NJU7640 Step-Down switching regulator IC with Over Current Protection GENERAL DESCRIPTION PACKAGE OUTLINE The NJU7640 is a low voltage operation high-speed switching regulator control IC for step-down converter, with a pulse-by-pulse over-current protection. The pulse-by-pulse over-current protection circuit can limit the over current in switching operation. It incorporates a totem pole output, which can drive an external MOS-FET easily. It also has a soft-start function and dead time control and their times are all adjustable with external parts. The NJU7640 is available in a small and thin 8-lead MSOP (TVSP) package. FEATURES PWM switching control Pulse-by-pulse over current protection Operating Voltage 2.2V to 8V Wide Oscillator Range 300kHz to 1MHz Maximum Duty Cycle 100% Quiescent Current 800A typ. Soft-Start Function Internal : 16ms typ. or adjustable Dead Time Control C-MOS Technology Package Outline NJU7640RB1 : MSOP8 (TVSP8)* NJU7640RB1 (MSOP8 (TVSP8)) PRODUCT VARIATION NJU7650 Constant Current Control NJU7640 Over Current Protection NJU7630 PWM Control *MEET JEDEC MO-187-DA / THIN TYPE PIN CONFIGURATION 1 8 2 7 3 6 4 5 NJU7640RB1 Ver.2012-08-03 PIN FUNCTION 1. OUT 2. V+ 3. FB 4. IN5. SENSE 6. DTC 7. RT 8. GND -1- NJU7640 BLOCK DIAGRAM + V 0.8V FB ERAMP 0.2V IN1V Vref Soft Start UVLO PWM V+ Buffer 0.2V SENSE OUT OCP OSC Blanking 0.5V OUT 0.5 RT A DTC RT GND RT -2- Ver.2012-08-03 NJU7640 ABSOLUTE MAXIMUM RATINGS PARAMETER SYMBOL Supply Voltage V+ Output Pin Current IO Power Dissipation PD Operating Temperature Range TOPR Storage Temperature Range TSTG MAXIMUM RATINGS +9 50 MSOP8 (TVSP8) :320 -40 to +85 -40 to +125 RECOMMENDED OPERATING CONDITIONS PARAMETER SYMBOL MIN. Operating Voltage V+ 2.2 Oscillator Timing Resistor RT 30 Oscillation Frequency fOSC 300 TYP. - 47 700 Under Voltage Lockout Block ON Threshold Voltage OFF Threshold Voltage Hysteresis Voltage Soft Start Block Soft Start Time Over Current Protection Block Current Limit Sense Voltage Delay Time Sense Blanking Time Oscillator Block RT Pin Voltage Oscillation Frequency Oscillate Supply Voltage Fluctuations Oscillate Temperature Fluctuations Ver.2012-08-03 MAX. 8 120 1,000 (Ta=25C) UNIT V k kHz (V+=3.3V, RT=47k, Ta=25C) ELECTRICAL CHARACTERISTICS PARAMETER (Ta=25C) UNIT V mA mW C C SYMBOL MIN. TYP. MAX. UNIT 1.9 1.8 60 2.0 1.9 100 2.1 2.0 - V V mV 8 16 24 ms 0.17 0.2 0.23 V - 160 - ns TBLANK - 90 - ns VRT fOSC -5% 630 0.5 700 +5% 770 V kHz VT_ON VT_OFF VHYS TSS VSENSE TDELAY TEST CONDITION V+= L H V+= H L VT_ON Duty=80% Voltage between V+-SENSE pin VSENSE+0.1V Delay time to OUT fDV V+=2.2V to 8V - 1 - % fDT Ta=-40C to +85C - 3 - % -3- NJU7640 (V+=3.3V, RT=47k, Ta=25C) ELECTRICAL CHARACTERISTICS PARAMETER Error Amplifier Block Reference Voltage Input Bias Current Open Loop Gain Gain Bandwidth Product Output Source Current Output Sink Current SYMBOL TEST CONDITION VB IB AV GB IOM+_1 IOM+_2 IOM- VFB=1V, VIN-=0.9V VFB=1V, VIN-=0.9V, V+=2.2V VFB=1V, VIN-=1.1V MIN. TYP. MAX. UNIT -1.0% -0.1 - - 25 4 0.10 1.00 - 80 1 55 9 0.16 +1.0% 0.1 - - 95 16 0.22 V A dB MHz mA mA mA 0.16 0.44 100 40 0.22 0.5 - 50 0.28 0.56 - 60 V V % % PWM Comparate Block Input Threshold Voltage Maximum Duty Cycle Output Block Output High Level ON Resistance Output Low Level ON Resistance General Characteristics Quiescent Current -4- VT_0 VT_50 MAXDUTY_1 MAXDUTY_2 Duty=0% Duty=50% VFB=0.9V VFB=0.9V, RDTC=47k ROH IO=-20mA - 10 20 ROL IO=+20mA - 5 10 RL=Non Load - 800 1200 A IDD Ver.2012-08-03 NJU7640 TYPICAL APPLICATIONS Step-Down Converter RSC FET L VIN VOUT SBD CIN COUT R2 NJU7640 1 OUT 2 V 3 C R1 GND 8 RT 7 FB DTC 6 IN- SENSE 5 + Ver.2012-08-03 4 RDTC CS CNF RNF RT -5- NJU7640 TYPICAL CHARACTERISTICS Oscillation Frequency vs. Timing Resistance 100 10 Oscillation Frequency fosc (kHz) 1000 Oscillation Frequency fOSC (kHz) Oscillation Frequency vs. Operating Voltage (V+=3.3V, Ta=25oC) 100 Timing Resistance RT (k) Duty Cycle vs. R o 700 680 660 0 2 4 6 8 + Operating Voltage V (V) 10 (V+=3.3V, RT=47k, Ta=25oC) (%) 75 UTY 60 Duty Cycle D (%) UTY -6- 720 100 T AX Duty Cycle M D (V+=3.3V, R =47k, Ta=25 C) 80 40 20 0 T 740 Duty Cycle vs. Current Limit Sense Voltage DTC 100 (R =47k, Ta=25oC) 50 25 0 0 20 40 60 80 100 Dead Time Control Resistance RDTC (k) 0 0.2 0.4 0.6 0.8 1 Current Limit Sense Voltage VSENSE (V) Ver.2012-08-03 NJU7640 1.002 1 0.998 0.996 0 2 4 6 8 Operating Voltage V+ (V) 10 Current Limit Sense Voltage V Reference Voltage VB (V) 1.004 SENSE (V+=3.3V, Ta=25oC) Current Limit Sense Voltage vs. Operating Voltage 0.23 0.22 0.21 0.2 0.19 0.18 0.17 T L 60 1200 Voltage Gain Av (dB) Quiescent Current IDD (A) 1400 1000 800 600 400 0 2 4 6 8 Operating Voltage V+ (V) 10 Error Amplifier Block Voltage Gain, Phase vs. Frequency (V+=3.3V, Gain=40dB, Ta=25 oC) Quiescent Current vs. Operating Voltage (R =47k, R =Non Load, Ta=25oC) (V+=3.3V, Ta=25oC) Phase 45 180 135 Gain 30 90 15 45 Phase (deg) Reference Voltage vs. Operating Voltage (V) TYPICAL CHARACTERISTICS 200 0 0 Ver.2012-08-03 2 4 6 8 Operating Voltage V+ (V) 10 0 0.1 1 10 100 1000 Frequency f (kHz) 0 10000 -7- NJU7640 TYPICAL CHARACTERISTICS + V =1.95V 12 10 4 0 -50 -25 0 25 50 75 100 125 Ambient Temperature Ta (oC) Error Amplifier Block Output Source Current vs. Temperature (VFB=1V, VIN-=0.9V) V+=8V 100 V+=3.3V 10 V+=1.95V 1 -50 V+=3.3V V+=8V 50 -25 0 25 50 75 100 125 Ambient Temperature Ta (oC) V+=3.3V 6 4 2 0 -50 0.15 V+=8V -25 0 25 50 75 100 125 Ambient Temperature Ta (oC) Error Amplifier Block Output Sink Current vs. Temperature (VFB=1V, VIN- =1.1V) V+=1.95V, 3.3V, 8V 0.1 0.05 0 -50 -25 0 25 50 75 100 125 Ambient Temperature Ta (oC) Soft Start Time vs. Temperature Delay Time vs. Temperature (VSENSE +0.1V Delay time to OUT) 200 100 V+=1.95V 8 0.2 -25 0 25 50 75 100 125 Ambient Temperature Ta (oC) V+=1.95V 150 12 Output Sink Current IOM- (mA) Output Source Current IOM+ (mA) (ns) DELAY Delay Time T V+=8V 2 0 -50 -8- V+=3.3V 6 250 Output Block Output Low Level ON Resistance vs. Temperature (Io=+20mA) 10 8 1000 14 24 Soft Start Time Tss (ms) Output High Level ON Resistance ROH () 14 Output Low Level ON Resistance ROL () Output Block Output High Level ON Resistance vs. Temperature (Io=-20mA) (V+=3.3V) 22 20 18 16 14 12 10 8 -50 -25 0 25 50 75 100 125 o Ambient Temperature Ta ( C) Ver.2012-08-03 NJU7640 TYPICAL CHARACTERISTICS Current Limit Sense Voltage vs. Temperature (V) Reference Voltage vs. Temperature + (V =3.3V) SENSE 1.005 1 0.995 0.99 -50 -25 0 25 50 75 100 125 o Ambient Temperature Ta ( C) Current Limit Sense Voltage V Reference Voltage VB (V) 1.01 (V+=3.3V) 0.21 0.205 0.2 0.195 0.19 -50 -25 0 25 50 75 100 125 Ambient Temperature Ta (oC) Oscillator Frequency vs. Temperature 760 (V =3.3V, RT=47k) 2.06 740 Threshold Voltage (V) Oscillator Frequency fOSC (kHz) + 720 700 680 660 640 -50 -25 0 25 50 75 100 125 Ambient Temperature Ta (oC) Under Voltage Lockout Block vs. Temperature 2.02 VT_ON 1.98 1.94 VT_OFF 1.9 1.86 -50 -25 0 25 50 75 100 125 Ambient Temperature Ta (oC) Quiescent Current vs. Temperature Quiescent Current IDD (A) 1000 T 800 600 400 200 0 -50 Ver.2012-08-03 (V+=3.3V, R =47k) -25 0 25 50 75 100 125 Ambient Temperature Ta (oC) -9- NJU7640 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. - 10 - Ver.2012-08-03 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: NJR: NJU7640RB1-TE1