LT8410

LT8410 LINER

Document overview

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Technical content

APPLICATIONS

DESCRIPTION

The L T®8410/L T8410-1 are ultralow power boost converters with integrated power switch, Schottky diode and output disconnect circuitry. The parts control power delivery by varying both the peak inductor current and switch off- time. This control scheme results in low output voltage ripple as well as high effi ciency over a wide load range. The quiescent current is a low 8.5μA, which is further reduced to 0μA in shutdown. The internal disconnect circuitry allows the output voltage to be blocked from the input during shutdown. High value (12.4M/0.4M) resistors are integrated on chip for output voltage detection, signifi cantly reducing input referred quiescent current. The L T8410/-1 also features a comparator built into the SHDN pin, over voltage protection for the CAP and V OUT pins, built in soft-start and comes in a tiny 8-pin 2mm × 2mm DFN package. General Purpose Bias with Wide Input Voltage L, L T , L TC and L TM are registered trademarks of Linear Technology Corporation. Hot Swap is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131.

FEATURES

n Ultralow Quiescent Current 8.5μA in Active Mode 0μA in Shutdown Mode n Comparator Built into SHDN pin n Low Noise Control Scheme n Adjustable FB reference voltage n Wide Input Range: 2.5V to 16V n Wide Output Range : Up to 40V n Integrated Power NPN Switch 25mA Current Limit (L T8410) 8mA Current Limit (L T8410-1) n Integrated Schottky Diode n Integrated Output Disconnect n High Value (12.4M/0.4M) Feedback Resistors Integrated n Built in Soft-Start (Optional Capacitor from VREF to GND) n Overvoltage Protection for CAP and VOUT pins n Tiny 8-Pin 2mm × 2mm DFN package SW CAP GND CHIP ENABLE FBP 8410-1 TA01a L T8410 2.2μF 0.1μF 100μH 0.1μF 0.1μF* VOUT = 16V VIN 2.5V to 16V VCC VOUT VREFSHDN 604K 412K *HIGHER VALUE CAPACITOR IS REQUIRED WHEN THE VIN IS HIGHER THAN 5V LOAD CURRENT (mA) 0.01 VOUT PEAK-TO-PEAK RIPPLE (mV) 8410-1 TA02 1010.1 VIN = 3.6V LOAD CURRENT (mA) 0.01 EFFICIENCY (%) 100 8410-1 TA03 100100.1 1 VIN = 12V VIN = 5V VIN = 3.6V Output Voltage Ripple vs Load Current Effi ciency vs Load Current

PIN CONFIGURATION ABSOLUTE MAXIMUM RATINGS V V Operating Temperature Range (Note 2)..–40°C to 125°C (Note 1) TOP VIEW SHDN VCC GND SW FBP VREF CAP V OUT DC PACKAGE 8-PIN (2mm s 2mm) PLASTIC DFN 3 6 TJMAX = 125°C, θJA = 88°C/W EXPOSED PAD (PIN #9) IS GND, MUST BE SOLDERED TO PCB

ELECTRICAL CHARACTERISTICS

PARAMETER CONDITIONS MIN TYP MAX UNITS Minimum Operating Voltage 2.2 2.5 V Maximum Operating Voltage 16 V Reference Voltage l 1.220 1.235 1.255 V VREF Current Limit (Note 3) 10 μA VREF Discharge Time 70 μS VREF Line Regulation 0.01 %/V Quiescent Current Not Switching l 8.5 12 μA Quiescent Current in Shutdown V SHDN = 0V l 01 μ A Quiescent Current from VOUT and CAP V OUT = 16V 3 μA Minimum Switch Off Time After Start-Up (Note 4) During Start-Up (Note 4) 240 600 nS nS Switch Current Limit L T8410 L T8410-1 l l mA mA The l denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN =3.0V, VSHDN =VIN unless otherwise noted. (Note 2) ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE L T8410EDC#PBF L T8410EDC#TRPBF LDQR 8-Lead (2mm × 2mm) Plastic DFN – 40°C to 125°C L T8410IDC#PBF L T8410IDC#TRPBF LDQR 8-Lead (2mm × 2mm) Plastic DFN – 40°C to 125°C L T8410EDC-1#PBF L T8410EDC-1#TRPBF LFCC 8-Lead (2mm × 2mm) Plastic DFN – 40°C to 125°C L T8410IDC-1#PBF L T8410IDC-1#TRPBF LFCC 8-Lead (2mm × 2mm) Plastic DFN – 40°C to 125°C Consult L TC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container . Consult L TC Marketing for information on non-standard lead based fi nish parts. For more information on lead free part marking, go to: http://www.linear .com/leadfree/ For more information on tape and reel specifi cations, go to: http://www.linear .com/tapeandreel/

TYPICAL PERFORMANCE CHARACTERISTICS UVLO vs Temperature Line Regulation SHDN Minimum Input Voltage High vs Temperature L T8410 Switching Waveform at No Load L T8410 Switching Waveform at 0.5mA Load L T8410 Switching Waveform at 3mA Load VCC = 3.6V VOUT = 16V 50μs/DIV INDUCTOR CURRENT 10mA/DIV SW VOLTAGE 10V/DIV VOUT VOLTAGE 2mV/DIV AC COUPLED 8410-1 G13 VCC = 3.6V VOUT = 16V 2μs/DIV INDUCTOR CURRENT 20mA/DIV SW VOLTAGE 10V/DIV VOUT VOLTAGE 10mV/DIV AC COUPLED 8410-1 G14 VCC = 3.6V VOUT = 16V 500ns/DIV INDUCTOR CURRENT 20mA/DIV SW VOLTAGE 10V/DIV VOUT VOLTAGE 10mV/DIV AC COUPLED 8410-1 G15 TEMPERATURE (°C) –40 UVLO VOL TAGE (V) 2.6 2.4 2.2 1.6 1.8 1.4 8410-1 G16 12080400 VCC RISING VCC FALLING VCC VOL TAGE (V) OUTPUT VOL TAGE CHANGE (%) 0.3 0.25 0.2 0.15 0.05 0.1 8410-1 G17 161248 VOUT = 16V TEMPERATURE (°C) –40 SHDN MINIMUM INPUT VOL TAGE HIGH (V) 1.5 1.4 1.3 1.1 1.2 8410-1 G18 12080400 SHDN RISING SHDN FALLING

TYPICAL PERFORMANCE CHARACTERISTICS Output Disconnect PMOS Current vs CAP to VOUT Voltage Difference L T8410 Start-Up Waveforms Without Capacitor at VREF Pin L T8410 Start-Up Waveforms With 0.1μF Capacitor at VREF Pin CAP TO VOUT VOL TAGE DIFFERENCE (V) PMOS CURRENT (mA) 8410-1 G19 161284 VCAP = 16V L T8410 L T8410-1 SHDN VOLTAGE 5V/DIV INDUCTOR CURRENT 20mA/DIV CAP VOLTAGE 5V/DIV VOUT VOLTAGE 5V/DIV VCC = 3.6V VOUT = 16V 2ms/DIV 8410-1 G21 SHDN VOLTAGE 5V/DIV INDUCTOR CURRENT 20mA/DIV CAP VOLTAGE 5V/DIV VOUT VOLTAGE 5V/DIV VCC = 3.6V VOUT = 16V 200μs/DIV 8410-1 G20 VOUT VOLTAGE 200mV/DIV AC COUPLED INDUCTOR CURRENT 20mA/DIV LOAD CURRENT 0.5mA/DIV VCC = 3.6V VOUT = 16V 2ms/DIV 8410-1 G22 SWITCH CURRENT (mA) SWITCH VCESAT (mV) 300 250 200 150 100 8410-1 G24 252015105 L T8410 T ransient Response 0.5mA→1.5mA→0.5mA Load Pulse SW Saturation Voltage vs Switch Current (L T8410)

SHDN (Pin 1): Shutdown Pin. This pin is used to enable/ disable the chip. Drive below 0.3V to disable the chip. Drive above 1.4V to activate the chip. Do not fl oat this pin. V CC (Pin 2): Input Supply Pin. Must be locally bypassed to GND. See typical applications section. GND (Pin 3 and Pin 9): Ground. Tie directly to local ground plane. Pin 9 is fl oating but must be grounded for proper shielding. SW (Pin 4): Switch Pin. This is the collector of the internal NPN power switch. Minimize the metal trace area connected to this pin to minimize EMI. V OUT (Pin 5): Drain of Output Disconnect PMOS. Place a bypass capacitor from this pin to GND. CAP (Pin 6): This is the cathode of the internal Schottky Diode. Place a bypass capacitor from this pin to GND. VREF (Pin 7): Reference Pin. Soft-start can be achieved by placing a capacitor from this pin to GND. This cap will be discharged for 70μs (typical) at the beginning of start-up and then be charged to 1.235V with a 10μA current source. FBP(Pin 8): Positive Feedback Pin. This pin is the error amplifi er’s positive input terminal. To achieve the desired output voltage, choose the FBP pin voltage (V FBP) according to the following formula: VFBP = VOUT / 31.85 For protection purposes, the output voltage can not exceed 40V even if VFBP is driven higher than VREF. BLOCK DIAGRAM DISCHARGE CONTROL ENABLE CHIP 1.235V VREF VCC FBP FB VC GNDGND 400K CAP MAX 10μA SWSHDN 12.4M VOUT SWITCH CONTROL TIMING AND PEAK CURRENT CONTROL 1.235V 5 6 4 OUTPUT DISCONNECT CONTROL 1.235V

the FB node voltage to be equal to the FBP pin voltage. full control of the output voltage during operation. as many different sizes and shapes are available. IN is the input voltage to the boost circuit. Table 1. Recommended Inductors for L T8410/-1

required. A 47nF to 220nF 0402 capacitor will be suffi cient. Table 2 shows a list of several capacitor manufacturers. and for their entire selection of related parts. Table 2. Recommended Ceramic Capacitor Manufactures Figure 1. FBP to VOUT T ransfer Curve the load to the CAP pin instead of the VOUT pin. is the input voltage to the boost circuit.

component placement is shown in Figure 3. Figure 3. Recommended Board Layout

8410 TA06

Figure 4. 16V Output Converter with Wide Input Voltage

2.2μF 0.1μF 0.1μF 150μH 0.1μF V OUT = 34V VIN 2.5V to 16V VCC VOUT VREFSHDN 133K 866K TURN ON/OFF C1: 2.2μF , 16V, X5R, 0603 C2: 0.1μF , 100V, X5R, 0603 C3: 0.1μF , 100V, X5R, 0603 * C4: 0.1μF , 16V, X7R, 0402 L1: COILCRAFT LPS3314-154ML * HIGHER CAPACITANCE VALUE IS REQUIRED FOR C3 WHEN THE V IN IS HIGHER THAN 8V 34V Output Converter with Wide Input Voltage Effi ciency vs Load Current LOAD CURRENT (mA) 0.01 EFFICIENCY (%) 8410-1 TA10 1010.1 VIN = 12V VIN = 3.6V VIN = 5V VIN (V) I OUT (mA) 3.6 0.8 5 1.2 12 4.0 TYPICAL APPLICATIONS

Figure 5. Capacitor Charger with the L T8410-1

Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However , no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. PACKAGE DESCRIPTION 2.00 p0.10 (4 SIDES) NOTE: 1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE 0.40 p 0.10 BOTTOM VIEW—EXPOSED PAD 0.64 p 0.10 (2 SIDES) 0.75 p0.05 R = 0.115 TYP R = 0.05 TYP 1.37 p0.10 (2 SIDES) PIN 1 BAR TOP MARK (SEE NOTE 6)

0.200 REF

0.00 – 0.05 (DC8) DFN 0106 REVØ 0.23 p 0.05

0.45 BSC

0.25 p 0.05 1.37 p0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 0.64 p0.05 (2 SIDES)1.15 p0.05 0.70 p0.05 2.55 p0.05 PACKAGE OUTLINE R = 0.20 OR 0.25 s 45o CHAMFER 8-Lead Plastic DFN (2mm × 2mm) (Reference L TC DWG # 05-08-1719 Rev Ø)

Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear .com © LINEAR TECHNOLOGY CORPORATION 2008 LT 1108 • PRINTED IN USA RELATED PARTS TYPICAL APPLICATION PART NUMBER DESCRIPTION COMMENTS L T1946/L T1946A 1.5A (I SW), 1.2MHz/2.7MHz, High Effi ciency Step-Up DC/DC Converters VIN: 2.45V to 16V, VOUT(MAX) = 34V, IQ = 3.2mA, ISD < 1μA, 8-Lead MS Package L T3464 85mA (I SW), High Effi ciency Step-Up DC/DC Converter with Integrated Schottky and PNP Disconnect VIN: 2.3V to 10V, VOUT(MAX) = 34V, IQ = 25μA, ISD < 1μA, ThinSOT™ Package L T3471 Dual Output, Boost/Inverter, 1.3A (I SW), High Effi ciency Boost-Inverting DC/DC Converter VIN: 2.4V to 16V, VOUT(MAX) = ±40V, IQ = 2.5mA, ISD < 1μA, L T3473/L T3473A 1A (I SW), 1.2MHz, High Effi ciency Step-Up DC/DC Converter with Integrated Schottky Diode and Output Disconnect VIN: 2.2V to 16V, VOUT(MAX) = 36V, IQ = 100μA, ISD < 1μA, L T3494/L T3494A 180mA/350mA (I SW), High Effi ciency, Low Noise Step-Up DC/DC Converter with Output Disconnect VIN: 2.1V to 16V, VOUT(MAX) = 40V, IQ = 65μA, ISD < 1μA, L T3495/L T3495B/ L T3495-1/L T3495B-1 650mA/350mA (ISW), High Effi ciency, Low Noise Step-Up DC/DC Converter with Output Disconnect VIN: 2.3 V to 16V, VOUT(MAX) = 40V, IQ = 60μA, ISD < 1μA, DANGER HIGH VOL TAGE! OPERATION BY HIGH VOL TAGE TRAINED PERSONNEL ONL Y SW CAP GND FBP 8410-1 TA11 L T8410 2.2μF 0.1μF 0.1μF 100μH 0.1μF 0.1μF 0.1μF C4 0.1μF 0.1μF VIN 2.5V to 16V VCC VOUT VREFSHDN 143K 787K TURN ON/OFF C1: 2.2μF , 16V, X5R, 0603 C2 – C7: 0.1μF , 100V, X5R, 0603 C8: 0.1μF , 16V, X7R, 0402 D1 – D4: ON SEMI RB751S40T1G L1: MURATA LQH32CN101K53 OUTPUT = 100V 0.4mA (V IN = 5V) 1.4mA (VIN = 12V) D1 D2 D3 D4 FBP VOL TAGE (V) OUTPUT VOL TAGE (V) 140 120 100 8410-1 TA12 21 1.50.5 VIN = 5V LOAD CURRENT (mA) 0.01 EFFICIENCY (%) 8410-1 TA13 100.1 1 VOUT = 100V VIN = 12V VIN = 5V Output Voltage vs FBP Voltage Effi ciency vs Load Current High Voltage Power Supply Doesn’t Need a T ransformer