Datasheet

UNISONIC TECHNOLOGIES CO., LTD
UC4601
Preliminary
CMOS IC
PWM STEP-DOWN DC-DC
CONTROLLER
„
DESCRIPTION
The UTC UC4601 is a PWM step-down DC/DC controller. It has
a low supply current. The step-down DC/DC converter with low
ripple, high efficiency performance is conveniently configured with
additional external components, such as a power-transistor, an
inductor, a diode and capacitors. The output voltage can be adjusted
with external components.
The UTC UC4601 contains a high precision band-gap voltage
reference, a PWM control circuit, a soft-start circuit, a protection
circuit, an oscillator, an error amplifier with built-in compensation
network and input/output voltage detection circuits.
The UTC UC4601 based DC/DC converter can performance well
when maintaining stability, which is due to its built-in state-of-art
control algorithm. Further, if the term of maximum duty cycle retains
on a certain time, the embedded protection circuits restart the
operation with soft-start and repeat until the maximum duty cycle
condition is released. Finally, the internal UVLO function blocks
potentially unstable output when the input voltage reaches the UVLO
threshold or less. This is aiming at making this circuit standby for low
power consumption.
The UTC UC4601 can be applied in battery-powered equipment,
hand-held communication equipment, cameras, video instruments
such as VCRs, camcorders, household electrical appliances.
„
FEATURES
* 500kHZ oscillation frequency
* Input voltage varies from 2.3V to 18V
* Low temperature coefficient of output voltage: Typ. ±100ppm/°C
* Internal soft-start and protection function
* High efficiency up to 90% (TYP.)
* High output voltage accuracy: ±2%
* Standly current: 0.1μA (TYP.)
* CMOS output capability
„
ORDERING INFORMATION
Ordering Number
Lead Free
Halogen Free
UC4601L-AF5-R
UC4601G-AF5-R
Package
Packing
SOT-25
Tape Reel
UC4601L - AF5 - R
(1) Packing Type
(1) R: Tape Reel
(2) Package Type
(2) AF5: SOT-25
(3) Lead Free
(3) G: Halogen Free, L: Lead Free
www.unisonic.com.tw
Copyright © 2011 Unisonic Technologies Co., Ltd
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UC4601
Preliminary
CMOS IC
MARKING
„
4
5
UJ46
1
2
G: Halogen Free
L : Lead Free
3
„
PIN CONFIGURATION
„
PIN DESCRIPTION
PIN NO
1
2
3
4
5
PIN NAME
CE
GND
VFB
EXT
VIN
DESCRIPTION
Chip Enable. Active with “H”
Ground
Feedback Voltage
External Transistor Driver Pin (CMOS output)
Power input voltage
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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UC4601
„
Preliminary
CMOS IC
ABSOLUTE MAXIMUM RATING
PARAMETER
SYMBOL
RATINGS
UNIT
VIN Supply Voltage
VIN
20
V
Ext Pin Output Voltage
VEXT
-0.3 ~ VIN+0.3
V
CE Pin Input Voltage
VCE
-0.3 ~ VIN+0.3
V
VOUT/VFB Pin Input Voltage
VOUT/VFB
-0.3 ~ 6
V
Ext Pin Output Current
IEXT
±50
mA
Power Dissipation
PD
+250
mW
Operating Temperature
TOPR
-40 ~ +85
°C
Storage Temperature
TSTG
-55 ~ +125
°C
Note: 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.
„
OPERATING RANGE
PARAMETER
VIN Supply Voltage
Ext Pin Output Voltage
CE Pin Input Voltage
VOUT/VFB Pin Input Voltage
Ext Pin Output Current
„
SYMBOL
VIN
VEXT
VCE
VOUT/VFB
IEXT
RATINGS
2.5 ~ 18
-0.3 ~ VIN+0.3
-0.3 ~ VIN+0.3
-0.3 ~ 5.5
±50
UNIT
V
V
V
V
mA
ELECTRICAL CHARACTERISTICS (TOPR=25°C, unless otherwise specified)
PARAMETER
SYMBOL
ADJUSTABLE OUTPUT VOLTAGE TYPE
Operating Voltage
VIN
Feedback Voltage
VFB
Feedback Voltage Temperature
ΔVFB/ΔT
coefficient
Supply Current
IQ1
Shutdown Current
IQ2
Oscillator Frequency
fOSC
Maximum Duty Cycle
DMAX
Minimum Duty Cycle
DMIN
EXT “H” Output Current
IEXTH
EXT “L” Output Current
IEXTL
CE “H” Output Current
ICEH
CE “L” Output Current
ICEL
CE “H” Input Voltage
VCEH
CE “L” Input Voltage
VCEL
UVLO Voltage
VUVLO1
TEST CONDITIONS
VIN=VCE=8V, VEXT=7.9V, VFB=3V
VIN=VCE=8V, VEXT=0.1V, VFB=0V
VIN=VCE=VOUT=18V
VIN=VOUT=18V, VCE=0V
VIN=8V, VFB=0V
VIN=8V, VFB=0V
VIN=VCE=2.5V≥1.5V, VFB=0V
UVLO Release Voltage
VUVLO2
VIN=VCE=1.5V≥2.5V, VFB=0V
Delay Time by Soft-Start
Delay Time by Protection
TSST
TPROT
VIN=8V, ILOAD =10mA, VCE=0V≥2.5V
VIN=VCE=2.5V, VFB=2.5V≥0V
VIN=VCE=8V, ILOAD =350mA
TYP
MAX
UNIT
2.3
0.98
1.00
18
1.02
V
V
-40°C <TOPR<85°C
±100
VIN=VCE=18V, VFB=2V
VIN=18V, VCE=VFB=0V
VIN=VCE=8V, ILOAD =350mA
40
0.1
500
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
MIN
400
100
20
-0.3
1.8
-17
30
0
0
1.75
2.0
5
5
VUVLO1
+0.1
10
15
ppm/°C
80
1
600
0.3
2.25
μA
μA
kHZ
%
%
mA
mA
μA
μA
V
V
V
2.4
V
20
30
ms
ms
0
-10
0.5
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UC4601
„
Preliminary
CMOS IC
TYPICAL APPLICATION CIRCUIT
Adjustable Output Voltage Type. For example, Output Voltage=3.3V
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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