UC3845 ,SMPS ControllerMaximum ratings applied to the device are individual stress limitvalues (not normal operating condi ..
UC3845A ,HIGH PERFORMANCE CURRENT MODE PWM CONTROLLERMaximum Ratings.. 611 Device and Documentation Support........ 246.2 ESD Ratings........ 611.1 Devi ..
UC3845AD ,Current Mode PWMsUC2842A/3A/4A/5AUC3842A/3A/4A/5A® HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER.TRIMMED OSCILLATOR D ..
UC3845AD1 ,HIGH PERFORMANCE CURRENT MODE PWM CONTROLLERUC284XAUC384XAHIGH PERFORMANCE CURRENT MODE PWM CONTROLLERNOT FOR NEW DESIGN1
UC3845AD1013TR ,HIGH PERFORMANCE CURRENT MODE PWM CONTROLLERBlock Diagram (toggle flip flop used only in UC3844A and UC3845A)7ViUVLO34V85VVREF5 S/RREFGROUND 5V ..
UC3845AD8 ,Current Mode PWM ControllerSupport &Product Order Tools &TechnicalCommunityFolder Now Documents SoftwareUC1842A,UC1843A,UC1844 ..
UN2211 ,Composite DeviceFeatures• Costs can be reduced through downsizing of the equipment andreduction of the number of pa ..
UN2212 ,Composite DeviceFeatures• Costs can be reduced through downsizing of the equipment andreduction of the number of pa ..
UN2213 ,Composite DeviceAbsolute Maximum Ratings T = 25°CaParameter Symbol Rating UnitCollector-base voltage (Emitter open ..
UN2213 ,Composite DeviceTransistors with built-in ResistorUNR221x Series (UN221x Series)Silicon NPN epitaxial planar transi ..
UN2214 ,Composite DeviceAbsolute Maximum Ratings T = 25°CaParameter Symbol Rating UnitCollector-base voltage (Emitter open ..
UN2215 ,Composite DeviceTransistors with built-in ResistorUNR221x Series (UN221x Series)Silicon NPN epitaxial planar transi ..
UC2844N-UC2844N/-UC2845D-UC3845
SMPS Controller
UC3844, UC3845, UC2844,
UC2845
High Performance
Current Mode Controllers
The UC3844, UC3845 series are high performance fixed frequency
current mode controllers. They are specifically designed for Off−Line
and DC−to−DC converter applications offering the designer a cost
effective solution with minimal external components. These
integrated circuits feature an oscillator, a temperature compensated
reference, high gain error amplifier, current sensing comparator, and a
high current totem pole output ideally suited for driving a power
MOSFET.
Also included are protective features consisting of input and
reference undervoltage lockouts each with hysteresis, cycle−by−cycle
current limiting, a latch for single pulse metering, and a flip−flop
which blanks the output off every other oscillator cycle, allowing
output dead times to be programmed for 50% to 70%.
These devices are available in an 8−pin dual−in−line plastic package
as well as the 14−pin plastic surface mount (SOIC−14). The SOIC−14
package has separate power and ground pins for the totem pole output
stage.
The UCX844 has UVLO thresholds of 16 V (on) and 10 V (off),
ideally suited for off−line converters. The UCX845 is tailored for
lower voltage applications having UVLO thresholds of 8.5 V (on) and
7.6 V (off). Current Mode Operation to 500 kHz Output Switching Frequency Output Deadtime Adjustable from 50% to 70% Automatic Feed Forward Compensation Latching PWM for Cycle−By−Cycle Current Limiting Internally Trimmed Reference with Undervoltage Lockout High Current Totem Pole Output Input Undervoltage Lockout with Hysteresis Low Startup and Operating Current Direct Interface with ON Semiconductor SENSEFET Products Pb−Free Packages are Available
7(11)
6(10)
5(8)
3(5)
Vref
8(14)
4(7)
2(3)
1(1)
GND 5(9)
RTCT
Voltage
Feedback
Output
Comp.
