Eorex EP1117-FB 1a low dropout linear regulator Datasheet

eorex
EP1117
1A Low Dropout Linear Regulator
Features
Description
• Guaranteed Output Voltage Accuracy within 2%
• Fast Transient Response
• Load Regulation: 0.1% Typ.
• Line Regulation: 0.03% Typ.
• Low Dropout Voltage: 1.1V Typ. at IOUT =1A
• On-chip Thermal Limiting: 150°C Typ.
• Adjustable Output: 1.25~10.7V
• Standard 3-pin SOT-223 and TO252 Power
Packages
The EP1117 is a low dropout three-terminal
adjustable or fixed-voltage regulator with 1A
output current capability. The EP1117 is available
in an adjustable version, with output ranging from
1.25V to 10.7V and fixed output voltages of 1.8V,
2.5V, 3.3V and 5.0V. Dropout voltage is
guaranteed at a maximum of 1.3V at 1A. On-chip
thermal limiting provides protection against any
combination of overload that would create
excessive junction temperatures. The EP1117 is
available in the industry standard 3-pin the low
profile surface mount SOT-223 and TO-252
power packages.
Applications
• PC peripheral
• Low Voltage Logic Supplies
• Post Regulator for Switching Power Supply
Typical Application
Fixed Mode Regulator
1.25V to 10.7V Adjustable Regulator
VOUT
VIN
VIN
VOUT
EP1117
10uF
R1
120Ω
FB
R2
120Ω
⎛
⎝
VOUT= VREF × ⎜1 +
100uF
R2 ⎞
⎟
R1 ⎠
VREF =1.25V
R1≒100Ω~200Ω
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EP1117
Pin Assignment
Ordering Information
Pin Description
Pin
Name
Function
1
FB/GND
A resistor divider from this pin to the Vout pin and ground sets the
output voltage. (Ground only for Fixed-Mode)
2
VOUT
The output of the regulator. A minimum of 10uF capacitor (0.15Ω ≤
ESR ≤ 20Ω) must be connected from this pin to ground to insure
stability.
VIN
The input pin of regulator. Typically a large storage capacitor (0.15Ω
≤ ESR ≤ 20Ω) is connected from this pin to ground to insure that the
input voltage does not sag below the minimum dropout voltage
during the load transient response. This pin must always be 1.3V
higher than Vout in order for the device to regulate properly.
3
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EP1117
Absolute Maximum Rating (Note 1)
Symbol
Item
Rating
VI
Input Voltage
TJ
Operating Junction Temperature Range
Control Section
Power Transistor
TSTG
Storage Temperature Range
(Note 2)
Units
15
V
0 ~ +125
0 ~ +150
°C
-65 ~ +150
°C
TL
Lead Temperature (Soldering, 10s)
+260
°C
Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired.
Note 2: The values here show the absolute maximum rating, and for normal usage please refer the test
condition in Electrical Characteristics Table.
Electrical Characteristics (Note 3)
Unless otherwise noted, these specifications apply over CIN = 10μF, COUT = 10μF, and TA=0°C to 70°C.
Typical values refer to TA=25°C.
Symbol
VREF
VOUT
REGLINE
Parameter
Min.
Typ.
Max.
Units
TJ=0°C ~125°C,
10mA≤IOUT≤1A,
1.4V≤(VIN -VOUT) ≤10.75V
1.225
1.250
1.275
V
EP1117-18
TJ=0°C ~125°C,
0≤IOUT≤1.5A, 3.25V≤VIN ≤9V
1.764
1.800
1.836
EP1117-25
TJ=0°C ~125°C,
0≤IOUT≤ 1A, 3.95V≤VIN≤9V
2.450
2.500
2.550
EP1117-33
TJ=0°C ~125°C,
0≤IOUT≤1A, 4.75V≤VIN ≤12V
3.235
3.300
3.365
EP1117-50
TJ=0°C ~125°C,
0≤IOUT≤1A, 6.5V≤VIN ≤12V
4.900
5.000
5.100
EP1117-adj
IOUT=10mA, 1.5V≤
(Note4)
(VIN -VOUT)≤10.75V
0.03
0.2
EP1117-18
IOUT=0A,
(Note4)
3.25V≤VIN≤9V
1
6
EP1117-25
IOUT=0A,
(Note4)
3.95V≤VIN≤9V
1
6
EP1117-33
IOUT=0A,
(Note4)
4.75V≤VIN≤12V
1
6
EP1117-50
IOUT=0A,
(Note4)
6.5V≤VIN≤12V
1
10
Reference Voltage
Output
Voltage
Line
Regulation
Conditions
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EP1117
Electrical Characteristics (Continued) (Note 3)
Unless otherwise noted, these specifications apply over CIN = 10μF, COUT = 10μF, and TA=0°C to 70°C.
Typical values refer to TA=25°C.
Symbol
REGLOAD
VD
ILIMIT
Parameter
Load
Regulation
Conditions
Min.
Typ.
Max.
Units
%
EP1117
(VIN -VOUT)=3V,
(Note4)
0≤IOUT≤1A
0.1
0.4
EP1117-18
VIN=3.25V,
(Note4)
0≤IOUT≤1A
1
10
EP1117-25
VIN=3.95V,
(Note4)
0≤IOUT≤1A
1
10
EP1117-33
VIN=4.75V,
(Note4)
0≤IOUT≤1A
1
10
EP1117-50
VIN=6.5V,
(Note4)
0≤IOUT≤1A
1
15
1
1.05
1.1
1.1
1.2
1.3
mV
Dropout Voltage
IOUT=100mA
(Note5)
IOUT=500mA
IOUT=1A
Current Limit
(VIN -VOUT)=5V, TJ=25°C
1.1
V
A
FB Pin Current
(VIN -VOUT)=3V, IOUT=10mA
60
120
μA
∆IFB
FB Pin Current Change
10mA≤IOUT≤1A,
1.4V≤(VIN -VOUT)≤10.75V
0.2
5
μA
IO
Minimum Load Current
(VIN -VOUT)=10.75V
5
10
mA
Ripple Rejection
fRIPPLE=120Hz, VRIPPLE=
1VP-P, (VIN -VOUT)=3V
TR
Thermal Regulation
TJ=25°C, 30ms Pulse
TS
Temperature Stability
LS
Long-Term Stability
TJ=125°C, 1000Hrs
VN
RMS Output Noise
TJ=25°C, 10Hz≤F≤10KHz,
(% of VOUT)
θth
Thermal Resistance
Junction to case, at Tab
junction to ambient
θJA
Thermal
Resistance
OT
Over Temperature Point
IFB
PSRR
SOT-223
TO-252
(Note6)
Junction-to-Ambient (No
heat sink ;No air flow)
60
75
0.01
dB
0.02
%/W
0.5
%
0.3
%
0.003
%
15
°C/W
117
92
150
°C/W
°C
Note 3: 100% production test at +25°C. Specifications over the temperature range are guaranteed by design
and characterization.
Note 4: See thermal regulation specifications for changes in output voltage due to heating effects. Load line
regulations are measured at a constant junction temperature by low duty cycle pulse testing.
Note 5:Dropout voltage is specified over the full output current range of the device. Dropout voltage is
defined as the minimum input/output differential measured at the specified output current. Test
points and limits are also shown on the Dropout Voltage Curve.
Note 6: Minimum load current is defined as the minimum output current required to maintain regulation.
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Typical Performance Characteristics
Functional Block Diagram
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Output Voltage
The EP1117 develops a 1.25V reference voltage between the output and the FB terminal. By placing a
resistor between these two terminals, a constant current is caused to flow through R1 and down through
R2 to set the overall output voltage. Normally this current is chosen to be the specified minimum load
current of 10mA. For fixed voltage devices R1 and R2 are included in the device.
⎛
⎝
VOUT= VREF × ⎜1 +
R2 ⎞
⎟ +IFBR2
R1 ⎠
Figure 1-Basic Adjustable Regulator
Load Regulation
When the adjustable regulator is used, load regulation will be limited by the resistance of the wire
connecting the regulator to the load. The datasheet specification for load regulation is measured at the
output pin of the EP1117. Best load regulation is obtained when the top of the resistor divider (R1) is tied
directly to the output pin of the device, not to the load. For fixed voltage devices, the top of R1 is
internally connected to the output, and the ground pin can be connected to low side of the load. If R1
were connected to the load, RP is multiplied by the divider ratio, the effective resistance between the
regulator and the load would be: RP×(1+R2/R1), where RP is Parasitic Line Resistance.
Rp
Parasitic
Line Resistance
VIN
VIN
VOUT
EP1117
FB
R1
Connect
R1 to Case
RL
R2
Connect
R2 to Load
Figure 2-Connections for Best Load Regulation
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EP1117
Input Capacitor
An input capacitor of 10μF or greater is recommended. Tantalum or aluminum electrolytic capacitors can
be used for bypassing. Larger Values will improve ripple rejection by bypassing the input to the regulator.
Output Capacitor
The EP1117 requires an output capacitor to maintain stability and improve transient response. The
EP1117 output capacitor selection is dependent upon the ESR (equivalent series resistance) of the
output capacitor to maintain stability. When the output capacitor is 10μF or greater, the output capacitor
should have an ESR less than 1Ω. This will improve transient response as well as promote stability. A
low-ESR solid Tantalum capacitor works extremely well and provides good transient response and
stability over temperature. Aluminum electrolytes can also be used, as long as the ESR of the
capacitor is less than 1Ω. The value of the output capacitor can be increased without limit. Higher
capacitance values help to improve transient response and ripple rejection and reduce output noise.
Ripple Rejection
The curves for Ripple Rejection were generated using an adjustable device with the FB pin bypassed.
With a 22μF bypassing capacitor 75dB ripple rejection is obtainable at any output level. The impedance
of the FB pin capacitor, at the ripple frequency, should be<R1. R1 is normally in the range of 100Ω-200Ω.
The size of the required FB pin capacitor is a function of the input ripple frequency. At 120Hz, with
R1=100Ω, the FB pin capacitor should be 13μF. For fixed voltage devices, and adjustable devices
without a FB pin capacitor, the output ripple will increase as the ratio of the output voltage to the
reference voltage (VOUT/VREF).
Thermal Considerations
The EP1117 regulators have thermal protection to limit junction temperature to 150ºC. However, device
functionality is only guaranteed to a maximum junction temperature of +125ºC. A heat sink may be
required depending on the maximum power dissipation and maximum ambient temperature of the
application. Figure 3 and 4 show for the SOT-223 and TO-252 the measured values θ(JA) for different
copper area sizes using a 2 layers, 1.6mm, and 6Sq. cm FR-4 PCB with 2oz. copper and a ground plane
layer on the backside area used for heat sinking. It can be used as a rough guideline in estimating
thermal resistance. Both the SOT-223 and TO-252 packages use a copper plane on the PCB and the
PCB itself as a heat sink. To optimize the heat sinking ability of the plane and PCB, solder the tab of the
package to the plane.
Figure 3-θ(JA) vs copper area for SOT-223 package
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EP1117
Figure 4-θ(JA) vs copper area for TO-252 package
The thermal resistance for each application will be affected by thermal interactions with other
components on the board. Some experimentation will be necessary to determine the actual value.
The power dissipation of EP1117 is equal to: PD = (VIN - VOUT) × IOUT
Maximum junction temperature is equal to: TJUNCTION = TAMBIENT + (PD × θ(JA))
Note: TJUNCTION must not exceed 125°C
Safe Operation Area
2.80
2.95
3.10
2.50
2.65
2.35
2.05
2.20
1.75
1.90
1.45
1.60
1.00
1.15
1.30
0.85
Output Current (mA)
Using the experiment result of previous Thermal Consideration (choose the one with 1.5cm*1.5cm
polygene area) and θ(JA)=50°C/W spec, the safe operation area of EP1117 in SOT-223 and TO-252
packages can be obtained as Figure 5.
Figure 5-Safe Operation Area of EP1117 in SOT-223 and TO-252 packages
(Limited by Power Dissipation with TJUNCTION < 125°C)
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EP1117
Package Description
SOT-223 (Reference JEDEC Registration SOT-223)
D
B1
H
E
K
e
e1
A
A1
α
L
c
β
B
DIM
MILLIMETERS
INCHES
MIN.
NOM.
MAX.
MIN.
NOM.
MAX.
A
1.50
−
1.80
−
0.070
A1
0.02
−
0.08
0.059
0.001
−
0.003
B
0.60
−
0.80
0.023
−
0.031
B1
2.90
3.10
0.113
−
0.121
c
0.28
−
−
0.32
0.011
6.30
6.70
0.246
3.30
−
3.70
0.129
−
−
−
0.012
−
D
E
e
2.30 REF.
e1
4.60 REF.
0.261
0.144
0.090 REF.
0.179 REF.
H
6.70
−
7.30
0.261
−
0.285
L
0.91
−
1.10
0.035
−
0.043
K
1.50
−
2.00
0.059
−
0.078
α
0°
−
10°
0°
−
10°
β
13°
13°
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EP1117
Package Description (Continued)
TO-252
D
b
L2
E
L1
b1
e
e1
A1
L
H
c
A
Seating Plane
DIM
MILLIMETERS
MIN.
NOM.
c1
INCHES
MAX.
MIN.
NOM.
MAX.
A
2.18
2.29
2.40
0.094
0.89
−
1.14
0.086
0.035
0.090
A1
−
0.045
b
5.20
5.35
5.50
0.205
0.211
0.217
b1
0.61 TYP.
0.024 TYP.
c
0.45
0.52
0.58
0.018
0.020
0.023
c1
0.45
0.52
0.58
0.018
0.020
0.023
D
6.35
6.58
6.80
0.250
0.259
0.268
E
5.40
5.57
6.20
0.213
0.219
0.244
e
2.28 REF.
e1
4.57 REF.
0.090 REF.
0.180 REF.
H
9.00
9.70
10.40
0.354
L
0.51
−
−
0.020
−
−
L1
0.64
0.83
1.02
0.025
0.033
0.040
L2
0.88
−
1.27
0.035
−
0.050
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