MAXIM Manuals

The MAX1953/MAX1954/MAX1957 is a family of versatile, economical, synchronous current-mode, pulse-width modulation (PWM) buck controllers. These step-down controllers are targeted for applications where cost and size are critical. The MAX1953 operates at a fixed 1MHz switching fre- quency, thus significantly reducing external component size and cost. Additionally, excellent transient response is obtained using less output capacitance. The MAX1953 operates from low 3V to 5.5V input voltage and can sup- ply up to 10A of output current. Selectable current limit is provided to tailor to the external MOSFETs’ on-resistance for optimum cost and performance. The output voltage is adjustable from 0.8V to 0.86VIN.

MAX17498A/MAX17498B/MAX17498C are peak current-mode converters for flyback/boost applications

The MAX6620 is a four-channel linear voltage output driver for controlling fans. It directly controls the fan drive voltages via the I2C interface. Each output drives the base of an external bipolar transistor or the gate of a FET in high-side drive configuration. Voltage feedback at the fan’s power-supply terminal is used to force the correct out- put voltage. The MAX6620 offers two methods for fan control. In RPM mode, the MAX6620 monitors four fan tachometer logic outputs for precise (±1%) control of fan RPM and detection of fan failure. In DAC mode, each fan is dri- ven with a voltage resolution of 9 bits and the tachome- ter outputs of the fans are monitored for failure. The DAC_START input selects the fan power-supply voltage at startup to ensure appropriate fan drive when power is first applied. A watchdog feature turns the fans fully on to protect the system if there are no valid I2C communications within a preset timeout period. The MAX6620 operates from a 3.0V to 5.5V power sup- ply with low 250µA supply current, and the I2C-compati- ble interface makes it ideal for fan control in a wide range of cooling applications. The MAX6620 is avail- able in a 28-pin TQFN package and operates over the -40°C to +125°C automotive temperature range.

The MAX6513 is a fully integrated, remote temperature switch that uses an external P-N junction (typically a diode-connected transistor) as the sensing element to measure the remote temperature. When the temperature crosses a factory-programmed threshold, the device asserts a logic signal. Available trip thresholds are from +45°C to +125°C in 10°C increments. Accuracy is within ±3°C (TA = -5°C to +55°C) or ±5°C (TA = -40°C to +85°C). Hysteresis is pin selectable to 5°C or 10°C. The MAX6513 has an active-high CMOS output. The output is asserted when the temperature exceeds the threshold value. The active-high CMOS output can directly drive a power FET to control a cooling fan. The MAX6513 operates from a +3.0V to +5.5V supply and typically consumes 400µA of supply current. It is available in a 6-pin lead-free TDFN package.

The MAX1937/MAX1938/MAX1939 are a family of synchronous two-phase step-down controllers capable of delivering load currents up to 60A. The controllers utilize Quick-PWM™ control architecture in conjunction with active load-current voltage positioning. Quick-PWM control provides instantaneous load-step response, while programmable voltage positioning allows the converter to utilize full transient regulation limits, reducing the output capacitance requirement. The two phases operate 180° out-of-phase with an effective 500kHz switching frequency, thus reducing input and output current ripple, as well as reducing input filter capacitor requirements. The MAX1937/MAX1938/MAX1939 are compliant with AMD Hammer, Intel® Voltage-Regulator Module (VRM) 9.0/9.1, and AMD Athlon™ Mobile VID code specifications (see Table 1 for VID codes). The internal DAC provides ultra-high accuracy of ±0.75%. A controlled VID voltage transition is implemented to minimize both undervoltage and overvoltage overshoot during VID input change. Remote sensing is available for high output-voltage accuracy. The MOSFET switches are driven by a 6V gate-drive circuit to minimize switching and crossover conduction losses to achieve efficiency as high as 90%. The MAX1937/MAX1938/MAX1939 feature cycle-by-cycle current limit to ensure that the current limit is not exceeded. Crowbar protection is available to protect against output overvoltage. Applications include notebooks and desktops

MAX1856 is a low-cost SLIC (ringer and off-hook) power supply solution that uses standard off-the-shelf transformers from multiple vendors. It generates various output voltages: -24V and -72V (dual output) for both ringer and off-hook supplies for voice-enabled broadband consumer premises equipment (CPE), -48V for IP phones and routers, -5V and -15V (single or dual output) for DSL CO line drivers, or negative voltages as high as -185V for MEMS bias supplies. The output voltages are adjusted with an external voltage divider. Due to its wide operating voltage range, the MAX1856 operates from a low-cost, unregulated DC power supply for cost-sensitive applications like xDSL, cable modems, set-top boxes, LMDS, MMDS, WLL, and FTTH CPE. The MAX1856 provides low audio-band noise for talk battery and a sturdy output capable of handling the ring trip conditions for ring battery. The operating frequency can be set between 100kHz and 500kHz with an external resistor in free-running mode. For noise-sensitive applications, the MAX1856's operating frequency can be synchronized to an external clock over its operating frequency range. The flyback topology allows operation close to 50% duty cycle, offering high transformer utilization, low ripple current, and less stress on input and output capacitors. Internal soft-start minimizes startup stress on the input capacitor, without any external components. The MAX1856's current-mode control circuit provides excellent output voltage accuracy, resulting in lower system noise.

The MAX1692 is a low-noise, pulse-width-modulated (PWM), DC-DC step-down converter. It is suitable for powering logic and transmitters in small wireless systems. The device features an internal synchronous rectifier for high efficiency and does not require an external Schottky diode. It has excellent noise characteristics and fixed-frequency operation for easy post-filtering. The MAX1692 is ideally suited for Li-Ion battery applications and can also be used for +3V or +5V fixed input applications. It operates in four modes: Forced PWM mode, Synchronizable PWM mode, Idle Mode™ (PWM/PFM), and Shutdown mode. The MAX1692 can deliver over 600mA of output current, with an adjustable output voltage range from 1.25V to VIN and an input range from +2.7V to +5.5V. Other features include high efficiency, low dropout voltage, and a 1.2%-accurate 1.25V reference.

The MAX1700/MAX1701 are high-efficiency, low-noise, step-up DC-DC converters intended for use in battery-powered wireless applications. They use a synchronous-rectified pulse-width-modulation (PWM) boost topology to generate 2.5V to 5.5V outputs from battery inputs such as one to three NiCd/NiMH cells or one Li-Ion cell. Both devices have an internal 1A, 130mΩ N-channel MOSFET switch and a 250mΩ P-channel synchronous rectifier. With their internal synchronous rectifier, the MAX1700/MAX1701 deliver 5% better efficiency than similar non-synchronous converters. They also feature a pulse-frequency-modulation (PFM) standby mode to improve efficiency at light loads, and a 3µA shutdown mode. The MAX1700/MAX1701 come in 16-pin QSOP packages (which occupy the same space as an 8-pin SO). The MAX1701 includes two comparators to generate power-good and low-battery warning outputs. It also contains a gain block that can be used to build a linear regulator using an external P-channel pass device. For higher-power outputs, refer to the MAX1703. For dual outputs (step-up and linear regulator), refer to the MAX1705/MAX1706. For an on-board analog-to-digital converter, refer to the MAX848/MAX849. The MAX1701 evaluation kit is available to speed design time. Applications include digital cordless phones, personal communicators, PCS phones, palmtop computers, wireless handsets, hand-held instruments, and two-way pagers. Features include up to 96% efficiency, 1.1V IN guaranteed start-up, 0.15 mA standby current, and 3 µA shutdown current.

The MAX1556 evaluation board (EV kit) is a fully assembled and tested circuit board for evaluating the PWM step-down DC-DC converters MAX1556 and MAX1557. The operating voltage of the board is 2.6V ~ 5.5V, and it features high efficiency, small size, and adjustable output voltage.

The MAX1917 is a synchronous buck controller from MAXIM that can be used for DDR memory. It has a sourcing and sinking current of 25A, a standby current of less than 5µA, and an input voltage range of 1.5V to 3.6V. It has preset switching frequencies of 200kHz/300kHz/400kHz/550kHz, and a variable switching frequency of up to 1MHz.

The MAX8597/MAX8598/MAX8599 are three low-dropout, high-efficiency PWM step-down controllers that operate from a 4.5V to 28V input supply and generate output voltages down to 0.6V. The MAX8597/MAX8598/MAX8599 feature n-channel MOSFETs, which result in high efficiency and high-current-capability designs. The MAX8597/MAX8598/MAX8599 are available in 20-pin and 16-pin thin QFN packages, respectively, and are suitable for a wide range of applications.

The MAX1964/MAX1965 power-supply controllers are designed to address cost-sensitive applications demanding voltage sequencing/tracking, such as cable modem consumer premise equipment (CPE), xDSL CPE, and set-top boxes. Operating off a low-cost, unregulated DC supply (such as a wall adapter output), the MAX1964 generates three positive outputs and the MAX1965 generates four positive outputs and one negative output to provide an inexpensive system power supply. The MAX1964 includes a current-mode synchronous step-down controller and two positive regulator gain blocks. The MAX1965 has one additional positive gain block and one negative regulator gain block. The main synchronous step-down controller generates a high- current output that is preset to 3.3V or adjustable from 1.236V to 0.75 ✕ VIN with an external resistive-divider. The 200kHz operating frequency allows the use of low- cost aluminum-electrolytic capacitors and low-cost power magnetics. Additionally, the MAX1964/MAX1965 step-down controllers sense the voltage across the low- side MOSFET’s on-resistance to efficiently provide the current-limit signal, eliminating the need for costly cur- rent-sense resistors. The MAX1964/MAX1965 generate additional supply rails at low cost. The positive regulator gain blocks use an external PNP pass transistor to generate low voltage rails directly from the main step-down converter (such as 2.5V or 1.8V from the main 3.3V output) or higher voltages using coupled w

The DS1990A serial number iButton® is a rugged data carrier that serves as an electronic registration number for automatic identification. Data is transferred serially through the 1-Wire® protocol, which requires only a sin- gle data lead and a ground return. Every DS1990A is factory lasered with a guaranteed unique 64-bit regis- tration number that allows for absolute traceability. The durable stainless-steel iButton package is highly resis- tant to environmental hazards such as dirt, moisture, and shock. Its compact coin-shaped profile is self- aligning with mating receptacles, allowing the DS1990A to be used easily by human operators. Accessories enable the DS1990A iButton to be mounted on almost any object, including containers, pallets, and bags. Applications include Access Control, Work-In-Progress Tracking, Tool Management, and Inventory Control. Features: Can Be Read in Less Than 5ms; Operating Range: 2.8V to 6.0V, -40°C to +85°C. Common iButton Features: Unique Factory-Lasered 64-Bit Registration Number Ensures Error-Free Device Selection and Absolute Traceability Because No Two Parts are Alike; Built-In Multidrop Controller for 1-Wire Net; Digital Identification by Momentary Contact; Data Can Be Accessed While Affixed to Object; Economically Communicates to Bus Master with a Single Digital Signal at 16.3kbps; Button Shape is Self-Aligning with Cup-Shaped Probes; Durable Stainless-Steel Case Engraved with Registration Number Withstands Harsh Environments.

The DS1990A serial number iButton is a rugged data carrier that can be used as an electronic registration number for automatic identification systems. Each DS1990A contains a factory-programmed unique 64-bit registration number for absolute traceability. It has a working range of 2.8V to 6.0V and a read time of less than 5ms.