UCC3581D ,Micropower Voltage Mode PWMMAXIMUM RATINGSSupply Voltage (IDD ≤ 10mA). . . . . . . . . . . . . . . . . . . . . . . . 15VDIL-14 ..
UCC3583D ,Switch Mode Secondary Side Post RegulatorELECTRICAL CHARACTERISTICS:Unless otherwise stated, these specifications apply for T = –55°Cto125°C ..
UCC3583D ,Switch Mode Secondary Side Post Regulatorfeatures an undervoltage lockout (UVLO)• Average Current Limiting Loopcircuit, a soft start circuit ..
UCC3583D ,Switch Mode Secondary Side Post RegulatorFEATURES DESCRIPTION• Precision Secondary Side Post The UCC3583 is a synchronizable secondary side ..
UCC3583D ,Switch Mode Secondary Side Post RegulatorBLOCK DIAGRAMUDG-96201-2Note: Pin connections shown for 14-pin packages.SLUS299B - OCTOBER 1998 - R ..
UCC3583DTR ,Switch Mode Secondary Side Post RegulatorMAXIMUM RATINGSV ...... 15VDDDIL-14, SOIC-14 (Top View)I ..... 15mAVDDJ, N, or D PackagesRAMP .. –0 ..
UPA2452 ,Nch enhancement-type MOSFET (dual-drain-common-type)features a low on-state resistance and 3 4excellent switching characteristics, and is suitable for
UPA2452TL-E1 ,Nch enhancement-type MOSFET (dual-drain-common-type)DATA SHEETMOS FIELD EFFECT TRANSISTORµ PA2452N-CHANNEL MOS FIELD EFFECT TRANSISTOR FOR SWITCHING ..
UPA2502TM-E2 ,N-ch enhancement-type MOSFETDATA SHEETMOS FIELD EFFECT TRANSISTORµ PA2502N-CHANNEL MOS FIELD EFFECT TRANSISTOR FOR SWITCHING ..
UPA2700 ,Nch enhancement-type MOS FETDATA SHEETMOS FIELD EFFECT TRANSISTOR µµµµ PA2700GRSWITCHINGN-CHANNEL POWER MOS FETDESCRIPTIO ..
UPA2700GR-E1 ,Nch enhancement-type MOS FETELECTRICAL CHARACTERISTICS (TA = 25°C, All terminals are connected.)CHARACTERISTICS SYMBOL TEST CON ..
UPA2700GR-E1 ,Nch enhancement-type MOS FETFEATURES• Low on-state resistance6.0 ±0.314RDS(on)1 = 5.3 mΩ MAX. (VGS = 10 V, ID = 9.0 A)4.45.37 M ..
UCC3581D
Micropower Voltage Mode PWM
UCC1581
UCC2581
UCC3581
FEATURES Low 85μA Startup Current Low 300μA Operating Current Automatically Disabled
Startup Preregulator Programmable Minimum Duty
Cycle with Cycle Skipping Programmable Maximum
Duty Cycle Output Current 1A Peak
Source and Sink Programmable Soft Start Programmable Oscillator
Frequency External Oscillator
Synchronization Capability
Micropower Voltage Mode PWM
BLOCK DIAGRAM
DESCRIPTIONThe UCC3581 voltage mode pulse width modulatoris de-
signedto control low power isolated DC- DC converters applications such as Subscriber Line Power (ISDN
I.430). Primarily used for single switch forward and
flyback converters, the UCC3581 features BiCMOS cir-
cuitry for low startup and operating current, while main-
taining the ability to drive power MOSFETs at
frequencies upto 100kHz. The UCC3581 oscillator al-
lows the flexibilityto program both the frequency and the
maximum duty cycle with two resistors anda capacitor.A
TTL level inputis also providedto allow synchronization
to an external frequency source.
The UCC3581 includes programmable soft start circuitry,
overcurrent detection,a 7.5V linear preregulatorto con-
trol chip VDD during startup, and an on-board 4.0V logic
supply.
The UCC3581 provides functionsto maximize light load
efficiency that are not normally foundin PWM controllers. linear preregulator driverin conjunction with an exter-
nal depletion mode N-MOSFET provides initial controller
power. Once the bootstrap supplyis functional, the
preregulatoris shut downto conserve power. During light
load, poweris savedby providinga programmable mini-
mum duty cycle clamp. Whena duty cycle below the
minimumis called for, the modulator skips cyclesto pro-
vide the correct average duty cycle required for output
regulation. This effectively reduces the switching fre-
quency, saving significant gate drive and power stage
losses.
The UCC3581is availablein 14-pin plastic and ceramic
dual-in-line packages andina 14-pin narrow body small
outlineIC package (SOIC). The UCC1581is specifiedfor
operation from −55°Cto +125°C, the UCC2581is speci-
fied for operation from −40°C to +85°C, and the
UCC3581 is specified for operation from 0°C to +70°C.
