Switching Regulator IC for Buck Converter Current Mode Control w/ V/A MOSFET GENERAL DESCRIPTION The NJW15 is a current mode controlled buck converter with V/A MOSFET that operates wide input range from 6V to 35V. The NJW15 can realize a buck converter with minimal external components that it includes compensation circuit. The NJW15 is able to stable startup by soft start function. Also, it has over current protection and thermal shutdown circuit. It is suitable for supplying power to an Office Automation Equipment, Industrial Instrument, Amusement, Wireless Base Station Applications and so on. PACKAGE OUTLINE 1 2 3 FEATURES Current Mode Control Wide Input Range: Switching Current PWM Control Built-in Compensation Circuit Oscillating Frequency: Soft Start Function UVLO (Under Voltage Lockout) Over Current Protection Thermal Shutdown Function Package Outline 6V to V.5A min. 15kHz typ. ms typ. TO-22F-pin NJW15F PIN CONFIGURATION 1. V + 2. SW 3. GND. IN- NJW15FL BLOCK DIAGRAM V + SLOPE COMP. CURRENT SENSE TSD OCP UVLO Source Low Frequency Control OSC S Q R Buffer Drain IN- SW ER AMP PWM Soft Start Vref.V GND - 1 -
ABSOLUTE MAXIMUM RATINGS (Ta=25 C) PARAMETER SYMBOL MAXIMUM RATINGS UNIT Supply Voltage V + +5 V Drain Source pin Voltage V DSS -5 V IN- pin Voltage V IN- -.3 to +6 V Power Dissipation P D 2.1 (Device itself) W Junction Temperature Range Tj - to +15 C Operating Temperature Range T opr - to +5 C Storage Temperature Range T stg - to +15 C RECOMMENDED OPERATING CONDITIONS PARAMETER SYMBOL MIN. TYP. MAX. UNIT Supply Voltage V + 6 V IN- pin Voltage V IN- 5.5 V THERMAL CHARACTERISTICS PARAMETER SYMBOL THERMAL RESISTANCE UNIT Junction-to-Ambient Temperature θja 59.5 C/W Junction-to-Case ψjt 7.5 C/W POWER DISSIPATION vs. AMBIENT TEMPERATURE Power Dissipation vs. Ambient Temperature (Tj= ~15 o C) Power Dissipation P D (W) Infinity Heat Sink θ HS =5 o C/W θ HS = o C/W θ =2 o C/W HS Without Heat Sink -5-25 25 5 75 Ambient Temperature Ta ( o C) - 2 -
ELECTRICAL CHARACTERISTICS (Unless otherwise noted, V + =V, Ta=25 C) PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Under Voltage Lockout Block ON Threshold Voltage V T_ON V + = L H 5.2 5. 5.6 V OFF Threshold Voltage V T_OFF V + = H L..6. V Hysteresis Voltage V HYS mv Soft Start Block Soft Start Time T SS V B =.75V 5 2 ms Oscillator Block Oscillation Frequency f OSC V IN- =.7V 135 15 5 khz Oscillation Frequency (Low Frequency Control) f OSC_LOW V IN- =.V 5 khz Oscillation Frequency deviation (Supply voltage) f DV V + =6V to V 1 % Oscillation Frequency deviation (Temperature) f DT Ta=- C to +5 C 5 % Error Amplifier Block Reference Voltage V B -1.%. +1.% V Input Bias Current I B -.1 +.1 µa PWM Comparate Block Maximum Duty Cycle M AX D UTY V IN- =.7V 5 9 % Minimum ON Time T ON_min 66 5 ns Over Current Protection Cool Down Time t COOL 2 ms Output Block Output ON Resistance R ON I SW =A 55 mω Switching Current Limit I LIM.5.5 15 A Switching Current Limit 2 I LIM2 V + =3V.5.5 15 A Switching Leak Current I LEAK V + =5V, V SW =V 2 µa General Characteristics Quiescent Current I DD R L =no load, V IN- =.7V 7 9.5 ma - 3 -
MARK SPECIFICATION 15 JRC Part Number (Indicating NJW15F or NJW15FL) Logo Mark Lot 1 2 3 TYPICAL APPLICATIONS V IN 1 NJW15 2 L V OUT = R2 +1 x V B [V] R1 V OUT 3 C FB R2 C IN1 C IN2 SBD C OUT R FB R1 *When large current flows, V IN line may be unstable. Therefore, you should put C IN on near IC as much as possible. - -
TYPICAL CHARACTERISTICS 5 Oscillation Frequency vs. Supply Voltage (V IN- =.7V, Ta=25 C).1 Reference Voltage vs. Supply Voltage (Ta=25 C) Oscillation Frequnecny f OSC (khz) 155 15 15 1 Reference Voltage V B (V).5..795 135 2 3 Supply Voltage V + (V).79 2 3 Supply Voltage V + (V) Quiescent Current I DD (ma) 9 7 6 5 3 2 1 Quiescent Current vs. Supply Voltage (R L =no load, V IN- =.7V, Ta=25 C) 2 3 Supply Voltage V + (V) - 5 -
TYPICAL CHARACTERISTICS 5 Oscillation Frequency vs Temperature (V + =V, V IN- =.7V).1 Reference Voltage vs. Temperature (V + =V) Oscillation Frequency fosc (khz) 155 15 15 1 Reference Voltage V B (V).5..795 135.79 2 Switching Current Limit vs. Temperature (V + =V) 2 Switching Current Limit 2 vs. Temperature (V + =3V) Switching Current Limit I LIM (A) 1 1 Switching Current Limit I LIM2 (A) 1 1 Output ON Resistance vs. Temperature (I SW =A) 2 Switching Leak Current vs. Temperature (V + =5V, V SW =V) Output ON Resistance R ON (mω) 9 7 6 5 3 2 Switching Leak Current I LEAK (µa) 1 1 6 2-6 -
TYPICAL CHARACTERISTICS Under Voltage Lockout Voltage vs. Temperature 5.6 2 Soft Start Time vs. Temperature (V + =V, V B =.75V) Threshold Voltage (V) 5. 5.2 5..6 V T_ON V T_OFF Soft Start Time Tss (ms) 1 1 6. 9 Minimum ON Time vs. Temperature (V + =V) Maximum Duty Cycle vs. Temperature (V + =V, V IN- =.7V) Minimum ON Time t ON-min (ns) 7 6 5 3 2 V + =V V + =V V + =6V Maximum Duty Cycle M AX D UTY (%) 9 96 9 92 9 6 Quiescent Current I DD (ma) 9 7 6 5 3 2 1 Quiescent Current vs. Temperature (R L =no load, V IN- =.7V) V + =V V + =V V + =6V - 7 -
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. - -