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Document overview

  • Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
  • PDF pages: 15

Technical content

Features

  • 2A Output Current
  • Wide 4.5V to 23V Operating Input Range
  • Integrated Power MOSFET Switches
  • Output Adjustable from 0.925V to 18V
  • Up to 96% Efficiency
  • Programmable Soft-Start
  • Stable with Low ESR Ceramic Output Capacitors
  • Fixed 340KHZ Frequency
  • Cycle by Cycle Over Current Protection
  • In put Under Voltage Lockout
  • Package ： SOP-8L

Applications

  • Distributed Power Systems
  • Networking Systems
  • FPGA, DSP, ASIC Power Supplies
  • Green Electronics/ Appliances
  • Notebook Computers Please be aware that an Important Notice concerning availability, disclaimers, and use in critical applications of LSC products is at the end of this document.

2A 23V Synchronous Buck Converter 2 of 15 www.liteonsemi.com LSP5526 Rev. 06 2016/8/1 Block Diagram INTERNAL REGULATORS FB SS COMP EN 1.1V 0.3V 0.925V 2.5V 1.5V OVP SHUTDOWN COMPARATOR ERROR AMPLIFIER LOCKOUT COMPARATOR EN OK 6uA OSCILLATOR 340/120KHz RAMP CLK 1.2V OVP IN<4.10V IN CURRENT COMPARATOR CURRENT SENSE AMPLIFIER VIN BS SW GND S Q R Q

Ordering Information

Blank : ADJ S8 : SOP-8L A : Tape & Reel Output Voltage Package Packing LSP 5526 - Packing Package Output Voltage X XX X

2A 23V Synchronous Buck Converter 3 of 15 www.liteonsemi.com LSP5526 Rev. 06 2016/8/1 Pin Assignment 1 8 SS EN COMP FB BS SW GND (TOP View) SOP-8L VIN Pin Descriptions Pin Name Name Pin Description 1 BS Bootstrap. This pin acts as the positive rail for the high-side switch’s gate driver. Connect a 0.01uF capacitor between BS and SW. 2 VIN Input Supply. Bypass this pin to GND with a low ESR capacitor. See Input Capacitor in the Application Information section. 3 SW Switch Output. Connect this pin to the switchi ng end of the inductor. 4 GND Ground. 5 FB Feedback Input. The voltage at this pin is regulated to 0.925V. Connect to the resistor divider between output and ground to set output voltage. 6 COMP Compensation Pin. See Stability Compensation in the Application Information section. 7 EN Enable Input. When higher than 2.7V, this pin turns the IC on. When lower than 1.1V, this pin turns the IC off. Output voltage is discharged when the IC is off. This pin should not be left open. Recommend to put a 100KΩ pull-up resistor to Vin for startup. 8 SS Soft-Start Control Input. SS controls the soft-start period. Connect a capacitor from SS to GND to set the soft-start period. A 0.1uF capacitor sets the soft-start period to 15ms. To disable the soft-start feature, leave SS unconnected.

2A 23V Synchronous Buck Converter 4 of 15 www.liteonsemi.com LSP5526 Rev. 06 2016/8/1 Absolute Maximum Ratings (at T A=25°C) Note: Operate over the “Absolute Maximum Ratings” may cause permanent damage to the device. Exposure to such conditions for extended time may still affect the reliability of the device. Characteristics Value Unit Input Supply Voltage -0.3 to 25 V SW Voltage -0.3 to V IN + 0.3 V BS Voltage VSW – 0.3 to V SW + 6 V EN, FB, COMP Voltage -0.3 to 5 V Continuous SW Current Internally limited A Maximum Junction Temperature 150 °C Storage Temperature Range -65 to 150 °C SOP-8L Thermal Resistance (Junction to Case) 60 °C/W SOP-8L Thermal Resistance (Junction to Ambient) 150 °C/W SOP-8L Power dissipation 810 mW Moisture Sensitivity (MSL) Please refer the MSL label on the IC package bag/carton for detail Note1: Ratings apply to ambient temperature at 25°C Recommended Operating Conditions Characteristics Min Max Unit Input Supply Voltage 4.5 23 V Operating Junction Temperature -20 +125 °C

2A 23V Synchronous Buck Converter 5 of 15 www.liteonsemi.com LSP5526 Rev. 06 2016/8/1

Electrical Characteristics

(T A=25°C, unless otherwise specified) Characteristics Symbol Conditions Min Typ Max Unit Feedback Voltage VFB 4.5V ≤ VIN ≤ 23V 0.900 0.925 0.950 V Feedback Overvoltage Threshold 1.1 V High-Side Switch-On Resistance* 95 mΩ Low-Side Switch-On Resistance* 95 mΩ High-Side Switch Leakage V EN = 0V, V SW = 0V 10 uA Upper Switch Current Limit Minimum Duty Cycle 2.7 3.5 A COMP to Current Limit Transconductance GCOMP 3.3 A/V Error Amplifier Transconductance GEA ∆I COMP = ±10uA 920 uA/V Error Amplifier DC Gain* AVEA 480 V/V Switching Frequency fSW 340 KHz Short Circuit Switching Frequency V FB = 0 120 KHz Maximum Duty Cycle DMAX VFB = 0.8V 92 % Minimum On Time* 220 nS EN Shutdown Threshold Voltage V EN Rising 1.1 1.4 2 V EN Shutdown Threshold Voltage Hysteresis 180 mV EN Lockout Threshold Voltage 2.2 2.5 2.7 V EN Lockout Hysteresis 130 mV Supply Current in Shutdown V EN = 0 0.3 3.0 uA IC Supply Current in Operation V EN = 3V, V FB = 1.0V 1.3 1.5 mA Input UVLO Threshold Rising UVLO V EN Rising 3.80 4.05 4.40 V Input UVLO Threshold Hysteresis 100 mV Soft-start Current V SS = 0V 6 uA Soft-start Period C SS = 0.1uF 15 mS Thermal Shutdown Temperature* Hysteresis =25°C 16 0 °C Note : * Guaranteed by design.

2A 23V Synchronous Buck Converter 6 of 15 www.liteonsemi.com LSP5526 Rev. 06 2016/8/1 Application Circuit VIN = 12V V O U T = 5V /2A LS P 5526 V IN E N FB S W G N D C 1 N C C 6 10nF 44.2K R 2 10K R 3 10K C O M P R 4 100K B S R 1 C 4 1.6nF S S 0.1uF C 3 10uH 22uF C 7 22uF x 2 C 5 D 1 B 130/S K 13 (O ption) LSP5526 Circuit, 5V/2A output LSP5526 Circuit, 3.3V/2A output Note: C2 is required for separate EN signal.

to the peak-to-peak ripple current being 30% of the maximum output current. not saturate at the current limit. Typical inductor values for various output voltages are shown in Table 2. Table 2. Typical Inductor Values

during switching, its ESR also affects efficiency. small parallel 0.1uF ceramic capacitor is placed right next to the IC. capacitors, choose a capacitor with less than 50mΩ ESR. example Schottky diodes and their Manufacturers. B130 30V, 1A Lite-on semiconductor corp. SK13 30V, 1A Lite-on semiconductor corp. Figure 2. Stability Compensation

2A 23V Synchronous Buck Converter 9 of 15 www.liteonsemi.com LSP5526 Rev. 06 2016/8/1

2 COMPVEA

P CA Gf π= The second pole P2 is the output pole: OUTOUT OUT P CV If π2 2 = The first zero Z1 is due to R COMP and C COMP1 : COMPCOMP Z CRf π= And finally, the third pole is due to R COMP and C COMP2 (if C COMP2 is used): 2COMP COMP

3 P CR π 2

1f = The following steps should be used to compensate the IC: STEP1. Set the crossover frequency at 1/10 of the switching frequency via R COMP : VGG fCVR COMPEA SWOUTOUT COMP 925. 010

  • = π But limit R COMP to 10KΩ maximum. STEP2. Set the zero fZ1 at 1/4 of the crossover frequency. If R COMP is less than 10KΩ, the equation for CCOMP is: )(637. 0

1 FfcRC

STEP3. If the output capacitor’s ESR is high enough to cause a zero at lower than 4 times the crossover frequency, an additional compensation capacitor C COMP2 is required. The condition for using C COMP2 is: ESRCOUTR 1≥××× fsR C ESROUTπ And the proper value for C COMP2 is: COMP ESRCOUT OUT 2COMP R RCC = A reference table as follows: (5) (6) (7) (8) (9) (10) (11) (12)

Figure 3. Load Transient Testing VS Compensation Value

2A 23V Synchronous Buck Converter 11 of 15 www.liteonsemi.com LSP5526 Rev. 06 2016/8/1 Typical Characteristics Light Load Operation (No load) Heavy Load Operation (2A Load) Vin=12V, Iin=8.2 mA, Vout=3,3V Vin=12V, Vout=3,3V Startup Vin=12V, Vout=3.3V, Iout=1A through Vin. through Enable. Short Circuit Protection Vin=12V

2A 23V Synchronous Buck Converter 12 of 15 www.liteonsemi.com LSP5526 Rev. 06 2016/8/1 Typical Characteristics (Continued) SWITCHES RdsON vs JUNCTION TEMPERATURE (Vin=12V) 0.08 0.09 0.1 0.11 0.12 0.13 0.14 0.15 0.16 10 30 50 70 90 110 130 150 170 JUNCTION TEMPERATURE (C) SWITCHES RdsON

2A 23V Synchronous Buck Converter 13 of 15 www.liteonsemi.com LSP5526 Rev. 06 2016/8/1 Marking Information LSC LSP5526 VYYWWUZ Part ID LOGO V YYWW UZ Internal Code Date code WW ： Week(01~53) Output Voltage Blank ： ADJ SOP-8L

2A 23V Synchronous Buck Converter 14 of 15 www.liteonsemi.com LSP5526 Rev. 06 2016/8/1 Mechanical Information (1) Package type: SOP-8L Unit : mm Symbol Min Max A - 1.75 A1 0.10 0.25 A2 1.25 1.65 b 0.33 0.51 c 0.10 0.26 D 4.70 5.10 E 5.80 6.20 E1 3.70 4.10 e 1.27 REF L 0.40 1.27 L1 1.04 REF Gauge Plane 0.25 BSC θ 0 o 8 o

2A 23V Synchronous Buck Converter 15 of 15 www.liteonsemi.com LSP5526 Rev. 06 2016/8/1 MSL (Moisture Sensitive Level) Information IPC/JEDEC J-STD-020D.1 Moisture Sensitivity Levels Table LEVEL FLOOR LIFE SOAK REQUIREMENTS Standard Accelerated Equivalent 1 eV 0.40-0.48 eV 0.30-0.39 CONDITION TIME CONDITION TIME (hours) CONDITION TIME (hours) TIME (hours)

1 Unlimited ≤30 °C /85%

+5/-0 85 °C /85% RH NA NA NA 2 1 year ≤30 °C /60% RH 168 +5/-0 85 °C /60% RH NA NA NA 2a 4 weeks ≤30 °C /60% RH 696 2 +5/-0 30 °C /60% RH 120 -1/+0 168 3 168 hours ≤30 °C /60% RH 192 2 +5/-0 30 °C /60% RH -1/+0 4 72 hours ≤30 °C /60% RH 96 2 +2/-0 30 °C /60% RH +0.5/-0 5 48 hours ≤30 °C /60% RH 72 2 +2/-0 30 °C /60% RH +0.5/-0 a 24 hours ≤30 °C /60% RH 48 2 +2/-0 30 °C /60% RH +0.5/-0

6 Time on Label

(TOL) ≤30 °C /60% RH TOL 30 °C /60% RH NA NA NA Note 1: CAUTION - To use the ‘‘accelerated equivalent’’ soa k conditions, correlation of damage response (inclu ding electrical, after soak and reflow), should be established with the ‘‘ standard’’ soak conditions. Alternatively, if the k nown activation energy for moisture diffusion of the package materials is in t he range of 0.40 - 0.48 eV or 0.30 - 0.39 eV, the ‘ ‘accelerated equivalent’’ document JESD22-A120 provides a method for determining the diffusion coefficient. Note 2: The standard soak time includes a default value of 24 hours for semiconductor manufacturer’s exposure time (MET) between bake and bag and includes the maximum time allowed out of the bag at the distributor’s facility. If the actual MET is less than 24 hours the soak time may be reduced. For soak conditions o f 30 °C/60% RH, the soak time is reduced by 1 hour for each hour the MET is less than 24 hours. For soak conditions of 60 °C/60 % RH, the soak time is reduced by 1 hour for each 5 hours the MET is less than 24 hours. If the actual MET is greater than 24 hour s the soak time must be increased. If soak conditio ns are 30 °C/60% RH, the soak time is increased 1 hour for each hour that the act ual MET exceeds 24 hours. If soak conditions are 60 °C/60% RH, the soak time is increased 1 hour for each 5 hours that the actual MET exceeds 24 hours. Important Notice and Disclaimer LSC reserves the right to make changes to this docu ment and its products and specifications at any time without notice. Customers should obtain and c onfirm the latest product information and specifications before final design, purchase or use. LSC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does LSC assume any liabili ty for application assistance or customer product design. LSC does not warrant or accept any liabilit y with products which are purchased or used for any unintended or unauthorized application. No license is granted by implication or otherwise under any intellectual property rights of LSC. LSC products are not authorized for use as critical components in life support devices or systems without express written approval of LSC.