General 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

 

MAX6639 - 2-Channel Temperature Monitor with Dual, Automatic, PWM Fan-Speed Controller

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

DS3991V+C
 

DS3991 - Low-Cost CCFL Controller

General Description
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  

MAX6351 - Dual/Triple-Voltage μP Supervisory Circuits

General Description
The MAX16047/MAX16049 EEPROM-configurable system managers monitor, sequence, and track multiple system voltages. The MAX16047 manages up to twelve system voltages simultaneously, and the MAX16049 manages up to eight supply voltages. These devices integrate an analog- to-digital converter (ADC) for monitoring supply voltages, and configurable outputs for sequencing and tracking supplies (during power-up and power-down).
Nonvolatile EEPROM registers are configurable for storing upper and lower voltage limits, setting timing and sequencing requirements, and for storing critical fault data for read back following failures.
An internal 1% accurate 10-bit ADC measures each input and compares the result to one upper, one lower, and one selectable upper or lower limit. A fault signal asserts when a monitored voltage falls outside the set limits. Up to three independent fault output signals are configurable to assert under various fault conditions.
The integrated sequencer/tracker allows precise control over the power-up and power-down order of up to twelve (MAX16047) or up to eight (MAX16049) power supplies.
Four channels (EN_OUT1–EN_OUT4) support closedloop tracking using external series MOSFETs. Six outputs (EN_OUT1–EN_OUT6) are configurable with chargepump outputs to directly drive MOSFETs without closedloop tracking.
The MAX16047/MAX16049 include six programmable general-purpose inputs/outputs (GPIOs). In addition to serving as EEPROM-configurable I/O pins, the GPIOs are also configurable as dedicated fault outputs, as a watchdog input or output (WDI/WDO), or as a manual reset (MR).
The MAX16047/MAX16049 feature two methods of fault management for recording information during critical fault events. The fault logger records a failure in the internal EEPROM and sets a lock bit protecting the stored fault data from accidental erasure.
An I2C/SMBus™-compatible or a JTAG serial interface configures the MAX16047/MAX16049. These devices are offered in a 56-pin 8mm x 8mm TQFN package and are fully specified from -40°C to +85°C.

Features
* Operates from 3V to 14V
* 1% Accurate 10-Bit ADC Monitors 12/8 Inputs
* 12/8 Monitored Inputs with One Overvoltage/ One Undervoltage/One Selectable Limit
* Nonvolatile Fault Event Logger
* Power-Up and Power-Down Sequencing Capability
* 12/8 Outputs for Sequencing/Power-Good Indicators
* Closed-Loop Tracking for Up to Four Channels
* Two Programmable Fault Outputs and One Reset Output
* Six General-Purpose Input/Outputs Configurable as:
Dedicated Fault Output
Watchdog Timer Function
Manual Reset
* I2C/SMBus-Compatible and JTAG Interface
* EEPROM-Configurable Time Delays and Thresholds
* 100 Bytes of Internal User EEPROM
* 56-Pin (8mm x 8mm) TQFN Package
* -40°C to +85°C Operating Temperature Range

MAX16047ETN
MAX16049ETN

 

MAX16047 - 12-Channel/8-Channel EEPROM-Programmable System Managers with Nonvolatile Fault Registers

General Description
The MAX1556/MAX1557 are low-operating-current (16μA), fixed-frequency step-down regulators. High efficiency, low-quiescent operating current, low dropout, and minimal (27μA) quiescent current in dropout make these converters ideal for powering portable devices
from 1-cell Li-ion or 3-cell alkaline/NiMH batteries. The MAX1556 delivers up to 1.2A; has pin-selectable 1.8V, 2.5V, and 3.3V outputs; and is also adjustable. The MAX1557 delivers up to 600mA; has pin-selectable 1V, 1.3V, and 1.5V outputs; and is also adjustable.
The MAX1556/MAX1557 contain a low-on-resistance internal MOSFET switch and synchronous rectifier to maximize efficiency and dropout performance while minimizing external component count. A proprietary topology offers the benefits of a high fixed-frequency operation while still providing excellent efficiency at both light and full loads. A 1MHz PWM switching frequency keeps components small. Both devices also feature an adjustable soft-start to minimize battery transient loading.
The MAX1556/MAX1557 are available in a tiny 10-pin TDFN (3mm x 3mm) package.

Applications
PDAs and Palmtop Computers
Cell Phones and Smart Phones
Digital Cameras and Camcorders
Portable MP3 and DVD Players
Hand-Held Instruments

Features
* Up to 97% Efficiency
* 95% Efficiency at 1mA Load Current
* Low 16μA Quiescent Current
* 1MHz PWM Switching
* Tiny 3.3μH Inductor
* Selectable 3.3V, 2.5V, 1.8V, 1.5V, 1.3V, 1.0V, and Adjustable Output
* 1.2A Guaranteed Output Current (MAX1556)
* Voltage Positioning Optimizes Load-Transient Response
* Low 27μA Quiescent Current in Dropout
* Low 0.1μA Shutdown Current
* No External Schottky Diode Required
* Analog Soft-Start with Zero Overshoot Current
* Small, 10-Pin, 3mm x 3mm TDFN Package

MAX1557
MAX1556ETB
MAX1557ETB

 

MAX1556 - 16μA IQ, 1.2A PWM Step-Down DC-DC Converters