mm1548 Mitsumi Electronics, Corp., mm1548 Datasheet
mm1548
Related parts for mm1548
mm1548 Summary of contents
Page 1
... Controls the oscillator on the primary side using one photocoupler. 5. One photocoupler is used for constant-voltage/constant-current control and switching between energy- saving and normal modes. Package SOT-26A Pin Assignment SOT-26A Secondary-side Control for Energy-Saving AC Adaptor MM1548 60µA 1.5mA OUT 1 CNT ...
Page 2
... MITSUMI MITSUMI Block Diagram PC1 Primary-side switching control RL1 PO1 4 Photocoupler-turn-off 5k Over voltage detection 5 GND Secondary-side Control for Energy-Saving AC Adaptor MM1548 Load detection resistor RLS RLB V CNT Voltage buffer Input/output difference control (VCC-OUT=200mV) Load detection(current) (115mV 200mV) 1.25V Reference voltage V =4 ...
Page 3
... Connect to cathode of diode. GND Ground pin Overcurrent detection pin. 6 This pin doubles as output- pin. Connect Resistor for overcurrent detection between GND pin. Secondary-side Control for Energy-Saving AC Adaptor MM1548 Function pin, and connect collector CC Internal equivalent circuit 1.25V ...
Page 4
... PO1 output sink current 3 PO1 output source current Constant current mode selection 2pin(CNT pin) disable voltage Constant current mode selection threshold (between V and OUT) CC Secondary-side Control for Energy-Saving AC Adaptor MM1548 (Ta=25°C) Symbol T STG T OPR V max ...
Page 5
... I CC1 CC2 OUT CS PO1 PO2 PO3 V PO1 Measuring Circuit LSP1 LSP2 OL1 OL2 Secondary-side Control for Energy-Saving AC Adaptor MM1548 , PO4 CNT I PO1 A 4 PO1 GND CNT OUT ...
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... MITSUMI Measuring Circuit Measuring Circuit 4 PSRR2 V Measuring Circuit Measuring Circuit CS1 CS2 Secondary-side Control for Energy-Saving AC Adaptor MM1548 2SB1424 4 PO1 GND CNT 2 100Ω CS OUT PO1 GND CNT 10kΩ 100Ω CS OUT ...
Page 7
... MM1548 changes to the CC(constant current) mode, and the load current is controlled that CS voltage keeps V . CS1 1.5 Constant voltage control When MM1548 is in normal mode and isn't in constant current mode CV(constant voltage) mode, and PO1 current is controlled that V Secondary-side Control for Energy-Saving AC Adaptor MM1548 and OUT(200mV) CC ...
Page 8
... In MM1548 series, the output voltage can't be adjusted by external resistor, because referential voltage terminal (REF pin) for adjustment is build in the chip. Instead of voltage adjustment, you can chose output voltage by select the rank of MM1548 series. Output voltage is lower 0.2V (equal to in-out differential control voltage) than 5.1V(equal to the value set by ROS1 and ROS2) ...
Page 9
... S (Load detection resistor) - Energy saving detection current L 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 0.1 Secondary-side Control for Energy-Saving AC Adaptor MM1548 / RCS (V = 114.4mV) CS1 CS1 = V / RCS (V = 34mV) CS2 CS2 I= (VCS1) / RCS 0.22Ω RCS(constant current detection resistor) [Ω] S adjust method) ...
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... ON 4 Primary side switching OFF 5 114.4mV CS terminal (constant current control input) 0mV AC input Rectifying circuit Switching interruption control Secondary-side Control for Energy-Saving AC Adaptor MM1548 5.1V 4.9V 3.5V OUT 0V 0mA ON OFF Normal mode 200mV 2V OUT 0V 0mA ...
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... Load detection current (200mV/R Energy saving current (115mV PIN CC 2 OUT PIN 3 PO1 PIN 4 CNT PIN AC input Rectifying circuit Switching interruption control Secondary-side Control for Energy-Saving AC Adaptor MM1548 Load current decrease 0mA 5.1 V 4.9V 115mV 0V Open Open Load current increase S) L ...
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... MITSUMI Application Circuit INPUT 10 6.8 R20 L1 R1 AC100V D1 Q4 Secondary-side Control for Energy-Saving AC Adaptor MM1548 T1 D3 470 C13 Q1 µ 0.0056 R9 4700p Q2 Q3 470 C3 D2 R10 R14 100k Q6 R12 10k PH1 C11 2200p OUTPUT L2 470 + R15 Q5 DC4.9V 520mA V CNT OUT CC MM 1548 PO1 ...