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HT3420 Dataheets PDF



Part Number HT3420
Manufacturers HOTCHIP
Logo HOTCHIP
Description 2A 28V Synchronous Buck Converter
Datasheet HT3420 DatasheetHT3420 Datasheet (PDF)

Features z 2A Output Current Wide 4.5V to 28V Operating Input Range z Integrated Power MOSFET switches z Output Adjustable from 0.925V to 0.8Vin z Up to 96% Efficiency z Programmable Soft-Start z Stable with Low ESR Ceramic Output Capacitors z Fixed 340KHZ Frequency z Cycle-by-Cycle Over Current Protection z Short Circuit Protection z Input Under Voltage Lockout z Package: SOP-8L HT3420 2A 28V Synchronous Buck Converter General Description The HT3420 is a monolithic synchronous buck regulator. .

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Features z 2A Output Current Wide 4.5V to 28V Operating Input Range z Integrated Power MOSFET switches z Output Adjustable from 0.925V to 0.8Vin z Up to 96% Efficiency z Programmable Soft-Start z Stable with Low ESR Ceramic Output Capacitors z Fixed 340KHZ Frequency z Cycle-by-Cycle Over Current Protection z Short Circuit Protection z Input Under Voltage Lockout z Package: SOP-8L HT3420 2A 28V Synchronous Buck Converter General Description The HT3420 is a monolithic synchronous buck regulator. The device integrates 95 mΩ MOSFETS that provide 2A continuous load current over a wide operating input voltage of 4.5V to 28V. Current mode control provides fast transient response and cycleby-cycle current limit. An adjustable softstart prevents inrush current at turn on. Applications z Distributed Power Systems z Networking Systems z FPGA, DSP, ASIC Power Supplies z Green Electronics/ Appliances z Notebook Computers Typical Application Circuit 1 of 15 Ordering Information HT3420 Pin Assignments Pin Descriptions Pin Number 1 2 3 4 5 6 Name BS VIN SW GND FB COMP 7 EN 8 SS BS 1 VIN 2 SW 3 GND 4 SOP-8L (TOP View) 8 SS 7 EN 6 COMP 5 FB Description 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. Input Supply. Bypass this pin to GND with a low ESR capacitor. See Input Capacitor in the Application Information section. Switch Output. Connect this pin to the switching end of the inductor. Ground. 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. Compensation Pin. See Stability Compensation in the Application Information section. 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 start up. 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. 2 of 15 HT3420 Block Diagram FB 5 1.1V 0.3V OVP RAMP OSCILLATOR 340/120KHz CLK SS 8 0.925V COMP 6 EN 7 2.5V ERROR AMPLIFIER 6uA EN OK LOCKOUT COMPARATOR 1.5V SHUTDOWN COMPARATOR CURRENT SENSE AMPLIFIER SQ RQ CURRENT COMPARATOR 2 VIN 5V 1 BS 3 SW 1.2V OVP 4 GND IN<4.10V IN INTERNAL REGULATORS Absolute Maximum Ratings Parameter Value Unit Input Supply Voltage -0.3 to 30 V SW Voltage BS Voltage EN, FB, COMP Voltage -0.3 to VIN + 0.3 VSW – 0.3 to VSW + 6 -0.3 to 5. V V V Continuous SW Current Internally limited A Junction (Test on to Ambient Thermal Approximately 3 in2 Resistance (θJA) Copper Area 1oz copper FR4 board) 87 °C/W SOP-8L Power Dissipation Internal limit W Maximum Junction Temperature 150 °C Storage Temperature Range -65 to 150 °C Moisture Sensitivity (MSL) Please refer the MSL label on the IC package bag/carton for detail (Note: Exceeding these limits may damage the device., Even the duration of exceeding is very short. Exposure to absolute maximum rating conditions for long periods may affect device reliability.) 3 of 15 HT3420 Recommended Operating Conditions Parameter Min Input Supply Voltage 4.5 Operating Junction Temperature -20 Max 28 (1) +125 (2) Unit V °C (Note (1): Operating the IC over this voltage is very easy to cause over voltage condition to VIN pin, SW pin, BS pin & EN pin) (Note (2): If the IC experienced OTP, then the temperature may need to drop to <125 degree C to let the IC recover.) Electrical Characteristics (VIN = 12V, TA= 25°C unless otherwise specified.) Parameter Feedback Voltage Feedback Overvoltage Threshold Symbol VFB High-Side Switch-On Resistance* Low-Side Switch-On Resistance* High-Side Switch Leakage Upper Switch Current Limit* COMP to Current Limit Transconductance GCOMP Error Amplifier Transconductance Error Amplifier DC Gain* Switching Frequency Short Circuit Switching Frequency GEA AVEA fSW Maximum Duty Cycle Minimum On Time* DMAX EN Shutdown Threshold Voltage EN Shutdown Threshold Voltage Hysteresis EN Lockout Threshold Voltage EN Lockout Hysteresis Supply Current in Shutdown IC Supply Current in Operation Input UVLO Threshold Rising UVLO Input UVLO Threshold Hysteresis Soft-start Current Soft-start Period Thermal Shutdown Temperature* Note: * Guaranteed by design, not tested Test Conditions 4.5V ≤ VIN 28V VEN = 0V, VSW = 0V Minimum Duty Cycle ΔICOMP = ±10uA VFB = 0 VFB = 0.8V VEN Rising VEN = 0 VEN = 3V, VFB = 1.0V VEN Rising VSS = 0V CSS = 0.1uF Hysteresis = 25°C Min 0.900 2.7 Typ 0.925 1.1 95 95 3.5 Max 0.950 10 Unit V V mΩ mΩ uA A 3.3 A/V 920 480 340 120 92 220 1.1 1.4 uA/V V/V KHz KHz % nS 2V 180 mV 2.2 3.80 2.5 130 0.3 1.3 4.05 100 6 15 160 2.7 3.0 1.5 4.40 V mV uA .


HGT1S20N36G3VLS HT3420 V23084-C2001-A303


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