LP6483S 350KHz, 36V/3A Step-down Converter With Soft-Start
General Description
The LP6483S contains an independent 350KHz constant frequency, current mode, PWM step-down converters. The converter integrates a main switch and a synchronous rectifier for high efficiency without an external Schottky diode. The LP6483S is ideal for powering portable equipment that runs from a 2cell Lithium-Ion (Li+) battery. The converter can supply 3000mA of load current from a 4.5V to 30V input voltage. The output voltage can be regulated as low as 0.923V. The LP6483S can also run at 100% duty cycle for low dropout applications.
The LP6483S is available in a SOP8 and ESOP8 package and is rated over the -40°C to 85°C temperature range.
Order Information
LP6483S
□ □ □
F: Pb-Free
Package Type
SO: SOP-8
SP: ESOP-8(Exposed Pad)
Typical Application Circuit VIN
Features
?Input Voltage Range: 4.5V to 30V
?Output Voltage Range: 0.923V to 12V
?3000mA Load Current on Channel
?Up to 94% Efficiency
?90% Duty Cycle in Dropout
?<1u A Quiescent Current
?350KHz Switching Frequency
?Soft star Function
?Short Circuit Protection
?Current Mode Operation
?Thermal Fault Protection
?S O P-8a n d E S O P-8 Package
?RoHS Compliant and 100% Lead (Pb)-Free
Applications
?Portable Media Players
?Cellular and Smart mobile phone
?PDA/DSC
?GPS Applications
Marking Information
Device Marking Package Shipping LP6483S LPS
LP6483S
XXX
SO:SOP-8
SP:ESOP-8
3K/REEL mr you 136********
Typical Application Circuit
VIN
LP6483S(SOP-8) application circuit
U3VIN
LP6483S(ESOP-8) application circuit
Functional Pin Description
SOP-8(Top View) E SOP-8(Top View) Pin Description
Pin NO PIN DESCRIPTION
1 BS High-Side Gate Drive Boost Input. Connect a 0.01uF or greater capacitor from SW to BS to power the high side switch.
2 Vin Supply Input.
3 SW Switch Mode Connection to Inductor. This pin connects to the drains of the internal main and synchronous power MOSFET switches.
4 GND Ground.
5 FB Feedback Input. Connect FB to the center point of the external resistor divider. Normal voltage for this pin is 0.923V.
6 COMP Loop compensation input. Connect a series RC network from COMP to GND to Compensate the regulation control loop.
7 EN Enable Control Input. Drive EN above 2.5V to turn on the Channel. Drive EN below 0.3V to turn it off (shutdown current < 0.1μA).
8 SS Soft-start control input. Connect an external capacitor to program the soft-start.if unused, leave it open, which means internal soft-start function.
9 E-Pad Exposed Pad. The pin connect to GND.
Function Block Diagram
Absolute Maximum Ratings
?Input Voltage to GND ----------------------------------------------------------------------------------------------------------------- 36V
?SW to GND (VSW) ------------------------------------------------------------------------------------------------- -0.3V to VIN +0.3V
?FB to GND (VFB) --------------------------------------------------------------------------------------------------- -0.3V to VIN +0.3V
?EN to GND (VEN) ------------------------------------------------------------------------------------------------------------ -0.3V to 6V
?Operating Junction Temperature Range (TJ) ------------------------------------------------------------------ -40℃ to 150℃
?Maximum Soldering Temperature (at leads, 1 0sec) ----------------------------------------------------------------------260℃
Electrical Characteristics (VIN =VEN, typical values are TA=25℃ )
Symbol Parameter Conditions
LP6483S
Unit Min. Typ. Max.
Step-Down Converter
VIN Input Voltage 4.5 36 V
△VOUT Output Voltage Line Regulation ILOAD = 0
VIN = 2.5V to 5.5V
0.25 0.4 %/v
△VFB Reference Voltage
Line Regulation
VIN = 2.5V to 5.5V 0.25 0.4 %/v
VOUT Output Voltage Range 0.923 12 V IQ Quiescent Current VFB =0V,VIN1/IN2=4.2V 450 900 μA ISHDN Shutdown Current EN = GND 1 μA ILIM P-Channel Current Limit 4 A
RDS(ON)H High-Side Switch On Resistance 170 m
RDS(ON)L Low-Side Switch On Resistance 120 m
ILXLEAK LX Leakage Current
VEN1/EN2=0V,
VSW1/SW2=0 or 5V, VIN1/IN2=5V
1 μA
ΔVLine-reg/ΔVIN Line Regulation VINB = 2.8V to 5.5V 0.2 0.4 %/V
VFB Feedback Threshold Voltage
Accuracy
VINB = 3.6V,LP6483SAQVF 0.895 0.923 0.951 V
IFB FB Leakage Current VOUTB = 1 .0V 30 nA FOSC
Oscillator Frequency 300 350 400 KHz TS Startup Time From Enable to Output Regulation 120 μs
TSD Over-Temperature Shutdown
Threshold
150 ℃
THYS Over-Temperature Shutdown
Hysteresis
20 ℃
VEN(L) Enable Threshold Low 0.4 V VEN(H) Enable Threshold High 2.5 6 V IEN Input Low Current VINB = VENB = 5.5V -1 1 μA Note: Output Voltage: Vout = VFB X (1+R2/R1) Volts;
Typical Operating Characteristics
Packaging Information
SOP-8(LP6483SASOF)
ESOP-8(LP6483SASPF)