MC44603A Datasheet, PDF (1/24 Pages) ON Semiconductor – MIXED FREQUENCY MODE GREENLINE PWM CONTROLLER

Order this document by MC44603A/D
Advance Information
Enhanced Mixed Frequency
Mode GreenLine™ PWM
Controller:
Fixed Frequency, Variable Frequency,
Standby Mode
MC44603A
MIXED FREQUENCY MODE
GREENLINE PWM*
CONTROLLER:
The MC44603A is an enhanced high performance controller that is
specifically designed for off–line and dc–to–dc converter applications. This
device has the unique ability of automatically changing operating modes if
the converter output is overloaded, unloaded, or shorted, offering the
designer additional 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
GreenLine is a trademark of Motorola, Inc.
VARIABLE FREQUENCY,
FIXED FREQUENCY,
STANDBY MODE
* PWM = Pulse Width Modulation
16
1
P SUFFIX
PLASTIC PACKAGE
CASE 648
16
1
DW SUFFIX
PLASTIC PACKAGE
CASE 751G
(SOP–16L)
PIN CONNECTIONS
VCC 1
VC 2
Output 3
Gnd 4
Foldback Input 5
Overvoltage
Protection (OVP)
6
Current Sense Input 7
Demag Detection 8
16 Rref
15
RFrequency
Standby
14
Voltage Feedback
Input
13 Error Amp Output
12 RPower _Standby
11
Soft–Start/Dmax/
Voltage Mode
10 CT
9 Sync Input
(Top View)
ORDERING INFORMATION
Device
Operating
Temperature Range Package
MC44603AP
Plastic DIP–16
TA = –25° to +85°C
MC44603ADW
SOP–16L
This document contains information on a new product. Specifications and information herein
ar_Me _Osu_Tbj_Oec_Rt t_Oo c_Lh_Aang_Ae_Nw_Aith_Lo_Out _Gnot_Ii_Cce._{DEVICE DATA}
© Motorola, Inc. 1997
Rev 0
1