NJM2381 SWITCHING REGULATOR CONTROL IC FOR FLYBACK WITH CURRENT SENSE AMPLIFIER ■GENERAL DESCRIPTION ■PACKAGE OUTLINE The NJM2381 is a low voltage operation DC/DC converter control IC. It features totem pole output directly driving external bipolar transistor and operates at high switching frequency which improves transient response. It is suitable for LCD back light, and other portable applications. ■FEATURES ● PWM switching control ● Operating Voltage (3.6 to 32V) ● Wide Oscillator Range (5 to 350 kHz) ● Current Sensing Amplifier ● Soft-Start Function ● UVLO(Under Voltage Lockouts) ● Bipolar Technology ● Package Outline DIP14, DMP14, SSOP10 NJM2381D NJM2381M NJM2381V ■PIN CONFIGURATION 1 14 2 13 3 12 4 11 5 10 6 9 7 8 PIN FUNCTION 8.NC 1.NC 9. V+ 2.IN 1 3.IN 2 10.CS 11.CT 4.F.B 12.REF 5.GND 13.IN+ 6.OUT 7.NC 14.NC NJM2381D NJM2381M 1 10 2 9 3 8 4 7 5 6 NJM2381V PIN FUNCTION 6. V+ 1.IN-1 2.IN-2 7.CS 8.CT 3.F.B 9.REF 4.GND 10.IN+ 5.OUT Ver 3.2 - 1 - NJM2381 ■BLOCK DIAGRAM NC IN+ REF CT CS V+ NC 14 13 12 11 10 9 8 VREF CURRENT SENSE AMP OSC L.O U.V.LO 500Ω ER·AMP PWM 0.52V 1 2 3 4 NC IN-1 IN-2 F.B 5 GND 6 7 OUT NC (Package: DIP14, DMP14) IN+ REF 10 9 CT CS V+ 8 7 6 VREF CURRENT SENSE AMP OSC L.O U.V.LO 500Ω ER·AMP PWM 0.52V 1 - IN 1 2 3 - F.B IN 2 4 GND 5 OUT (Package: SSOP10) -2- NJM2381 ■ABSOLUTE MAXIMUM RATINGS (Ta=25°C ) PARAMETER SYMBOL Input Voltage V+ Reference Output Current IOR Output Current IO Differential Input Voltage VID Common Mode Input Voltage VIC Power Dissipation PD Operating Temperature Range Storage Temperature Range MAXIMUM RATINGS 36 10 ±50 2.5 -0.3 ∼ 2.5 (DIP 14) 700 (DMP 14) 300 (SSOP 10) 250 -40 ∼ +85 -50 ∼ +125 TOPR TSTG UNIT V mA mA V V mW °C °C ■ELECTRICAL CHARACTERISTICS (V+=6V,RT=33kΩ,CT=1000pF,Ta=25°C) REFERENCE VOLTAGE BLOCK PARAMETER SYMBOL Output Voltage Line Regulation Load Regulation OSCILLATOR BLOCK PARAMETER Oscillation Frequency Oscillate Fluctuations1 (Line Fluctuations) Oscillate Fluctuations2 (Temp Fluctuations) VREF LINE LOAD IOR=1mA + V =3.6 ∼ 32V, IOR=1mA IOR=0.1 ∼ 5.0mA SYMBOL TEST CONDITION RT=33kΩ, CT=1000pF MIN. TYP. MAX. UNIT 2.45 – – 2.50 6.8 5 2.55 20.7 30 V mV mV MIN. TYP. MAX. UNIT 105 1 125 – kHz % fOSC fdV V =3.6 ∼ 32V 85 – fdT Ta=-40 ∼ 85°C – 5 – % MIN. TYP. MAX. UNIT – – – – – – 7 50 100 – – – mV nA nA dB MHz V 1 V 200 µA CURRENT SENSE AMPLIFIER BLOCK PARAMETER SYMBOL Input Offset Voltage1 Input Offset Current1 Input Bias Current1 Open Loop Gain1 Gain Bandwidth Product1 Input Common Mode Voltage Ratio1 Maximum Output Voltage1 (F.B Pin) Maximum Source Current1 (F.B Pin) TEST CONDITION + TEST CONDITION VIO1 IIO1 IB1 A V1 GB1 VICM1 VOM-1 RNF=100kΩ – 2 5 5 90 0.6 0∼ VREF-0.8 – IOM+1 VOM=0.5V 40 85 -3- NJM2381 ■ELECTRICAL CHARACTERISTICS (V+=6V,RT=33kΩ,CT=1000pF,Ta=25°C) ERROR AMPLIFIER BLOCK PARAMETER SYMBOL TEST CONDITION MIN. Reference Voltage2 Input Bias Voltage2 Open Loop Gain2 Gain Bandwidth Product2 Maximum Output Voltage2 (F.B Pin) Maximum Source Current2 (F.B Pin) PWM COMPARATE BLOCK PARAMETER VB2 IB2 A V2 GB2 VOM-2 RNF=100kΩ IOM+2 VOM=0.5V SYMBOL Input Threshold Voltage (F.B Pin) Input Threshold Voltage (F.B Pin) Maximum Duty Cycle TEST CONDITION H-Output Voltage (OUT Pin) L-Output Voltage (OUT Pin) Output Source Current (OUT Pin) -4- 0.52 5 90 0.6 – 0.53 100 – – 1 V nA dB MHz V 40 85 200 µA MIN. TYP. MAX. UNIT 1.65 1.75 V VTH50 duty·cycle=50% – 1.88 – V Current Sense Amp.=HIGH Error Amp.=HIGH ,CS Pin=1.2V 55 64 85 % MIN. TYP. MAX. UNIT TEST CONDITION IBCS VTHCS0 CS Pin=1.8V duty·cycle=0% – – 250 0.25 650 0.35 nA V VTHCS50 duty·cycle=50% – 0.52 – V MIN. TYP. MAX. UNIT – – 60 2.70 2.52 180 – – – V V mV MIN. TYP. MAX. UNIT 3.50 – 8 4.00 0.25 11 – 0.65 – V V mA MIN. TYP. MAX. UNIT 1.2 1.5 1.8 V – – 1.6 3.5 2.2 4.8 mA mA TEST CONDITION VTHON VTHOFF VHYS SYMBOL VOH VOL ISOURCE GENERAL CHARACTERISTICS PARAMETER SYMBOL Latch Mode Threshold Voltage (CS Pin) Quiescent Current Average Quiescent Current 0.51 – – – – – UNDER VOLTAGE LOCKOUT BLOCK PARAMETER SYMBOL OUTPUT BLOCK PARAMETER UNIT duty·cycle=0% SOFT START CIRCUIT BLOCK PARAMETER SYMBOL ON Threshold Voltage OFF Threshold Voltage Hysteresis Voltage MAX. VTH0 αM Input Bias Current (CS Pin) Input Threshold Voltage (CS Pin) Input Threshold Voltage (CS Pin) TYP. TEST CONDITION RL=10kΩ Output Sink Current=20mA OUT Pin=0V TEST CONDITION VTHLA ICCLA ICCAV Latch Mode RL= , duty·cycle=50% NJM2381 ■ TYPICAL APPLICATIONS 330kΩ 4.7µF 330kΩ V + 1000pF 36kΩ 2.50V 10 9 8 VREF CURRENT SENSE AMP 7 6 VOUT OSC L.O U.V.LO 500Ω 0.52V 1 ER·AMP PWM 2 3 GND 4 5 (Package:SSOP10) -5- NJM2381 ■TIPICAL CHARACTERISTICS H Output Voltage vs. Source Current (V+=6V,RT=33kΩ,CT=1000pF, OUT Pin=0V,Ta=25°C) 1 L Output Voltage VOL (V) H Output Voltage VOH (V) 8 7 6 5 4 3 2 1 0.8 0.6 0.4 0.2 0 0 Oscilltor Frequency f OSC (kHz) 1000 2 4 6 8 10 20 30 40 50 60 Sink Current ISINK (mA) Oscillator Frequency vs. Timing Resistor (V+=6V,Ta=25°C) Oscillator Frequency vs. Timing Capacitor (V+=6V,Ta=25°C) 1000 CT=470pF 100 CT=1000pF RT=10kΩ RT=33kΩ 10 1 RT=100kΩ 1 1 10 100 1000 Timing Resistor RT (kΩ) 10000 10 Reference Voltage vs. Operating Voltage (V+=6V,Ta=25°C) 2.52 2.51 2.5 2.49 2.48 100 1000 10000 Timing Capacitor CT (pF) 100000 Operating Current vs. Operating Voltage (Ta=25°C) 6 Operating Voltage ICC (mA) Reference Voltage VREF (V) 10 Source Current ISOURCE (mA) 100 10 0 12 Oscillator Frequencey fOSC (kHz) 0 5 4 ICCAV 3 2 ICCLA 1 0 0 10 20 30 + Operating Voltage V (V) -6- L Output Voltage vs. Sink Current (V+=6V,RT=33kΩ,CT=1000pF,Ta=25°C) 40 0 10 20 30 + Operating Voltage V (V) 40 NJM2381 Maximum Duty Cycle vs. Oscillator Frequency (V+=6V,Ta=25°C) 80 70 60 50 40 30 20 10 0 10 Duty Cycle α (%) Maximum Duty Cycle αM (%) ■TIPICAL CHARACTERISTICS 100 Oscillator Frequency f OSC (kHz) 1000 Duty Cycle vs. CS Pin Voltage (V+=6V,Ta=25°C) 80 70 60 50 40 30 20 10 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 CS Pin Voltage VTHCS (V) -7- NJM2381 ■TIPICAL CHARACTERISTICS 3 140 Reference Voltage VREF (V) Oscillator Frequency f OSC (kHz) 160 Oscillator Frequency vs. Temperature (V+=6V,RT=33kΩ,CT=1000pF) 120 100 80 2.8 2.6 2.4 2.2 2 60 -50 -25 0 25 50 75 100 125 150 Ambient Temperature Ta (°C) -50 -25 0 25 50 75 100 125 150 Ambient Temperature Ta (°C) H Output Voltage vs. Temperature (V =6V,RL=10kΩ,RT=33kΩ,CT=1000pF) L Output Voltage vs. Trmperature (V =6V,ISINK=20mA,RT=33kΩ,CT=1000pF) + + 0.5 L Output Voltage V OL (V) H Output Voltage VOH (V) 10 Reference Voltage vs. Temperature (V+=6V,IOR=1mA) 8 6 4 2 0.4 0.3 0.2 0.1 0 0 -50 -25 0 25 50 75 100 125 150 Ambient Temperature Ta (°C) Operating Current ICC (mA) -50 -25 0 25 50 75 100 125 150 Ambient Temperature Ta (°C) 5 Operating Current vs. Temperature (V+=6V,RT=33kΩ,CT=1000pF) 4 3 ICCAV 2 ICCLA 1 0 -50 -25 0 25 50 75 100 125 150 Ambient Temperature Ta (°C) -8- [CAUTION] The specifications on this databook are only given for information , without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights.