DESCRIPTION The M66244FP is a high-speed digitally programmable PULSE WIDTH MODULATOR (PWM) which uses high-performance silicon gate CMOS process technology.Output PULSE WIDTH is proportional to a 6-bit DATA input value. Two additional CONTROL inputs determine if the PULSE is placed at the beginning , middle ,or end of the clock period. PULSE WIDTH and placement can be changed every clock cycle up to 72MHz.
FEATURES • Frequency 45MHz to 72MHz • 6 bit Resolution • Center, Leading, Trailing Edge Modulation • Single 3.3V Operation • JTAG (IEEE Standard 1149.1Test Port)
The NTE1722 is a high performance PULSE WIDTH MODULATOR integrated circuit in an 18–Lead DIP type package intended for fixed frequency switching regulators and other power control applications. Functions included in this IC are a temperature compensated voltage reference, sawtooth oscillator, error amplifier, PULSE WIDTH MODULATOR, PULSE metering and steering logic, and two high current totem pole outputs ideally suited for driving the capacitance of power FETs at high speeds.
DESCRIPTION The DS1052 is a programmable, 5-bit, PULSE-WIDTH MODULATOR featuring a 2-wire addressable controlled interface. The DS1052 operates from power supplies ranging from 2.7V up to 5.5V. The PWM output provides a signal that swings from 0V to VCC. The DS1052-100 requires a typical operating current of 100µA and a programmable shutdown supply current of 1µA.
FEATURES ◾ Single 5-bit, programmable, PULSE-WIDTH MODULATOR (PWM) ◾ Adjustable Duty Cycle: 0% to 100% ◾ 2.7V to 5.5V Operation ◾ Standard Frequency Value: 100kHz ◾ 2-Wire Addressable Interface ◾ Packages: 8-Pin (150-mil) SOIC and 8-Pin (118-mil) μSOP ◾ Operating Temperature: -40°C to +85°C
The SG3525A, SG3527A PULSE WIDTH MODULATOR control circuits offer improved performance and lower external parts count when implemented for controlling all types of switching power supplies. The on–chip +5.1 V reference is trimmed to ±1% and the error amplifier has an input common–mode voltage range that includes the reference voltage, thus eliminating the need for external divider resistors. A sync input to the oscillator enables multiple units to be slaved or a single unit to be synchronized to an external system clock. A wide range of deadtime can be programmed by a single resistor connected between the CT and Discharge pins. These devices also feature built–in soft–start circuitry, requiring only an external timing capacitor. A shutdown pin controls both the soft–start circuitry and the output stages, providing instantaneous turn off through the PWM latch with PULSEd shutdown, as well as soft–start recycle with longer shutdown commands. The under voltage lockout inhibits the outputs and the changing of the soft–start capacitor when VCC is below nominal. The output stages are totem–pole design capable of sinking and sourcing in excess of 200 mA. The output stage of the SG3525A features NOR logic resulting in a low output for an off–state while the SG3527A utilized OR logic which gives a high output when off.
• 8.0 V to 35 V Operation • 5.1 V ± 1.0% Trimmed Reference • 100 Hz to 400 kHz Oscillator Range • Separate Oscillator Sync Pin • Adjustable Deadtime Control • Input Undervoltage Lockout • Latching PWM to Prevent Multiple PULSEs • PULSE–by–PULSE Shutdown • Dual Source/Sink Outputs: ±400 mA Peak
The NTE1721 and NTE1723 are PULSE WIDTH MODULATOR control–circuits designed to offer improved performance and lowered external parts count when implemented for controlling all types of switching power supplies. The no–chip +5.1V reference is trimmed to ±1% and the input common–mode range of the errror amplifier includes the reference voltage, thus eliminating the need for external divider resistors. A sync input to the oscillator enables multiple units to be slaved or a single unit to be synchronized to an external system clock. A wide range of dead time can be programmed by a single resistor connected between the CT and the Discharge pins. These devices also feature a built–in soft–start circuitry, requiring only an external timing capacitor.
The NTE1729 is an inverter control unit in a 16–Lead DIP type package which provides all the control circuitry for PWM type switching regulators. Included in this device is the voltage reference, dual error amplifiers, oscillator, PULSE WIDTH MODULATOR, PULSE steering flip flop, dual alternating output switches, and dead time control.
■ Complete PWM Power Control Circuit
■ Adjustable Dead Time: 0 to 100%
■ No Double Pulsing of Same Output during Load Transient Condition
■ Dual Error Amplifiers have Wide Common Mode Input Voltage Capability: –0.3V to VCC –2V
The NTE1720 PWM switching regulator control circuit contains all the essential circuitry to implement single–ended or push–pull switching regulators. Included on the circuit are oscillator, voltage refer ence, a PULSE WIDTH MODULATOR, error amplifier, overload protection circuitry and output drivers.
A substance zener reference has been used to provide excellent stability with time and the reference has been used to provide excellent stability with time and the reference is trimmed at the wafer level to provide an initial accuracy of 2%. Additionally, the oscillator is trimmed to provide a medium toler ance of 6%.
The NTE1753 is a fixed–frequency PULSE WIDTH modulation control circuit in a 14–Lead DIP type pack age incorporating the primary building blocks required for the control of a switching power supply.
Output PULSE WIDTH modulation is accomplished by comparison of the positive sawtooth waveform across capacitor CT to either of two control signals. The output is enabled only during that portion of time when the sawtooth voltage is greater than the control signals. Therefore, an increase in control–signal amplitude causes a corresponding linear decrease of output PULSE WIDTH.
The control signals are external inputs that can be fed into the dead–time control, the error amplifier inputs, or the feed–back input. The dead–time control comparator has an effective 120mV input offset which limits the minimum output dead time to approximately the first 4% of the sawtooth–cycle time. This would result in a maximum duty cycle of 96%. Additional dead time may be imposed on the output by setting the dead time–control input to a fixed voltage, ranging between 0 to 3.3V.
• Complete PULSE WIDTH Modulation Control Circuitry
• On–Chip Oscillator with Master or Slave Operation
• On–Chip Error Amplifiers
• On–Chip 5.0 Volt Reference
• Adjustable Dead Time Control
• Uncommitted Output Transistor for 200mA Source or Sink