UNISEM US1050-33

US1050-33
5A LOW DROPOUT POSITIVE
FIXED 3.3V OUTPUT REGULATOR
DESCRIPTION
FEATURES
The US1050-33 product is a low dropout three terminal
fixed 3.3V output regulator with minimum of 5A output
current capability. This product is specifically designed
to provide well regulated supply for low voltage IC applications requiring 3.3V output. The US 1050-33 is guaranteed to have <1.3V drop out at full load current
making it ideal to provide well regulated output with supply voltage as low as 4.6V input.
Guaranteed < 1.3V Dropout at Full Load
Current
Fast Transient Response
1% Voltage Reference Initial Accuracy
Output Current Limiting
Built-in Thermal Shutdown
APPLICATIONS
Standard 3.3V Chip-Set and Logic Applications
TYPICAL APPLICATION
5V
C1
330uF
Vin
3
US1050-33 Vout
2
Gnd
3.3V / 5A
C2
330uF
1
1050-33app1-1.1
Typical application of US1050-33
Tj (°C)
0 TO 150
Rev. 1.1
10/27/00
3 PIN PLASTIC
TO220 (T)
US1050-33CT
3 PIN PLASTIC
TO263 (M)
US1050-33CM
2 PIN PLASTIC
POWER FLEX (P)
US1050-33CP
3 PIN PLASTIC
TO252 (D)
US1050-33CD
2-33
US1050-33
ABSOLUTE MAXIMUM RATINGS
Input Voltage (Vin) .................................................................. 7V
Power Dissipation ............................................ Internally Limited
Storage Temperature Range .............................. -65°C TO 150°C
Operating Junction Temperature Range .................. 0°C TO 150°C
PACKAGE INFORMATION
3 PIN PLASTIC TO220 ( T )
3 PIN PLASTIC TO263 ( M )
2 PIN PLASTIC POWER FLEX ( P ) 3 PIN PLASTIC TO252 ( D )
FRONT VIEW
3
Tab is
Vout
Vin
2
Vout
1
Gnd
θJT=2.7°C/W θJA=60°C/W
Tab is
Vout
FRONT VIEW
FRONT VIEW
FRONT VIEW
3
Vin
2
Vout
1
Gnd
θJA=35°C/W for 1" Square pad
3
Tab is
Vout
Vin
Tab is
Vout
4
1
Vin
1
Gnd
4
Adj
θJA=70°C/W for 1" Square pad
3
θJA=70°C/W for 0.5" Sq pad
ELECTRICAL SPECIFICATIONS
Unless otherwise specified ,these specifications apply over ,Cin=1uF,Cout=10uF,and Tj=0 to 150°C.Typical
values refer to Tj=25°C.
PARAMETER
Output Voltage
Line Regulation
Load Regulation (note 1)
Dropout Voltage
(note 2)
Current Limit
Minimum Load Current
(note 3)
Thermal Regulation
Ripple Rejection
Adjust Pin Current Change
Temperature Stability
Long Term Stability
RMS Output Noise
SYM
Vo
∆VO
TEST CONDITION
Io=10mA,Tj=25°C,Vin=5V
Io=10mA, Vin=5V
Io=10mA,4.7V<Vin<7V
Vin=5V,Vadj=0,10mA<Io<5A
Note 2 , Io=5A
Vin=5V,dVo=100mV
Vin=5V
30 mS PULSE,Vin-Vo=3V,Io=5A
f=120HZ ,Co=25uF Tan
Io=2.5A,Vin-Vo=3V
Io=10mA,Vin-Vo=1.5V,Tj=25
Vin=5V,Vadj=0V,Io=10mA
Tj=125°C,1000 Hrs
Tj=25°C 10hz<f<10khz
Note 1 : Low duty cycle pulse testing with Kelvin connections are required in order to maintain accurate data.
Note 2 : Drop-out voltage is defined as the minimum
differential voltage between Vin and Vout required to maintain regulation at Vout. It is measured when the output
voltage drops 1% below its nominal value.
2-34
MIN
TYP
3.267 3.300
3.234 3.300
MAX
3.330
3.366
0.2
0.4
UNITS
V
1.1
1.3
5
10
V
A
mA
0.01
0.02
%/W
5.1
60
70
0.2
0.5
0.3
0.003
5
1
%
%
dB
uA
%
%
%Vo
Note 3 : Minimum load current is defined as the minimum current required at the output in order for the output voltage to maintain regulation. Typically the resistor
dividers are selected such that it automatically maintains this current.
Rev. 1.1
10/27/00
US1050-33
PIN DESCRIPTIONS
PIN #
1
2
PIN SYMBOL
Gnd
Vout
3
Vin
PIN DESCRIPTION
This pin must be connected to GND plane using a low inductance short connection.
The output of the regulator. A minimum of 10uF capacitor must be connected
from this pin to ground to insure stability.
The input pin of the regulator. Typically a large storage capacitor is connected
from this pin to ground to insure that the input voltage does not sag below the
minimum drop out voltage during the load transient response. This pin must
always be 1.3V higher than Vout in order for the device to regulate properly.
BLOCK DIAGRAM
Vin 3
2 Vout
+
1.25V
+
CURRENT
LIMIT
THERMAL
SHUTDOWN
1 Gnd
1050-33blk1-1.0
Figure 1 - Simplified block diagram of the US1050-33
APPLICATION INFORMATION
Stability
The US1050-33 requires the use of an output capacitor
as part of the frequency compensation in order to make
the regulator stable. Typical designs for microprocessor applications use standard electrolytic capacitors with
a typical ESR in the range of 50 to 100 mΩ and an
output capacitance of 500 to 1000uF. Fortunately as
the capacitance increases, the ESR decreases resulting in a fixed RC time constant. The US1050-33 takes
advantage of this phenomena in making the overall regulator loop stable.For most applications a minimum of
100uF aluminum electrolytic capacitor such as Sanyo
MVGX series ,Panasonic FA series as well as the
Nichicon PL series insures both stability and good transient response.
Rev. 1.1
10/27/00
2-35