NJM2392 PWM DC/DC Converter IC ■GENERAL DESCRIPTION ■PACKAGE OUTLINE The NJM2392 is a PWM DC/DC converter IC. It features fixed frequency type PWM control for better noise handling and to avoid intermittent oscillation observed in a simplified controller. It is suitable for Step-Up, Step-Down and Inverting applications. In addition, it contains a pulse-by-pulse current limit circuit and can be set by an external resistance. NJM2392D NJM2392M ■FEATURES ● Operating Voltage 3.0V to 40V ● Wide Oscillator Frequency 1kHz to 150kHz ● Internal High Power Transistor 1.5A max. ● Internal Over Current Limit Circuit ● PWM switching control ● Bipolar Technology ● Package Outline NJM2392D : DIP8 NJM2392M : DMP8 ■PIN CONFIGURATION ■BLOCK DIAGRAM 1 8 2 7 3 6 4 5 NJM2392D NJM2392M PIN FUNCTION 1. CS 2. ES 3. CT 4. GND 5. IN6. V+ 7. SI 8. CD CS 1 Q R 8 CD 7 SI 6 V+ 5 IN- PWM Logic 1.5A S 160Ω ES 2 OSC Block MAX ON Duty 9:1 CT Ipk Sense 300mV 3 Error AMP PWM COMP Vref 1.25V GND 4 Buffer Ver.2008-08-29 -1- NJM2392 ■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.2008-08-29 NJM2392 ■ELECTRICAL CHARACTERISTICS DC Characteristics (V+=5V, Ta=25°C) PARAMETER SYMBOL OSCILLATOR BLOCK Oscillation Frequency Charge Current Discharge Current Voltage Swing Discharge to Charge Current Ratio CURRENT LIMIT Peak Current Sense Voltage OUTPUT SWITCH Saturation Voltage 1 Saturation Voltage 2 Output Transistor Bias Resistance DC Voltage Gain Collector Off-State Current ERROR AMPLIFIER Threshold Voltage Input Bias Current fOSC Ichg Idis VOSC Iratio TEST CONDITIONS IN-=0V, CT=1nF CT=1nF Ichg/Idis Vipk Vsat1 Vsat2 Darlington Connection (CS=CD), ISW=0.7A ISW=0.7A, IC(driver)=50mA (Forced β≈14) Rbias hFE IC(Off) Vth IIB GENERAL CHARACTERISTICS Operating Current ICC ISW=0.7A,VCE=5.0V VCE=40V IN-=0V CT=1nF, SI=V+, IN->Vth, ES=GND MIN. TYP. MAX. UNIT 18 11 110 – 27 18 180 0.5 36 27 300 – kHz µA µA VP-P – 9 – – 250 300 350 mV – 1.0 1.3 V – 0.5 0.7 V – 160 – Ω 35 – 120 0.01 – 1 – µA 1.225 – 1.250 300 1.275 900 V nA – 2.8 4.0 mA (note) Output switch tests are performed under pulsed conditions to minimize power dissipation. Ver.2008-08-29 -3- NJM2392 ■TYPICAL APPLICATIONS Step-Down Converter VIN RSC L1 7 8 1 2 C1 NJM2392 6 4 VOUT 3 5 R2 CIN CT R1 D1 COUT Step-Up Converter VIN RSC L1 D1 VOUT RC COUT C1 7 8 1 2 3 5 R2 NJM2392 6 4 CIN R1 CT Inverting Converter VIN RSC D1 7 1 8 2 NJM2392 6 CIN 4 VOUT C1 3 5 R2 CT L1 R1 COUT D1 use to schottky diode. -4- Ver.2008-08-29 NJM2392 ■ TYPICAL APPLICATIONS Step-Down Converter (High Current) VIN RSC RBE RBC L1 8 7 1 C1 NJM2392 6 VOUT 2 4 5 3 R2 CIN CT F D1 R1 COUT Step-Up Converter (High Current) VIN RSC L1 D1 RC1 RC2 COUT C1 7 VOUT 8 1 R2 2 NJM2392 6 CIN 4 3 CT 5 RBE R1 D1 use to schottky diode. Ver.2008-08-29 -5- NJM2392 ■TIMING CHART Error AMP Output Oscillator Waveform OSC Block to FF, NOR HIGH LOW ON Switch Output OFF Ipk Sense Output HIGH LOW -6- Ver.2008-08-29 NJM2392 ■TYPICAL CHARACTERISTICS Oscillator Frequency vs. Timing Capacitor Switch ON/OFF TIme vs.Timing Capacitor (V+=5V, SI=V+, Pin 5=GND, Ta=25oC) (V+=5V, SI=V+, Pin 5=GND, Ta=25oC) 100 OFF Switch ON/OFF Time t ,t (µs) 10 tON 10 ON OSC Oscillator Frequency (kHz) f 100 1 10 100 1000 10000 Timing Capacitor CT (pF) t 1 10 100000 sat2 1.2 1 0.8 0.6 0.4 0.2 0 1.4 (V) 1.4 0 0.8 0.6 0.4 0.2 0 + (mA) CC Operating Current I IB Input Bias Current I (nA) 200 100 0 Ver.2008-08-29 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 IN- Terminal Voltage (V) 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Collector Current IC (A) o (C =1nF, S =V , IN->V , Es=GND, Ta=25 C) I th 4 T (V =5V, Ta=25 C) 300 0 Operating Current vs. Operating Voltage o 400 (V+=5V, Ic(driver)=50mA,β≅14, Ta=25oC) 1 Input Bias Current vs. IN- Terminal Voltage 500 10000 1.2 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Collector Current IC (A) + 100 1000 Timing Capacitor CT (pF) Saturation Voltage 2 vs. Collector Current (V+=5V, CS=CD, Ta=25oC) Saturation Voltage2 V Saturation Voltage 1 Vsat1 (V) Saturation Voltage 1 vs. Collector Current OFF 3 2 1 0 0 10 20 30 Operating Voltage V+ (V) 40 -7- NJM2392 ■TYPICAL CHARACTERISTICS Threshold Voltage vs. Temperature Discharge to Charge Ratio vs. Temperature + th 1.27 1.26 11 ratio 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) 10 9 8 -50 -25 0 25 50 75 100 125 150 o Ambient Temperature Ta ( C) Saturation Voltage 1 vs. Temperature Saturation Voltage 2 vs. Temperature + + (V =5V, CS=CD, ISW =0.7A) (V =5V, Isw=0.7A, Ic(driver)=50mA,β≅14) (V) 0.8 sat2 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 V Saturation Voltage 1 V sat1 (V) 1.2 0.6 0.4 0.2 0 -50 -25 0 25 50 75 100 125 150 Ambient Temperature Ta (oC) Operating Current vs. Temperature -8- + (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 360 (V =5V) 12 Discharge to Charge Current Ratio I (V) 1.28 Threshold Voltage V + (V =5V) (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.2008-08-29 NJM2392 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.2008-08-29 -9-