NJM2381M

NJM2381 SWITCHING REGULATOR CONTROL IC FOR FLYBACK WITH CURRENT SENSE AMPLIFIER sGENERAL DESCRIPTION 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. sPACKAGE OUTLINE NJM2381D NJM2381M sFEATURES q PWM switching control q Operating Voltage (3.6 to 32V) q W ide Oscillator Range (5 to 350 kHz) q Current Sensing Amplifier q Soft-Start Function q UVLO(Under Voltage Lockouts) q Bipolar Technology q Package Outline DIP14, DMP14, SSOP10 NJM2381V sPIN CONFIGURATION 1 2 3 4 5 6 7 14 13 12 11 10 9 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 2 3 4 5 10 9 8 7 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 sBLOCK DIAGRAM NC 14 IN+ 13 REF 12 CT 11 CS 10 V+ 9 NC 8 VREF CURRENT SENSE AMP OSC L.O U.V.LO 500Ω ER·AMP 0.52V PWM 1 NC 2 IN-1 3 IN-2 4 F.B 5 GND 6 OUT 7 NC (Package: DIP14, DMP14) IN+ 10 REF 9 CT 8 CS 7 V+ 6 VREF CURRENT SENSE AMP OSC L.O U.V.LO 500Ω ER·AMP 0.52V PWM 1 IN 1 - 2 IN 2 - 3 F.B 4 GND 5 OUT (Package: SSOP10) -2- NJM2381 sABSOLUTE 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 TOPR TSTG MAXIMUM RATINGS 36 10 ±50 2.5 -0.3 ∼ 2.5 (DIP 14) 700 (DMP 14) 300 (SSOP 10) 250 -40 ∼ +85 -50 ∼ +125 UNIT V mA mA V V mW °C °C sELECTRICAL 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 + TEST CONDITION IOR=1mA V =3.6 ∼ 32V, IOR=1mA IOR=0.1 ∼ 5.0mA MIN. 2.45 – – TYP. 2.50 6.8 5 MAX. 2.55 20.7 30 UNIT V mV mV SYMBOL fOSC fdV fdT + TEST CONDITION RT=33kΩ, CT=1000pF V =3.6 ∼ 32V Ta=-40 ∼ 85°C MIN. 85 – – TYP. 105 1 5 MAX. 125 – – UNIT kHz % % 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) VIO1 IIO1 IB1 A V1 GB1 VICM1 VOM-1 IOM+1 TEST CONDITION MIN. – – – – – – TYP. 2 5 5 90 0.6 0∼ VREF-0.8 – 85 MAX. 7 50 100 – – – 1 200 UNIT mV nA nA dB MHz V V µA RNF=100kΩ VOM=0.5V – 40 -3- NJM2381 sELECTRICAL 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 Input Threshold Voltage (F.B Pin) Input Threshold Voltage (F.B Pin) Maximum Duty Cycle VB2 IB2 A V2 GB2 VOM-2 IOM+2 0.51 – – – – 40 TYP. 0.52 5 90 0.6 – 85 MAX. 0.53 100 – – 1 200 UNIT V nA dB MHz V µA RNF=100kΩ VOM=0.5V SYMBOL VTH0 VTH50 αM TEST CONDITION duty·cycle=0% duty·cycle=50% Current Sense Amp.=HIGH Error Amp.=HIGH ,CS Pin=1.2V MIN. – – 55 TYP. 1.65 1.88 64 MAX. 1.75 – 85 UNIT V V % SOFT START CIRCUIT BLOCK PARAMETER SYMBOL Input Bias Current (CS Pin) Input Threshold Voltage (CS Pin) Input Threshold Voltage (CS Pin) IBCS VTHCS0 VTHCS50 TEST CONDITION CS Pin=1.8V duty·cycle=0% duty·cycle=50% MIN. – – – TYP. 250 0.25 0.52 MAX. 650 0.35 – UNIT nA V V UNDER VOLTAGE LOCKOUT BLOCK PARAMETER SYMBOL ON Threshold Voltage OFF Threshold Voltage Hysteresis Voltage OUTPUT BLOCK PARAMETER H-Output Voltage (OUT Pin) L-Output Voltage (OUT Pin) Output Source Current (OUT Pin) VTHON VTHOFF VHYS TEST CONDITION MIN. – – 60 TYP. 2.70 2.52 180 MAX. – – – UNIT V V mV SYMBOL VOH VOL ISOURCE TEST CONDITION RL=10kΩ Output Sink Current=20mA OUT Pin=0V MIN. 3.50 – 8 TYP. 4.00 0.25 11 MAX. – 0.65 – UNIT V V mA GENERAL CHARACTERISTICS PARAMETER SYMBOL Latch Mode Threshold Voltage (CS Pin) Quiescent Current Average Quiescent Current VTHLA ICCLA ICCAV TEST CONDITION MIN. 1.2 TYP. 1.5 1.6 3.5 MAX. 1.8 2.2 4.8 UNIT V mA mA Latch Mode RL= , duty·cycle=50% – – -4- NJM2381 s TYPICAL APPLICATIONS 330kΩ 36kΩ 2.50V 1000pF 4.7µF 330kΩ V + 10 9 8 7 6 VOUT VREF CURRENT SENSE AMP OSC L.O U.V.LO 500Ω 0.52V ER·AMP PWM GND 1 2 3 4 5 (Package:SSOP10) -5- NJM2381 sTIPICAL CHARACTERISTICS H Output Voltage vs. Source Current (V+=6V,RT=33kΩ,CT=1000pF, OUT Pin=0V,Ta=25°C) L Output Voltage VOL (V) L Output Voltage vs. Sink Current (V+=6V,RT=33kΩ,CT=1000pF,Ta=25°C) 8 H Output Voltage VOH (V) 7 6 5 4 3 2 1 0 0 1 0.8 0.6 0.4 0.2 0 2 4 6 8 10 12 0 10 20 30 40 50 60 Source Current ISOURCE (mA) Oscillator Frequency vs. Timing Resistor (V+=6V,Ta=25°C) Sink Current ISINK (mA) Oscillator Frequency vs. Timing Capacitor (V+=6V,Ta=25°C) 1000 Oscilltor Frequency f OSC (kHz) 1000 Oscillator Frequencey fOSC (kHz) 100 CT=470pF 100 RT=10kΩ RT=33kΩ RT=100kΩ 1 10 CT=1000pF 10 1 1 10 100 1000 Timing Resistor RT (kΩ) 10000 10 100 1000 10000 Timing Capacitor CT (pF) 100000 Reference Voltage VREF (V) 2.52 2.51 2.5 2.49 2.48 0 Reference Voltage vs. Operating Voltage (V+=6V,Ta=25°C) Operating Voltage ICC (mA) 6 5 4 3 2 1 0 Operating Current vs. Operating Voltage (Ta=25°C) ICCAV ICCLA 10 20 + 30 40 0 10 20 + 30 40 Operating Voltage V (V) Operating Voltage V (V) -6- NJM2381 sTIPICAL CHARACTERISTICS Maximum Duty Cycle vs. Oscillator Frequency (V+=6V,Ta=25°C) Maximum Duty Cycle αM (%) 80 70 60 50 40 30 20 10 0 10 100 Oscillator Frequency f OSC (kHz) 1000 80 70 60 50 40 30 20 10 0 0 Duty Cycle vs. CS Pin Voltage (V+=6V,Ta=25°C) Duty Cycle α (%) 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 CS Pin Voltage VTHCS (V) -7- NJM2381 sTIPICAL CHARACTERISTICS Oscillator Frequency vs. Temperature (V+=6V,RT=33kΩ,CT=1000pF) 160 Oscillator Frequency f OSC (kHz) 140 120 100 80 60 3 Reference Voltage VREF (V) 2.8 2.6 2.4 2.2 2 Reference Voltage vs. Temperature (V+=6V,IOR=1mA) -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) 10 H Output Voltage VOH (V) 8 6 4 2 0 H Output Voltage vs. Temperature (V =6V,RL=10kΩ,RT=33kΩ,CT=1000pF) + 0.5 L Output Voltage V OL (V) 0.4 0.3 0.2 0.1 0 L Output Voltage vs. Trmperature (V =6V,ISINK=20mA,RT=33kΩ,CT=1000pF) + -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) Operating Current ICC (mA) 5 4 3 Operating Current vs. Temperature (V+=6V,RT=33kΩ,CT=1000pF) ICCAV 2 1 0 -50 -25 0 25 50 75 100 125 150 Ambient Temperature Ta (°C) ICCLA [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. -8-