MAXIM Manuals

The DS1825 digital thermometer provides 9 to 12-bit centigrade temperature measurements and has an alarm function with NV user-programmable upper and lower trigger points. The DS1825 communicates over a 1-Wire bus that by definition requires only one data line (and ground) for communication with a central microprocessor. It has a unique 64-bit serial code stored in an on-board ROM, making it ideal for multidrop distributed temperature sensing applications.

The MAX6615/MAX6616 is a temperature sensor that monitors two temperature channels. It can be used to monitor the internal chip temperature and the temperature of an external thermistor, or the temperatures of two external thermistors. The temperature data controls a PWM output signal to adjust the speed of a cooling fan, thereby minimizing noise when the system is running cool, but providing maximum cooling when power dissipation increases. The fans’ tachometer output signals are monitored by the MAX6615/MAX6616 to detect fan failure. If a fan failure is detected, the FAN_FAIL output is asserted. The 2-wire serial interface accepts standard system management bus (SMBusTM) write byte, read byte, send byte, and receive byte commands to read the temperature data and program the alarm thresholds. The programmable alarm output can be used to generate interrupts, throttle signals, or overtemperature shut- down signals. The MAX6616 features six GPIOs to provide additional flexibility. All of the GPIOs power-up as inputs, with the exception of GPIO0, which powers up as either an input or an output as determined by connecting the PRESET pin to ground or VCC. The MAX6616 is available in a 24-pin QSOP package, while the MAX6615 is available in a 16-pin QSOP pack- age. Both devices operate from a single-supply voltage range of 3.0V to 5.5V, have operating temperature ranges of -40°C to +125°C, and consume just 500µA of supply current. The device can be applied to desktop computers, servers, power supplies, and network equipment.

MAX6514/MAX6515 are low-cost, fully integrated temperature switches that assert a logic signal when their die temperature crosses a factory-programmed threshold. Operating from a 2.7V to 5.5V supply, these devices feature a fixed voltage reference, an analog temperature sensor, and a comparator. They are available with factory-trimmed temperature trip thresholds from -45°C to +15°C and +35°C to +115°C in 10°C increments, and are accurate to ±1°C (typ). These devices require no external components and typically consume 22µA of supply current. Hysteresis is pin selectable at 2°C or 10°C. The MAX6514/MAX6515 are offered with hot-temperature thresholds (+35°C to +115°C), asserting when the temperature is above the threshold or with cold-temperature thresholds (-45°C to +15°C), asserting when the temperature is below the threshold. The MAX6514/MAX6515 can be used over a -35°C to +125°C range with a supply voltage of 2.7V to 5.5V. For applications sensing temperature down to -45°C, a supply voltage above 4.5V is required. The MAX6514 has an active-high, push-pull output. The MAX6515 has an active-low, open-drain output. These devices are available in a space-saving 5-pin SOT23 package and operate over the -55°C to +125°C temperature range. Applications include Over/Undertemperature Protection, Fan Control, Test Equipment, Temperature Control, Temperature Alarms, Notebook, Desktop PCs, RAID Servers.

The MAX6661 is a remote temperature sensor and fan-speed regulator that provides complete closed-loop fan control. It integrates thermal measurement and fan regulation, which can be programmed by the user over the SPI bus. The device enables automatic fan control that is proportional to the remote junction temperature, and the temperature feedback loop can be broken at any time for system control over the fan speed. Fan speed is voltage controlled, reducing acoustic noise and maximizing fan reliability. Temperature data is updated every 500ms and can be read over the SPI interface. The MAX6661 is accurate to 1°C (max) when the remote junction is between +60°C to +100°C. Data is formatted as a 10-bit + sign word with 0.125°C resolution. The MAX6661 is specified between -40°C to +125°C and is available in a 16-pin QSOP package.

This document introduces the features and characteristics of MAX6505-MAX6508 temperature switches, including the functions, working principles, models, and application scenarios.

MAX1744/MAX1745 are high-voltage, step-down DC-DC controllers capable of handling up to 36V inputs. These parts use a proprietary current-limited control scheme for excellent light- and full-load efficiency, while their 330kHz (max) switching frequency permits small external components for space-critical applications.

The MAX6516-MAX6519 low-cost, fully integrated tem- perature switches assert a logic signal when their die temperature crosses a factory-programmed threshold. Operating from a 2.7V to 5.5V supply, these devices feature a fixed voltage reference, an analog tempera- ture sensor, and a comparator. They are available with factory-trimmed temperature trip thresholds from -45°C to +115°C in 10°C increments, and are accurate to ±0.5°C (typ). These devices require no external compo- nents and typically consume 22µA of supply current. Hysteresis is pin selectable at 2°C or 10°C. The MAX6516–MAX6519 are offered with hot-tempera- ture thresholds (+35°C to +115°C), asserting when the temperature is above the threshold, or with cold-tem- perature thresholds (-45°C to +15°C), asserting when the temperature is below the threshold. These devices provide an analog output proportional to temperature and are stable with any capacitive load up to 1000pF. The MAX6516–MAX6519 can be used over a range of -35°C to +125°C with a supply voltage of 2.7V to 5.5V. For applications sensing temperature down to -45°C, a supply voltage above 4.5V is required. The MAX6516 and MAX6518 have an active-high, push-pull output. The MAX6517 and MAX6519 have an active-low, open-drain output. These devices are avail- able in a space-saving 5-pin SOT23 package and oper- ate over the -55°C to +125°C temperature range.

The MAX6654 is a precise digital thermometer that reports the temperature of both a remote P-N junction and its own die. The remote junction can be a diode-connected transistor that replaces conventional thermistors or thermocouples. The 2-wire serial interface accepts standard System Management Bus (SMBus)TM commands to program the alarm thresholds and to read temperature data. Measurements can be done automatically and autonomously, with the conversion rate programmed by the user, or programmed to operate in a single-shot mode. The adjustable conversion rate allows the user to optimize supply current and temperature update rate to match system needs.

The DS1620 Digital Thermometer and Thermostat provides 9–bit temperature readings which indicate the temperature of the device and has three thermal alarm outputs, can also act as a thermostat.

The MAX8867/MAX8868 are low-noise, low-dropout linear regulators that operate from a 2.5V to 6.5V input and deliver up to 150mA. Typical output noise for these devices is just 30µVRMS, and typical dropout is only 165mV at 150mA. The output voltage is preset to voltages in the range of 2.5V to 5.0V, in 100mV increments. The MAX8867 and MAX8868 are pin-compatible with the MAX8863 and MAX8864, except for the BP pin. Designed with an internal P-channel MOSFET pass transistor, the MAX8867/MAX8868 maintain a low 100µA supply current, independent of the load current and dropout voltage. Other features include a 10nA logic-controlled shutdown mode, short-circuit and thermal-shutdown protection, and reverse battery protection. The MAX8868 also includes an auto-discharge function, which actively discharges the output voltage to ground when the device is placed in shutdown. Both devices come in regular and thin 5-pin SOT23 packages.

Introduces the characteristics of DS18B20 digital thermometer, including working temperature range, accuracy, power supply, communication protocol, etc.

The MAX1954A is an upgraded version of the MAX1954, which uses a synchronous current-mode control, pulse-width modulation (PWM) buck controller. The input voltage range is 3.0V to 13.2V, and the output voltage can be adjusted to 0.8V. The IC operates at a fixed 300kHz switching frequency and provides up to 25A of output current with efficiency up to 95%.

MAX1954A is a switch power supply chip launched by Maxim company, which adopts PWM control technology. The input voltage range is 3.0V to 13.2V, the output voltage range is 0.8V to Vin, and it supports a maximum current output of 25A. The efficiency is up to 95%.

The MAX5590–MAX5595 are octal, 12/10/8-bit, voltage-output digital-to-analog converters (DACs) with buffered outputs and a 3µs maximum settling time at the 12-bit level. The DACs operate from a +2.7V to +5.25V analog supply and a separate +1.8V to +5.25V digital supply. The 20MHz 3-wire serial interface is compatible with SPI™, QSPI™, MICROWIRE™, and digital signal processor (DSP) protocol applications. Multiple devices can share a common serial interface in direct-access or daisy-chained configuration. The MAX5590–MAX5595 provide two multifunction, user-programmable, digital I/O ports. The externally selectable power-up states of the DAC outputs are either zero scale, midscale, or full scale. Software-selectable FAST and SLOW settling modes decrease settling time in FAST mode, or reduce supply current in SLOW mode. The MAX5590/MAX5591 are 12-bit DACs, the MAX5592/MAX5593 are 10-bit DACs, and the MAX5594/MAX5595 are 8-bit DACs. The MAX5590/MAX5592/MAX5594 provide unity-gain-configured output buffers, while the MAX5591/MAX5593/MAX5595 provide force-sense-configured output buffers. The MAX5590–MAX5595 are specified over the extended -40°C to +85°C temperature range, and are available in space-saving 24-pin and 28-pin TSSOP packages.