Description
The A4447 is a 2 A, high efficiency general-purpose buck regulator designed for a wide variety of applications. The output voltage is adjustable from 0.8 to 24 V, based on a resistor divider and the 0.8 V ± 2 % reference. External components include an external clamping diode, inductor, and filter capacitor. The off-time is determined by an external resistor to ground. It operates in both continuous and discontinuous modes to maintain light load regulation. An internal blanking circuit is used to filter out transients due to the reverse recovery of the external clamp diode. Typical blanking time is 200 ns.
This new device is ideal for various end products including applications with 8 to 50 V input voltage range and require up to 2 A output current, such as uninterruptible power supplies, point of sale (POS) applications, and industrial applications with 24 or 36 V bus.
Features and Benefits
*Wide input voltage range: 8 to 50 V
*Integrated low RDS(on) DMOS switch
*2 A continuous output current
*Adjustable fixed off-time
*Highly efficient
*Adjustable output: 0.8 to 24 V
*Small package with exposed thermal pad
Applications include
*Printer power supplies
*Office automation equipment
*POS thermal, laser, photo, and inkjet printers
*Tape drives
*Industrial applications
A4447SLJTR-T
Description
The ATS617 gear-tooth sensor IC is a peak-detecting device that uses automatic gain control and an integrated capacitor to provide extremely accurate gear edge detection down to low operating speeds. Each device consists of a high-temperature plastic shell that holds together a samarium-cobalt pellet, a pole piece, and a differential open-collector Hall IC that has been optimized to the magnetic circuit. This small package can be easily assembled and used in conjunction with a wide variety of gear shapes and sizes.
The technology used for this device is Hall-effect based. The device incorporates a dual-element Hall IC that switches in response to differential magnetic signals created by ferromagnetic targets. The sophisticated processing circuitry contains an A-to-D converter that self-calibrates (normalizes) the internal gain of the device to minimize the effect of air gap variations. The patented peak-detecting filter circuit provides immunity to magnet and system offsets and has the ability to discriminate relatively fast changes such as those caused by tilt, gear wobble, and eccentricities. This easy-tointegrate solution provides first falling edge detection and stable operation to extremely low rpm. The ATS617 can be used as a replacement for the ATS616.
The ATS617 is ideal for use in systems that gather speed, position, and timing information using gear-tooth-based configurations. This device is particularly suited to those applications that require extremely accurate duty cycle control or accurate edge-detection, such as automotive camshaft sensing.
The ATS617 is provided in a 4-pin SIP that is Pb (lead) free, with a 100% matte tin plated leadframe.
Features and Benefits
*Self-calibrating for tight timing accuracy
*First-tooth detection
*Immunity to air gap variation and system offsets
*Immunity to signature tooth offsets
*Integrated capacitor provides analog peak and valley information
*Low timing-accuracy drift with temperature changes
*Low radiated emissions
*Integrated, series resistor on VCC pin for improved transient immunity
*Large air gap capability
*Small, integrated package
*Optimized magnetic circuit
*Undervoltage lockout (UVLO)
*Wide operating voltage range
ATS617LSGTN-T
Description
The SCM1106M inverter power module (IPM) device provides a robust, highly-integrated solution for optimally controlling 3-phase motor power inverter systems and variable speed control systems used in energy-conserving designs to drive motors of residential and commercial appliances. These ICs take 85 to 253 VAC input voltage, and 10 A (continuous) output current. They can withstand voltages of up to 600 V (IGBT breakdown voltage).
The SCM1100M series employs a new, small-footprint proprietary DIP package. The IC itself consists of all of the necessary power elements (six IGBTs), pre-drive ICs (three), and flyback diodes (six), needed to configure the main circuit of an inverter, as well as a bootstrap circuit (three bootstrap diodes and three boot resistors) as a high-side drive power supply. This enables the main circuit of the inverter to be configured with fewer external components than traditional designs.
Applications include residential white goods (home appliances)
and commercial appliance motor control, such as:
*Air conditioner fan motor
*Refrigerator compressor motor
*Washing machine main motor
*Air conditioner compressor motor
Features and Benefits
*Each half-bridge circuit consists of a pre-driver circuit that is completely independent from the others
*Protection against simultaneous high- and low-side turning on
*Bootstrap diodes with series resistors for suppressing inrush current are incorporated
*CMOS compatible input (3.3 to 5 V)
*Designed to minimize simultaneous current through both high- and low-side IGBTs by optimizing gate drive resistors
*UVLO protection with auto restart
*Overcurrent protection with off-time period adjustable by an external capacitor
*Fault (FO indicator) signal output at protection activation: UVLO (low side only), OCP, and STP
*Proprietary power DIP package
Description
The A1442 is a full-bridge motor driver designed to drive low-voltage, brushless dc motors. Commutation of the motor is achieved by use of a single Hall element sensor to detect the rotational position of an alternating-pole ring magnet. A highdensity CMOS semiconductor process allows the integration of all the necessary electronics. This includes the Hall element sensor, the motor control circuitry, and the full output bridge. Low-voltage design techniques have been employed to achieve full device functionality down to low VDD values. This fully integrated single chip solution provides enhanced reliability (including reverse battery protection and output short circuit protection) and eliminates the need for any external support components.
The A1442 employs a soft-switching algorithm to reduce audible switching noise and EMI interference. A micropower sleep mode can be enabled by an external signal, to reduce current consumption for battery management in portable electronic devices. This feature allows the removal of a FET transistor for switching the device on and off.
The A1442 is optimized for vibration motor applications in cellular phones, pagers, electronic toothbrushes, hand-held video game controllers, and low power fan motors.
The small package outline and low profile make this device ideally suited for use in applications where printed circuit board area and component headroom are at a premium. It is available in a lead (Pb) free, 6 pin MLP/DFN microleadframe package, with an exposed pad for enhanced thermal dissipation.
Features and Benefits
*Low voltage operation
*Reverse voltage protection on VDD and S¯ ¯ L¯ E¯ E¯ Ppins
*Output short circuit and thermal shutdown protections
*Soft switching algorithm to reduce audible switching noise and EMI interference
*Unidirectional working mode provides motor rotation in one direction
*Hall chopper stabilization technique for precise signal response over operating range
*Sleep mode pin allowing external logic signal enable/disable to reduce average power consumption
*Antistall feature guarantees continuous rotation
* Low current consumption sleep mode
*Single-chip solution for high reliability
*Miniature MLP/DFN package
A1442EEWLT-P
Description
The A1172 is an ultra-sensitive, pole-independent Hall-effect switch with a latched digital output. It features operation at low supply currents and voltages, making it ideal for batteryoperated electronics. The 1.65 to 3.5 V operating supply voltage and unique clocking algorithm reduce the average operating power requirements to less than 15 μW with a 2.75 V supply.
The A1172 has two push-pull output structures. Omnipolar activation for the output function is available on each output structure. As such, either a north or south pole of sufficient strength turns the available outputs off or on. The A1172 contains two complementary outputs. Therefore, for a fixed magnetic field, one output will be in a high voltage state and one output will be in a low voltage state.
Improved stability is made possible through dynamic offset cancellation using chopper stabilization, which reduces the residual offset voltage normally caused by device overmolding, temperature dependencies, and thermal stress. This device
Features and Benefits
*Micropower operation
*Operation with either north or south poleno magnetic orientation required during assembly
*1.65 to 3.5 V battery operation
*Chopper stabilization
-Superior temperature stability
-Extremely low switchpoint drift
-Insensitive to physical stress
*Sol id state reliability
*Small size: WLCSP (≈ 1 mm × 1 mm × 0.5 mm)
*Complementary, push-pull outputs eliminate need for pull-up resistor
Description
The A3986 is a dual full-bridge gate driver with integrated microstepping translator suitable for driving a wide range of higher power industrial bipolar 2-phase stepper motors (typically 30 to 500 W). Motor power is provided by external N-channel power MOSFETs at supply voltages from 12 to 50 V.
This device contains two sinusoidal DACs that generate the reference voltage for two separate fixed-off-time PWM current controllers. These provide current regulation for external power MOSFET full-bridges.
Motor stepping is controlled by a two-wire step and direction interface, providing complete microstepping control at full-,half-, quarter-, and sixteenth-step resolutions. The fixed-off time regulator has the ability to operate in slow-, mixed-, or fast-decay modes, which results in reduced audible motor noise, increased step accuracy, and reduced power dissipation.
The translator is the key to the easy implementation of this IC. Simply inputting one pulse on the STEP input drives the motor one step (full, half, quarter, or sixteenth depending on the microstep select input). There are no phase-sequence tables, high frequency control lines, or complex interfaces to program. This reduces the need for a complex microcontroller.
Features and Benefits
*2-wire step and direction interface
*Dual full-bridge gate drive for N-channel MOSFETs
*Operation over 12 to 50 V supply voltage range
*Synchronous rectification
*Cross-conduction protection
*Adjustable mixed decay
*Integrated sinusoidal DAC current reference
*Fixed off-time PWM current control
A3986SLD-T, A3986SLDTR-T
Description
The ATS675 is the next generation of the Allegro® True Power-On State (TPOS) sensor family, offering improved accuracy compared to prior generations, gradual TPOS to Running Mode adjustment for accuracy-shift reduction, and longer output fall time for improved radiated emissions performance. The ATS675 provides absolute zero-speed performance and TPOS information.
The sensor incorporates a single-element Hall IC with an optimized custom magnetic circuit that switches in response to magnetic signals created by a ferromagnetic target. The IC
contains a sophisticated digital circuit designed to eliminate the detrimental effects of magnet and system offsets. Signal processing is used to provide device performance at zero target
speed, independent of air gap, and which adapts dynamically to the typical operating conditions found in automotive applications, particularly camshaft-sensing applications.
High resolution peak-detecting DACs are used to set the adaptive switching thresholds of the device, ensuring high accuracy despite target eccentricity. Internal hysteresis in the thresholds
reduces the negative effects of anomalies in the magnetic signal (such as magnetic overshoot) associated with targets used in many automotive applications. The resulting output of the
device is a digital representation of the ferromagnetic target profile. The ATS675 also includes a low bandwidth filter that increases the noise immunity and the signal-to-noise ratio of the sensor.
The device package is lead (Pb) free, with 100% matte tin leadframe plating.
Features and Benefits
*Chopper stabilized; optimized for automotive cam sensing applications
*Optimized absolute timing accuracy step size through gradual transition from TPOS to Running Mode
*High immunity to signal anomalies resulting from magnetic overshoot and peak-to-peak field variation
*Tight timing accuracy over full operating temperature range
*True zero-speed operation
*Automatic Gain Control circuitry for air gap independent switchpoints
*Operation at supply voltages down to 3.3 V
*Digital output representing target profile
*Undervoltage lockout (UVLO)
*Patented Hall IC-magnet system
*Increased output fall time for improved radiated emissions performance
ATS675LSETN-LT-T, ATS675LSETN-HT-T
Description
The A6281 is a 3-channel constant current LED driver that has a wide range of output currents. The A6281 controls LED brightness with a Pulse Width Modulation (PWM) scheme that gives the application the capability of displaying a billion colors in an RGB cluster. The maximum current is set by an external resistor.
The LED brightness is controlled by performing PWM control on the outputs. The brightness data of the PWM signal for each LED is stored in three 10-bit registers. The peak value for each LED can be adjusted (dot-corrected) to compensate for mismatch, aging, and temperature effects. All the internal latched registers are loaded by a 32-bit shift register. One address bit controls whether dot correction/clock divider ratio or brightness data is loaded into the registers. The remaining bits are used for the data.
The A6281 is designed to minimize the number of components needed to drive LEDs with large pixel spacing. A large number of A6281s can be daisy chained together and controlled by just four control signals (clock, serial data, latch, and output enable). Each of these inputs is buffered to drive the next chip in the chain. Also, VIN can be tied to the LED voltage supply bus, thus eliminating the need for a separate chip supply bus or an external regulator.
Features and Benefits
*3 × 10-bit PWM brightness settings
*3 × 7-bit dot correction current settings
*5 to 17 V operation
*Wide output current range, 10 to 150 mA per channel
*Internally generated PWM clock
*Serial port operates at up to 5 MHz
*Data and clock logic architecture allows single microcontroller control of large quantities of seriallyconnected A6281s at fast data transfer rate
*Buffered logic outputs to drive cables
*Thermal shutdown and UVLO protection
*Power-On Reset
Applications
*Colored, large-character LED signs
*Scrolling, colored marquees
*Architectural lighting
*High intensity monochrome displays
*Large video and graphic displays
A6281EESTR-T
Description
The A3955 is designed to drive one winding of a bipolar stepper motor in a microstepping mode. The outputs are rated for continuous output currents to ±1.5 A and operating voltages to 50 V. Internal pulse width modulated (PWM) current control combined with an internal three-bit nonlinear digitalto-analog converter allows the motor current to be controlled in full-, half-, quarter-, or eighth-step (microstepping) modes. Nonlinear increments minimize the number of control lines necessary for microstepping. Microstepping provides increased step resolution, and reduces torque variations and resonance problems at low speed.
Internal circuitry determines whether the PWM current-control circuitry operates in a slow (recirculating) current-decay mode, fast (regenerative) current-decay mode, or in a mixed
current-decay mode in which the off-time is divided into a period of fast current decay and with the remainder of the fixed off-time spent in slow current decay. The combination of
user-selectable current-sensing resistor and reference voltage, digitally selected output current ratio; and slow, fast, or mixed current-decay modes provides users with a broad, variable
range of motor control.
Internal circuit protection includes thermal shutdown with hysteresis, transient-suppression diodes, and crossover-current protection. Special power-up sequencing is not required.
The A3955 is supplied in a choice of two power packages; a 16-pin dual-in-line plastic package with copper heat-sink tabs (suffix ‘B’), and a 16-lead plastic SOIC with internally fused pins (suffix ‘LB’). For both package styles, the thermally enhanced pins are at ground
potential and need no electrical isolation. Both packages are lead (Pb) free, with leadframe plating 100% matte tin.
Features and Benefits
*±1.5 A continuous output current
*50 V output voltage rating
*Internal PWM current control
*3-bit nonlinear DAC
*Fast, mixed fast/slow, and slow current-decay modes
*Internal transient-suppression diodes
*Internal thermal shutdown circuitry
*Crossover-current and UVLO protection
A3955SB-T, A3955SLB-T, A3955SLBTR-T
Description
The Series STR-F6600 is specifically designed to satisfy the requirements for increased integration and reliability in off-line quasi-resonant flyback converters.
The series incorporates a primary control and drive circuit with discrete avalanche-rated power MOSFETs.
Covering the power range from below 25 watts up to 300 watts for 100/115/230 VAC inputs, and up to 150 watts for 85 to 265 VAC universal input, these devices can be used in a range of applications, from battery chargers and set top boxes, to televisions, monitors, and industrial power supply units.
Cycle-by-cycle current limiting, under-voltage lockout with hysteresis, over-voltage protection, and thermal shutdown protects the power supply during the normal overload and fault conditions.
Over-voltage protection and thermal shutdown are latched after a short delay.
The latch may be reset by cycling the input supply.
Low-current startup and a low-power standby mode selected from the secondary circuit completes a comprehensive suite of features.
The series is provided in a five-pin overmolded TO-3P style package, affording dielectric isolation without compromising thermal characteristics.
FEATURES
*Flyback Operation with Quasi-Resonant Soft Switching
for Low Power Dissipation and EMI
*Rugged Avalanche-Rated MOSFET
*Choice of MOSFET Voltage and rDS(on)
*Full Over-Current Protection (no blanking)
*Under-Voltage Lockout with Hysteresis
*Over-Voltage Protection
*Direct Voltage Feedback
*Low Start-up Current (<400 μA)
*Low-Frequency, Low-Power Standby Operation
*Overmolded 5-Pin Package
