MAXIM Manuals

The MAX541/MAX542 are serial-input, voltage-output, 16-bit digital-to-analog converters (DACs) that operate from a single +5V supply. They provide 16-bit performance (±1LSB INL and DNL) over temperature without any adjustments. The DAC output is unbuffered, resulting in a low supply current of 0.3mA and a low offset error of 1LSB. The DAC output range is 0V to VREF. For bipolar operation, matched scaling resistors are provided in the MAX542 for use with an external precision op amp (such as the MAX400), generating a ±VREF output swing. The MAX542 also includes Kelvin-sense connections for the reference and analog ground pins to reduce layout sensitivity. A 16-bit serial word is used to load data into the DAC latch. The 10MHz, 3-wire serial interface is compatible with SPI™/QSPI™/MICROWIRE™, and it also interfaces directly with optocouplers for applications requiring isolation. A power-on reset circuit clears the DAC output to 0V (unipolar mode) when power is initially applied. The MAX541 is available in 8-pin plastic DIP and SO packages. The MAX542 is available in 14-pin plastic DIP and SO packages. Applications: High-Resolution Offset and Gain Adjustment, Industrial Process Control, Automated Test Equipment, Data-Acquisition Systems

The MAX4737/MAX4738/MAX4739 are low-voltage, low on-resistance (RON) quad single-pole/single throw (SPST) analog switches operating from a single +1.8V to +5.5V supply.

The MAX8550/MAX8551 integrate a synchronous-buck PWM controller to generate VDDQ, a sourcing and sinking LDO linear regulator to generate VTT, and a 10mA reference output buffer to generate VTTR. The buck controller drives two external N-channel MOSFETs to generate output voltages down to 0.7V from a 2V to 28V input with output currents up to 15A. The LDO can sink or source up to 1.5A continuous and 3A peak current. Both the LDO output and the 10mA reference buffer output can be made to track the REFIN voltage. These features make the MAX8550/MAX8551 ideally suited for DDR memory applications in desktops, notebooks, and graphic cards. The PWM controller in the MAX8550/MAX8551 utilizes Maxim’s proprietary Quick-PWM™ architecture with programmable switching frequencies of up to 600kHz. This control scheme handles wide input/output voltage ratios with ease and provides 100ns response to load transients while maintaining high efficiency and a relatively constant switching frequency. The MAX8550 offers fully programmable UVP/OVP and skip-mode options ideal in portable applications. Skip mode allows for improved efficiency at lighter loads. The MAX8551, which is targeted towards desktop and graphic-card applications, does not offer the pulse-skip feature. The VTT and VTTR outputs track to within 1% of VREFIN / 2. The high bandwidth of this LDO regulator allows excellent transient response without the need for bulk capacitors, thus reducing cost and board space.

MAX786 is a system-engineered power-supply controller for notebook computers or similar battery-powered equipment. It provides two high-performance step-down (buck) pulse-width modulators (PWMs) for +3.3V and +5V. Other features include dual, low-dropout, micropower linear regulators for CMOS/RTC back-up, and two precision low-battery-detection comparators. High efficiency (95% at 2A; greater than 80% at loads from 5mA to 3A) is achieved through synchronous recti- fication and PWM operation at heavy loads, and Idle ModeTM operation at light loads. The MAX786 uses physically small components, thanks to high operating frequencies (300kHz/200kHz) and a new current-mode PWM architecture that allows for output filter capacitors as small as 30µF per ampere of load. Line- and load-transient responses are terrific, with a high 60kHz unity-gain crossover frequency allowing output transients to be corrected within four or five clock cycles. Low sys- tem cost is achieved through a high level of integration and the use of low-cost, external N-channel MOSFETs. Other features include low-noise, fixed-frequency PWM operation at moderate to heavy loads, and a synchro- nizable oscillator for noise-sensitive applications such as electromagnetic pen-based systems and communi- cating computers. The MAX786 is a monolithic, BiCMOS IC available in fine-pitch, surface-mount SSOP packages.

The MAX774/MAX775/MAX776 inverting switching regulators deliver high efficiency over three decades of load current. A unique current-limited, pulse-frequency-modulated (PFM) control scheme provides the benefits of pulse-width modulation (high efficiency with heavy loads), while using less than 100µA of sup- ply current (vs. 2mA to 10mA for PWM converters). The result is high efficiency over a wide range of loads. These ICs also use tiny external components; their high switching frequency (up to 300kHz) allows for less than 5mm diameter surface-mount magnetics. The MAX774/MAX775/MAX776 accept input voltages from 3V to 16.5V, and have preset output voltages of -5V, -12V, and -15V, respectively. Or, the output voltage can be user-adjusted with two resistors. Maximum VIN - VOUT differential voltage is limited only by the break- down voltage of the chosen external switch transistor. These inverters use external P-channel MOSFET switch- es, allowing them to power loads up to 5W. If less power is required, use the MAX764/MAX765/MAX766 inverting switching regulators with on-board MOSFETs.

The MAX7500/MAX7501/MAX7502 is a temperature sensor product of MAXIM company, which uses high-precision, sigma-delta, analog-to-digital converter (ADC) to accurately measure temperature and provide over-temperature alarm/interrupt/shutdown output through the I2C bus interface.

The MAX349/MAX350 are 8-channel and dual 4-channel serially controlled multiplexers (muxes). These muxes conduct equally well in either direction. On-resistance (100Ω max) is matched between switches to 16Ω max and is flat (10Ω max) over the specified signal range. These CMOS devices can operate continuously with dual power supplies ranging from ±2.7V to ±8V or a single supply between +2.7V and +16V. Each mux can handle rail-to-rail analog signals. The off-leakage current is only 0.1nA at +25°C or 5nA at +85°C. Upon power-up, all switches are off and the internal shift registers are reset to zero. The serial interface is compatible with SPI™/QSPI™ and MICROWIRE™. Functioning as a shift register, it allows data (at DIN) to be clocked in synchronously with the rising edge of clock (SCLK). The shift register’s output (DOUT) enables several MAX349s or MAX350s to be daisy chained. All digital inputs have 0.8V or 2.4V logic thresholds, ensuring both TTL and CMOS-logic compatibility when using ±5V supplies or a single +5V supply.

The MAX2264/MAX2265/MAX2266 evaluation kits (EV kits) simplify evaluation of the MAX2264/MAX2265/ MAX2266 power amplifiers (PAs), which are designed for operation in IS-98-based CDMA, IS-136-based TDMA, and PDC cellular phones operating in the 900MHz range. The kits enable testing of the devices’ RF performance and require no additional support circuitry. The EV kits’ signal inputs and outputs use SMA connectors to facilitate the connection of RF test equipment. Each kit is assembled with either the MAX2264, MAX2265 or MAX2266 and incorporates input and output matching components optimized for the 824MHz to 849MHz RF frequency band. These EV kits are capable of operating at RF frequencies from 750MHz to 1000MHz with the appropriate matching components.

The MAX187 evaluation system consists of a MAX187 evaluation kit and Maxim 68HC16 microcontroller module. The system can function as a data acquisition system, storing samples from the MAX187 in memory and displaying the conversion results on the host computer. It can also evaluate the MAX187's shutdown feature and monitor the supply current in various modes of operation.

The MAX1226/MAX1228/MAX1230 are serial 12-bit analog-to-digital converters (ADCs) with an internal reference and an internal temperature sensor. These devices feature on-chip FIFO, scan mode, internal clock mode, internal averaging, and AutoShutdown™. The maximum sampling rate is 300ksps using an external clock. The MAX1230 has 16 input channels, the MAX1228 has 12 input channels, and the MAX1226 has 8 input channels. All input channels are configurable for single-ended or differential inputs in unipolar or bipolar mode. All three devices operate from a +5V supply and contain a 10MHz SPI™/QSPI™/MICROWIRE™-compatible serial port. The MAX1230 is available in 28-pin 5mm x 5mm QFN with exposed pad and 24-pin QSOP packages. The MAX1226/MAX1228 are only available in QSOP packages. All three devices are specified over the extended -40°C to +85°C temperature range.

The MAX1132/MAX1133 are 200ksps, 16-bit ADCs. These serially interfaced ADCs connect directly to SPI™, QSPI™, and MICROWIRE™ devices without external logic. They combine an input scaling network, internal track/hold, clock, a +4.096V reference, and three general-purpose digital output pins (for external multiplexer or PGA control) in a 20-pin SSOP package. The excellent dynamic performance (SINAD ≥ 85dB), high-speed (200ksps), and low power (7.5mA) of these ADCs, make them ideal for applications such as indus- trial process control, instrumentation, and medical applications. The MAX1132 accepts input signals of 0 to +12V (unipolar) or ±12V (bipolar), while the MAX1133 accepts input signals of 0 to +4.096V (unipo- lar) or ±4.096V (bipolar). Operating from a single +4.75V to +5.25V analog supply and a +4.75V to +5.25V digital supply, power-down modes reduce current consumption to 1mA at 10ksps and further reduce supply current to less than 20µA at slower data rates. A serial strobe output (SSTRB) allows direct con- nection to the TMS320 family of digital signal proces- sors. The MAX1132/MAX1133 user can select either the internal clock, or an external serial-interface clock for the ADC to perform analog-to-digital conversions. The MAX1132/MAX1133 feature internal calibration cir- cuitry to correct linearity and offset errors. On-demand calibration allows the user to optimize performance. Three user-programmable logic outputs are provided for the control of a multiplexer or PGA.