UC3525BDW ,Regulating Pulse Width ModulatorsMAXIMUM RATINGS RECOMMENDED OPERATING CONDITIONS(Note 1)Supply Voltage, (+VIN) +40VCollector Suppl ..
UC3525BDWG4 ,Regulating Pulse Width Modulators 16-SOIC 0 to 70BLOCK DIAGRAMUDG-95055SLUS376 JULY 1995UC3527B Not Recommended For New DesignsUC1525B UC1527BUC2525 ..
UC3525BDWTR ,Regulating Pulse Width ModulatorsELECTRICAL CHARACTERISTICS:Unless otherwise stated, these specifications apply for T = –55°C to +12 ..
UC3525BDWTRG4 ,Regulating Pulse Width Modulators 16-SOIC 0 to 70UC3527B Not Recommended For New DesignsapplicationUC1525B UC1527BINFOUC2525B UC2527BavailableUC3525 ..
UC3525BN ,Regulating Pulse Width ModulatorsFEATURES DESCRIPTION• 8 to 35V Operation The UC1525B/1527B series of pulse width modulator integrat ..
UC3526ADW ,Regulating Pulse Width ModulatorsUC1526AUC2526AUC3526ARegulating Pulse Width Modulator
UMA4N , PNP -100mA -50V Complex Digital Transistors (Bias Resistor Built-in Transistors
UMA4N , PNP -100mA -50V Complex Digital Transistors (Bias Resistor Built-in Transistors
UMA4NT1 , Dual Common Emitter Bias Resistor Transistors
UMA5N , PNP -100mA -50V Complex Digital Transistors (Bias Resistor Built-in Transistors)
UMA5N , PNP -100mA -50V Complex Digital Transistors (Bias Resistor Built-in Transistors)
UMA7N , Emitter common (dual digital transistors)
UC3525BDW-UC3525BDWG4-UC3525BDWTR-UC3525BDWTRG4-UC3525BN
Regulating Pulse Width Modulators
UC1525B UC1527B
UC2525B UC2527B
UC3525B UC3527B
DESCRIPTIONThe UC1525B/1527B seriesof pulse width modulator integrated circuits
are designedto offer improved performance and lowered external parts
count when usedin designingall typesof switching power supplies. The
on-chip +5.1V buried zener referenceis trimmedto ±0.75% and the input
common-mode rangeof the error amplifier includes the reference voltage,
eliminating external resistors.A sync inputto the oscillator allows multiple
unitstobe slavedora single unittobe synchronizedto an external system
clock.A single resistor between the CT and the discharge terminals provide wide rangeof dead time adjustment. These devices also feature built-in
soft-start circuitry with only an external timing capacitor required.A shut-
down terminal controls both the soft-start circuitry and the output stages,
providing instantaneous turn off through the PWM latch with pulsed shut-
down,as wellas soft-start recycle with longer shutdown commands. These
functions are also controlledby an undervoltage lockout which keeps the
outputsoff and the soft-start capacitor discharged for sub-normal input volt-
ages. This lockout circuitry includes approximately 500mVof hysteresis for
jitter-free operation. Another featureof these PWM circuitsisa latch follow-
ing the comparator. Oncea PWM pulse has been terminated for any rea-
son, the outputs will remain off for the durationof the period. The latchis
reset with each clock pulse. The output stages are totem-pole designs ca-
pableof sourcingor sinkingin excessof 200mA. The UC1525B output
stage features NOR logic, givinga LOW output for an OFF state. The
UC1527B utilizes OR logic which resultsina HIGH output level when OFF.
Regulating Pulse Width Modulators
FEATURES8to 35V Operation 5.1V Buried Zener Reference
Trimmedto ±0.75% 100Hzto 500kHz Oscillator Range Separate Oscillator Sync Terminal Adjustable Deadtime Control Internal Soft-Start Pulse-by-Pulse Shutdown Input Undervoltage Lockout with
Hysteresis Latching PWMto Prevent Multiple
Pulses Dual Source/Sink Output Drivers Low Cross Conduction Output Stage Tighter Reference Specifications
BLOCK DIAGRAMUC3527B Not Recommended For New Designs
