General Description
The MX7705 low-power, 2-channel, serial-output analog-to-digital converter (ADC) includes a sigma-delta modulator with a digital filter to achieve 16-bit resolution with no missing codes. This ADC is pin compatible and software compatible with the AD7705. The MX7705 features an on-chip input buffer and programmable-gain amplifier (PGA). The device offers an SPI™-/QSPI™-/MICROWIRE™-compatible serial interface.
The MX7705 operates from a single 2.7V to 5.25V supply. The operating supply current is 320μA (typ) with a 3V supply. Power-down mode reduces the supply current to 2μA (typ).
Self-calibration and system calibration allow the MX7705 to correct for gain and offset errors. Excellent DC performance (±0.003% FSR INL) and low noise (650nV) make the MX7705 ideal for measuring low-frequency signals with a wide dynamic range. The device accepts fully differential bipolar/unipolar inputs. An internal input buffer allows for input signals with high source impedances. An on-chip digital filter, with a programmable cutoff and output data rate, processes the output of the sigma-delta modulator. The first notch frequency of the digital filter is chosen to provide 150dB rejection of common-mode 50Hz or 60Hz noise and 98dB rejection of normal-mode 50Hz or 60Hz noise. A PGA and digital filtering allow signals to be directly acquired with little or no signal-conditioning requirements.
The MX7705 is available in 16-pin PDIP, SO, and TSSOP packages.
Features
*Pin Compatible and Software Compatible with the AD7705
*16-Bit Sigma-Delta ADC
*Two Fully Differential Input Channels
*0.003% Integral Nonlinearity with No Missing Codes
*Interface with Schmitt Triggers on Inputs
*Internal Analog Input Buffers
*PGA from 1 to 128
*Single (2.7V to 3.6V) or (4.75V to 5.25V) Supply
*Low Power
-1mW (max), 3V Supply
-2μA (typ) Power-Down Current
*SPI-/QSPI-/MICROWIRE-Compatible 3-Wire Serial Interface
*16-Pin PDIP, SO, and TSSOP Packages
Applications
*Industrial Instruments
*Weigh Scales
*Strain-Gauge Measurements
*Loop-Powered Systems
*Flow and Gas Meters
*Medical Instrumentation
*Pressure Transducers
*Thermocouple Measurements
*RTD Measurements
MX7705EPE, MX7705EWE, MX7705EUE
'Maxim' related articles 34
- 2009/10/15 MX7705 - 16-Bit, Low-Power, 2-Channel, Sigma-Delta ADC
- 2009/08/24 MAX14527 - Adjustable Overvoltage Protector with High Accuracy
- 2009/07/07 MAX202E - 15kV ESD-Protected, +5V RS-232 Transceivers
- 2009/05/11 MAX1907A - Quick-PWM Master Controllers for Voltage-Positioned CPU Core Power Supplies (IMVP-IV)
- 2009/03/14 MAX6730 - Single-/Dual-/Triple-Voltage uP Supervisory Circuits with Independent Watchdog Output
- 2009/01/17 MAX19999 - Dual, SiGe High-Linearity, 3000MHz to 4000MHz Downconversion Mixer with LO Buffer
- 2008/12/01 MAX8741 - 500kHz Multi-Output Power-Supply Controllers with High Impedance in Shutdown
- 2008/05/22 MAX6639 - 2-Channel Temperature Monitor with Dual, Automatic, PWM Fan-Speed Controller
- 2008/02/29 DS3991 - Low-Cost CCFL Controller
- 2008/02/18 MAX6351 - Dual/Triple-Voltage μP Supervisory Circuits
The MAX14527/MAX14528 overvoltage protection devices feature a low 100mΩ (typ) RON internal FET and protect low-voltage systems against voltage faults up to +28V. When the input voltage exceeds the overvoltage threshold, the internal FET is turned off to prevent damage to the protected components.
The overvoltage protection threshold can be adjusted with optional external resistors to any voltage between 4V and 8V. With the OVLO input set below the external OVLO select voltage, the MAX14527/MAX14528 automatically choose the internal ±2.5% accurate trip thresholds. The internal overvoltage thresholds (OVLO) are preset to 5.75V typical (MAX14527) or 6.76V typical (MAX14528). The MAX14527/MAX14528 are also protected against overcurrent events with an internal thermal shutdown.
The MAX14527/MAX14528 are offered in a small, 8-pin TDFN-EP package and operate over the -40°C to +85°C extended temperature range.
Features
*Input Voltage Protection Up to +28V
*Preset Internal ±2.5% Accurate OVLO Thresholds
-5.75V (MAX14527)
-6.76V (MAX14528)
*Adjustable Overvoltage Protection Trip Level
*Integrated 100mΩ (typ) n-Channel MOSFET Switch
*Soft-Start to Minimize In-Rush Current
*Automatic Overvoltage Protection Trip-Level Selection
*Internal 15ms Startup Delay
*Thermal Shutdown Protection
*8-Pin TDFN (2mm x 2mm) Package
*-40°C to +85°C Operating Temperature Range
Applications
*Cell Phones
*Media Players
*PDAs and Palmtop Devices
MAX14528, MAX14527ETA+T, MAX14528ETA+T
The MAX202E–MAX213E, MAX232E/MAX241E line drivers/receivers are designed for RS-232 and V.28 communications in harsh environments. Each transmitter output and receiver input is protected against ±15kV electrostatic discharge (ESD) shocks, without latchup. The various combinations of features are outlined in the Selector Guide. The drivers and receivers for all ten devices meet all EIA/TIA-232E and CCITT V.28 specifications at data rates up to 120kbps, when loaded in accordance with the EIA/TIA-232E specification.
The MAX211E/MAX213E/MAX241E are available in 28-pin SO packages, as well as a 28-pin SSOP that uses 60% less board space. The MAX202E/MAX232E come in 16-pin TSSOP, narrow SO, wide SO, and DIP packages. The MAX203E comes in a 20-pin DIP/SO package, and needs no external charge-pump capacitors. The MAX205E comes in a 24-pin wide DIP package, and also eliminates external charge-pump capacitors. The MAX206E/MAX207E/MAX208E come in 24-pin SO, SSOP, and narrow DIP packages. The MAX232E/MAX241E operate with four 1μF capacitors, while the MAX202E/MAX206E/MAX207E/MAX208E/ MAX211E/MAX213E operate with four 0.1μF capacitors, further reducing cost and board space.
Next-Generation Device Features
*For Low-Voltage Applications
MAX3222E/MAX3232E/MAX3237E/MAX3241E/MAX3246E: ±15kV ESD-Protected Down to 10nA, +3.0V to +5.5V, Up to 1Mbps, True RS-232 Transceivers (MAX3246E Available in a UCSP™ Package)
*For Low-Power Applications
MAX3221/MAX3223/MAX3243: 1μA Supply Current, True +3V to +5.5V RS-232 Transceivers with Auto-Shutdown™
*For Space-Constrained Applications
MAX3233E/MAX3235E: ±15kV ESD-Protected, 1μA, 250kbps, +3.0V/+5.5V, Dual RS-232 Transceivers with Internal Capacitors
*For Low-Voltage or Data Cable Applications
MAX3380E/MAX3381E: +2.35V to +5.5V, 1μA, 2Tx/2Rx RS-232 Transceivers with ±15kV ESDProtected I/O and Logic Pins
Applications
*Notebook, Subnotebook, and Palmtop Computers
*Battery-Powered Equipment
*Hand-Held Equipment
MAX213E, MAX232E, MAX241E, MAX202ECSE, MAX202ECPE
MAX1907A - Quick-PWM Master Controllers for Voltage-Positioned CPU Core Power Supplies (IMVP-IV)
Maxim 2009/05/11 09:25The MAX1907A/MAX1981A are single-phase, Quick-PWM™ master controllers for IMVP-IV™ CPU core supplies. Multi-phase operation is achieved using a Quick-PWM slave controller (MAX1980). Multiphase operation reduces input ripple current requirements and output voltage ripple while easing component selection and layout difficulties. The MAX1907A/MAX1981A include active voltage positioning with adjustable gain and offset, reducing power dissipation and bulk output capacitance requirements.
The MAX1907A/MAX1981A are intended for two different notebook CPU core applications: either bucking down the battery directly, or 5V system supply to create the core voltage. The single-stage conversion method allows these devices to directly step down high-voltage batteries for the highest possible efficiency. Alternatively, two-stage conversion (stepping down the 5V system supply instead of the battery) at higher switching frequency provides the minimum possible physical size.
The MAX1907A/MAX1981A meet the IMVP-IV specifications and include logic to interface with the CPU power good signals from the VCCP and VCCMCH rails within the system. The regulator features power-up sequencing, automatically ramping up to the Intel-specified boot voltage. The MAX1907A/MAX1981A feature independent four-level logic inputs for setting the boot voltage (B0–B2) and the suspend voltage (S0–S2).
The MAX1907A/MAX1981A include output undervoltage protection, thermal protection, and system power-OK (SYSPOK) input/output. When any of these protection features detect a fault, the MAX1907A/MAX1981A immediately shut down. Additionally, the MAX1907A includes overvoltage protection.
The MAX1907A/MAX1981A are available in a thin 40-pin QFN package.
Features
*Quick-PWM Master Controllers
*Multiphase Conversion with Slave Controller (MAX1980)
*Active Voltage Positioning with Adjustable Gain and Offset
*Adjustable Slew Rate Control
*±0.75% VOUT Accuracy Over Line, Load, and Temperature
*6-Bit On-Board DAC (16mV Increments)
*0.700V to 1.708V Output Adjust Range
*Selectable 200kHz/300kHz/550kHz/1000kHz Switching Frequency
*2V to 28V Battery Input Voltage Range
*Drive Large Synchronous Rectifier MOSFETs
*Output Overvoltage Protection (MAX1907A Only)
*Undervoltage and Thermal Fault Protection
*Power Sequencing and Selectable Boot Voltage
*Low-Profile 40-Pin Thin QFN, 6mm ✕ 6mm Package
Applications
*IMVP-IV™ Notebook Computers
*Single-Phase CPU Core Supply
*Multiphase CPU Core Supply
*Voltage-Positioned Step-Down Converters
*Servers/Desktop Computers
MAX1981A, MAX1907AETL, MAX1981AETL
MAX6730 - Single-/Dual-/Triple-Voltage uP Supervisory Circuits with Independent Watchdog Output
Maxim 2009/03/14 10:29The MAX6730–MAX6735 single-/dual-/triple-voltage microprocessor (μP) supervisors feature a watchdog timer and manual reset capability. The MAX6730–MAX6735 offer factory-set reset thresholds for monitoring voltages from +0.9V to +5V and an adjustable reset input for monitoring voltages down to +0.63V. The combination of these features significantly improves system reliability and accuracy when compared to separate ICs or discrete components.
The active-low reset output asserts and remains asserted for the reset timeout period after all the monitored voltages exceed their respective thresholds. Multiple factoryset reset threshold combinations reduce the number of external components required. The MAX6730/MAX6731 monitor a single fixed voltage, the MAX6732/MAX6733 monitor two fixed voltages, and the MAX6734/MAX6735 monitor two fixed voltages and one adjustable voltage. All devices are offered with six minimum reset timeout periods ranging from 1.1ms to 1120ms.
The MAX6730–MAX6735 feature a watchdog timer with an independent watchdog output. The watchdog timer prevents system lockup during code execution errors. A watchdog startup delay of 54s after reset asserts allows system initialization during power-up. The watchdog operates in normal mode with a 1.68s delay after initialization. The MAX6730/MAX6732/MAX6734 provide
an active-low, open-drain watchdog output. The MAX6731/MAX6733/MAX6735 provide an active-low, push-pull watchdog output.
Other features include a manual reset input (MAX6730/MAX6731/MAX6734/MAX6735) and push-pull reset output (MAX6731/MAX6733/MAX6735) or open-drain reset output (MAX6730/MAX6732/MAX6734). The MAX6730–MAX6733 are offered in a tiny SOT23-6 package. The MAX6734/MAX6735 are offered in a space-saving SOT23-8 package. All devices are fully specified over the extended temperature range (-40°C to +85°C).
Features
*VCC1 (Primary Supply) Reset Threshold Voltages from +1.575V to +4.63V
*VCC2 (Secondary Supply) Reset Threshold Voltages from +0.79V to +3.08V
*Adjustable RSTIN Threshold for Monitoring Voltages Down to +0.63V (MAX6734/MAX6735 Only)
*Six Reset Timeout Options
*Watchdog Timer with Independent Watchdog Output 35s (min) Initial Watchdog Startup Period 1.12s (min) Normal Watchdog Timeout Period
*Manual Reset Input (MAX6730/MAX6731/MAX6734/MAX6735)
*Guaranteed Reset Valid down to VCC1 or VCC2 = +0.8V
*Push-Pull RESET or Open-Drain RESET Output
*Immune to Short VCC Transients
*Low Supply Current: 14μA (typ) at +3.6V
*Small 6-Pin and 8-Pin SOT23 Packages
Applications
*Multivoltage Systems
*Telecom/Networking Equipment
*Computers/Servers
*Portable/Battery-Operated Equipment
*Industrial Equipment
*Printer/Fax
*Set-Top Boxes
MAX6730UTLD3-T, MAX6730UTSD3-T, MAX6730UTRD3-T
MAX19999 - Dual, SiGe High-Linearity, 3000MHz to 4000MHz Downconversion Mixer with LO Buffer
Maxim 2009/01/17 09:49The MAX19999 dual-channel downconverter provides 8.3dB of conversion gain, +24dBm input IP3, +11.4dBm 1dB input compression point, and a noise figure of 10.5dB for 3000MHz to 4000MHz WiMAX™ and LTE diversity receiver applications. With an optimized LO frequency
range of 2650MHz to 3700MHz, this mixer is ideal for low-side LO injection architectures.
In addition to offering excellent linearity and noise performance, the MAX19999 also yields a high level of component integration. This device includes two double-balanced passive mixer cores, two LO buffers, and a pair of differential IF output amplifiers. Integrated onchip baluns allow for single-ended RF and LO inputs.
The MAX19999 requires a nominal LO drive of 0dBm and a typical supply current of 388mA at VCC = +5.0V or 279mA at VCC = +3.3V.
The MAX19999 is pin compatible with the MAX19997A 1800MHz to 2900MHz mixer and pin similar with the MAX19985/MAX19985A and MAX19995/MAX19995A series of 700MHz to 2200MHz mixers, making this entire family of downconverters ideal for applications where a common PCB layout is used across multiple frequency bands.
The MAX19999 is available in a compact 6mm x 6mm, 36-pin thin QFN package with an exposed pad. Electrical performance is guaranteed over the extended temperature range, from TC = -40°C to +85°C.
Features
*3000MHz to 4000MHz RF Frequency Range
*2650MHz to 3700MHz LO Frequency Range
*50MHz to 500MHz IF Frequency Range
*8.3dB Conversion Gain
*+24dBm Input IP3
*10.5dB Noise Figure
*+11.4dBm Input 1dB Compression Point
*74dBc Typical 2 x 2 Spurious Rejection at PRF = -10dBm
*Dual Channels Ideal for Diversity Receiver Applications
*Integrated LO Buffer
*Integrated LO and RF Baluns for Single-Ended Inputs
*Low -3dBm to +3dBm LO Drive
*Pin Compatible with the MAX19997A 1800MHz to 2900MHz Mixer
*Pin Similar to the MAX9995/MAX9995A and MAX19995/MAX19995A 1700MHz to 2200MHz
Mixers and the MAX9985/MAX9985A and MAX19985/MAX19985A 700MHz to 1000MHz
Mixers
*39dB Channel-to-Channel Isolation
*Single +5.0V or +3.3V Supply
*External Current-Setting Resistors Provide Option for Operating Device in Reduced-Power/Reduced-Performance Mode
Applications
*3.5GHz WiMAX and LTE Base Stations
*Fixed Broadband Wireless Access
*Microwave Links
*Wireless Local Loop
*Private Mobile Radios
*Military Systems
MAX19999ETX+, MAX19999ETX+T
MAX8741 - 500kHz Multi-Output Power-Supply Controllers with High Impedance in Shutdown
Maxim 2008/12/01 09:46The MAX8741/MAX8742 are buck-topology, step-down, switch-mode, power-supply controllers that generate logic-supply voltages in battery-powered systems. These high-performance, dual/triple-output devices include onboard power-up sequencing, power-good signaling with
delay, digital soft-start, secondary winding control, lowdropout circuitry, internal frequency-compensation networks, and automatic bootstrapping.
Up to 97% efficiency is achieved through synchronous rectification and Maxim’s proprietary Idle Mode™ control scheme. Efficiency is greater than 80% over a 1000:1 load-current range, which extends battery life in system suspend or standby mode. Excellent dynamic response corrects output load transients within five clock cycles.
Strong 1A on-board gate drivers ensure fast external n-channel MOSFET switching.
These devices feature a logic-controlled and synchronizable, fixed-frequency, pulse-width-modulation (PWM) operating mode. This reduces noise and RF interference in sensitive mobile communications and pen-entry applications.
Asserting the SKIP pin enables fixed-frequency mode, for lowest noise under all load onditions.
The MAX8741/MAX8742 include two PWM regulators, adjustable from 2.5V to 5.5V with fixed 5.0V and 3.3V modes. All these devices include secondary feedback regulation, and the MAX8742 contains a 12V/120mA linear regulator. The MAX8741 includes a secondary feedback
input (SECFB), plus a control pin (STEER) that selects which PWM (3.3V or 5V) receives the secondary feedback signal. SECFB provides a method for adjusting the secondary winding voltage regulation point with an external resistor-divider, and is intended to aid in creating
auxiliary voltages other than fixed 12V.
The MAX8741/MAX8742 contain internal output overvoltage- and undervoltage-protection features.
Features
*97% Efficiency
*4.2V to 30V Input Range
*2.5V to 5.5V Dual Adjustable Outputs
*Selectable 3.3V and 5V Fixed or Adjustable Outputs (Dual Mode™)
*12V Linear Regulator
*Adjustable Secondary Feedback (MAX8741)
*5V/50mA Linear-Regulator Output
*Precision 2.5V Reference Output
*Programmable Power-Up Sequencing
*Power-Good (RESET) Output
*Output Overvoltage Protection
*Output Undervoltage Shutdown
*333kHz/500kHz Low-Noise, Fixed-Frequency Operation
*Low-Dropout, 98% Duty-Factor Operation
*2.5mW Typical Quiescent Power (12V Input, Both SMPSs On)
*4μA Typical Shutdown Current
Applications
*Notebook and Subnotebook Computers
*PDAs and Mobile Communicators
*Desktop CPU Local DC-DC Converters
MAX8741EAI, MAX8741ETJ, MAX8742EAI, MAX8742ETJ
MAX6639 - 2-Channel Temperature Monitor with Dual, Automatic, PWM Fan-Speed Controller
Maxim 2008/05/22 09:37General Description
The MAX6639 monitors its own temperature and one external diode-connected transistor or the temperatures of two external diode-connected transistors, typically available in CPUs, FPGAs, or GPUs.
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.
Temperature data can be read at any time over the SMBus, and three programmable alarm outputs can be used to generate interrupts, throttle signals, or overtemperature shutdown signals.
The temperature data is also used by the internal dual-PWM fan-speed controller to adjust the speed of up to two cooling fans, thereby minimizing noise when the system is running cool, but providing maximum cooling when power dissipation increases.
Speed control is accomplished by tachometer feedback from the fan, so that the speed of the fan is controlled, not just the PWM duty cycle.
Accuracy of speed measurement is ±4%.
The MAX6639 is available in 16-pin QSOP and 16-pin thin QFN 5mm x 5mm packages.
It operates from 3.0V to 3.6V and consumes just 500μA of supply current.
Features
* Two Thermal-Diode Inputs
* Up to 25kHz PWM Output Frequency
* Three Selectable SMBus Addresses
* Local Temperature Sensor
* 1°C Remote Temperature Accuracy
* Two PWM Outputs for Fan Drive (Open Drain; Can be Pulled Up to +13.5V)
* Programmable Fan-Control Characteristics
* Automatic Fan Spin-Up Ensures Fan Start
* Controlled Rate-of-Change Ensures Unobtrusive Fan-Speed Adjustments
* ±3% Fan-Speed Measurement Accuracy
* Temperature Monitoring Begins at POR for Fail- Safe System Protection
* OT and THERM Outputs for Throttling or Shutdown
* Measures Temperatures Up to +150°C
* MAX6639F is Optimized for n = 1.021 for Penryn Compatability
Applications
* Desktop Computers
* Notebook Computers
* Projectors
* Servers
* Networking Equipment
MAX6639AEE
MAX6639ATE
MAX6639FAEE
MAX6639F
General Description
The DS3991 is a controller for cold-cathode fluorescent lamps (CCFLs) that are used to backlight liquid-crystal displays (LCDs). The DS3991 is available for both push-pull and half-bridge drive topologies.
The DS3991 converts a DC voltage (5V to 24V) to the high-voltage (300VRMS to 1400VRMS) AC waveform that is required to power the CCFLs. The push-pull and halfbridge drive schemes use a minimal number of external components, which reduces component and assembly cost and makes the printed circuit board (PCB) design easy to implement. Both drive schemes provide an efficient DC to AC conversion and produce near-sinusoidal waveforms.
Features
* CCFL Controller for Backlighting LCD Panels
* Minimal External Components Required
* Lamp Fault Monitoring for Lamp-Open, Lamp- Overcurrent, Failure-to-Strike, and Overvoltage
Conditions
* Accurate (±5%) On-Board Oscillator for Lamp Frequency (40kHz to 80kHz)
* Accurate (±5%) On-Board Oscillator for DPWM Burst-Dimming Frequency (80Hz to 300Hz)
* Device Supply Undervoltage Lockout
* Inverter Supply Undervoltage and Overvoltage Lockouts
* Soft-Start on Burst-Dimming Minimizes Audible Transformer Noise
* Strike Frequency Boost
* 100% to < 10% Dimming Range
* Low Cost
* Single-Supply Operation Range: 4.5V to 5.5V
* Temperature Range: -40°C to +85°C
* 16-Pin SO Package (150 mils)
Applications
LCD PC Monitors
LCD TVs
The MAX6351–MAX6360 microprocessor (μP) supervisors with multiple reset voltages significantly improve system reliability and accuracy compared to separate ICs or discrete components. If any input supply voltage drops below its associated preset threshold, all reset outputs are asserted. In addition, the outputs are valid as long as either input supply voltage remains greater than +1.0V.
All devices in this series have an active-low debounced manual reset input. In addition, the MAX6358/MAX6359/ MAX6360 offer a watchdog-timer input with a 46.4s startup
timeout period and a 2.9s timeout period. The MAX6355/MAX6356/MAX6357 offer an additional voltage monitor input to monitor a third voltage.
The MAX6351 features two active-low, push-pull reset outputs, one is referenced to VCC1 and the other is referenced to VCC2. The MAX6353/MAX6356/MAX6359 offer an active-low, push-pull reset output referenced to VCC1.
The MAX6354/MAX6357/MAX6360 offer an active-low, push-pull reset output referenced to VCC2.
All these devices are offered with a wide variety of voltage threshold levels, as shown in the Voltage Threshold Levels table. They are available in 5- and 6-pin SOT23 packages and operate over the extended (-40°C to +85°C) temperature range.
Features
* Precision Monitoring of Multiple +1.8V, +2.5V, +3.0V, +3.3V, and +5V Power-Supply Voltages
* Precision Factory-Set Power-Supply Reset Thresholds
* 20μA Supply Current
* 100ms min Power-On Reset Pulse Width
* Debounced TTL/CMOS-Compatible Manual-Reset Input
* Watchdog Timer 46.4s Startup Timeout 2.9s Normal Timeout
* Fully Guaranteed Over Temperature
* Guaranteed RESET Valid to VCC1 = 1V or VCC2 = 1V
* Power-Supply Transient Immunity
* No External Components for Dual-Voltage Systems
* Small 5- and 6-Pin SOT23 Packages
* Low Cost
MAX6352
MAX6353
MAX6354
MAX6355
MAX6356
MAX6357
MAX6358