MOTOROLA
50 ANALOG AND INTERFACE INTEGRATED CIRCUITS
SELECTOR GUIDE & CROSS REFERENCE
Switching Regulator Control Circuits (continued)
Single–Ended GreenLine Controllers
Enhanced Mixed Frequency Mode GreenLine PWM Controller:
Fixed Frequency, Variable Frequency, Standby Mode
MC44603AP, DW
TA = –25° to +85°C, Case 648, 751G
The MC44603A is an enhanced high performance control-
ler that is specifically designed for off–line and dc–to–dc con-
verter applications. This device has the unique ability of auto-
matically changing operating modes if the converter output is
overloaded, unloaded, or shorted, of fering the designer addi-
tional protection for increased system reliability. The
MC44603A has several distinguishing features when
compared to conventional SMPS controllers. These features
consist of a foldback facility for overload protection, a
standby mode when the converter output is slightly loaded, a
demagnetization detection for reduced switching stresses on
transistor and diodes, and a high current totem pole output
ideally suited for driving a power MOSFET. It can also be
used for driving a bipolar transistor in low power converters
(< 150 W). It is optimized to operate in discontinuous mode
but can also operate in continuous mode. Its advanced
design allows use in current mode or voltage mode control
applications.
Current or Voltage Mode Controller
•Operation up to 250 kHz Output Switching Frequency
•Inherent Feed Forward Compensation
•Latching PWM for Cycle–by–Cycle Current Limiting
•Oscillator with Precise Frequency Control
High Flexibility
•Externally Programmable Reference Current
•Secondary or Primary Sensing
•Synchronization Facility
•High Current Totem Pole Output
•Undervoltage Lockout with Hysteresis
Safety/Protection Features
•Overvoltage Protection Against Open Current and Open
Voltage Loop
•Protection Against Short Circuit on Oscillator Pin
•Fully Programmable Foldback
•Soft–Start Feature
•Accurate Maximum Duty Cycle Setting
•Demagnetization (Zero Current Detection) Protection
•Internally Trimmed Reference
•Enhanced Output Drive
GreenLine Controller: Low Power Consumption in
Standby Mode
•Low Startup and Operating Current
•Fully Programmable Standby Mode
•Controlled Frequency Reduction in Standby Mode
•Low dV/dT for Low EMI Radiations
High Safety Standby Ladder Mode GreenLine PWM Controller
MC44604P
TA = –25° to +85°C, Case 648
The MC44604 is an enhanced high performance controller
that is specifically designed for off–line and dc–to–dc con-
verter applications.
The MC44604 is a modification of the MC44603. The
MC44604 offers enhanced safety and reliable power man-
agement in its protection features (foldback, overvoltage
detection, soft–start, accurate demagnetization detection).
Its high current totem pole output is also ideally suited for
driving a power MOSFET but can also be used for driving a
bipolar transistor in low power converters (< 150 W).
In addition, the MC44604 offers a new efficient way to
reduce the standby operating power by means of a patented
standby ladder mode operation of the converter significantly
reducing the converter consumption in standby mode.
Current or Voltage Mode Controller
•Operation Up to 250 kHz Output Switching Frequency
•Inherent Feed Forward Compensation
•Latching PWM for Cycle–by–Cycle Current Limiting
•Oscillator with Precise Frequency Control
High Flexibility
•Externally Programmable Reference Current
•Secondary or Primary Sensing
•High Current Totem Pole Output
•Undervoltage Lockout with Hysteresis
Safety/Protection Features
•Overvoltage Protection Facility Against Open Loop
•Protection Against Short Circuit on Oscillator Pin
•Fully Programmable Foldback
•Soft–Start Feature
•Accurate Maximum Duty Cycle Setting
•Demagnetization (Zero Current Detection) Protection
•Internally Trimmed Reference
GreenLine Controller:
•Low Startup and Operating Current
•Patented Standby Ladder Mode for Low Standby Losses
•Low dV/dT for Low EMI