgraded. Each device has a precision reference with a 20ppm/°C max temperature coefficient. This represents a 4 to 7 times improvement over similar 3½ digit converters. Existing TC7107 based systems may be upgraded without changing external passive component values. The TC7107A drives common anode light emitting diode (LED) displays directly with 8mA per segment. A low-cost, high-resolution indicating meter requires only a display, four resistors, and four capacitors. The TC7107A reduces linearity error to less than 1 count. Rollover error (the difference in readings for equal magnitude but opposite polarity input signals) is below ±1 count. High impedance differential inputs offer 1pA leakage current and a 1012 Ohm input impedance. The differential reference input allows ratiometric measurements for ohms or bridge transducer measurements. The 15µVp-p noise performance guarantees a great reading. The auto-zero cycle guarantees a zero display reading with a zero-volts input.

The TC7109A is a 12-bit plus sign, CMOS low-power analog-to-digital converter (ADC). Only eight passive components and a crystal are required to form a complete dual-slope integrating ADC. The improved Voh source current TC7109A has features that make it an attractive per-channel alternative to analog multiplexing for many data acquisition applications. These features include typical input bias current of 1pA, drift of less than 1 µV/°C, input noise typically 15 µVp-p, and auto-zero. True differential input and reference allow measurement of bridge-type transducers such as load cells, strain gauges, and temperature transducers. In the handshake mode, the TC7109A will operate with industry-standard UARTs in controlling serial data transmission - ideal for remote data logging. The TC7109A has improved overrange recovery performance and higher output drive capability than the TC7109.

The TC7116A is a 3½ digit CMOS analog-to-digital converter (ADC) containing all the active components necessary to construct a 0.05% resolution measurement system. Seven-segment decoders, polarity and digit drivers, voltage reference, and clock circuit are integrated on-chip. The TC7116A drives liquid crystal displays (LCDs) and includes a backplane driver. These devices incorporate a display hold (HLDR) function. The TC7116A reduces linearity error to less than 1 count. Roll-over error (the difference in readings for equal magnitude but opposite polarity input signals) is below ±1 count. High-impedance differential inputs offer 1 pA leakage current and a 1012 Ohm input impedance. The auto-zero cycle guarantees a zero display reading with a 0V input. The TC7116A features a precision, low-drift internal reference, and is functionally identical to the TC7116.

The TC7117 is a 3½ digit CMOS analog-to-digital converter (ADC) containing all the active components necessary to construct a 0.05% resolution measurement system. Seven-segment decoders, polarity and digit drivers, voltage reference, and clock circuit are integrated on-chip. The TC7117 drives common anode light emitting diode (LED) displays directly with an 8mA drive current per segment. These devices incorporate a display hold (HLDR) function. Roll-over error (the difference in readings for equal magnitude but opposite polarity input signals) is below ±1 count. High-impedance differential inputs offer 1 pA leakage current and a 1012 Ohm input impedance. The auto-zero cycle guarantees a zero display reading with a 0V input.