®
RT2515H
2A, Low Input Voltage, Ultra-Low Dropout LDO Regulator
with Enable
General Description
Features
The RT2515H is a high performance positive voltage
regulator designed for use in applications requiring ultralow input voltage and ultra-low dropout voltage at up to 2
amperes. It operates with an input voltage as low as 1.4V,
with output voltage programmable as low as 0.5V. The
RT2515H features ultra low dropout, ideal for applications
where output voltage is very close to input voltage.
Additionally, the RT2515H has an enable pin to further
reduce power dissipation while shutdown. The RT2515H
provides excellent regulation over variations in line, load
and temperature. The RT2515H is available in the SOP-8
(Exposed Pad) package. The output voltage can be set
by an external divider depending on how the FB pin is
configured.
Applications
Ordering Information
Input Voltage as Low as 1.4V
Ultra-Low Dropout Voltage 400mV @ 2A
Over-Current Protection
Over-Temperature Protection
1μ
μA Input Current in Shutdown Mode
Enable Control
RoHS Compliant and Halogen Free
Telecom/Networking Cards
Motherboards/Peripheral Cards
Industrial Applications
Wireless Infrastructure
Set Top Box
Medical Equipment
Notebook Computers
Battery Powered Systems
RT2515H
Package Type
SP : SOP-8 (Exposed Pad-Option 2)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Pin Configuration
(TOP VIEW)
NC
8
Note :
EN
2
Richtek products are :
VIN
NC
3
RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.
GND
ADJ
6
VOUT
5
NC
9
4
GND
7
SOP-8 (Exposed Pad)
Suitable for use in SnPb or Pb-free soldering processes.
Marking Information
RT2515HGSP : Product Number
RT2515H
GSPYMDNN
YMDNN : Date Code
Copyright © 2018 Richtek Technology Corporation. All rights reserved.
DS2515H-03 April 2018
is a registered trademark of Richtek Technology Corporation.
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RT2515H
Typical Application Circuit
RT2515H
3
VIN
VIN
VOUT
6
C1
10µF
Chip Enable
VOUT =
2
0.5(R1+R2)
R2
VOUT
R1
ADJ 7
C2
10µF
R2
EN
GND
8,
9 (Exposed Pad)
(V)
Figure 1. Adjustable Voltage Regulator
Functional Pin Description
Pin No.
Pin Name
Pin Function
1, 4, 5
NC
No internal connection.
Chip enable (Active-High). Pulling this pin below 0.4V turns the regulator off,
reducing the quiescent current to a fraction of its operating value. The device will
be enabled if this pin is left open. Connect to VIN if not being used.
Input voltage. For regulation at full load, the input to this pin must be between
(VOUT + 0.5V) and 6V. Minimum input voltage is 1.4V. A large bulk capacitance
should be placed closely to this pin to ensure that the input supply does not sag
below 1.4V. Also a minimum of 10F ceramic capacitor should be placed directly at
this pin.
2
EN
3
VIN
6
VOUT
Output voltage. A minimum of 10F capacitor should be placed directly at this pin.
7
ADJ
If connected to the VOUT pin, the output voltage will be set at 0.5V. If external
feedback resistors are used, the output voltage will be determined by the resistor
ratio.
Ground. The exposed pad must be soldered to a large PCB and connected to GND
for maximum power dissipation.
8,
GND
9 (Exposed pad)
Functional Block Diagram
RSENSE
VOUT
VIN
VPUMP
-
-
+
+
ADJ
VIN
0.5µA
0.5V
EN
VIN
Thermal
Shutdown
VOUT
+
VIN
-
GND
Reverse Voltage
Shutdown
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Reference
Generator
is a registered trademark of Richtek Technology Corporation.
DS2515H-03 April 2018
RT2515H
Absolute Maximum Ratings
(Note 1)
Supply Voltage, VIN -----------------------------------------------------------------------------------------------------Other I/O Pin --------------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C
SOP-8 (Exposed Pad) --------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2)
SOP-8 (Exposed Pad), θJA ---------------------------------------------------------------------------------------------SOP-8 (Exposed Pad), θJC --------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3)
HBM (Human Body Model) ----------------------------------------------------------------------------------------------
Recommended Operating Conditions
−0.3V to 7V
−0.3V to 6V
2.04W
49°C/W
15°C/W
260°C
150°C
−65°C to 150°C
2kV
(Note 4)
Supply Voltage, VIN ------------------------------------------------------------------------------------------------------ 1.4V to 6V
Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C
Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C
Electrical Characteristics
(VIN = 1.4V to 6V, IOUT = 10μA to 2A, VADJ = VOUT , −40°C ≤ TA ≤ 85°C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
Quiescent Current
IQ
VIN = 3.3V, IOUT = 0A
--
0.7
1.5
mA
Shutdown Current
ISHDN
VIN = 6V, VEN = 0V
--
1.5
10
A
VIN = VOUT + 0.5V, IOUT = 10mA,
TA = 25C
2
--
2
1.4V VIN 6V, IOUT = 10mA
3
--
3
Output Voltage
VOUT
VIN = 1.8V, IOUT = 0.8A, T A = 25C
%
Line Regulation
VLINE
IOUT = 10mA
--
0.2
0.4
%/V
Load Regulation
VLOAD
IOUT = 10mA to 2A
--
0.5
1.5
%
IOUT = 1A, VIN 1.6V
--
120
200
IOUT = 1A, 1.4V < VIN < 1.6V
--
--
400
IOUT = 1.5A, VIN 1.6V
--
180
300
IOUT = 1.5A, 1.4V < VIN < 1.6V
--
--
500
IOUT = 2A, VIN 1.6V
--
240
400
IOUT = 2A, 1.4V < VIN < 1.6V
--
--
600
2.3
3
4.4
Dropout Voltage
Current Limit
VDROP
ILIM
VIN = 3.3V
Copyright © 2018 Richtek Technology Corporation. All rights reserved.
DS2515H-03 April 2018
mV
A
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RT2515H
Parameter
Symbol
Test Conditions
Min
Typ
Max
VIN = 3.3V, VADJ = VOUT,
IOUT = 10mA, TA = 25C
0.495
--
0.505
VIN = 3.3V, VADJ = VOUT,
IOUT = 10mA
0.49
--
0.51
Unit
Feedback
ADJ Reference Voltage
ADJ Pin Current
VADJ
V
IADJ
VADJ = 0.5V
--
20
200
nA
IEN
VEN = 0V, VIN = 6V
--
1
10
A
Logic-High
VIH
VIN = 3.3V
1.6
--
--
Logic-Low
VIL
VIN = 3.3V
--
--
0.4
OTP Trip Level
--
160
--
°C
Hysteresis
--
30
--
°C
Enable
EN Pin Current
EN Threshold
Voltage
V
Over Temperature Protection
Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are
stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in
the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may
affect device reliability.
Note 2. θJA is measured at TA = 25°C on a high effective thermal conductivity four-layer test board per JEDEC 51-7. θJC is
measured at the exposed pad of the package.
Note 3. Devices are ESD sensitive. Handling precaution is recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
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is a registered trademark of Richtek Technology Corporation.
DS2515H-03 April 2018
RT2515H
Typical Operating Characteristics
Quiescent Current vs. Temperature
Reference Voltage vs. Temperature
1.15
0.520
Quiescent Current (mA)
Reference Voltage (V)
0.515
0.510
0.505
VIN = 5V
0.500
VIN = 3.3V
0.495
0.490
0.95
VIN = 5V
0.75
VIN = 3.3V
0.55
0.485
VOUT = 2.52V
0.35
0.480
-50
-25
0
25
50
75
100
-50
125
-25
0
Shutdown Current vs. Temperature
75
100
125
UVLO vs. Temperature
1.20
1.50
1.05
1.40
Logic-High
1.30
VIN = 5V
UVLO (V)
Shutdown Current (µA)1
50
Temperature (°C)
Temperature (°C)
0.90
25
0.75
VIN = 3.3V
1.20
1.10
Logic-Low
0.60
1.00
0.45
0.90
0.30
0.80
VEN = 5V
-50
-25
0
25
50
75
100
125
-50
-25
0
Temperature (°C)
Dropout Voltage vs. Load Current
50
75
100
125
EN Threshold Voltage vs. Temperature
1.3
350
EN Threshold Voltage (V)
300
Dropout Voltage (mV)
25
Temperature (°C)
125°C
250
25°C
200
150
−40°C
100
50
Logic-High
1.2
1.1
1.0
Logic-Low
0.9
0.8
VOUT = 2.5V
VIN = 5V
0.7
0
0
0.5
1
1.5
Load Current (A)
Copyright © 2018 Richtek Technology Corporation. All rights reserved.
DS2515H-03 April 2018
2
-50
-25
0
25
50
75
100
125
Temperature (°C)
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RT2515H
Load Transient Response
Line Transient Response
VOUT
(20mV/Div)
VIN
(1V/Div)
VOUT
(10mV/Div)
IOUT
(1A/Div)
VIN = 3.3V, VOUT = 2.5V, IOUT = 1A to 2A
VIN = 3.3V to 4.3V, VOUT = 2.5V, IOUT = 2A
Time (50μs/Div)
Time (500μs/Div)
Power On from EN
Power Off from EN
VEN
(5V/Div)
VEN
(5V/Div)
VOUT
(2V/Div)
VOUT
(2V/Div)
I IN
(2A/Div)
I IN
(2A/Div)
VIN = 3.3V, VOUT = 2.5V, IOUT = 2A
VIN = 3.3V, VOUT = 2.5V, IOUT = 2A
Time (250μs/Div)
Time (250μs/Div)
PSRR
0
IOUT = 1mA
IOUT = 100mA
IOUT = 300mA
-10
PSRR (dB)
-20
-30
-40
-50
-60
-70
VIN = 3.25V to 3.35V, VOUT = 2.5V
-80
100
1000
10000
100000
1000000
Frequency (Hz)
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is a registered trademark of Richtek Technology Corporation.
DS2515H-03 April 2018
RT2515H
Application Information
The RT2515H is a low voltage, low dropout linear regulator
with an external bias supply input capable of supporting
an input voltage range from 1.4V to 6V with a fixed output
voltage from 1V to 2V in 0.1V increments.
Output Voltage Setting
The RT2515H output voltage is adjustable from 1.4V to
6V via the external resistive voltage divider. The output
voltage is set according to the following equation :
VOUT = VADJ 1+ R1
R2
For ADJ pin noise immunity, the resistive divider total value
of R1 and R2 are suggested not over 100kΩ, where VADJ
is the reference voltage with a typical value of 0.5V.
Feed-Forward Capacitor (CFF)
The RT2515H is designed to be stable without the external
feed-forward capacitor (CFF). However, an external feedforward capacitor between VOUT and ADJ pin is often
adoptd to optimizes the transient, noise, and PSRR
performance. Regarding to the resistance value of the
voltage divider, the recommended CFF values are as below :
CFF = 1nF, for both R1 and R2 are larger than 1kΩ
CFF = 10nF, for both R1 and R2 are smaller than 1kΩ
RT2515H
VIN
VIN
VOUT
VOUT
CIN
COUT
R1
*CFF
EN
ADJ
GND
R2
Figure 2. Application Circuit with CFF
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DS2515H-03 April 2018
Chip Enable Operation
The RT2515H goes into sleep mode when the EN pin is in
a logic low condition. In this condition, the pass transistor,
error amplifier, and band gap are all turned off, reducing
the supply current to only 10μA (max.). The EN pin can
be directly tied to VIN to keep the part on.
UVLO Protection
The RT2515H provides an input Under Voltage Lockout
protection (UVLO). When the input voltage exceeds the
UVLO rising threshold voltage (1.2V typ.), the device
resets the internal circuit and prepares for operation. If
the input voltage falls below the UVLO falling threshold
voltage during normal operation, the device will be shut
down. A hysteresis (140mV typ.) between the UVLO rising
and falling threshold voltage is designed to avoid noise.
Current Limit
The RT2515H contains an independent current limit
circuitry, which monitors and controls the pass transistor's
gate voltage, limiting the output current to 3A (typ.).
CIN and COUT Selection
The RT2515H is designed specifically to work with low
ESR ceramic output capacitor for space saving and
performance consideration. Using a ceramic capacitor with
effective capacitance range from 10μF to 47μF on the
output ensures stability.
The input capacitor must be located at a distance of no
more than 0.5 inch from the input pin of the chip. However,
a capacitor with larger value and lower ESR (Equivalent
Series Resistance) is recommended since it will provide
better PSRR and line transient response. For general
applications, an input capacitor of at least 10μF or greater
is highly recommended.
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RT2515H
Thermal protection limits power dissipation in the
RT2515H. When the operation junction temperature
exceeds 160°C, the OTP circuit starts the thermal
shutdown function and turns the pass element off. The
pass element turns on again after the junction temperature
cools by 30°C.
The RT2515H output voltage will be closed to zero when
output short circuit occurs as shown in Figure 3. It can
reduce the IC temperature and provides maximum safety
to end users when output short circuit occurs.
VOUT Short to GND
VOUT
ILIM
ILIM’
IOUT
IC Temperature
thermal test board. The maximum power dissipation at TA
= 25°C can be calculated by the following formula :
P D(MAX) = (125°C − 25°C) / (49°C/W) = 2.04W for
SOP-8 (Exposed Pad) package
The maximum power dissipation depends on the operating
ambient temperature for fixed T J(MAX) and thermal
resistance, θJA. The derating curve in Figure 4 allows the
designer to see the effect of rising ambient temperature
on the maximum power dissipation.
3.2
Maximum Power Dissipation (W)
Thermal Considerations
Four-Layer PCB
2.8
2.4
2.0
1.6
1.2
0.8
0.4
0.0
0
Figure 3. Short Circuit Protection when Output Short
Circuit Occurs
25
50
75
100
125
Ambient Temperature (°C)
Figure 4. Derating Curve of Maximum Power Dissipation
For continuous operation, do not exceed absolute
maximum junction temperature. The maximum power
dissipation depends on the thermal resistance of the IC
package, PCB layout, rate of surrounding airflow, and
difference between junction and ambient temperature. The
maximum power dissipation can be calculated by the
following formula :
PD(MAX) = (TJ(MAX) − TA) / θJA
where TJ(MAX) is the maximum junction temperature, TA is
the ambient temperature, and θJA is the junction to ambient
thermal resistance.
For recommended operating condition specifications, the
maximum junction temperature is 125°C. The junction to
ambient thermal resistance, θJA, is layout dependent. For
SOP-8 (Exposed Pad) package, the thermal resistance,
θJA, is 49°C/W on a standard JEDEC 51-7 four-layer
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DS2515H-03 April 2018
RT2515H
Outline Dimension
H
A
M
EXPOSED THERMAL PAD
(Bottom of Package)
Y
J
X
B
F
C
I
D
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
4.801
5.004
0.189
0.197
B
3.810
4.000
0.150
0.157
C
1.346
1.753
0.053
0.069
D
0.330
0.510
0.013
0.020
F
1.194
1.346
0.047
0.053
H
0.170
0.254
0.007
0.010
I
0.000
0.152
0.000
0.006
J
5.791
6.200
0.228
0.244
M
0.406
1.270
0.016
0.050
X
2.000
2.300
0.079
0.091
Y
2.000
2.300
0.079
0.091
X
2.100
2.500
0.083
0.098
Y
3.000
3.500
0.118
0.138
Option 1
Option 2
8-Lead SOP (Exposed Pad) Plastic Package
Richtek Technology Corporation
14F, No. 8, Tai Yuen 1st Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789
Richtek products are sold by description only. Customers should obtain the latest relevant information and data sheets before placing orders and should verify
that such information is current and complete. Richtek cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek
product. Information furnished by Richtek is believed to be accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use;
nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent
or patent rights of Richtek or its subsidiaries.
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