Ver 1.3
BCT1117
1A Bipolar Linear Regulator
Features
Description
BCT1117 is a series of low dropout
three-terminal regulators with a dropout of 1.3V
at 1A load current. BCT1117 features a very low
standby current 2mA compared to 5mA of
competitor.
Other than a fixed version, Vout = 1.2V, 1.8V,
2.5V, 3.3V, 5V, and 12V, BCT1117 has an
adjustable version, which can provide an output
voltage from 1.25 to 12V with only two external
resistors.
BCT1117 offers thermal shut down and current
limit functions, to assure the stability of chip and
power system. And it uses trimming technique
to guarantee output voltage accuracy within 2%.
Other output voltage accuracy can be
customized on demand, such as 1%.
BCT1117 is available in SOT-223, TO-252
power package.
Maximum output current is 1A
Range of operation input voltage: Max 15V
Line Regulation: 0.1%/V(typ.)
Standby current: 2mA(typ.)
Load Regulation: 10mV(typ.)
Environment Temperature:-20℃-85℃
Applications
Power Management for Computer Mother
Board, Graphic Card
LCD Monitor and LCD TV
DVD Decode Board
ADSL Modem
Post Regulators For Switching Supplies
Pin Configurations (Top View)
SOT-223-3
TOP VIEW
Tab is Vout
1:Vss/ADJ
2:Vout
3:Vin
MARKING
2
1
3
1
TO-252-3
TOP VIEW
Tab is Vout
MARKING
1:Vss/ADJ
2:Vout
3:Vin
2
3
Pin Functions
PIN
I/O
DESCRIPTION
Name
TO-252
SOT-223
ADJ/GND1
1
1
-
VIN
3
3
I
Input voltage pin for the regulator.
VOUT
2, Tab
2, Tab
O
Output voltage pin for the regulation.
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Adjust pin for adjustable output option.
Ground Pin for fixed output.
1
Ver 1.3
Ordering Information
Part
1
BCT1117ELTXX -TR
1
BCT1117EOTXX -TR
Pin-Package
SOT-223-3
TO-252-3
Temp-Range
-40°C to +85°C
-40°C to +85°C
Top Mark
1117
1117
Supplied as:
3000units/Tape & Reel
3000units/Tape & Reel
Note 1: XX:voltage version(12:1.2V, 15:1.5V, 18:1.8V, 25:2.5V, 33:3.3V, 50:5.0V, 120:12V, ADJ:Adjustable)
Typical Application Circuit
Selection Table
Marking
Part No.
Output Voltage
XX=12
1.2V
XX=18
1.8V
1117
XX=25
2.5V
XXYYZZ
XX=33
3.3V
XX=50
5.0V
XX=120
12.0V
XX=ADJ
Adjustable
Package
SOT-223
TO-252
ORDERING INFORMATION
Marking
Designator
1117
1117
XXYYZZ
Description
Product code
XX
Output Voltage(1.2~12.0V)
YY
DATE CODE (YEAR)
ZZ
DATA CODE (WEEK)
Note:”XX” stands for output voltages. Other voltages can be specially customized
Parameters
Description
Temperature&Rohs
C:-40~85℃, Pb Free Rohs Std.
Package type
L:SOT-223 O:TO-252
PIN number
3
Packing type:
TR: Tape&Reel (Standard)
Voltage accuracy
1%(Customized)
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2
Ver 1.3
Block Diagram
Absolute Maximum Ratings
Max Input Voltage …………………………………… 15V
Storage Temperature(Ts) ………… -40℃~150℃
Max Operating Junction Temperature(Tj) ……… 150℃
Lead Temperature & Time ………… 260℃(10S)
Ambient Temperature(Ta) ………………… -40℃~ 85℃
Caution: Exceed these limits to damage to the device. Exposure to absolute maximum rating conditions may affect
device reliability.
RECOMMENDED WORK CONDITIONS
Recommended maximum input voltage…………………………………………………………………………………… 12V
Recommended operating junction temperature(Tj)…………………………………………………………………… -20~125℃
Exceptional foBCT1117-12V, the maximum input voltage for BCT1117-12V is 20V.
Thermal Information
Parameter
Package
Rating
Unit
Package thermal
resistance
SOT-223
20
℃/W
TO-252
12.5
℃/W
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3
Ver 1.3
Electrical Characteristics
(CIN=10uF, COUT=10uF, TA = 25℃, unless otherwise specified.)
Symbol
Vref
Parameter
Conditions
Reference
BCT1117-ADJ
voltage
10mA≤Iout≤1A , Vin=3.25V
BCT1117-1.2V
0≤Iout≤1A , Vin=3.2V
BCT1117-1.8V
0≤Iout≤1A , Vin=3.8V
BCT1117-2.5V
Vout
Output
0≤Iout≤1A , Vin=4.5V
voltage
BCT1117-3.3V
0≤Iout≤1A , Vin=5.3V
BCT1117-5.0V
0≤Iout≤1A , Vin=7.0V
BCT1117-12.0V
0≤Iout≤1A , Vin=14V
BCT1117-1.2V
Iout=10mA, 2.7V≤Vin≤10V
BCT1117-ADJ
Iout=10mA, 2.75V≤Vin≤12V
BCT1117-1.8V
Iout=10mA, 3.3V≤Vin≤12V
△Vout
Line
BCT1117-2.5V
regulation
Iout=10mA, 4.0V≤Vin≤12V
BCT1117-3.3V
Iout=10mA, 4.8V≤Vin≤12V
BCT1117-5.0V
Iout=10mA, 6.5V≤Vin≤12V
BCT1117-1.8V
Iout=10mA, 13.5V≤Vin≤20V
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Min
Typ
Max
Unit
1.225
1.25
1.275
V
1.176
1.2
1.224
V
1.764
1.8
1.836
V
2.45
2.5
2.55
V
3.234
3.3
3.366
V
4.9
5
5.1
V
11.76
12
12.24
V
0.1
0.2
%/V
0.1
0.2
%/V
0.1
0.2
%/V
0.1
0.2
%/V
0.1
0.2
%/V
0.1
0.2
%/V
0.1
0.2
%/V
4
Ver 1.3
(CONTINUED)
Symbol
Parameter
Conditions
Min
BCT1117-1.2V
Vin =2.7V, 10mA≤Iout≤1A
BCT1117-ADJ
Vin =2.75V, 10mA≤Iout≤1A
BCT1117-1.8V
Vin =3.3V, 10mA≤Iout≤1A
△Vout
Load
BCT1117-2.5V
regulation
Vin =4.0V, 10mA≤Iout≤1A
BCT1117-3.3
Vin =4.8V, 10mA≤Iout≤1A
BCT1117-5.0
Vin =6.5V, 10mA≤Iout≤1A
BCT1117-12.0V
Vin =13.5V, 10mA≤Iout≤1A
Vdrop
Ilimit
Imin
Iq
IAdj
Ichange
ΔV/ΔT
Typ
Max
Unit
10
30
mV
10
30
mV
10
30
mV
10
30
mV
10
30
mV
10
30
mV
10
30
mV
Dropout
Iout =100mA
1.23
1.3
V
voltage
Iout=1A
1.3
1.5
V
Current limit
Vin-Vout=2V;Tj =25℃
Minimum
1
A
BCT1117-ADJ
2
10
mA
BCT1117-1.2V,Vin=10V
2
5
mA
BCT1117-1.8V,Vin=12V
2
5
mA
Quiescent
BCT1117-2.5V,Vin=12V
2
5
mA
Current
BCT1117-3.3V,Vin=12V
2
5
mA
BCT1117-5.0V,Vin=12V
2
5
mA
BCT1117-12.0V,Vin=20V
2
5
mA
55
120
uA
0.2
10
uA
load current
Adjust pin
BCT1117-ADJ
current
Vin=5V,10mA≤Iout≤1A
Iadj change
BCT1117-ADJ
Vin=5V,10mA≤Iout≤1A
Temperature
±100
ppm
coefficien
θJC
Thermal
SOT-223
20
resistance
TO-252
10
℃/W
Note1: All test are conducted under ambient temperature 25°C and within a short period of time 20ms
Note2: Load current smaller than minimum load current of BCT1117-ADJ will lead to unstable or oscillation output.
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5
Ver 1.3
DETAILED DESCRIPTION
BCT1117 is a series of low dropout voltage, three terminal regulators. Its application circuit is very simple:
the fixed version only needs two capacitors and the adjustable version only needs two resistors and two
capacitors to work. It is composed of some modules including start-up circuit, bias circuit, bandgap,
thermal shutdown, current limit, power transistors and its driver circuit and so on.
The thermal shut down modules can assure chip and its application system working safety when the
junction temperature is larger than 140°C.
The bandgap module provides stable reference voltage, whose temperature coefficient is compensated
by careful design considerations. The temperature coefficient is under 100 ppm/°C. And the accuracy of
output voltage is guaranteed by trimming technique.
TYPICAL APPLICATION
BCT1117 has an adjustable version and six fixed versions (1.2V, 1.8V, 2.5V, 3.3V, 5V and 12V)
Fixed Output Voltage Version
Application circuit of BCT1117 fixed version
1) Recommend using 10uF tan capacitor as bypass capacitor (C1) for all application circuit.
2) Recommend using 10uF tan capacitor to assure circuit stability.
Adjustable Output Voltage Version
Application Circuit of BCT1117-ADJ
The output voltage of adjustable version follows the equation: Vout=1.25×(1+R2/R1)+IAdj×R2. We
can ignore IAdj because IAdj (about 50uA) is much less than the current of R1 (about 2~10mA).
1) To meet the minimum load current (>10mA) requirement, R1 is recommended to be 125ohm or
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6
Ver 1.3
lower. As BCT1117-ADJ can keep itself stable at load current about 2mA, R1 is not allowed to be higher
than 625ohm.
2) Using a bypass capacitor (CADJ) between the ADJ pin and ground can improve ripple rejection.
This bypass capacitor prevents ripple from being amplified as the output voltage is increased. The
impedance of CADJ should be less than R1 to prevent ripple from being amplified. As R1 is normally in the
range of 100Ω~500Ω, the value of CADJ should satisfy this equation: 1/(2π×fripple×CADJ)