ELM610DA 1.3A 36V PWM step down DC/DC converter ■General description ELM610DA consists of step-down switching regulator with PWM control, reference voltage source, oscillation circuit, error amplifier, internal PMOS, etc. ELM610DA provides low-ripple power, high efficiency, and excellent transient characteristics; PWM control circuit is able to vary the duty ratio linearly from 0 up to 100%. ELM610DA also contains error amplifier circuit as well as soft-start circuit that prevents overshoot at during startup. Internal enable function, over current protect function and short circuit protect function will reduce the operation frequency from 150kHz to 30kHz when overmuch current or short circuit occurs. Meanwhile, internal compensation block is able to minimize the quantity of required external component. With internal P-channel Power MOS, and externally connected coil, capacitor, and diode, ELM610DA is able to function as step-down switching regulator. By the small package of SOP-8, ELM610DA is capable of working as ideal power supply units for portable devices while providing outstanding features such as low current consumption. Since this converter accommodates input voltage up to 36V, ELM610DA is also suitable for operations which adopt AC adapter. ■Features ■Application • Input voltage : 5.5V to 36V • Output voltage : 0.8V to Vin • Output current : 1.3A • Duty ratio : 0% to 100% • Constant frequency : Typ.150kHz • Soft-start • Thermal shutdown protection • Short circuit protection • Built-in internal P-channel MOS • Package : SOP-8 • • • • • • • • • PC motherboard LCD monitor Graphic card DVD, blu-ray player Telecom equipment ADSL modem Printer and other peripheral equipment Microcomputer power supply Network power supply ■Maximum absolute ratings Parameter VIN power supply voltage Apply voltage to FB Apply voltage to EN Apply voltage to SW Apply voltage to VC Power dissipation Operating temperature range Storage temperature range Symbol Vin Vfb Ven Vsw Vc Pd Top Tstg Limit -0.3 to +40 GND-0.3 to Vin GND-0.3 to Vin+0.3 GND-0.3 to Vin+0.3 Vin-20 to Vin+0.3 300 -40 to +85 -65 to +150 Caution: Permanent damage to the device may occur when ratings above maximum absolute ones are used. 7- 1 Unit V V V V V mW °C °C Rev.1.1 ELM610DA 1.3A 36V PWM step down DC/DC converter ■Selection guide ELM610DA-N Symbol a b c Package Product version Taping direction D: SOP-8 A N: Refer to PKG file ELM610DA - N ↑↑ ↑ ab c * Taping direction is one way. ■Pin configuration SOP-8(TOP VIEW) 8 7 6 5 Pin No. 1 2 3 4 1 2 3 4 5, 6 7, 8 Pin name Pin description FB Feedback(0.82V operation) Enable / Disable EN H: Normal operation mode.(Step-down operation) L: Shutdown mode.(All circuits deactivated) Add an external capacitor to VIN. VC The voltage is set to Vin -7V VIN IC power supply Switch. Connect external inductor/diode to here. SW Minimize trace area at this pin to reduce EMI. GND GND ■Standard circuit ELM610DA Vout=Vfb(1+R1/R2) 7- 2 Rev.1.1 ELM610DA 1.3A 36V PWM step down DC/DC converter ■Block diagram Vin VC Oscillation circuit SW PWM control circuit Thermal shutdown protection FB Error amplifier Reference voltage source and soft start EN GND ■Electrical characteristics Parameter Input voltage EN pin input voltage (*1) Feedback voltage Feedback bias current Current limit Quiescent current (switch off) Current consumption during power off Voltage clamp Oscillation frequency Frequency of current limit or short circuit protect Vin=24V, Top=25°C, unless otherwise specified Symbol Condition Min. Typ. Max. Unit Vin 5.5 36.0 V 2.0 Venh Evaluate oscillation at SW pin V 0.8 Venl Evaluate oscillation stop at SW pin Vfb Iout=0.1A 0.803 0.820 0.836 V Ifb Iout=0.1A 0.1 0.5 µA Icl 2.0 A Ignd EN ≥ Ven_h, Vfb=1V 1 2 mA Ignd_off EN ≤ Ven_l Vc Fosc No load Foscl 1 10 µA Vin-6 120 Vin-7 150 Vin-8 180 V kHz 20 30 40 kHz 1 2 % 0.2 0.5 % 80 87 100 mΩ % 50 μS ΔVout Vin=12V to 36V, Iout=0.2A Vout ΔVout Load regulation Iout=0.1 to 1.3A Vout Internal MOSFET Rdson Rds(on) Vfb=0V, Iout=1A Efficiency η Vin=24V, Vout=5V, Iout=1.3A (*1) : Rise time and fall time of the EN pin use under the following conditions, please. EN pin rise time & fall time tr, tf Ven=VenI to VenH Line regulation 7- 3 Rev.1.1 ELM610DA 1.3A 36V PWM step down DC/DC converter ■Application notes PWM Control ELM610DA is DC/DC converter which consists pulse-width modulation (PWM) system. In converters of ELM610DA, the pulse width varies according toe the load current, within the range from 0 to 100%. The ripple voltage produced by switching can easily be removed through the filter since switching frequency remains constant; ELM610DA is capable of providing low-ripple power within broad ranges of input voltage and load current. ■Test circuits ■Marking SOP-8 ELM 610DA abc Mark ELM610DA Content Product name abc Assembly lot No.: 000 to 999 repeated 7- 4 Rev.1.1 ELM610DA 1.3A 36V PWM step down DC/DC converter ■Typical characteristics V=1.8V : Cin=330µF, Cout=330µF, L=22µH, R1=5.1kΩ, R2=4.3kΩ, Top=25°C •• Vout=1.8V Vout-Vin Iout=1mA Vout (V) 2.0 100mA 1A Vin=24V 1.6 1.2 10mA 0.8 4 8 40 20 0 0.1 1 10 100 Vin (V) Iout (mA) Vout-Iout Vfb-Top Vin=24V 1.8 1000 Vin=12V, Iout=0.1A 0.90 Vfb (V) Vout (V) Vin=6V 60 12 16 20 24 28 32 36 2 Vin=12V 80 0.4 0 EFFICIENCY-Iout 100 EFFICIENCY (%) 2.4 0.85 Vin=6V Vin=12V 0.80 1.6 0.1 1 10 100 Iout (mA) -40 1000 20 40 Top (�) 60 Vin=12V, No load 80 Vin=12V, Iout=1mA�1A Vout (V) 2.5 2 1 2 1.5 2 1 0 0 2 4 6 1 0 0 8 10 12 14 16 18 20 Time (ms) 7- 5 40 80 120 Time (ms) 160 Iout (A) 2 0 Ven (V) Vout (V) 0 Load Transient Response Start Response 3 -20 200 Rev.1.1 ELM610DA 1.3A 36V PWM step down DC/DC converter •• Vout=3.3V V=3.3V : Cin=330µF, Cout=330µF, L=22µH, R1=13.1kΩ, R2=4.3kΩ, Top=25°C Vout-Vin 4.0 100mA Iout=1mA 3.5 1A EFFICIENCY (%) Vout (V) 3.0 2.5 EFFICIENCY-Iout 100 10mA 2.0 1.5 1.0 Vin=24V Vin=12V 80 Vin=6V 60 40 20 0.5 0 4 8 0 0.1 12 16 20 24 28 32 36 3.5 1 10 100 Vin (V) Iout (mA) Vout-Iout Vfb-Top 1000 Vin=12V, Iout=0.1A 0.90 Vin=24V Vfb (V) 3.3 3.2 Vin=5V 3.1 0.1 1 Vin=12V 10 100 Iout (mA) 0.85 0.80 -40 1000 Start Response 4 3 20 40 Top (�) 60 80 Vin=12V, Iout=1mA�1A Vout (V) 3.5 2 1 3 2.5 2 0 2 1 1 Ven (V) Vout (V) 0 Load Transient Response Vin=12V, No load 3.5 -20 0 0 0 2 4 6 Iout (V) Vout (V) 3.4 0 10 20 30 40 50 60 70 80 90 100 8 10 12 14 16 18 20 Time (ms) Time (ms) 7- 6 Rev.1.1 ELM610DA 1.3A 36V PWM step down DC/DC converter • Vout=5.0V V=5.0V : Cin=330µF, Cout=330µF, L=22µH, R1=22kΩ, R2=4.3kΩ, Top=25°C Vout-Vin 6.0 1A 100mA Iout=1mA EFFICIENCY (%) Vout (V) 5.0 4.0 10mA 3.0 2.0 1.0 0 4 8 EFFICIENCY-Iout 100 Vin=24V 80 Vin=12V Vin=6V 60 40 20 0 0.1 12 16 20 24 28 32 36 1 10 1000 Iout (mA) Vin (V) Vfb-Top Vout-Iout 5.2 100 Vin=12V, Iout=0.1A 0.90 Vin=24V Vfb (V) Vout (V) 5 4.8 0.85 Vin=6V Vin=12V 0.80 4.6 0.1 1 10 100 Iout (mA) -40 1000 Start Response 6 5 20 40 Top (�) 60 80 Vout (V) 4 3 2 Vin=12V, Iout=1mA�1A 5 4 3 1 0 2 1 1 0 0 0 2 4 6 8 10 12 14 16 18 20 Iout(A) 2 Ven (V) Vout (V) 0 Load Transient Response Vin=12V, No load 6 -20 0 10 20 30 40 50 60 70 80 90 100 Time (ms) Time (mS) 7- 7 Rev.1.1