ILC6377

ILC6377 IMPALA | Alldatasheet

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Impala Linear Corporation 1(408) 574-3939 www.impalalinear.com June 1999 ILC6377 1.3 The ILC6377 is a 95% efficient, 300kHz step-down DC-DC converter in an SO-8 package; capable of delivering 500mA output current. The device is also capable of driving an external FET for higher output current applications. The ILC6377 uses a unique p-channel architecture with built-in charge pump to maintain low on-resistance, even at low input voltages. At high or normal currents the ILC6377 operates in PWM mode with 300kHz operating frequency. When the load current drops and the device hits approxi- mately 17% duty cycle, it automatically switches over to PFM or pulse skipping mode. PFM (pulse frequency mod- ulation) mode of operation extends efficiency at light loads. Start-up is controlled via an external soft-start capacitor. The device will automatically re-enter start-up mode when an output current overload condition is sensed; thus providing automatic short-circuit protection. Voltage lockout prevents faulty operation below the minimum operating voltage level. In shutdown, the ILC6377 consumes only 1.5mA current. The ILC6377SO-XX offers fixed 3.3V or 5V ouput while ILC6377SO-Adj allows adjustable output. Both versions of ILC6377 are available in an SO-8 surface mount package. ! ±2.5% accurate output voltages ! Guaranteed 500mA output current ! 95% efficiency ! 55mA no load battery input current ! 1.5mA shutdown current ! Built in short circuit and overcurrent protection ! Undervoltage lockout and soft-start ! External transistor drive available for higher Iout ! 300kHz operation ! Automatic switchover to PFM mode at low currents for longest battery life ! Fixed 3.3V or 5V or adjustable output ! SO-8 package ! Cellular Phones ! Palmtops and PDAs ! Portable Instrumentation ! Buck Converter for Industrial / Networking Applications PW M/ P F M Prot ection LX GND EXT1 RA MP WA VE VIN VOU T P_BS T GA TE DR IV ER GE NE RA TOR , OSCILLATORCONTR OLLE R PWM Com p EX T2 Error Am p S/ D , So ft star t , Vref S/ D, Vr ef with So f t- start ILC6377 (TOP V I EW )3 8 LX FB EXT1 S/D, GNDP_BS T EX T2 VIN ILC637 7SO-Adj CSS ILC6377 (TOP V I EW )3 LX VOU T EXT1 45S/D, GND P_BS T EX T2 VIN CSS SO -8 P ack age ILC63 77SO-XX

Ordering Information

ILC6377SO-33 3.3V, 300 kHz step-down PWM/PFM converter ILC6377SO-50 5V, 300 kHz step-down PWM/PFM converter ILC6377SO-Adj Adjustable, 300 kHz step-down PWM/PFM converter Pin Symbol Function

1 VIN Power Supply

2 EXT2 External gate drive pin (low when

P-Ch FET is ON)

3 P-BST P-Ch gate boost

4 S/D

Softstart, Vref Shutdown, also soft-start capacitor pin and Vref output

5 VOUT/FB Output voltage sense pin for

ILC6377SO-XX; 1V feedback for ILC6377SO adj

6 GND Ground connection

7 EXT1 External gate drive pin (low when

P-Ch FET is on)

8 LX Inductor switch pin

0.5A, 300kHz, SO-8 PWM/PFM Step Down Converter with Shutdown Impala Linear Corporation General Description Features

Applications

Pin Package Configurations Pin Description

0.5A, 300kHz, SO-8 PWM/PFM Step Down Converter with Shutdown Impala Linear Corporation 2(408) 574-3939 www.impalalinear.com June 1999 ILC6377 1.3 Conditions VIN 3.5V, No Loads VS/D = 0V Open Loop Measurement, VS/D = VIN, VLX = VIN - 0.4V, VOUT = 3V Open Loop Measurement, VOUT = VIN, VLX = 0V Measurement Waveform at EXT pin VIN = 3.6V IOUT = 20mA No Load Minimum VIN when Vref does not start up Vref rises to 0V from 0.9V Parameter Output Voltage Input Voltage Output Voltage Input Current Supply Shutdown Current L X Switch On - Resistance LX Switch Leakage Current Oscillator Frequency Max Duty Cycle PFM Duty Cycle Efficiency Undervoltage Lockout Soft-Start Time Symbol VOUT VIN IOUT IIN IS/D Rds(on) ILXL FOSC MAXDTY PFMDTY EFFI VUVLO TSS Unless Otherwise specified all limits are at V OUT = 3.3V, VIN = 4V, FOSC=300kHz, IOUT = 130mA,TA = 25°C. Circuit configuration of figure 1. Parameter VIN Input Voltage Pin VOUT Pin (ILC6370SO-XX) FB Pin (ILC6377SO-Adj) Voltage on LX pin Peak Switch Current on LX pin Voltage on P_BST pin Current EXT1, EXT2 pins Voltage on all other pins Continuous Total Power Dissipation Operating Ambient Temperature Storage Temperature Symbol VIN VOUT VFB VLX ILX VDP_BST IEXT1, IEXT2 PD TOPR TSTG Ratings -0.3 to +12 -0.3 to +12 -0.3 to V IN +12 VIN - VLX = 0.3 to +12 700 VIN - VP_BST = 0.3 to +12 ±50 -0.3 to VIN 500 -30~+80 -40~+125 Units V V V mA V mA V mA Typ 3.300 600 1.5 0.64 300 100 10.0 Min 3.218 500 255 6.0 Max 3.383 2.5 0.85 2.0 345 1.8 16.0 Units V V mA µA µA Ω µA kHz V msec Absolute Maximum Ratings (TA=25°C)

0.5A, 300kHz, SO-8 PWM/PFM Step Down Converter with Shutdown Impala Linear Corporation 3(408) 574-3939 www.impalalinear.com June 1999 ILC6377 1.3 Min 4.875 500 255 6.0 3.0 0.65 Typ 5.000 600 1.5 0.44 300 100 10.0 5.0 Symbol VOUT VIN IOUT IIN IS/D Rds(on) ILXL FOSC MAXDTY PFMDTY EFFI VUVLO TSS TPRO VS/D REXtHI REXtLOW Parameter Output Voltage Input Voltage Output Current Input Supply Current Shutdown Current L X Switch On-Resistance LX Switch Leakage Current Oscillator Frequency Max Duty Cycle PFM Duty Cycle Efficiency Undervoltage Lockout Soft-Start Time Internal Protection Time Shutdown Input Voltage EXT1, EXT2 Hi On-Resistance EXT1, EXT2 Low On-Resistance Parameter Internal Protection Time Shutdown Input Voltage EXT1, EXT2 Hi On-Resistance EXT1, EXT2 Low On-Resistance Symbol TPRO VSD REXtHI REXtLOW Conditions Time from VOUT = 0V to VS/D going low High = Regulator “ON” Low = Regulator “OFF” 3V applied to VOUT with no external components 3.6V applied to VOUT with no external components Min 3.0 0.65 Typ 5.0 3.5 Max 8.0 0.2 Units Msec V Ω Ω Conditions VIN 5.25V, No Load VS/D = 0V Open Loop Measurement, VS/D = VIN, VLX =VIN - 0.4V, VOUT = 4.5V Open Loop Measurement, VOUT = VIN, VLX = 0V Measure Waveform at EXT pin VIN = 5.3V IOUT = 20mA No Load Minimum VIN when Vref does not start up Vref rises to 0V from 0.9V Time form VOUT m = 0V to VS/D going low High = Regulator “ON” Low = Regulator “OFF” Open Loop Measurement Open Loop Measurement Max 5.125 110 2.5 0.58 2.0 345 1.8 16.0 8.0 0.2 Units V V mA µA µA Ω µA kHz V msec msec V Ω Ω Unless Otherwise specified all limits are at V OUT = 3.3V, VIN = 4V, FOSC=300kHz, IOUT = 130mA,TA = 25°C. Circuit configuration of figure 1. Unless Otherwise specified all limits are at V OUT = 5.0V, VIN = 6V, FOSC=300kHz, IOUT = 200mA, TA = 25°C. Circuit configuration of figure 1.

0.5A, 300kHz, SO-8 PWM/PFM Step Down Converter with Shutdown Impala Linear Corporation 4(408) 574-3939 www.impalalinear.com June 1999 ILC6377 1.3 Parameter Symbol Conditions Min Typ Max Units Feedback Voltage (pin5) V FB .995 1.000 1.015 V Input Voltage V OUT RFB1 + RFB2 < 2MΩ 38 V Output Current I OUT 500 600 mA Input Supply Current I IN VIN 5.25V, No Load 71 110 µA Shutdown Current I S/D VS/D = 0V 1.5 2.5 µA LX Switch On-Resistance R ds(on) Open Loop Measurement, VS/D = VIN, 0.44 0.58 Ω VLX = VIN - 0.4V, VOUT = 4.5V LX Switch On-Resistance I LXL Open Loop Measurement, VOUT = VIN, 2.0 µA VLX = 0V Shutdown Input Voltage V S/D High = Regulator “ON” 0.65 0.2 V Low = Regulator “OFF” Oscillator Frequency F OSC Measure Waveform at EXT pin VIN = 255 300 345 kHz 5.3V IOUT = 20mA Max Duty Cycle MAXDTY 100 % PFM Duty Cycle PFMDTY No Load 10 17 25 % Efficiency EFFI 95 % Undervoltage Lockout V UVLO Minimum VIN when Vref does not start up 1 1.8 V Soft-Start Time T SS Vref rises to 0V from 0.9V 6.0 10.0 16.0 msec Internal Protection Time T PRO Time from VOUT m = 0V to VS/D going low 3.0 5.0 8.0 msec EXT1, EXT2 Hi On-Resistance REXtHI Open Loop Measurement 24 32 Ω EXT1, EXT2 Low On-Resistance REXtLOW Open Loop Measurement 20 26 Ω Unless Otherwise specified all limits are at V OUT programmed to 5.0V, VIN = 6V, FOSC=300kHz, IOUT = 200mA, TA = 25°C. Circuit configuration of figure 1.

0.5A, 300kHz, SO-8 PWM/PFM Step Down Converter with Shutdown Impala Linear Corporation 5(408) 574-3939 www.impalalinear.com June 1999 ILC6377 1.3 VOU T ILC6377 (TOP V I EW ) CL VIN S/D CSS SD1 L *CIN Fig 1. Typical step-down DC-DC converter app lication SD1 : MA735 Schottky Diode ( MATSUSHITA ) CL : 10V/47µ F T antalum Capacitor ( NICHICON, F93 ) CSS : 4700pF Ceramic Capacitor CIN : 16V / 10µF T antalum Capacitor ( NICHICON, F93 ) 22µH 47µF 10µF External component selection Proper selection of external components is important for achieving high performance. The output inductor selected should have low DC resistance on the order of 0.2W or less and saturation current rating of 1A or higher. Recommended inductors are Sumida CD54 (22mH, 0.18W max DC resistance) or Coilcraft DO3308P-223 (22mH, 0.18W max DC resistance) or equivalent. The catch diode should be a schottky diode with low for- ward drop and rated at 1A or greater current, MA735 or it’s equivalent is recommended. Input and output capacitors should be tantalum capacitors with low equivalent series resistance (ESR) and voltage rat- ing higher than the actual application. Soft-start Pin 4 of ILC6377 functions as the soft-start pin as well as the shutdown pin. A soft-start capacitor (from pin 4 to ground) controls the rate at which the power supply starts up; thus preventing large overshoots at the output as well as large in- rush current. The value for CSS should be 100pF or greater. Shutdown The ILC6377 is placed in shutdown mode by taking pin 4 to ground. In shutdown, the quiescent current of the device is under 2mA. When using the shutdown feature, pin 4 must be driven from an open collector or open drain output with- out employing an external pull-up resistor, as shown in fig- ure 2. Since pin 4 is also used to charge an external capac- itor for soft-start, this pin should not be driven from a push- pull CMOS type output. Over-current and short-circuit protection In the event of an over-current or short-circuit condition, the ILC6377 cycles the soft-start pin in a hiccup mode to provide fault protection. When the output voltage decreases due to overload, the ILC6377 will operate continuously at the max- imum duty cycle. If the period of maximum duty cycle oper- ation exceeds TPRO (typically 5 msec), pin 4 will be pulled low; thus discharging the external soft-start capacitor CSS. This action inhibits the regulator’s PWM action. Next, the ILC6377’s soft-start circuitry starts recharging CSS and initi- ates a controlled start-up. If the overload condition continues to exist, the above sequence of events will repeat; thus con- tinuing to cycle the soft-start function. Note that very little power is dissipated with this method of fault protection versus constant current limit protection. Even though the internal power MOSFET is pulsed on and off at high peak current, the DC current is low; thus leading to low power dissipation even under short-circuit conditions. Keep in mind that the duration of maximum duty cycle condition is used to trigger the ILC6377’s fault protec- tion circuit. As such, a small input-output (V IN - VOUT) differential voltage may trigger the device’s fault protec- tion circuitry even at low output current. Undervoltage Lockout The undervoltage lockout feature prevents faulty operation by disabling the operation of the regulator when input volt- age is below the minimum operating voltage, VUVLO. When the input voltage is lower than VUVLO the device disables the internal P-channel MOSFET and provides “high” output at both EXT1 and EXT2 outputs. Figure 2 shows a typical fixed output voltage step-down DC-DC converter application circuit for ILC6377SO-XX Fig. 1: Typical step-down wn DC-DC converter application

external transistors; thus allowing design flexibility. the gate drive to the internal P-channel MOSFET i.e. channel MOSFET is shown in figure 2. Figure 3. P-Channel Negative low input voltages and high output currents. exceed 10V, otherwise damage to the device may occur. P_BST pin is clamped to a safe negative voltage.

6 CFB RFB1

( L ) and output capacitor ( CL ) values chosen. and the vicinity of inductive flux.

0.5A, 300kHz, SO-8 PWM/PFM Step Down Converter with Shutdown Impala Linear Corporation 7(408) 574-3939 www.impalalinear.com June 1999 ILC6377 1.3 Output Voltage vs. Output Current ILC6377SO-33 ILC6377SO-33 ILC6377SO-50 ILC6377SO-33 3.5 3.4 3.3 3.2 3.1 3.0 OUTPUT VOLTAGE: VOUT (V) 0.1 1 10 100 1000 OUTPUT CURRENT: IOUT (mA) VIN = 3.96 VIN = 3.96 VIN = 4.0V 5.0V 5.0V 5.0V 8.0V 8.0V 8.0V 10.0V VIN = 6.0V 8.0V L = 22µH (CD54) L = 10µH (CD54) L = 22µH (CD54) L = 47µH (CD105) OUTPUT CURRENT: IOUT (mA) OUTPUT VOLTAGE: VOUT (V) 3.5 3.4 3.3 3.2 3.1 3.0 0.1 1 10 100 1000 OUTPUT CURRENT: IOUT (mA) OUTPUT VOLTAGE: VOUT (V) OUTPUT CURRENT: IOUT (mA) 0.1 1 10 100 1000 3.5 3.4 3.3 3.2 3.1 3.0 OUTPUT VOLTAGE: VOUT (V) 5.4 5.2 5.0 4.8 4.6 4.4 0.1 1 10 100 1000 Typical Performance Characteristics General conditions for all curves: Circuit of figure 1; L = 20µH (Sumida, CD54), C IN = 47µF (tantalum) with 0.1µF (ceramic), CL = 47µH (tantalum) MA735 (Matsushita) schottky diode, C SS = 4700pF (ceramic), TA = 25°C unless otherwise noted.

0.5A, 300kHz, SO-8 PWM/PFM Step Down Converter with Shutdown Impala Linear Corporation 8(408) 574-3939 www.impalalinear.com June 1999 ILC6377 1.3 ILC6377SO-50 ILC6377SO-33 ILC6377SO-33 ILC6377SO-33 OUTPUT CURRENT: IOUT (mA) EFFICIENCY: EFFI(%)EFFICIENCY: EFFI(%) OUTPUT CURRENT: IOUT (mA) 100 0.1 1 10 100 1000 6.0V 6.0V 8.0V 10.0V 8.0V 5.0V 5.0V 5.0V VIN = 3.96 VIN = 3.96 VIN = 4.0 VIN = 6.0V L = 22µH (CD54) L = 10µH (CD54) L = 47µH (CD105) L = 22µH (CD54) OUTPUT CURRENT: IOUT (mA) 100 0.1 1 10 100 1000 100 0.1 1 10 100 1000 EFFICIENCY: EFFI(%) OUTPUT CURRENT: IOUT (mA) 100 0.1 1 10 100 1000 EFFICIENCY: EFFI(%) Typical Performance Characteristics General conditions for all curves: Circuit of figure 1; L = 20µH (Sumida, CD54), C IN = 47µF (tantalum) with 0.1µF (ceramic), CL = 47µH (tantalum) MA735 (Matsushita) schottky diode, C SS = 4700pF (ceramic), TA = 25°C unless otherwise noted.

0.5A, 300kHz, SO-8 PWM/PFM Step Down Converter with Shutdown Impala Linear Corporation 9(408) 574-3939 www.impalalinear.com June 1999 ILC6377 1.3 ILC6377SO-33 ILC6377SO-33 ILC6377SO-33 ILC6377SO-33 ILC6377SO-33 ILC6377SO-33 AMBIENT TEMP.: Ta(°C) AMBIENT TEMP.: Ta(°C) AMBIENT TEMP.: Ta(°C)AMBIENT TEMP.: Ta(°C) AMBIENT TEMP.: Ta(°C) OUTPUT vs. AMBIENT TEMPERATURE SUPPLY CURRENT vs. AMBIENT TEMPERATURE LX ON RESISTANCE vs. AMBIENT TEMPERATURESTAND-BY CURRENT vs. AMBIENT TEMPERATURE OSCILLATION FREQUENCY vs. AMBIENT TEMPERATURE PFM DUTY RATIO vs. AMBIENT TEMPERATURE 3.40 3.35 3.30 3.25 3.20 3.40 3.35 3.30 3.25 3.20 3.40 3.35 3.30 3.25 3.20 3.40 3.35 3.30 3.25 3.20 3.40 3.35 3.30 3.25 3.20 3.40 3.35 3.30 3.25 3.20 -40 -20 0 20 40 60 80 -40 -20 0 20 40 60 80 -40 -20 0 20 40 60 80 -40 -20 0 20 40 60 80 -40 -20 0 20 40 60 80 -40 -20 0 20 40 60 80 AMBIENT TEMP.: Ta(°C) OUTPUT VOLTAGE: VOUT1, VOUT2(V) SUPPLY CURRENT: IDD(µA) OUTPUT VOLATAGE: VOUT(V) LX SWITCH RESISTANCE: RSWON(Ω )PFM DUTY RATIO: PFMDTY(%) OSCILLATION FREQUENCY: FOSC(kHz) VOUT2 VOUT1 VOUT1 Typical Performance Characteristics General conditions for all curves: Circuit of figure 1; L = 20µH (Sumida, CD54), C IN = 47µF (tantalum) with 0.1µF (ceramic), CL = 47µH (tantalum) MA735 (Matsushita) schottky diode, C SS = 4700pF (ceramic), TA = 25°C unless otherwise noted.

0.5A, 300kHz, SO-8 PWM/PFM Step Down Converter with Shutdown Impala Linear Corporation 10(408) 574-3939 www.impalalinear.com June 1999 ILC6377 1.3 ILC6377SO-33 ILC6377SO-33 ILC6377SO-33 ILC6377SO-33 ILC6377SO-33 EFFICIENCY vs. AMBIENT TEMPERATURE MINIMUM OPERATING VOLTAGE vs. AMBIENT TEMPERATURE SOFT-START TIME vs. AMBIENT TEMPERATURE CE “L” VOLTAGE vs. AMBIENT TEMPERATURE CE “H” VOLTAGE vs. AMBIENT TEMPERATURE CE “H” VOLTAGE: VCEH(V) SOFT-START TIME: TSS(V) CE “L” VOLTAGE: VCEL(V) EFFICIENCY: EFFI(%) MIN. OPERATING VOLTAGE: VOUT(V) -40 -20 0 20 40 60 80 -40 -20 0 20 40 60 80 -40 -20 0 20 40 60 80 -40 -20 0 20 40 60 80 -40 -20 0 20 40 60 80 AMBIENT TEMP.: Ta(°C) AMBIENT TEMP.: Ta(°C) AMBIENT TEMP.: Ta(°C) AMBIENT TEMP.: Ta(°C) AMBIENT TEMP.: Ta(°C) 1.0 0.8 0.6 0.4 0.2 0.0 100 1.0 0.8 0.6 0.4 0.2 0.0 1.8 1.6 1.4 1.2 1.0 0.8 Typical Performance Characteristics General conditions for all curves: Circuit of figure 1; L = 20µH (Sumida, CD54), C IN = 47µF (tantalum) with 0.1µF (ceramic), CL = 47µH (tantalum) MA735 (Matsushita) schottky diode, C SS = 4700pF (ceramic), TA = 25°C unless otherwise noted.

0.5A, 300kHz, SO-8 PWM/PFM Step Down Converter with Shutdown Impala Linear Corporation 11(408) 574-3939 www.impalalinear.com June 1999 ILC6377 1.3 ILC6377SO-33 ILC6377SO-33 ILC6377SO-33 ILC6377SO-33 ILC6377SO-33 TIME (0.5msec/div) TIME (0.5msec/div)TIME (0.5msec/div) TIME (0.5msec/div) TIME (0.5msec/div) OUTPUT VOLTAGE VOUT(V)OUTPUT VOLTAGE VOUT(V) OUTPUT VOLTAGE VOUT(V) OUTPUT VOLTAGE VOUT(V) OUTPUT VOLTAGE VOUT(V) OUTPUTCURRENT IOUT(mA) OUTPUTCURRENT IOUT(mA) OUTPUTCURRENT IOUT(mA) OUTPUTCURRENT IOUT(mA) OUTPUTCURRENT IOUT(mA)OUTPUTCURRENT IOUT(mA) OUTPUT VOLTAGE VOUT(V) 3.4 3.3 3.2 3.1 3.0 2.9 3.4 3.3 3.2 3.1 3.0 2.9 3.4 3.3 3.2 3.1 3.0 2.9 3.4 3.3 3.2 3.1 3.0 2.9 3.4 3.3 3.2 3.1 3.0 2.9 TIME (0.5msec/div) 500 400 300 200 100 500 400 300 200 100 500 400 300 200 100 500 400 300 200 100 500 400 300 200 100 Output Voltage Output Voltage Output Voltage Output Voltage Output Voltage Output Voltage Output Current Output Current Output Current Output Current Output CurrentOutput Current 100mA 300mA 300mA 300mA300mA 100mA 100µA 100µA 100µA 100µA100µA 100µA VIN = 4V, IOUT = 100µA - 100mA VIN = 4V, IOUT = 100µA - 100mA VIN = 4V, IOUT = 300mA - 100µA VIN = 4V, IOUT = 300mA - 10mAVIN = 4V, IOUT = 10mA - 300mA VIN = 4V, IOUT = 100mA - 100µA ILC6377SO-33 500 400 300 200 100 Typical Performance Characteristics General conditions for all curves: Circuit of figure 1; L = 20µH (Sumida, CD54), C IN = 47µF (tantalum) with 0.1µF (ceramic), CL = 47µH (tantalum) MA735 (Matsushita) schottky diode, C SS = 4700pF (ceramic), TA = 25°C unless otherwise noted.