MAXIM Manuals

The MAX1709 is a high-power step-up DC-DC converter that delivers up to 20W at a fixed (3.3V or 5V) or adjustable (2.5V to 5.5V) output from a +0.7V to +5V supply.

The MAX195 is a 16-bit successive-approximation analog-to-digital converter (ADC) that combines high speed, high accuracy, low power consumption, and a 10µA shutdown mode. Internal calibration circuitry corrects linearity and offset errors to maintain the full rated performance over the operating temperature range without external adjustments. The capacitive-DAC architecture provides an inherent 85ksps track/hold function. The MAX195, with an external reference (up to +5V), offers a unipolar (0V to VREF) or bipolar (-VREF to VREF) pin-selectable input range. Separate analog and digital supplies minimize digital-noise coupling. The chip select (CS) input controls the three-state serial-data output. The output can be read either during conversion as the bits are determined, or following conversion at up to 5Mbps using the serial clock (SCLK). The end-of-conversion (EOC) output can be used to interrupt a processor, or can be connected directly to the convert input (CONV) for continuous, full-speed conversions. The MAX195 is available in 16-pin DIP, wide SO, and ceramic sidebraze packages.

The MAX548A/MAX549A/MAX550A are serial, 8-bit voltage-output digital-to-analog converters (DACs) that operate from a single +2.5V to +5.5V supply. Their ±1LSB TUE specification is guaranteed over temperature. Operating current (supply current plus reference current) is typically 75µA per DAC with VDD = 2.5V. In shutdown, the DAC is disconnected from the reference, reducing current drain to less than 1µA. The MAX548A/MAX549A allow each DAC to be shut down independently. The 10MHz, 3-wire serial interface is compatible with SPI™/QSPI™ and Microwire™ interface standards. Double-buffered inputs provide flexibility when updating the DACs; the input and DAC registers can be updated individually or simultaneously. The MAX548A is a dual DAC with an asynchronous load input; it uses VDD as the reference input. The MAX549A is a dual DAC with an external reference input. The MAX550A is a single DAC with an external reference input and an asynchronous load input. The MAX548A/MAX549A/MAX550A’s low power consumption and small µMAX and DIP packages make these devices ideal for portable and battery-powered applications.

The MAX9856 is a high-performance, low-power stereo audio CODEC designed for MP3, personal media players (PMPs), or other portable multimedia devices. Using on-board stereo DirectDrive® headphone amplifiers, the CODEC can output 30mW into stereo 32Ω headphones while operating from a single 1.8V power supply. Very low 9mW playback power consumption makes it an ideal choice for battery-powered applications. The MAX9856 provides microphone input amplifiers, plus flexible input selection, signal mixing, and automatic gain control (AGC). Comprehensive load-impedance sensing allows the MAX9856 to autodetect most common audio and audio/video headset and jack plug types. Outputs include stereo DirectDrive line outputs and DirectDrive headphone amplifiers. The stereo ADC can convert audio signals from either internal or external microphones that can be configured for single-ended or differential signal inputs. Line inputs can be configured as stereo, differential, or mono and fed through one channel of the microphone path. The analog inputs selected can be gain ranged or mixed with other input sources prior to conversion to digital. The ADC path also features programmable digital highpass filters to remove DC offset voltages and wind noise. The MAX9856 supports all common sample rates from 8kHz to 48kHz in both master and slave mode. The serial digital audio interfaces support a variety of formats including I2S, left-justified, and PCM modes. The MAX9856 has a low-power design and is suitable for a variety of applications including MP3 players, portable music players, digital audio players, and portable computers.

MAX668/MAX669 is a constant-frequency, pulse-width modulating (PWM), current-mode DC-DC controller designed for a wide range of DC-DC conversion applications including step-up, SEPIC, flyback, and isolated-output configurations. Power levels of 20W or more can be controlled with conversion efficiencies of over 90%

The MAX17000 pulse-width modulation (PWM) controller provides a complete power solution for notebook DDR, DDR2, and DDR3 memory. It comprises a step-down controller, a source-sink LDO regulator, and a reference buffer to generate the required VDDQ, VTT, and VTTR rails. The VDDQ rail is supplied by a step-down converter using Maxim’s proprietary Quick-PWM™ controller. The high-efficiency, constant-on-time PWM controller handles wide input/output voltage ratios (low duty-cycle applications) with ease and provides 100ns response to load transients while maintaining a relatively constant switching frequency. The Quick-PWM architecture circumvents the poor load-transient timing problems of fixed-frequency current-mode PWMs while also avoiding the problems caused by widely varying switching frequencies in conventional constant-on-time and constant-off-time PWM schemes. The controller senses the current to achieve an accurate valley current-limit protection. It is also built in with overvoltage, undervoltage, and thermal protections. The MAX17000 can be set to run in three different modes: power-efficient SKIP mode, low-noise forced-PWM mode, and standby mode to support memory in notebook computer standby operation. The switching frequency is programmable from 200kHz to 600kHz to allow small components and high efficiency. The VDDQ output voltage can be set to a preset 1.8V or 1.5V, or be adjusted from 1.0V to 2.5V by an external resistor-divider.

The ICL7665 is a low-power, high-precision voltage monitor chip produced by Maxim. It uses externally programmable thresholds and hysteresis outputs for µP voltage monitoring, low battery detection, power failure and brownout detection, battery backup switching and power supply fault monitoring.

The MAX1703 is a high-efficiency, low-noise, step-up DC-DC converter intended for use in battery-powered wireless applications. It uses a synchronous-rectified pulse-width-modulation (PWM) boost topology to gen- erate a 2.5V to 5.5V output from battery inputs, such as one to three NiCd/NiMH cells or one Li-Ion cell. The device includes a 2A, 75mΩ, N-channel MOSFET switch and a 140mΩ, P-channel synchronous rectifier. With its internal synchronous rectifier, the MAX1703 delivers up to 5% better efficiency than similar nonsyn- chronous converters. It also features a pulse-frequency- modulation (PFM) low-power mode to improve efficiency at light loads, and a 1µA shutdown mode. The MAX1703 comes in a 16-pin narrow SO package and includes an uncommitted comparator that generates a power-good or low-battery-warning output. It also contains a linear gain block that can be used to build a linear regulator. For lower-power outputs and a smaller package, refer to the MAX1700/MAX1701. For dual outputs (step-up plus linear regulator), refer to the MAX1705/MAX1706. For an on-board analog-to-digital converter, refer to the MAX848/MAX849. The MAX1703 evaluation kit is available to speed designs.

The MAX823/MAX824/MAX825 are microprocessor (μP) supervisory circuits from MAXIM that combine reset output, watchdog, and manual reset input functions in 5-pin SOT23 and SC70 packages. They significantly improve system reliability and accuracy compared to separate ICs or discrete components. The MAX823/MAX824/MAX825 are specifically designed to ignore fast transients on VCC. Seven preprogrammed reset threshold voltages are available (see Reset Threshold Table). All three devices have an active-low reset output, which is guaranteed to be in the correct state for VCC down to 1V. The MAX823 also offers a watchdog input and manual reset input. The MAX824 offers a watchdog input and a complementary active-high reset. The MAX825 offers a manual reset input and a complementary active-high reset. The Selector Guide explains the functions offered in this series of parts.

DS1859 Dual, Temperature-Controlled Resistors with Internally Calibrated Monitors

MAX17019 is a high-input-voltage quad-output controller (up to 38V). It provides a compact, low-cost controller capable of providing four independent regulators—a main stage, a 3AP-P internal step-down, a 5AP-P internal step-down, and a 2A source/sink linear regulator. The input voltage is up to 38V. This makes it an excellent choice for automotive applications. The internal switching regulators include 5V synchronous MOSFETs that can be powered directly from a single Li+ cell or from the main 3.3V/5V power stages. Finally, the linear regulator is capable of sourcing and sinking 2A to support DDR termination requirements or to generate a fixed output voltage. The step-down converters use a peak current-mode, fixed-frequency control scheme—an easy to implement architecture that does not sacrifice fast-transient response. This architecture also supports peak current-limit protection and pulse-skipping operation to maintain high efficiency under light-load conditions. Separate enable inputs and independent open-drain power-good outputs allow flexible power sequencing. A soft-start function gradually ramps up the output volt- age to reduce the inrush current. Disabled regulators enter high-impedance states to avoid negative output voltage created by rapidly discharging the output through the low-side MOSFET. The MAX17019 also includes output undervoltage, output overvoltage, and thermal-fault protection. The MAX17019 is available in a 48-pin QFN package.

The MAX1117/MAX1118/MAX1119 are low-power, 8-bit, dual-channel analog-to-digital converters (ADCs) with internal track/hold (T/H) voltage reference, clock, and serial interface. They feature low power consumption, automatic shutdown mode, and internal clock, making them suitable for various applications.

The MAX1806 is a low-dropout linear regulator that operates from a +2.25V to +5.5V supply and delivers a guaranteed 500mA load current with a low 175mV dropout. The high-accuracy (±1%) output voltage is preset at an internally trimmed voltage (see Selector Guide) or can be adjusted from +0.8V to +4.5V with an external resis- tive-divider. An internal PMOS pass transistor allows low 210µA supply current, making this device ideal for portable equipment such as personal digital assistants (PDAs), cellular phones, cordless phones, and other equip- ment, including base stations and docking stations. Other features include an active-low, power-OK output that indicates when the output is out of regulation, a 0.02µA shutdown mode, short-circuit protection, and thermal shutdown protection. The MAX1806 comes in a miniature 1.3W, 8-pin power-µMAX package with a metal pad on the underside of the package.

MAX1846/MAX1847 high-efficiency PWM inverting controllers allow designers to implement compact, low- noise, negative-output DC-DC converters for telecom and networking applications. Both devices operate from +3V to +16.5V input and generate -2V to -200V output. To minimize switching noise, both devices feature a current-mode, constant-frequency PWM control scheme. The operating frequency can be set from 100kHz to 500kHz through a resistor. The MAX1846 is available in an ultra-compact 10-pin µMAX package. Operation at high frequency, compatibility with ceramic capacitors, and inverting topology without transformers allow for a compact design. Compatibility with electrolytic capacitors and flexibility to operate down to 100kHz allow users to minimize the cost of external components. The high-current output drivers are designed to drive a P-channel MOSFET and allow the converter to deliver up to 30W. The MAX1847 features clock synchronization and shutdown functions. The MAX1847 can also be configured to operate as an inverting flyback controller with an N- channel MOSFET and a transformer to deliver up to 70W. The MAX1847 is available in a 16-pin QSOP package. Current-mode control simplifies compensation and provides good transient response. Accurate current-mode control and over current protection are achieved through low-side current sensing.