SECOS SU1086

SU1086
1.5A Low Dropout Positive
Adjustable or Fixed-Mode Regulator
Elektronische Bauelemente
RoHS Compliant Product
Description
The SU1086 is a low dropout at positive adjustable or fixed-mode
regulator with min. of 1.5 A output current capability. The product is
specifically designed to provide well-regulated supply for low voltage
IC applications such as high-speed bus termination and low current
3.3V logic supply. SU1086 is also well suited for other applications
such as VGA cards. SU1086 is guaranteed to have lower than 1.4V
dropout at full load current making it ideal to provide well regulated
outputs of 1.25 to 5V with 4.7 to 12V input supply.
Features
* 1.4V Max. Dropout Full Load Current
* 3-Terminal Adjustable or Fixed 1.5V,1.8V,2.5V,3.3V,5.0V
* Output Current Limiting
* Fast Transient Response
* Built-in Thermal Shutdown
REF.
A
b
L4
c
L3
L1
E
Millimeter
REF.
Min.
Max.
4.40
4.80
c2
0.76
1.00
b2
0.00
0.30 B D
0.36
0.5
e
1.50 REF.
L
2.29
2.79
9.80
10.4
L2
Millimeter
Min.
Max.
1.25
1.45
1.17
1.47
8.6
9.0
2.54 REF.
14.6
15.8
0˚
8˚
1.27 REF.
Typical Circuit
Block Diagram
http://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
Any changing of specification will not be informed individual
Page 1 of 4
SU1086
1.5A Low Dropout Positive
Elektronische Bauelemente
Adjustable or Fixed-Mode Regulator
Pin Descriptions
Name
I/O
PIN#
Adj (GND)
FUNCTION
1
Adjustable (Ground only for fixed mode)
The output of the regulator. A minimum of 10uF capacitor must be connected from this pin to
ground to insure stability.
Vout
O
2
Vin
I
3
The input pin of regulator .Typically a large storage capacitor is connected from this pin to ground
to insure that the input voltage does not sag below the min. dropout voltage during the load
transient response .This pin must always be 1.4V higher than Vout in order for the device to
regulate properly.
tage does not sag below the minimum dropout voltage during the load
V higher than Vout in order for the device to
Absolute Maximum Ratings
Parameter
Ratings
Symbol
DC Supply Voltage
Unit
-0.3 to 12
VIN
Power Dissipation
PD
Storage Temperature Range
TST
-65~+150
Operating Juction Temperature Range
TOP
0~+150
V
Internally Limited
o
C
o
C
Electrical Characteristics
Parameter
Reference Voltage
Output Voltage
Conditions
TYP
MAX
UNIT
Io=10mA, TJ =25 , (Vin-Vout )=1.5V
1.225
1.250
1.275
V
SU1086-1.5
Io=10mA, TJ =25 , 3V Vin 12V
1.470
1.500
1.530
V
SU1086-1.8
Io=10mA, TJ =25 , 3.3V Vin 12V
1.764
1.800
1.836
V
SU1086-2.5
Io=10mA, TJ =25 , 4V Vin 12V
2.450
2.500
2.550
V
SU1086-3.3
Io=10mA, TJ =25 , 4.8V Vin 12V
3.235
3.300
3.365
V
Io=10mA, TJ =25 , 6.5V Vin 12V
4.900
5.000
SU1086-5.0
Line Regulator
MIN
SU1086-ADJ
SU1086-XXX
Io=10mA, Vout+1.5<Vin<12
-
-
5.100
0.2
V
%
SU1086-ADJ
Vin=3.3V, 0mA<Io<1.5A, TJ=25
(Note 1,2)
-
-
1
%
SU1086-1.5
Vin=3.0V, 0mA<Io<1.5A, TJ=25
(Note 1,2)
-
12
15
mV
SU1086-1.8
Vin=3.3V, 0mA<Io<1.5A, TJ =25
-
15
18
mV
SU1086-2.5
Vin=4.0V, 0mA<Io<1.5A, TJ=25
(Note 1,2)
-
20
25
mV
SU1086-3.3
Vin=5.0V, 0mA<Io<1.5A, TJ=25
(Note 1,2)
-
26
33
mV
SU1086-5.0
Vin=8.0V, 0mA<Io<1.5A, TJ=25
(Note 1,2)
-
40
50
mV
Dropout Voltage
(Vin-Vout)
SU1086-XXX
Io=1.5A( Vout=1% Vout)
-
1.3
1.4
V
Current Limit
SU1086-XXX
Vin-Vout=5V
1.6
-
-
A
Minimum Load Current
SU1086-XXX
0
-
5
10
mA
Thermal Regulation
TA=25 , 30ms pulse
Load Regulation
Ripple Rejection
Temperature Stability
TJ 125
-
0.008
0.04
%/W
F=120Hz, COUT=25uF, Tantalum, Io=1.5A
SU1086-XXX
Vin=Vout+3V
Io=10mA
Thermal Resistance
Junction–to-Ambient
(No heat sink ;No air flow)
Thermal Resistance
Junction-to-Case
(Note 1,2)
Control Circuitry/Power Transistor
-
60
70
dB
-
0.5
-
%
-
83
-
/W
-
0.65/2.7
-
/W
Note 1: See thermal regulation specifications for changes in output voltage due to heating effects. Line and load regulation are measured
at a constant junction Temperature by low duty cycle pulse testing. Load regulation is measured at the output lead =1/18” from the
package.
Note 2: Line and load regulation are guaranteed up to the maximum power dissipation of 15W. Power dissipation is determined by the
difference in input and output and the output current. Guaranteed maximum power dissipation will not be available over the full
input/output range.
Note 3: Quiescent current is defined as the minimum output current required in maintaining regulation. At 12V input/output differential the
device is guaranteed to regulate if the output current is greater than 10mA.
http://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
Any changing of specification will not be informed individual
Page 2 of 4
SU1086
Elektronische Bauelemente
1.5A Low Dropout Positive
Adjustable or Fixed-Mode Regulator
Functional Description
Introduction
The SU1086 adjustable or fixed-mode Low Dropout (LDO) regulator is a 3 terminal device which can easily be
programmed by internal mask change to any voltage within the range of 1.25 to Vin-1.4V. The SU1086 only needs 1.4V
differential between Vin and Vout to maintain output regulation, in addition, the output voltage tolerances are also extremely
tight and they include the transient response as port of the specification. For example, Intel VRE specification calls for a
total of +/-100mV including initial tolerance, load regulation and 0 to 1.5A load step. The SU1086 is specifically designed
to meet the fast current transient needs as well as providing an accurate initial voltage, reducing the overall system cost
with the need for fewer output capacitors.
Load Regulation
Since the SU1086 is only a 3 terminal device, it is not possible to provide true remote sensing of the output voltage at the
load. But it can supply good load regulation by internal feedback bypass the external loss such as adjustable mode.
Stability
The SU1086 requires the use of an output capacitor as part of the frequency compensation in order to make the regulator
stable .For most applications a minimum of 10uF aluminum electrolytic capacitor insures both stability and good transient
response.
Thermal Design
The SU1086 incorporates an internal shutdown that protects the device when the junction temperature exceeds the
maximum allowable junction temperatures. Although this device can operate with junction temperatures in the range of
150 , it is recommended that the selected heat sink be chosen such that during maximum continuous load operation the
junction temperature is kept below the temperature.
Layout Consideration
The output capacitors must be located as close to the Vout terminal of the device as possible .It is recommended to use a
section of a layer of the PC board as a plane to connect the Vout pin to the output capacitors to prevent any high frequency
oscillation that may result due to excessive trace inductance.
h tp://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
Any changing of specification will not be informed individual
Page 3 of 4
SU1086
Elektronische Bauelemente
1.5A Low Dropout Positive
Adjustable or Fixed-Mode Regulator
Performance Characteristics
h tp://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
Any changing of specification will not be informed individual
Page 4 of 4