NJM2393 Step-Down PWM DC/DC Converter IC ■GENERAL DESCRIPTION ■PACKAGE OUTLINE The NJM2393 is a step down PWM DC/DC converter IC. An internal 1.5A power transistor, a pulse-by-pulse current limit circuit and a 1% precision reference make the NJM2393 suitable for a wide range of step down applications. The NJM2393 features 100% maximum duty cycle for low voltage drop operation. ■FEATURES •Operating Voltage •Wide Oscillator Frequency •Precision Reference Voltage •Internal High Power Transistor •Maximum duty ratio •Internal Over Current Limit Circuit •PWM switching control •Bipolar Technology •Package Outline NJM2393D NJM2393M NJM2393M 3.0V~40V 1kHz~150kHz Vth=1.25V ± 1% 1.5A max. 100% : DIP8 : DMP8 ■PIN CONFIGURATION ■BLOCK DIAGRAM 1 8 2 7 3 6 4 5 NJM2393D NJM2393M NJM2393D PIN FUNCTION 1. CS 2. ES 3. CT 4. GND 5. IN6. V+ 7. SI 8. CD CS 1 8 CD 7 SI 6 V+ 5 IN- R Q PWM Logic 1.5A S 160Ω ES 2 OSC Block MAX Duty =100% CT Ipk Sense 300mV 3 Error AMP PWM COMP Vref 1.25V GND 4 Buffer Ver.2009-09-28 -1- NJM2393 ■ABSOLUTE MAXIMUM RATINGS (Ta=25°C) PARAMETER SYMBOL Maximum Supply Voltage V+ Comparator Input Voltage VIR Output Driver Voltage VC(driver) Output Switch Voltage VSW Output Driver Current IC(driver) Output Switch Current ISW Power Dissipation PD MAXIMUM RATINGS 40 -0.3 ~ 40 (note) 40 40 100 1.5 DIP8 875 DMP8 580 (*1) 750 (*2) -40 ~ +85 -50 ~ +150 UNIT V V V V mA A mW °C °C (note) When supply voltage is less than 40V, the absolute maximum input voltage is equal to the supply voltage. (*1) At on PC board : 114.3mm × 76.2mm × 1.6mm(2 layer FR-4) : Conform to EIA/JEDEC (*2) At on PC board :114.3mm × 76.2mm × 1.6mm(4 layer FR-4) : Conform to EIA/JEDEC Operating Temperature Range Storage Temperature Range Topr Tstg ■POWER DISSIPATION vs. AMBIENT TEMPERATURE Power Dissipation vs. Ambient Temperature (Topr=-40~+85oC, Tj= ~150oC) DIP8 800 Power Dissipation P D (mW) 1000 600 400 DMP8 At on 4 layer PC Board At on 2 layer PC Board 200 0 0 -2- 25 50 75 100 o Ambient Temperature Ta ( C) Ver.2009-09-28 NJM2393 ■ELECTRICAL CHARACTERISTICS DC Characteristics (V+=5V, Ta=25°C) PARAMETER SYMBOL OSCILLATOR BLOCK Oscillation Frequency Charge Current Discharge Current Voltage Swing CURRENT LIMIT Peak Current Sense Voltage fOSC Ichg Idis VOSC TEST CONDITIONS IN-=Vth -5mV, CT=1nF CT=1nF Vipk MIN. TYP. MAX. UNIT 18 11 110 - 27 18 180 0.5 36 27 300 - kHz µA µA VP-P 250 300 350 mV - 1.0 1.3 V - 0.5 0.7 V - - 0.3 V - 160 - Ω 35 100 120 0.01 - 1 - µA % 1.2375 - 1.250 100 1.2625 200 V nA - 2.8 4.0 mA OUTPUT SWITCH Saturation Voltage 1 Vsat1 Saturation Voltage 2 Vsat2 Saturation Voltage 3 Output Transistor Bias Resistance DC Voltage Gain Collector Off-State Current Maximum duty ratio Vsat3 ERROR AMPLIFIER Threshold Voltage Input Bias Current Darlington Connection (CS=CD), ISW=0.7A ISW=0.7A, IC(driver)=50mA (Forced β≈14) ISW=3mA, IC(driver)=5mA Rbias hFE ISW=0.7A,VCE=5.0V IC(Off) VCE=40V MAXDUTY IN-=0V Vth IIB GENERAL CHARACTERISTICS Operating Current ICC IN-=Vth CT=1nF, SI=V+, IN->Vth, ES=GND (note) Output switch tests are performed under pulsed conditions to minimize power dissipation. Ver.2009-09-28 -3- NJM2393 ■TYPICAL APPLICATIONS Step-Down Converter VIN RSC L1 7 8 1 2 C1 NJM2393 6 4 VOUT 5 3 R2 CIN CT R1 D1 COUT Step-Down Converter (High Current) RSC VIN RBE RBC L1 7 1 8 C1 NJM2393 6 4 VOUT 2 3 5 R2 CIN CT F D1 R1 COUT D1 use to schottky diode. ■TIMING CHART Error AMP Output Oscillator Waveform OSC Block to FF, NOR HIGH LOW ON Switch Output OFF Ipk Sense Output HIGH LOW -4- Ver.2009-09-28 NJM2393 ■TYPICAL CHARACTERISTICS Saturation Voltage 1 vs. Collector Current Oscillator Frequency vs. Timing Capacitor + + Saturation Voltage 1 Vsat1 (V) (V =5V, SI=V , Pin 5=GND, Ta=25 C) 10 OSC Oscillator Frequency (kHz) f 100 1 10 100 1000 10000 Timing Capacitor CT (pF) 1.4 1.2 1 0.8 0.6 0.4 0.2 0 100000 (V =5V, Ic(driver)=50mA,β≅14, Ta=25 C) (V) sat3 1.2 1 0.8 0.6 0.4 0.2 0 0 (V+=5V, Ic(driver)=5mA,Ta=25oC) 0.1 0.08 0.06 0.04 0.02 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Collector Current IC (A) 0 + (mA) CC 300 200 100 0 Ver.2009-09-28 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 IN- Terminal Voltage (V) 20 o (C =1nF, S =V , IN->V , Es=GND, Ta=25 C) I th 4 T (V =5V, Ta=25 C) Operating Current I IB Input Bias Current I (nA) + o 400 5 10 15 Collector Current IC (mA) Operating Current vs. Operating Voltage Input Bias Current vs. IN- Terminal Voltage 500 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Collector Current IC (A) o Saturation Voltage3 V Saturation Voltage2 V sat2 (V) + 0 Saturation Voltage 3 vs. Collector Current Saturation Voltage 2 vs. Collector Current 1.4 (V+=5V, CS=CD, Ta=25oC) o 3 2 1 0 0 10 20 30 Operating Voltage V+ (V) 40 -5- NJM2393 ■TYPICAL CHARACTERISTICS Saturation Voltage 1 vs. Temperature Threshold Voltage vs. Temperature (V+=5V, CS=CD, ISW =0.7A) + (V =5V) (V) sat1 th 1.27 Threshold Voltage V 1.2 1.26 1.25 1.24 1.23 1.22 1.21 1.2 -50 -25 0 25 50 75 100 125 150 o Ambient Temperature Ta ( C) Saturation Voltage 1 V (V) 1.28 1.1 1 0.9 0.8 0.7 0.6 -50 -25 0 25 50 75 100 125 150 Ambient Temperature Ta (oC) Saturation Voltage 2 vs. Temperature Saturation Voltage 3 vs. Temperature + (mV) (V =5V, Isw=0.7A, Ic(driver)=50mA,β≅14) sat3 0.6 0.4 0.2 0 -50 -25 0 25 50 75 100 125 150 Ambient Temperature Ta (oC) Saturation Voltage 3 V Saturation Voltage 2 V sat2 (V) 0.8 (V+=5V, Isw=3mA, Ic(driver)=5mA) 8 6 4 2 0 -50 -25 0 25 50 75 100 125 150 Ambient Temperature Ta (oC) Operating Current vs. Temperature -6- + + 360 (V =5V) 340 320 300 280 260 240 -50 -25 0 25 50 75 100 125 150 o Ambient Temperature Ta ( C) 5 Operating Current ICC (mA) Current Limit Sense Voltage V ipk (mV) Current Limit Sense Voltage vs. Temperature (V =5V, C =1nF, S =V+, IN->V , Es=GND) T I th 4 3 2 1 0 -50 -25 0 25 50 75 100 125 150 o Ambient Temperature Ta ( C) Ver.2009-09-28 NJM2393 MEMO 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. Ver.2009-09-28 -7-