Datasheet

UNISONIC TECHNOLOGIES CO., LTD
UD05303
Preliminary
CMOS IC
3A, 1MHz, HIGH EFFICIENCY

DESCRIPTION
The UTC UD05303 is a high-efficiency 1MHz synchronous
step-down DC-DC regulator IC capable of delivering up to 3A
output current. The UTC UD05303 operates over a wide input
voltage ranging form 3~5.5V and integrate main switch and
synchronous switch with very low RDS(ON) to minimize the
conduction loss.
Low output voltage ripple and small external inductor and
capacitor sizes are achieved with 1MHz switching provides the
system reset function and facilitates the output sequencing design.

FEATURES
* Low RDS(ON) for internal switches (top/bottom) 100mΩ/70mΩ, 3A
* 3~5.5V input voltage range
* 1MHz switching frequency minimizes the external components
* Internal softstart limits the inrush current
*100% dropout operation
* Output power good indicator
* RoHS compliant and halogen free
* Compact and thermally enhanced SO8 package with exposed
paddle

ORDERING INFORMATION
Ordering Number
UD05303G-SH2-R
Package
HSOP-8
Packing
Tape Reel
UD05303G-SH2-R

(1)Packing Type
(1) R: Tape Reel
(2)Package Type
(2) SH2: HSOP-8
(3)Green Package
(3) G: Halogen Free and Lead Free
MARKING
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Copyright © 2015 Unisonic Technologies Co., Ltd
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UD05303
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
Preliminary
CMOS IC
PIN CONFIGURATION
NC
1
8
PG
IN
2
7
EN
LX
3
6
NC
GND
4
5
FB
GND
PIN DESCRIPTION
PIN NO.
1, 6
2
3
4, paddle
PIN NAME
NC
IN
LX
GND
5
FB
7
EN
8
PG
DESCRIPTION
No connections
Input pin. Decouple this pin to GND pin with at test 1μF ceramic cap
Inductor pin. Connect this pin to the switching node of inductor
Ground pin
Output feedback pin. Connect this pin to the center point of the output resistor
divide (as shown in figure 1)to program the output voltage: VOUT=0.6*(1+R1/R2)
Enable control. Pull high to turn on. Do not float
Power good indicator. When the output voltage exceeds 90% of regulation point,
it becomes open drain; low otherwise
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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UD05303

Preliminary
CMOS IC
ABSOLUTE MAXIMUM RATING
PARAMETER
SYMBOL
RATINGS
UNIT
Supply Input Voltage
VIN
6.0
V
Enable, FB Voltage
VFB
VIN+0.6
V
Junction Temperature
TJ
150
°C
Storage Temperature
TSTG
-65~150
°C
Notes: 1. Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.
2. The device is not guaranteed to function outside its operating conditions.

RECOMMENDED OPERATING CONDITIONS
PARAMETER
Supply Input Voltage
Junction Temperature
Ambient Temperature

RATINGS
3 ~ 5.5
-40 ~ 125
-40 ~ 85
UNIT
V
°C
°C
SYMBOL
θJA
θJC
RATINGS
143
14
UNIT
°C/W
°C/W
THERMAL DATA
PARAMETER
Junction to Ambient
Junction to Case

SYMBOL
VIN
TJ
TA
ELECTRICAL CHARACTERISTICS (VIN=3.6V, VOUT=2.5V, L=2.2uH, COUT=10uF, TA=25°C, IMAX=1A
unless otherwise specified)
PARAMETER
Input Voltage Range
Shutdown Current
Feedback Reference Voltage
FB Input Current
PFET RON
NEET RON
PFET Current Limit
EN Rising Threshold
EN Falling Threshold
Input UVLO Threshold
UVLO Hysteresis
Oscillator Frequency
Min On Time
Max Duty Cycle
Thermal Shutdown Temperature
SYMBOL
VIN
ISHDN
VREF
IFB
RDS(ON),P
RDS(ON),N
ILIM
VENH
VENL
VUVLO
VHYS
FOSC
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TEST CONDITIONS
MIN
3
EN=0
VFB=VIN
0.588
-50
TYP
0.1
0.6
MAX
5.5
1
0.612
50
0.1
0.07
3.6
1.5
0.4
2.9
0.2
1
50
IOUT=100mA
100
150
UNIT
V
μA
V
nA
Ω
Ω
A
V
V
V
V
MHz
ns
%
°C
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Preliminary
CMOS IC
TYPICAL APPLICATION CIRCUIT
ON/OFF
EN
VIN
IN
LX
R3
L
VOUT
R1
PG
COUT
C1(opt.)
FB
R2
GND
Figure 1. Schematic Diagram
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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