mc44603a ON Semiconductor, mc44603a Datasheet
mc44603a
Available stocks
Related parts for mc44603a
mc44603a Summary of contents
Page 1
... Controller: Fixed Frequency, Variable Frequency, Standby Mode 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 ...
Page 2
... Maximum ratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit values (not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied, damage may occur and reliability may be affected. 1. ESD data available upon request. MC44603A Symbol ( ...
Page 3
... Synchronization Pulse Width must be shorter than t 8. This function can be inhibited by connecting Pin 8 to GND. This allows a continuous current mode operation. 9. This function can be inhibited by connecting Pin 10. The MC44603A can be shut down by connecting the Soft−Start pin (Pin 11) to Ground. MC44603A and V ...
Page 4
... Synchronization Pulse Width must be shorter than t 8. This function can be inhibited by connecting Pin 8 to GND. This allows a continuous current mode operation. 9. This function can be inhibited by connecting Pin 10. The MC44603A can be shut down by connecting the Soft−Start pin (Pin 11) to Ground. MC44603A and V ...
Page 5
... Synchronization Pulse Width must be shorter than t 8. This function can be inhibited by connecting Pin 8 to GND. This allows a continuous current mode operation. 9. This function can be inhibited by connecting Pin 10. The MC44603A can be shut down by connecting the Soft−Start pin (Pin 11) to Ground. MC44603A and V ...
Page 6
... I ref R Pwr Stby Feed− 1.0 mA back 2R 14 Error Amplifier + 2.5 V Compensation 13 5 Foldback Input = Sink only = Positive True Logic MC44603A R F Stby Stby V Demag Out Reference Synchro Block V V ref OSC prot OSC Thermal I Shutdown Discharge ...
Page 7
... AMBIENT TEMPERATURE (°C) A Figure 4. Oscillator Frequency versus Temperature 600 V CC 400 200 A Current 0 −200 −400 Voltage −600 −800 −1000 1.0 ms/Div Figure 6. Output Waveform MC44603A 10000 25° Stby 1000 300 1 Figure 3. Standby Mode Timing Capacitor 0.43 0.42 0.41 0.40 0. ...
Page 8
... I , SINK OUTPUT CURRENT (mA) sink Figure 10. Sink Output Saturation Voltage versus Sink Current 2.60 2.55 2.50 2.45 2.40 −50 − AMBIENT TEMPERATURE (°C) A Figure 12. Voltage Feedback Input versus Temperature MC44603A 2.5 2.0 1 ref C = 820 pF T 1.0 75 100 0 100 I Figure 9. Source Output Saturation Voltage 80 60 ...
Page 9
... ref C = 820 2.0 4.0 6.0 8 SUPPLY VOLTAGE (V) CC Figure 18. Supply Current versus Supply Voltage MC44603A 100 qJA D(max ref C = 820 100 0 10 Figure 15. Thermal Resistance and Maximum Power Dissipation versus P.C.B. Copper Length ...
Page 10
... Turn−On (UVLO2) versus Temperature ref C = 820 pF T 17.5 Pin 6 Open 17 16.5 16 −50 − AMBIENT TEMPERATURE (°C) A Figure 24. Protection Level on V versus Temperature MC44603A 9.50 9.25 9.00 V Increasing CC 8.55 8.50 75 100 −50 −25 Figure 21. Disable Voltage After Threshold Turn−On (UVLO1) versus Temperature 2.60 2.55 2.50 2.45 V Decreasing CC 2.40 2 ...
Page 11
... A capacitor, resistor or a voltage source connected to this pin limits the switching duty−cycle. This pin can max Voltage−Mode be used as a voltage mode control input. By connecting Pin 11 to Ground, the MC44603A can be shutdown voltage level applied to the R P Standby turn into the reduced frequency mode of operation (i ...
Page 12
... MC44603A No−Take Over Startup Restart prot V stup−th V disable1 V disable2 V ref UVLO1 V Pin 11 (Soft−Start) V OVP Out Output Ï Ï Ï Ï Ï Ï Ï Ï Ï Ï Ï Ï Ï Ï Ï Ï Ï Ï Ï Ï Ï Ï ...
Page 13
... MC44603A stup−th V disable1 V disable2 V ref UVLO1 V Pin 11 (Soft−Start) Output (Pin 0.3 mA Figure 30. Switching Off Behavior Stby V Demag Out V OSC V OSC prot V Demag Out Synchronization Input Oscillator Figure 31. Oscillator http://onsemi.com 13 Ï Ï Ï ...
Page 14
... Figure 33. Error Amplifier Compensation ). The Error Amp OL Current Sense Comparator and PWM Latch The MC44603A can operate as a current mode controller voltage mode controller. In current mode operation, the MC44603A uses the current sense comparator. The output switch conduction is initiated by the oscillator and ...
Page 15
... T sources = I and fact, C charge discharge MC44603A connected to the charging current source (0.4 I the discharge current source has to be higher than the charge current to be able to decrease the C to Figure 36). This condition is performed, its value being (2.0 I normal working and (0.4 I ...
Page 16
... Figure 38). MC44603A That is why, the MC44603A demagnetization detection consists of a comparator that can compare the auxiliary winding voltage to a reference that is typically equal to 65 mV. V ...
Page 17
... SW SN−CLN frequency. Consequently, standby losses can be minimized by decreasing the switching frequency as much as possible. The MC44603A was designed to operate at a standby frequency lower than the normal working one. • Standby Power Calculations with MC44603A During a switching period, the energy drawn by the transformer during the on− ...
Page 18
... Z V OSC Soft−Start Oscillator Capacitor Figure 43. D and Soft−Start max MC44603A Voltage )/3 Stby max Figure 44. Maximum Duty Cycle Control Using the internal current source (0.4 I voltage can easily be set by connecting a resistor to this pin capacitor is connected to Pin 11, the voltage increases ...
Page 19
... V (maximum value of V disable1 ((V ) stup−th min to stabilize. The large hysteresis and the low startup current of the ref MC44603A make it ideally suited for off−line converter applications where efficient bootstrap startup techniques are required. V OVP out τ In Out Delay 2 ...
Page 20
... R17 22 k R18 R19 R25 C12 1 Diode D15 is required if the negative current into the output pin exceeds 15 mA. Figure 49. 250 W Input Power Off−Line Flyback Converter with MOSFET Switch MC44603A C1 R20 220 5.0 W C17 1N4934 C2 220 mF ...
Page 21
... W Input Power Fly−Back Converter 185 V − 270 V Mains Range MC44603AP & MTP6N60E Tests Line Regulation 150 V 130 V 114 V 7.0 V Load Regulation 150 V Cross Regulation 150 V Efficiency Standby Mode P input Switching Frequency Output Short Circuit Startup DEVICE ORDERING INFORMATION Device ...
Page 22
... PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.13 TOTAL IN EXCESS OF THE B DIMENSION AT MAXIMUM MATERIAL CONDITION. MILLIMETERS DIM MIN MAX A 2.35 2.65 A1 0.10 0.25 B 0.35 0.49 C 0.23 0.32 D 10.15 10.45 E 7.40 7.60 e 1.27 BSC H 10.05 10.55 h 0.25 0.75 L 0.50 0. Semiconductor Website: http://onsemi.com Order Literature: http://www.onsemi.com/litorder For additional information, please contact your local Sales Representative. MC44603A/D ...