LTC3529 1.5A, 1.5MHz Step-Up DC/DC Converter in 2mm × 3mm DFN DESCRIPTION FEATURES n n n n n n n n n n n n n The LTC®3529 is a 5V output, synchronous, fixed frequency step-up DC/DC converter optimized for USB On-The-Go (OTG) hosting applications. This compact USB OTG 5V VBUS converter features a 1.5MHz switching frequency, internal compensation and a tiny 2mm × 3mm DFN package. The LTC3529 can operate from input voltages as low as 1.8V. Compact Solution for 5V USB On-The-Go VBUS Power 5V at 500mA from Single Li-Ion Cell Automatic Fault Detection High Efficiency: Up to 95% VIN Range: 1.8V to 5.25V Fixed 5V Output Short-Circuit Protection 1.5MHz Low Noise, Fixed Frequency PWM Inrush Current Limiting and Internal Soft-Start Output Disconnect <1μA Quiescent Current in Shutdown VIN > VOUT Operation 8-Lead, 2mm × 3mm DFN Package USB OTG-specific features include a fault flag with 22ms deglitching to indicate when the bus is overloaded, output disconnect and short-circuit protection. Following a fault, the LTC3529 can be programmed to either latchoff or restart after a time-out duration. Additional features include a <1μA shutdown mode, soft-start, inrush current limiting and thermal overload protection. Anti-ring circuitry reduces EMI during low power operation. The LTC3529 is offered in an 8-lead 2mm × 3mm × 0.75mm DFN package. APPLICATIONS n n n n n Personal Media Players Digital Video Cameras Digital Multimedia Broadcast Tuners Digital Cameras Smart Phones L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 6404251, 6166527. TYPICAL APPLICATION Li-Ion Battery to 5V Synchronous Boost Converter Efficiency vs Load Current 4.7μH Li-Ion 0.8 80 3.3μF LTC3529 VIN SW 370Ω FAULT SNSGND AUTO-RESTART OFF ON RST VOUT COUT 10μF OFF ON SHDN PGND 3529 TA01a VOUT 5V 500mA EFFICIENCY (%) + 0.9 90 0.7 EFFICIENCY 70 0.6 60 0.5 50 0.4 40 0.3 30 POWER LOSS (W) 2.5V TO 4.2V 100 0.2 20 POWER LOSS 10 0 1 10 100 LOAD CURRENT (mA) VIN = 3.6V INDUCTOR = 4.7μH, COOPER BUSSMANN SD25-4R7 0.1 0 1000 3529 TA01b 3529fb 1 LTC3529 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) VIN, VOUT Voltage ........................................... –0.3 to 6V SHDN, RST, FAULT Voltage ............................ –0.3 to 6V SW Voltage DC.............................................................. –0.3 to 6V Pulsed <100ns .............................................–1V to 7V Operating Temperature Range (Note 2) ...–40°C to 85°C Maximum Junction Temperature (Note 3) ............ 125°C Storage Temperature Range .................. –65°C to 125°C TOP VIEW 8 VIN VOUT 1 SW 2 7 RST 9 SHDN 3 6 SNSGND 5 FAULT PGND 4 DCB PACKAGE 8-LEAD (2mm s 3mm) PLASTIC DFN TJMAX = 125°C, θJA = 64°C/W EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3529EDCB#PBF LTC3529EDCB#TRPBF LCTZ 8-Lead (2mm × 3mm) Plastic DFN –40°C to 85°C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 3.6V, VOUT = 5V unless otherwise noted. PARAMETER CONDITIONS MIN Input Voltage Range 1.8 l Output Voltage Quiescent Current - Shutdown VSHDN = 0V, VOUT = 0V NMOS Switch Leakage Current VIN = VSW = 5V l VSW = 0V, VOUT = 5V l PMOS Switch Leakage Current TYP 4.85 MAX UNITS 5.25 V 5 5.15 V 0.01 1 μA 0.3 15 μA 0.3 15 μA NMOS Switch On Resistance 0.09 Ω PMOS Switch On Resistance 0.12 Ω 40 ns NMOS Current Limit VOUT = 4.5V (Note 4) Current Limit Delay Time to Output (Note 5) l 1.5 Maximum Duty Cycle VOUT = 4.5V l Minimum Duty Cycle VOUT = 5.5V l Switching Frequency VOUT = 4.5V l 1.2 SHDN, RST Input High Voltage l 1 SHDN, RST Input Low Voltage l SHDN, RST Input Current VSHDN, VOUT, VRST = 5.5V Soft-Start Time Line Regulation VIN = 1.8V to 5.25V l 80 A 87 % 0 1.5 1.8 % MHz V 0.01 0.35 V 1 μA 2 ms 0.03 %/V 3529fb 2 LTC3529 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 3.6V, VOUT = 5V unless otherwise noted. PARAMETER CONDITIONS FAULT Delay Time VOUT = 0V FAULT Output Low Voltage IFAULT = 5mA, VOUT = 0V FAULT Leakage Current VFAULT = 5.5V MIN TYP MAX 12 22 35 60 ms mV 10 Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The LTC3529 is guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the –40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. UNITS μA Note 3: This IC includes overtemperature protection that is intended to protect the device during momentary overload conditions. Junction temperature will exceed 125°C when overtemperature protection is active. Continuous operation above the specified maximum operating junction temperature may impair device reliability. Note 4: Current measurements are performed when the LTC3529 is not switching. The current limit values in operation will be somewhat higher due to the propagation delay of the comparators. Note 5: Specification is guaranteed by design and not 100% tested in production. TYPICAL PERFORMANCE CHARACTERISTICS 2 Alkaline Cells to 5V Efficiency VIN = 3V 90 EFFICIENCY 80 0.7 VIN = 1.8V 0.5 70 60 0.4 50 0.3 40 VIN = 1.8V 30 EFFICIENCY 0.4 50 0.3 40 0.2 20 0.1 POWER LOSS 1 0 1000 10 100 LOAD CURRENT (mA) COUT = 10μF INDUCTOR = 4.7μH, COOPER BUSSMANN SD25-4R7 0 10 100 LOAD CURRENT (mA) 1 3529 G01 Soft-Start Waveforms POWER LOSS COUT = 10μF INDUCTOR = 4.7μH, COOPER BUSSMANN SD25-4R7 Load Transient Response VOUT 5V/DIV 0.1 10 VIN = 3V 0 0.5 60 30 0.2 20 10 0.6 POWER LOSS (W) 70 80 0.7 VIN = 4.1V VIN = 3.6V VIN = 3V 90 0.6 POWER LOSS (W) EFFICIENCY (%) Li-Ion Battery to 5V Efficiency 100 EFFICIENCY (%) 100 0 1000 3529 G02 VOUT Ripple VOUT 200mV/DIV IL 200mA/DIV VOUT 5mV/DIV IL 500mA/DIV SHDN 5V/DIV 2ms/DIV VIN = 3.6V VOUT = 5V COUT = 10μF L = 2.2μH 3529 G03 200μs/DIV VIN = 3.6V VOUT = 5V COUT = 10μF L = 2.2μH 3529 G04 1μs/DIV 3529 G05 VIN = 3.6V COUT = 10μF L = 4.7μH ILOAD = 200mA 3529fb 3 LTC3529 TYPICAL PERFORMANCE CHARACTERISTICS Output Voltage Change vs Temperature Maximum Output Current vs VIN 1.90 1.0 1600 1.85 0.8 1400 1.80 0.6 1.75 1.70 1.65 1.60 1.55 0.2 0 –0.2 –0.6 1.45 –0.8 1.40 –45 –25 –5 15 35 55 75 TEMPERATURE (°C) 800 600 400 200 –1.0 –50 95 115 1000 –0.4 1.50 0 50 100 TEMPERATURE (°C) 0 1.5 150 3529 G06 Switching Frequency Variation vs Temperature 18 8 16 6 QUIESCENT CURRENT (mA) NORMALIZED TO 25°C (%) 1μs/DIV VIN = 3.6V COUT = 10μF L = 4.7μH 2.5 3.0 3.5 VIN (V) 4 2 0 –2 –4 –6 4.5 5.0 3529 G08 14 12 10 8 6 4 2 –8 –10 –50 –30 –10 10 30 50 70 TEMPERATURE (°C) 90 110 0 1.5 2.5 3.5 VIN (V) 3529 G10 RDS(ON) vs Temperature 4.5 5.5 3529 G11 Load Regulation 0.5 160 VIN = 3.3V L = 4.7μH 0.4 PMOS 140 4.0 No-Load Input Current vs VIN 10 IL 25mA/DIV 3529 G09 2.0 3529 G07 SW Pin Anti-Ringing SW 2V/DIV L = 4.7μH 1200 0.4 IOUT (mA) CHANGE FROM 25°C (%) CURRENT LIMIT (A) Current Limit vs Temperature 0.3 VOUT CHANGE (%) RDS(ON) (mΩ) 120 100 NMOS 80 60 40 0.1 0 –0.1 –0.2 –0.3 20 0 –50 0.2 –0.4 –0.5 –25 0 25 50 75 TEMPERATURE (°C) 100 125 3529 G12 0 100 200 300 ILOAD (mA) 400 500 3529 G13 3529fb 4 LTC3529 PIN FUNCTIONS VOUT (Pin 1): Converter Output, Voltage Sense Input and Drain of the Internal Synchronous Rectifier MOSFET. Driver bias is derived from VOUT. PCB trace length from VOUT to the output filter capacitor(s) should be as short and wide as possible. SW (Pin 2): Switch Node. This node connects to one side of the inductor. Keep PCB traces as short and wide as possible to reduce EMI and voltage overshoot. If the inductor current falls to zero, or SHDN is low, an internal 100Ω anti-ringing switch is connected between SW and VIN to minimize EMI. SHDN (Pin 3): Active-Low Shutdown Input. Forcing this pin above 1V enables the converter. Forcing this pin below 0.35V disables the converter. Do not float this pin. PGND (Pin 4): High Current Ground Connection. The PCB trace connecting this pin to ground should be as short and as wide as possible. SNSGND (Pin 6): This pin must be connected to ground. RST (Pin 7): Logic Input to Select Automatic Restart or Latchoff Following a Fault Shutdown. • RST = High: Auto-reset mode. In this mode, the LTC3529 will automatically attempt to restart 22ms (typically) after a fault shutdown. • RST = Low: Latchoff mode. In this mode, the LTC3529 will latch off for a fault shutdown. The IC will not restart until the SHDN pin is toggled or the supply voltage is cycled. VIN (Pin 8): Input Supply Pin. Exposed Pad (Pin 9): Small Signal Ground. This is the ground reference for the internal circuitry of the LTC3529 and must be connected directly to ground. FAULT (Pin 5): Open-Drain Fault Indicator Output. Pulls low when an overcurrent condition exists for more than 22ms. 3529fb 5 LTC3529 BLOCK DIAGRAM L1 4.7μH VIN 1.8V TO 5.25V + – 8 CIN 3.3μF 3 VIN SHDN 2 SW BULK CONTROL SIGNALS VIN ANTI-RING 1 VOUT 6 SNSGND CLOCK – + PWM LOGIC AND DRIVERS VOUT, 5V COUT 10μF IZERO COMP CURRENT SENSE FAULT OR THERMAL SHUTDOWN 5 FAULT 22ms FAULT TIMER R1 1.875M – SOFT-START SD GM ERROR AMPLIFIER + – THERMAL SD – + PWM COMP ILIM COMP 1.25V REFERENCE + + 3 + RC 1.25V R2 625k C2 OSCILLATOR 2A CC 7 RST 4 PGND 9 GND (BP) 3529 BD OPERATION The LTC3529 is a 1.5MHz synchronous boost converter in an 8-lead 2mm × 3mm DFN package. The device operates with an input voltage as low as 1.8V and features fixedfrequency current-mode PWM control for exceptional line and load regulation. Internal MOSFET switches with low RDS(ON) and low gate charge enable the device to maintain high efficiency over a wide range of load current. PWM Operation light loads, the LTC3529 will exhibit pulse-skipping operation. Soft-Start The LTC3529 provides soft-start by ramping the inductor current limit from zero to its peak value in approximately 2ms. The internal soft-start capacitor is discharged in the event of a fault, thermal shutdown or when the IC is disabled via the SHDN pin. The LTC3529 operates in a fixed-frequency PWM mode using current-mode control at all load currents. At very 3529fb 6 LTC3529 OPERATION Oscillator An internal oscillator sets the switching frequency to 1.5MHz. Shutdown The LTC3529 is shut down by pulling the SHDN pin below 0.35V, and activated by pulling the SHDN pin above 1V. Note that SHDN can be driven above VIN or VOUT, as long as it is limited to less than the absolute maximum rating. Error Amplifier The error amplifier is a transconductance amplifier with an internal compensation network. Internal clamps limit the minimum and maximum error amplifier output voltage to improve the large-signal transient response. Current Sensing Lossless current sensing converts the peak current signal of the N-channel MOSFET switch into a voltage that is summed with the internal slope compensation. The summed signal is compared to the error amplifier output to provide a peak current control command for the PWM. Peak switch current is limited to approximately 2A independent of input or output voltage. latchoff mode is highly recommended for maximum level of robustness. Note: When VOUT is released from a short-circuit condition, it is possible for the output to momentarily exceed the maximum output voltage rating. In cases where repeated shorts are expected, VOUT should be protected by the addition of a 5.6V Zener clamp from VOUT to GND. Alternatively, COUT can be increased to 47μF or greater. Zero-Current Comparator The zero-current comparator monitors the inductor current to the output and shuts off the synchronous rectifier when this current falls below approximately 20mA. This prevents the inductor current from reversing in polarity, thereby improving efficiency at light loads. Anti-Ringing Control The anti-ringing circuit connects a resistor across the inductor to damp the ringing on SW in discontinuous conduction mode. The ringing of the resonant circuit formed by L and CSW (capacitance on the SW pin) is low energy but can cause EMI radiation. Output Disconnect The current limit comparator shuts off the N-channel MOSFET switch when the current limit threshold is reached. The current limit comparator delay time to output is typically 40ns. The LTC3529 provides true output disconnect by eliminating body diode conduction of the internal P-channel MOSFET rectifier. This allows VOUT to go to zero volts during shutdown, drawing no current from the input source. It also provides inrush current limiting at turn-on, minimizing surge currents seen by the input supply. Fault Detection Thermal Shutdown To prevent the device from providing power to a shorted output, the switch current is monitored to detect an overcurrent condition. In the event that the switch current reaches the current limit for longer than 22ms, the fault flag is asserted (FAULT pulls low) and the device is shut down. If the auto-restart option is enabled (RST high), the device will automatically attempt to restart every 22ms until the short is removed. If auto-restart is disabled (RST low), the IC will remain shut down until being manually restarted by toggling SHDN or cycling the input voltage. A soft-start sequence is initiated when the device restarts. If output short-circuits are common in the application, If the die temperature reaches approximately 160°C, the device enters thermal shutdown, the fault flag is asserted (FAULT pulls low) and all switches are turned off. The device is enabled and a soft-start sequence is initiated when the die temperature drops by approximately 10°C. Current Limit PCB Layout Due to the high frequency operation of the LTC3529, board layout is extremely critical to minimize transients caused by stray inductance. Keep the output filter capacitor as close as possible to the VOUT pin and use very low ESR/ESL ceramic capacitors tied to a good ground plane. 3529fb 7 LTC3529 APPLICATIONS INFORMATION The basic LTC3529 application circuit is shown in the Typical Application on the front page. The external component selection is determined by the desired output current and ripple voltage requirements of each particular application. However, basic guidelines and considerations for the design process are provided in this section. Although ceramic capacitors are recommended, low ESR tantalum capacitors may also be used. A small ceramic capacitor in parallel with a larger tantalum capacitor is recommended in demanding applications that have large load transients. Input Capacitor Selection Output Capacitor Selection A low ESR (equivalent series resistance) output capacitor should be used at the output of the LTC3529 to minimize the output voltage ripple. Multilayer ceramic capacitors are an excellent choice as they have extremely low ESR and are available in small footprints. X5R and X7R dielectric materials are strongly recommended over Y5V dielectric because of their improved voltage and temperature coefficients. Neglecting the capacitor ESR and ESL (equivalent series inductance), the peak-to-peak output voltage ripple can be calculated by the following formula, where f is the frequency in MHz, COUT is the capacitance in μF, and ILOAD is the output current in amps. ΔVP −P = ILOAD ( VOUT – VIN ) COUT • VOUT • f Low ESR input capacitors reduce input switching noise and reduce the peak current drawn from the battery. It follows that ceramic capacitors are also a good choice for input decoupling and should be located as close as possible to the device. A 3.3μF input capacitor is sufficient for most applications. Larger values may be used without limitation. Capacitor Vendor Information Both the input and output capacitors used with the LTC3529 must have low ESR and be designed to handle the large AC currents generated by switching converters. The vendors in Table 1 provide capacitors that are well suited to LTC3529 application circuits. Table 1. Capacitor Vendor Information MANUFACTURER WEB SITE The internal loop compensation of the LTC3529 is designed to be stable with output capacitor values of 6.5μF or greater. This complies with USB On-The-Go specifications, which limit the output capacitance to 6.5μF. In general use of the LTC3529, the output capacitor should be chosen large enough to reduce the output voltage ripple to acceptable levels. A 6.8μF to 10μF output capacitor is sufficient for most applications. Larger values up to 22μF may be used to obtain extremely low output voltage ripple and improved transient response. PHONE FAX Taiyo Yuden www.t-yuden.com (408) 573-4150 (408) 573-4159 TDK www.component. tdk.com (847) 803-6100 (847) 803-6296 Sanyo www.secc.co.jp (619) 661-6322 (619) 661-1055 AVX www.avxcorp.com (803) 448-9411 (803) 448-1943 Murata www.murata.com (814) 237-1431 (814) 238-0490 Sumida www.sales@ us.sumida.com (408) 321-9660 (408) 321-9308 3529fb 8 LTC3529 APPLICATIONS INFORMATION Inductor Selection PCB Layout Guidelines The LTC3529 can utilize small surface-mount chip inductors due to its fast 1.5MHz switching frequency. Larger values of inductance will allow slightly greater output current capability by reducing the inductor ripple current. Increasing the inductance above 10μH will increase component size while providing little improvement in output current capability. The LTC3529 switches large currents at high frequencies. Special care should be given to the PCB layout to ensure stable, noise-free operation. Figure 1 depicts the recommended PCB layout to be utilized for the LTC3529. A few key guidelines follow: USB On-The-Go specifications limit output capacitance to 6.5μF. When using a 6.5μF output capacitance, a 4.7μH inductor must be used to maintain stability. Larger inductors may be used with larger output capacitors. The minimum inductance value for a given allowable inductor ripple ΔI (in Amps peak-to-peak) is given by: L> ( VIN(MIN) • VOUT – VIN(MIN) ΔI • f • VOUT ) µH where VIN(MIN) is the minimum input voltage, f is the operating frequency in MHz (1.5MHz Typ), and VOUT is the output voltage (5V). The inductor current ripple is typically set for 20% to 40% of the maximum inductor current (IP). High frequency ferrite core inductor materials reduce frequency dependent power losses compared to cheaper powdered iron cores, improving efficiency. To achieve high efficiency, a low ESR inductor should be utilized. The inductor must have a saturation current rating greater than the worst case average inductor current plus half the ripple current. Molded chokes and some chip inductors usually do not have enough core to support peak LTC3529 inductor currents. To minimize radiated noise, use a shielded inductor. See Table 2 for suggested components and suppliers. 1. All circulating current paths should be kept as short as possible. This can be accomplished by keeping the copper traces to all components in Figure 1 short and wide. Capacitor ground connections should via down to the ground plane in the shortest route possible. The bypass capacitors on VIN and VOUT should be placed close to the IC and should have the shortest possible paths to ground. 2. The PGND pin should be shorted directly to the exposed pad, as shown in Figure 1. This provides a single point connection between the small signal ground and the power ground, as well as a wide trace for power ground. 3. All the external components shown in Figure 1 and their connections should be placed over a complete ground plane. 4. Use of multiple vias in the die attach pad will enhance the thermal environment of the converter, especially if the vias extend to a ground plane region on the exposed bottom surface or inner layers of the PCB. 8 VIN VOUT 1 7 RST SW 2 Table 2. Representative Surface Mount Inductors SHDN 3 6 SNSGND MAX MANUFACTURER PART NUMBER VALUE CURRENT (μH) (A) PGND 4 5 FAULT DCR (Ω) HEIGHT (mm) Sumida CDRH5D16NP 4.7 2.15 0.064 1.8 TDK VLF5014S 4.7 2 0.098 1.4 Coilcraft MSS6122 4.7 1.82 0.065 2.2 Cooper Bussmann SD25-4R7 4.7 2.3 0.043 2.5 MULTIPLE VIAs TO GROUND PLANE Figure 1. LTC3529 Recommended PCB Layout 3529fb 9 LTC3529 TYPICAL APPLICATIONS Li-Ion Battery to 5V at 100mA or 500mA for USB OTG Host Supply L1* 4.7μH + 2.5V TO 4.2V Li-Ion 3.3μF 1.8V LTC3529 VIN SW 1M FAULT SNSGND TO μP AUTO-RESTART OFF ON RST VOUT, 5V VOUT COUT 6.8μF OFF ON SHDN *L1: SUMIDA CDRH5D16NP PGND 3529 TA02a Overcurrent Event VRST High Overcurrent Event VRST Low VOUT 5V/DIV VOUT 5V/DIV LOAD CURRENT 1A/DIV LOAD CURRENT 1A/DIV FAULT 2V/DIV FAULT 2V/DIV 3529 TA02b 20ms/DIV 2 Alkaline Cells to 5V at 350mA 2 Alkaline Cells to 5V Efficiency 100 L1* 4.7μH EFFICIENCY 80 2-CELL ALKALINE CIN 3.3μF LTC3529 VIN 270Ω AUTO-RESTART OFF ON SW FAULT SNSGND RST VOUT, 5V VOUT COUT 6.8μF OFF ON SHDN PGND EFFICIENCY (%) + VIN = 3V 90 0.7 70 0.5 60 0.4 50 0.3 40 VIN = 1.8V 30 3529 TA03a 0.2 20 0.1 POWER LOSS 10 VIN = 3V 0 *L1: SUMIDA CDRH5D16NP 0.6 VIN = 1.8V POWER LOSS (W) 1.8V TO 3.2V 3529 TA02c 20ms/DIV 1 10 100 LOAD CURRENT (mA) COUT = 6.8μF INDUCTOR = 4.7μH, COOPER BUSSMANN SD25-4R7 0 1000 3529 TA03b 3529fb 10 LTC3529 PACKAGE DESCRIPTION DCB Package 8-Lead Plastic DFN (2mm × 3mm) (Reference LTC DWG # 05-08-1718 Rev A) 0.70 ±0.05 1.35 ±0.05 3.50 ±0.05 1.65 ± 0.05 2.10 ±0.05 PACKAGE OUTLINE 0.25 ± 0.05 0.45 BSC 1.35 REF RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED R = 0.115 TYP R = 0.05 5 TYP 2.00 ±0.10 (2 SIDES) 0.40 ± 0.10 8 1.35 ±0.10 1.65 ± 0.10 3.00 ±0.10 (2 SIDES) PIN 1 NOTCH R = 0.20 OR 0.25 × 45° CHAMFER PIN 1 BAR TOP MARK (SEE NOTE 6) (DCB8) DFN 0106 REV A 4 0.200 REF 1 0.23 ± 0.05 0.45 BSC 0.75 ±0.05 1.35 REF BOTTOM VIEW—EXPOSED PAD 0.00 – 0.05 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 3529fb 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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 11 LTC3529 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC3400/LTC3400B 600mA (ISW), 1.2MHz, Synchronous Step-Up DC/DC Converter 92% Efficiency, VIN: 0.85V to 5V, VOUT(MAX) = 5V, IQ = 19μA/300μA, ISD <1μA, ThinSOT™ Package LTC3401 1A (ISW), 3MHz, Synchronous Step-Up DC/DC Converter 97% Efficiency, VIN: 0.85V to 5V, VOUT(MAX) = 5.5V, IQ = 38μA, ISD <1μA, MS10 Package LTC3402 2A (ISW), 3MHz, Synchronous Step-Up DC/DC Converter 97% Efficiency, VIN: 0.85V to 5V, VOUT(MAX) = 5.5V, IQ = 38μA, ISD <1μA, MS10 Package LTC3421 3A (ISW), 3MHz Synchronous Step-Up DC/DC Converter with Output Disconnect 94% Efficiency, VIN: 0.85V to 4.5V, VOUT(MAX) = 5.25V, IQ = 12μA, ISD <1μA, 4mm × 4mm QFN-24 Package LTC3422 1.5A (ISW), 3MHz Synchronous Step-Up DC/DC with Output Disconnect Converter 94% Efficiency, VIN: 0.85V to 4.5V, VOUT(MAX) = 5.25V, IQ = 25μA, ISD <1μA, 3mm × 3mm DFN-10 Package LTC3426 2A (ISW), 1.5MHz, Step-Up DC/DC Converter 92% Efficiency, VIN: 1.6V to 5.5V, VOUT(MAX) = 5V, IQ = 600μA, ISD <1μA, ThinSOT Package LTC3427 500mA (ISW), 1.25MHz Synchronous Step-Up DC/DC Converter with Output Disconnect 94% Efficiency, VIN: 1.8V to 5V, VOUT(MAX) = 5.25V, IQ = 350μA, ISD <1μA, 2mm × 2mm DFN-6 Package LTC3429/LTC3429B 600mA (ISW), 550kHz, Synchronous Step-Up DC/DC Converter with Soft-Start/Output Disconnect 96% Efficiency, VIN: 0.85V to 4.3V, VOUT(MAX) = 5V, IQ = 20μA, ISD <1μA, ThinSOT Package LTC3458/LTC3458L 1.4A/1.7A (ISW), 1.5MHz Synchronous Step-Up DC/DC 94% Efficiency, VIN: 0.85V to 6V, VOUT(MAX) = 7.5V/6V, IQ = 15μA, ISD <1μA, 3mm × 4mm DFN-12 Package LTC3459 80mA (ISW), Synchronous Step-Up DC/DC Converter 92% Efficiency, VIN: 1.5V to 5.5V, VOUT(MAX) = 10V, IQ = 10μA, ISD <1μA, ThinSOT Package LT3494/LT3494A 180mA/350mA (ISW), High Efficiency Step-Up DC/DC Converter with Output Disconnect 85% Efficiency, VIN: 2.3V to 16V, VOUT(MAX) = 38V, IQ = 65μA, ISD <1μA, 2mm × 3mm DFN-6, ThinSOT Package LTC3525-3/ LTC3525-3.3/ LTC3525-5 400mA (ISW), Synchronous Step-Up DC/DC Converter with Output Disconnect 94% Efficiency, VIN: 0.85V to 4V, VOUT(MAX) = 3V/3.3V/5V, IQ = 7μA, ISD <1μA, SC-70 Package LTC3526/LTC3526L/ 500mA (ISW), 1MHz Synchronous Step-Up DC/DC LTC3526B Converter with Output Disconnect 94% Efficiency, VIN: 0.85V to 5V, VOUT(MAX) = 5.25V, IQ = 9μA, ISD <1μA, 2mm × 2mm DFN-6 Package LTC3527/LTC3527-1 Dual 800mA and 400mA (ISW), 2.2MHz, Synchronous Step-Up DC/DC Converter with Output Disconnect 94% Efficiency, VIN: 0.7V to 5V, VOUT(MAX) = 5.25V, IQ = 12μA, ISD <1μA, 3mm × 3mm QFN-16 Package LTC3528 1A (ISW), 1MHz Synchronous Step-Up DC/DC Converter with Output Disconnect 94% Efficiency, VIN: 0.7V to 5V, VOUT(MAX) = 5.25V, IQ = 12μA, ISD <1μA, 2mm × 3mm DFN-8 Package LTC3537 600mA, 2.2MHz, Synchronous Step-Up DC/DC Converter with Output Disconnect and 100mA LDO 94% Efficiency, VIN: 0.7V to 5V, VOUT(MAX) = 5.25V, IQ = 30μA, ISD <1μA, 3mm × 3mm QFN-16 Package LTC3539 2A , 2MHz, Synchronous Step-Up DC/DC Converter with Output Disconnect 94% Efficiency, VIN: 0.7V to 5V, VOUT(MAX) = 5.25V, IQ = 10μA, ISD <1μA, 2mm × 3mm DFN-8 Package ThinSOT is a trademark of Linear Technology Corporation. 3529fb 12 Linear Technology Corporation LT 0709 REV B • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2009