Step Down Switching Regulator  
NON-SYNCHRONOUS 
Part No. Features VIN(Range)(V) VFB(V) IQ(mA) ISTBY(uA) Package
IOUT(A) η()
P2520* 2.0A 340kHz, 20V Step Down Converter 7.0V~20V 1.293V 700uA 8uA HSOP-8  
2.0A Up to 95%
P3586 3.0A 1.2MHz , PWM Step-down Switching Regulator

* 10μA Shutdown Supply Current
* Frequency fold back at Short Circuit
* Protection Circuits: UVLO, Thermal Shutdown, OCP
*Low ESR Output Capacitor Application.
 3.6V~20V 0.8V 3.0mA 10uA SOP-8
3.0A Up to 92%
P1596 1.5A 150KHz, PWM Step-down Switching Regulator

* Voltage mode non-synchronous PWM control
* Thermal-shutdown and current-limit protection
* Low power standby mode
* Internal current and thermal limit
* Built-in switching transistor on chip
4.5V~22V 1.23V(Adj)
2.5V,3.3V,
5.0V,12.0V(Fixed)
5.0mA 70uA TO-220B TO-220-5 TO-263-5 HSOP-8
1.5A Up to 90%
P1785 2.0A 300KHz, PWM Step-down Switching Regulator
With Internal OCSET

* Soft-start, Current Limit, Enable function
* Thermal Shutdown function
* Built-in internal SW P-channel MOS
* Duty ratio: 0% to 100% PWM control
3.6V~23V 0.8V - 10uA SOP-8
2.0A Up to 95%
P1885 2.0A 300KHz, PWM Step-down Switching Regulator

* Soft-start, Current Limit, Enable function
* Thermal Shutdown function
* Built-in internal SW P-channel MOS
* Duty ratio: 0% to 100% PWM control
3.6V~23V 0.8V - 10uA SOP-8
2.0A Up to 95%
P1786 3,0A 300KHz, PWM Step-down Switching Regulator
With external OCSET

* Duty ratio: 0% to 100% PWM control
* Soft-start, current limit, enable function
* Thermal shutdown function
* Built-in internal SW P-channel MOS
4.0V~23V 0.8V - 10uA SOP-8 
3.0A Up to 95%
P1886 3,0A 300KHz, PWM Step-down Switching Regulator
Internal Frequency Compensation With Fewer Component Count

* Soft-start, Current Limit, Enable function
* Thermal Shutdown function
* Built-in internal SW P-channel MOS
* Duty ratio: 0% to 100% PWM control
4.0V~23V 0.8V - 10uA SOP-8 HSOP-8
3.0A Up to 95%
P1888 3,0A 300KHz, PWM Step-down Switching Regulator

* Soft-start, Current Limit, Enable function
* Thermal Shutdown function
* Built-in internal SW P-channel MOS
* Duty ratio: 0% to 100% PWM control
4.0V~23V 1.28V - 10uA SOP-8
3.0A Up to 88%
UD24121 1.4MHz, 1.2A STEP-DOWN CONVERTER

* 0.35Ω Internal Power MOSFET Switch
* Stable with Low ESR Output Ceramic Capacitors
* Up to 92% Efficiency
* 0.1μA Shutdown Mode
* Thermal Shutdown
* Cycle-by-Cycle Over Current Protection
4.5V~24V Up to 92% 0.8mA 3uA SOT-26
1.2A
P1595 1.5A 200KHz, PWM Step-down Switching Regulator

* Output Voltage In Adjustable Output Version.
* Short Circuit Protect
* On/Off Shutdown Control Input.
* Voltage Mode Non-Synchronous Pulse Width Modulation (PWM)
Control.
4.5V~24V 0.75V 4.0mA 2uA SOT-89-5
1.5A Up to 85%
P1696 2.0A 200KHz, PWM Step-down Switching Regulator

*Low power standby mode
*Internal OCP and OTP
4.5V~24V 1.23V(Adj)
2.5V,3.3V,
5.0V,12.0V(Fixed)
5.0mA 80uA SOP-8  HSOP-8 
2.0A Up to 90%
P1583 2.5A 380KHz, PWM Step-down Switching Regulator

* Frequency foldback at short circuit
* Thermal shutdown
* Under voltage lock output
* Current mode with low ESR output ceramic capacitors
* Up to 90% efficiency
4.0V~24V 1.222V 2mA 36uA HSOP-8
2.5A Up to 90%
P1586* 1.5A 1.25MHz, PWM Step-down Switching Regulator 3.0V~25V 1.2V 1.0mA 6uA HSOP-8  MSOP-8
1.5A Up to 90%
P1593* 1.0A 200KHz, PWM Step-down Switching Regulator with Soft start 4.5V~26V 0.75V 3.5mA 2uA SOT-25 SOP-8
1.2A Up to 85%
P4590* 4.0A 380kHz, Asynchronous Step-Down Converter  4.5V~26V Up to 91% 2.0mA 5uA HSOP-8
4.0A
P1580 2.5A 380KHz, PWM Step-down Switching Regulator

* Frequency Feedback at Short Circuit
* Thermal Shutdown
* Under Voltage Lock Output
* Current Mode With Low ESR Output Ceramic Capacitors
* Up to 90% Efficiency
3.5V~28V 1.222V 1.7mA 5uA HSOP-8
2.5A Up to 90%
P1986 3.0A 330KHz, PWM Step-down Switching Regulator
Built-In Soft Start With Fewer Component Count

* Duty ratio varies from 0% to 100% PWM control
* Built-in switch P-channel power MOS
* Halogen Free
3.6V~28V 0.8V 3.0mA 2uA SOP-8 
3.0A Up to 95%
P2583 3.0A 380KHz, PWM Step-down Switching Regulator

* Frequency FoldBack at Short Circuit
* Thermal Shutdown
* Under Voltage Lock Output
* Current Mode with Low ESR Output Ceramic Capacitors
* Up to 90% Efficiency
3.6V~28V 1.222V 2.2mA 20uA SOP-8
3.0A Up to 90%
UC34363 2.0A 75KHz, PWM  Switching Regulator

* CV/CC linear charge
* PWM control Mode
* Available charge current
* Over Voltage protect ,Over Current Protect
* Enable Control function
* Very Low Power Dissipation in Standby Mode
 8.0V to 30V 3.0V  - 7mA SOP-8
3.0A Up to 90%
LD4040* 4.0A 300KHz, 32V Buck DC to DC Converter 3.6V~32V 0.8V 5.0mA 200uA TO-252-5
4.0A Up to 90%
P3596 3.0A 150KHz, PWM Step-down Switching Regulator

*Low power standby mode
*High efficiency
*Internal current and thermal limit
4.5V~35V 1.23V(Adj)
2.5V,3.3V,
5.0V,12.0V(Fixed)
5.0mA 80uA TO-220-5 TO-220B TO-263-5
3.0A Up to 85%
UD36061 2MHz, 0.6A STEP-DOWN CONVERTER

* > 90% Efficiency
* Internally Compensated
* Internal Soft-Start
* Precision Current Limit Without Current Sensing Resistor
* 3μA Low Shutdown Supply Current
3.6V~36V Up to 90% 0.13mA 3uA SOT-26
0.6A
UC34463 2.0A 200KHz, PWM Buck Switching Regulator

* Voltage mode non-synchronous PWM control
* Thermal-shutdown and current-limit protection
* ON/OFF shutdown control input
* Low power standby mode
* Built-in switching transistor on chip
 Up to 40V 5.0V 5.0mA 70uA SOP-8  HSOP-8 
2.0A Up to 85%
P3576 2.0A 50KHz, PWM Step-down Switching Regulator

* Low power standby mode
* Internal current and thermal limit
* Built-in Switching Transistor On Chip.
4.5V~40V 1.23V(Adj)
1.5V,3.3V,
5.0V,12V(Fixed)
4.0mA 100uA SOP-8
2.0A Up to 90%
LD1596 2.0A 150kHz, 40V Buck DC/DC Converter With Constant Current Loop

* Minimum Drop Out 1.5V
* Internal Optimize Power Transistor
* Excellent line and load regulation
* TTL shutdown capability
* ON/OFF pin with hysteresis function
4.5V~40V 1.235V 5.0mA 200uA SOP-8  HSOP-8 
2.0A Up to 83%
P2576 3.0A 52KHz, PWM Step-down Switching Regulator

* Requires 4 External Components
* TTL Shutdown
* Low Power Standby Mode
* Thermal Shutdown,
* Current Limit Protection
7.0V~40V 1.23V(Adj)
5.0V(Fixed)
5.0mA 50uA SOP-8  HSOP-8 TO-220B 
TO-220-5 TO-263-5
3.0A Up to 85%
UMC33167 5.0A 72kHz, STEP-UP/DOWN/INVERTING SWITCHING REGULATORS

* Precision 2% Reference
* 0% ~ 95% Output Duty Cycle
* Cycle-by-Cycle Current Limiting
* Undervoltage Lockout with Hysteresis
* Internal Thermal Shutdown
7.5V~40V Up to 95% - 100uA TO220-5 TO-220B
5.0A
P4596 3.0A 200KHz, PWM Control  Step-Down Converter

* Duty ratio0%~100% PWM control
* Enable with Soft-Start function
* Oscillation frequency can be set by outside resistance
* Current Limit, SCP and OTP
8.0V~40V 0.815V 3.0mA 56uA HSOP-8
3A Up to 91%
P34563 PWM CONTROL 3A STEP-DOWN CONVERTER

* Oscillation frequency: 100KHz
* Duty ratio: 0%~100% PWM control
* Enable and auto restart function.
* Short Circuit Protect (SCP).
* Thermal Shutdown function / Internal OVP.
* Built-in internal SW P-channel MOS.
8.0V~40V 1.10V(typ) 7.0mA 5uA HSOP-8
3.0A  
P1690 0.4A 150KHz, PWM Step-down Switching Regulator

* High efficiency up to 85%
* Maximum Duty Cycle 100%
* Built in OTP
* Built in SCP
* Built in OCP
5V~65V 1.25V 5mA 200uA SOP-8
0.4A Up to 85%
P2576HV* - - - - - -
- -
*: Under  Development          
SYNCHRONOUS   
Part No. Features VIN(Range)(V) VFB(V) IQ(mA) ISTBY(uA) Package
IOUT(A) η()
UC3666 1.6MHz, Dual Channel 1A High Efficiency Step-Down DC/DC Converter

* Current mode operation
* Fixed frequency operation
* Over-temperature protection circuit
* RoHS Compliant (100% green available)
2.5V~5.5V 90%  - 0.1uA DFN3030-10
0.8A
UC3656 1.6MHz, 1.0A High Efficiency Step-Down DC/DC Converter

* Schottky Diode is Saved
* Internal ON/OFF
* 100% Duty Cycle Allows Low Dropout Operation
* Stand-by Current: 1μA (Max.)
2.5V~5.5V 90% 300uA 0.5uA SOT-25
1.0A
UD05103 1.5MHz/1MHz, 1A HIGH-EFFICIENCY SYNCHRONOUS STEP-DOWN CONVERTER

* Shutdown Current < 1μA
* 100% Duty Cycle Operation
* Current Mode Operation
* Internal Soft-Start.
* Current Limit Protection
* Over-temperature Protection.
* Input Under Voltage Lockout (UVLO)
2.5V~5.5V Up to 95% 600uA 1.0uA SOT-25
1.0A
UC3657* 1.2MHz , 1.2A Synchronous Buck  Converter 2.5V~5.5V Up to 95% 300uA 0.5uA TDFN-10(3x3) SOP-8 TSSOP-8
1.2A
UD05121 1.5MHz, 1.2A Synchronous  Step-Down Regulator

* Up to 95% Efficiency
* Less than 1μA Shutdown Current
* Thermal Shutdown Protection
* Current limit and short circuit protections.
* Build-in soft start function
2.5V~5.5V Up to 95% 350uA 1.0uA SOT-25
1.2A
UD05151 1.5MHz, 1.5A HIGH-EFFICIENCY SYNCHRONOUS STEP-DOWN CONVERTER

* Shutdown Current < 1μA
* 100% Duty Cycle Operation
* Current Mode Operation
* Internal Soft-Start
* Current Limit Protection
* Over-temperature Protection
* Input Under Voltage Lockout (UVLO)
3.0V~5.5V Up to 90% 80uA 1.0uA SOT-25
1.5A
UD05158 1.5MHz, 1.5A LOW NIOSE SYNCHRONOUS STEP-DOWN CONVERTER

* Shutdown Current < 1μA
* 100% Duty Cycle Operation
* Current Mode Operation
* Internal Soft-Start.
* Current Limit Protection
* Over-temperature Protection.
* Input Under Voltage Lockout (UVLO)
2.7V~5.5V Up to 95% 200uA 1.0uA DFN2020-6
1.5A
UD05205 1.5MHz, 2A SYNCHRONOUS BUCK CONVERTER

* 150/120mΩ Internal Power MOSFET Switch
* Stable with Low ESR Output Ceramic Capacitors
* Up to 95% Efficiency
* Less than 1μA Shutdown Current
* Thermal Shutdown Protection
* Current limit and short circuit protections.
* Build-in soft start function
2.5V~5.5V Up to 95% 350uA 1uA SOT-25
2A
UD05201 1.2MHz, 2A SYNCHRONOUS STEP-DOWN CONVERTER

* High Efficiency: Up to 96%
* Low RDS(ON) Internal Switches: 0.15Ω
* Current limit, Enable function
* Short Circuit Protect (SCP)
* Build-in Soft Start function
* 1μA Shutdown Current
2.6V~5.5V Up to 96% 400uA 1.0uA SOT-8
2A
UD05202 1MHz, 2A SYNCHRONOUS STEP-DOWN CONVERTER

* Low RDS(ON) for internal switches (top/bottom) 180mΩ/120mΩ
* Internal soft-start limits the inrush current
* 100% dropout operation
3V~5.5V - 80uA 10uA HSOP-8
2A
UD05203 1MHz, 2A SYNCHRONOUS STEP DOWN REGULATOR

* Low RDS(ON) for internal switches (top/bottom) 130mΩ/100mΩ
* Internal softstart limits the inrush current
* 100% dropout operation
3V~5.5V - 80uA 1uA HSOP-8
2A
UD05206 1.5MHz, 2A SYNCHRONOUS STEP DOWN REGULATOR

* Shutdown Current < 1μA
* 100% Duty Cycle Operation
* Current Mode Operation
* Internal Soft-Start
* Current Limit Protection
* Over-temperature Protection
* Input Under Voltage Lockout (UVLO)
2.5V~5.5V Up to 100% 128uA 1uA HSOP-8
2A
UD05251 1.2MHz, 2.5A SYNCHRONOUS STEP DOWN REGULATOR

* High Efficiency: Up to 94%
* Current limit, Enable function
* Short Circuit Protect (SCP)
* Build-in Soft Start function
* 1μA Shutdown Current
2.6V~5.5V Up to 94% 400uA 1uA HSOP-8 DFN3030-8
2.5A
UC3658* 1MHz, 3.0A Synchronous  Step-Down Regulator 3V~5.5V Up to 95% - 1.0uA HSOP-8
3.0A
UD05302 1MHz, DUAL 3A SYNCHRONOUS STEP DOWN REGULATOR

* Low RDS(ON) for internal switches (top/bottom) 110mΩ/80mΩ
* Internal softstart limits the inrush current
* 100% dropout operation
3V~5.5V - 80uA 10uA HSOP-8
3.0A
UD05303 1MHz, 3A HIGH EFFICIENCY synchronous step-down DC-DC regulator

* Low RDS(ON) for internal switches (top/bottom) 100mΩ/70mΩ
* Internal softstart limits the inrush current
* 100% dropout operation
* Output power good indicator
* RoHS compliant and halogen free
3V~5.5V - - - HSOP-8
3.0A
UC3655-XX 1.3MHz 0.5A Synchronous Buck  Converter

* Very High Efficiency 92%
* Low Ripple Rejection Voltage 10mV
* With PWM / PFM Automatic Switching Control
* Maximum Duty Ratio is 100%
* Ceramic Capacitor Available
2.0V~6.0V 90% 70uA 1.0uA SOT-25
0.5A
UC3206 3MHz 0.6A Inductor Built-in Step-Down “micro DC/DC” Converters

* Maximum duty cycle: 100%
* High efficiency : 92% (TYP.)
* High speed soft-start circuit and Current limiter circuit built-in
* CL high speed auto discharge
* Low ESR ceramic capacitor compatible
2.0V~6.0V 85% 35uA 1.0uA SOT-25
0.6A
UD05104 2.25MHz, 1A SYNCHRONOUS STEP-DOWN DC/DC CONVERTER

* 100% Duty Cycle Operation
* Internal Soft-Start
* Cycle-by-Cycle Current Limit Protection
* Over-Load and Hiccup Mode Short Circuit
* Thermal Shutdown Protection
2.5V~6.0V - 40uA 1.5uA SOT-25
1A
UD05104A * +/-2% 0.6V Feedback Voltage Accuracy
* 1MHz Switching Frequency
* 100% Duty Cycle Operation
* Built-in 170mΩ/150mΩ Power Switch
* Cycle-by-Cycle Current Limit Protection
* with Soft-start, OTP, Over-Load and Hiccup Mode Short Circuit
2.5V~6.0V - 40uA 1.5uA SOT-25
1A
UCD0318* 500KHz, 3.0A Synchronous Rectified Step-Down Converter 4.5V~16V Up to 95% 2000uA 1.0uA HSOP-8
3.0A
USR1021 500KHz, 3.0A PWM Control  Step-Down Converter

* Internal soft start
* 1.5% initial output accuracy
* Cycle-by-cycle current limit
* Thermal shutdown
* Short-circuit protection
4.5V~16V Up to 95% 3500uA 3.0uA SOP-8
3.0A
UD18204 500KHz, 2A SYNCHRONOUS RECTIFIED STEP-DOWN DC/DC CONVERTER

* High Efficiency up to 90%
* Power Saving Mode (PSM) during the light Load Operation
* Current Mode Operation
* Over-temperature Protection
* Over-current Protection
4.5V~18V Up to 90% - - SOT-26
2.0A
USR1051 400KHz, 3.0A PWM Control  Step-Down Converter with Soft start

* Synchronous Buck
* Cycle-by-cycle current limit
* Pre-bias start-up
* Thermal shutdown
* Short-circuit protection
4.5V~18V Up to 95% 1600uA 1.0uA HSOP-8
3.0A
P1482 340KHz, 2.0A Synchronous Rectified Step-Down Converter

* Integrated Power MOSFET Switches
* Programmable Soft-Start
* Stable with Low ESR Ceramic Output Capacitors
* Cycle-by-Cycle Over Current Protection
6V~23V Up to 93% 5000uA  - SOP-8
2.0A
P1482A 340KHz, 2.0A Synchronous Rectified Step-Down Converter

* Integrated Power MOSFET Switches
* Programmable Soft-Start
* Stable with Low ESR Ceramic Output Capacitors
* Cycle-by-Cycle Over Current Protection
6V~23V Up to 93% 5000uA  - HSOP-8
2.0A
P1484 340KHz, 3.0A Synchronous Rectified Step-Down Converter

* Integrated Power MOSFET Switches
* Programmable Soft-Start
* Stable with Low ESR Ceramic Output Capacitors
* Cycle-by-Cycle Over Current Protection
6.0V~23V Up to 93% 3500uA  - SOP-8
3.0A
P1484A 340KHz, 3.0A Synchronous Rectified Step-Down Converter

* Integrated Power MOSFET Switches
* Programmable Soft-Start
* Stable with Low ESR Ceramic Output Capacitors
* Cycle-by-Cycle Over Current Protection
6.0V~23V Up to 93% 3500uA  - HSOP-8
3.0A
P2680 2.0A 340kHz, Step Down Converter

* Output Adjustable
* Frequency FoldBack at Short Circuit
* VIN Under-voltage Lockout
* Thermal Shutdown
* OCP
* Programmable Soft-Start
7.0V~26V 0.923V 900uA 8uA HSOP-8  
2.0A Up to 95%
SR2803 330KHz, 3.0A Synchronous Buck Regulator.

* Duty ratio varies from 0% to 92% PWM control
* Thermal shutdown and SCP function and soft-start, current limit,
enable function
* Low ESR output capacitor(Multi-layer chip capacitor) application
4.0V~28V Up to 95% 3000uA 2.0uA SOP-8
3.0A
UD36241 * CC/CV Mode Control
* Adjustable Load Line Compensation
* 200mΩ Internal Power MOSFET Switch
* Current Mode Control
* Fixed Frequency Operation : 100kHz
* Programmable Output Current Limit
* Lowe EMI signature
* Cycle-by-Cycle Over Current Protection
* Input Under Voltage Lockout
* with OTP
9V~36V 1V 4 3uA HSOP-8
2.4A -
UCC36351 160KHz, 3.5A SYNCHRONOUS BUCK CONVERTER WITH CC/CV

* Integrated 75/45mΩ Power MOSFET Switches
* Up to 93% Efficiency
* Stable with Low ESR Ceramic Output Capacitors
* Cycle-by-Cycle Over Current Protection
* Input Under/Over Voltage Lockout
8V~36V Up to 93% 1.5mA - HSOP-8
3.5A
UCC36451 160KHz, 4.5A SYNCHRONOUS BUCK CONVERTER WITH 2CH CC/CV

* Integrated 75mΩ high side Power MOSFET Switches
* Up to 95% Efficiency
* Stable with Low ESR Ceramic Output Capacitors
* Cycle-by-Cycle Over Current Protection
* Input Under/Over Voltage Lockout
8V~36V Up to 95% 2mA - HSOP-8
4.5A
UD38251 160KHz, 2.5A SYNCHRONOUS BUCK CONVERTER

* Integrated 140mΩ Power MOSFET Switches
* Up to 93% Efficiency
* Internal Soft-Start
* Cycle-by-Cycle Over Current Protection
* Input Under/Over Voltage Lockout
8V~38V Up to 93% 1.5mA 1.3mA HSOP-8
2.5A
UD38252 160KHz, 2.5A SYNCHRONOUS BUCK CONVERTER WITH CC/CV

* Integrated 140mΩ Power MOSFET Switches
* Up to 92% Efficiency
* Internal Soft-Start.
* Cycle-by-Cycle Over Current Protection
* Input Under/Over Voltage Lockout
8V~38V Up to 92% 1.5mA - HSOP-8
2.5A
UD38501 160KHz, 5A SYNCHRONOUS BUCK CONVERTER

* Integrated 80mΩ high side Power MOSFET Switches
* Up to 95% Efficiency
* Internal Soft-Start
* Cycle-by-Cycle Over Current Protection
* Input Under/Over Voltage Lockout
8V~38V Up to 95% 1.5mA 1.3mA HSOP-8
5A
*: Under  Development
Step-Down DC-DC PWM or PFM  Controller (Buck)  
Part No. Features VIN(Range)(V) η() IQ(uA) ISTBY(uA) Package
UC3750-XX 600kHz PWM /PFM Buck  Controller

* Built-in soft-start (SS)
* Automatic PWM/PFM switchover under light load condition
* Internal under-voltage lockout (UVLO) protection
* Low profile and minimum external components
2.45V~5.5V 92% 50uA(Typ) 0.3uA SOT-25
UC4601 500kHz PWM Step-down DC-DC Controller

* Internal soft-start and protection function
* High efficiency up to 90% (TYP.)
* Standly current: 0.1μA (TYP.)
* CMOS output capability
2.5~18V 90% 40uA(Typ) 1.0uA SOT-25
M7085 1MHz PFM STEP-DOWN Controller

* High efficiency 90% and up is possible
* Low dropout operation100% duty cycle
* Two methods of over-current protection
4.5V~35V 93% 300uA(Typ)  - MSOP-8
USR1101 5V/12V Synchronous Buck PWM DC-DC Controller

* Drives all low cost N-channel MOSFETs
* PWM control mode
* Internal soft-start
* RoHS compliant and 100% lead (Pb)-free
5V±5%,12V±10% 88% 6mA(Typ)  - SOP-8
*: Under  Development