Page 1
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2A Ultra Low Dropout Linear Regulator GS7105
Features
Maximum 2A Low-Dropout Voltage Regulator
Ultra Low Dropout Voltage
Typically 220mV at 2A Output Current
High Output Accuracy over Line, Load and
Temperature
Build-In Soft-Start
Excellent startup under load from 0 to 2A
Power-On-Reset Monitoring on Both V
VIN Pins
Power-OK Output function
Foldback over Current Protection and
Thermal shutdown
0.1μA (typ) Shutdown Supply Current
Low ESR Output Capacitor(Multi-layer Chip
Capacitors (MLCC)) Applicable
DD
and
General Description
The GS7105 can deliver up to 2A of continuous
output current with a typical dropout voltage of
only 220mV using internal n-channel MOSFETs.
The linear regulator uses a separate VDD supply
to power the control circuitry and drive the Inter-
nal n-channel MOSFETs. The output voltage is
adjustable from 0.8V to the voltage that is very
close to VIN.
The GS7105 allows the use of low-ESR ceramic
capacitor as low as 10uF. Moreover the IC
provide good performance on both line transient
response and load transient response.
The GS7105 provides foldback over current limit
and thermal shutdown to prevent the linear
regulator from damage. Built-in soft-start
Vout Pull Low Resistance when Disable
PSOP-8, TDFN10-3x3
Green Product (RoHS, Lead-Free,
Halogen-Free Compliant)
Applications
Notebook PC Applications
Motherboard Applications
Low Voltage Logic Supplies
Microprocessor and Chipset Supplies
Graphic Cards
Cordless phones
minimizes stress on the input power source by
reducing capacitive inrush current on start-up.
During start-up, POK remain low until the output
reaches 92% of its rating value.
The GS7105 is available in PSOP-8 package or
TDFN10- 3x3 package.
Green Solution Technology Co.,LTD.
Rev.:1.51 1 Sep-15
Page 2
4
3
2
5
1
6
7
8
VDD
VIN
EN
NC
POK
VOUT
FB
GND
VDD
VIN
ON
EN
VOUT
100K
R1
5K
R2
10K
10uF
1uF
10uF
C
(Option)
GS7105
Delay
OTP
Soft
Start
POR
OCP
3
4
2
1
8
7
6
92%*VREF
VIN
VDD
EN
VOUT
POK
FB
GND
Error
AMP
Error
Amplifier
Error
AMP
400K
2A Ultra Low Dropout Linear Regulator GS7105
Typical Application
Figure1 Typical Application of GS7105
Function Block Diagram
Figure 2 Function Block Diagram
Green Solution Technology Co.,LTD.
Rev.:1.51 2 Sep-15
Page 3
Pin No.
Name
I/O type
Pin Function
PSOP8
TDFN10-3x3
1 5 POK
O
Open drain output. Setting high impedance once V
OUT
reaches 92% of its rating voltage
2 6 EN
I
Chip Enable (active high). The device will be shutdown if
this pin is left open.
3
7,8,9
VIN
I
Input Voltage. Large bulk capacitance should be placed
closely to this pin. A 10μF ceramic capacitor is
recommended at this pin.
4
10
VDD
I
Supply voltage for control circuit. A 3V to 5V supply voltage
for control circuit is recommended and supply voltage
should be 1.5V higher than the output voltage.
5 NC
Not connected
6
1,2,3
VOUT
O
Output Voltage. The power output of the device.
7 4 FB
I
Feedback Voltage. This pin is connected to the center tap of
an external resistor divider network to set the output voltage
as V
OUT
= 0.8(R1+R2)/R2.
8
11
GND
I
Ground.
No
Item
Contents
1
Package
SO: PSOP-8(B)
TD: TDFN10-3x3
2
Shipping
R: Tape & Reel
POK
EN
VIN
VDD
GND
FB
VOUT
NC
VOUT
VOUT
VOUT
FB
POK
GND
GND
VDD
VIN
VIN
VIN
EN
PSOP-8
TDFN10-3x3
2. Shipping
1. Package
GS7105PP- R
2A Ultra Low Dropout Linear Regulator GS7105
Pin Configuration
Pin Descriptions
Ordering Information
Example: GS7105 PSOP-8(B) Tape & Reel ordering information is “GS7105SO-R”
Green Solution Technology Co.,LTD.
Rev.:1.51 3 Sep-15
Page 4
Parameter
Symbol
Limits
Units
Supply Voltage
VIN
-0.3 < VIN< 6
V
Control Voltage
VDD
-0.3 < VDD< 6
V
Output Voltage
V
OUT
-0.3 < V
OUT
< 5
V
EN, FB, POK
-0.3 < (V
EN, VFB, VPOK
) < 6
V
Package Power Dissipation at TA≦25°C
P
D_PSOP-8
1333
mW
Package Power Dissipation at TA ≦25°C
P
D_TDFN10-3x3
1670
mW
Junction Temperature
TJ
- 45 ~ 150
°C
Storage Temperature
T
STG
- 65 ~ 150
°C
Lead Temperature (Soldering) 10S
T
LEAD
260
°C
ESD (Human Body Mode) (Note 2)
V
ESD_HBM
2K
V
ESD (Machine Mode) (Note 2)
V
ESD_MM
200
V
Parameter
Symbol
Limits
Units
Thermal Resistance Junction to Ambient
θ
JA_PSOP-8
75
°C/W
Thermal Resistance Junction to Case
θ
JC_PSOP-8
12
°C/W
Thermal Resistance Junction to Ambient
θ
JA_TDFN10-3x3
60
°C/W
Thermal Resistance Junction to Case
θ
JC_TDFN10-3x3
5
°C/W
Parameter
Symbol
Limits
Units
Supply Voltage
VIN
1.0 < VIN< Min{5.2,VDD}
V
Control Voltage
VDD
3.0 < VDD< 5.5
V
Junction Temperature
TJ
- 40 ~ 125
°C
2A Ultra Low Dropout Linear Regulator GS7105
Absolute Maximum Rating (Note 1)
Thermal Information (Note 3)
Recommend Operating Condition (Note 4)
Green Solution Technology Co.,LTD.
Rev.:1.51 4 Sep-15
Page 5
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Units
Supply Voltage Section
VDD Operation Voltage
Range
VDD
V
DD
Input Range, V
OUT=VREF
3.0 5.5
V
VIN Operation Voltage
Range
VIN
V
IN
Input Range, V
OUT=VREF
1.0
Min{5.2
,VDD}
V
Quiescent current
IQ
VDD=VIN=VEN=5V,I
OUT
=0A,
V
OUT=VREF
1.0
1.5
mA
VDD Input current
I
VDD
VDD=VIN=VEN=5V, I
OUT
=0A,
V
OUT=VREF
1.0
1.5
mA
Control Input Current
in Shutdown
I
VDD_SD
VDD=VIN=5.0V, I
OUT
=0A,
VEN=0V
0.1 2 uA
VDD POR Threshold
V
DDRTH
2.4
2.7 3 V
VDD POR Hysteresis
0.15
0.2 V
VIN POR Threshold
V
INRTH
0.55
0.75
0.95
V
VIN POR Hysteresis
0.13
0.20 V
Output Voltage
Reference Voltage
V
REF
I
OUT
=1mA, V
OUT=VREF
0.784
0.8
0.816
V
Output Voltage
Accuracy
-2.0
+2.0
%
Line Regulation (VDD)
△ V
LINE_VDD
VDD=4V to 5V, I
OUT
=1mA,
V
OUT=VREF
, VIN=2V
0.03
0.2
%
Line Regulation (VIN)
△ V
LINE_IN
VIN=1.2V to 5V, I
OUT
=1mA,
V
OUT=VREF
0.01
0.1
%
Load Regulation
(Note 5)
△ V
LOAD
I
OUT
=1mA to 3 A, V
OUT=VREF
0.1
1.5
%
V
OUT
Pull Low
Resistance
VDD=VIN=5.0V, VEN=0V
130 Ω
Dropout Voltage
Dropout Voltage
(Note 6)
V
DROP
V
OUT=VREF
, I
OUT
=1A
110
210
mV
V
OUT
= V
REF
, I
OUT
=2A
220
320
mV
Protection
Current Limit
ILIM
VDD=VIN=VEN=5V, V
OUT
= V
REF
3.5 A
Short Circuit Current
I
FOLDBACK
V
OUT
<0.2V
100 mA
Thermal Shutdown
Temperature
TSD
TJ Rising
160
°C
2A Ultra Low Dropout Linear Regulator GS7105
Electrical Characteristics
(VIN= V
+0.5V, VEN=VDD=5V, CIN=C
OUT
=10uF, TA=TJ=25°C )
OUT
Green Solution Technology Co.,LTD.
Rev.:1.51 5 Sep-15
Page 6
Thermal Shutdown
Returned Temperature
110
°C
Enable
EN
Threshold
Logic-Low
Voltage
VDD=5V
0.6
V
Logic-High
Voltage
VDD=5V
1.4
V
EN Input Bias Current
IEN
VEN=5V
12
20
uA
Power OK
POK Rising Threshold
V
REF
Rising
92 %
POK Hysteresis
V
REF
falling
8
%
POK Sink Capability
I
PGOOD
=1mA
0.2
0.4
V
POK Delay
-40°C ~125°C
1.3 mS
2A Ultra Low Dropout Linear Regulator GS7105
Note 1.Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the
device. These are for stress ratings. 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 for extended periods may remain possibility to
affect device reliability.
Note 2.Devices are ESD sensitive. Handling precaution recommended.
Note 3.θ
is measured in the natural convection at TA=25°C on a high effective thermal conductivity test
JA
board (4 Layers, 2S2P) of JEDEC 51-7 thermal measurement standard. The case point of θJC is
on the expose pad for PSOP-8 package.
Note 4.The device is not guaranteed to function outside its operating conditions.
Note 5. Regulation is measured at constant junction temperature by using a 2ms current pulse. Devices
are tested for load regulation in the load range from 1mA to 2A.
Note 6. The Dropout voltage is defined as VIN-V
, which is measured when V
OUT
is 0.98*V
OUT
OUT(NORMAL)
.
The Dropout voltage is measured at constant junction temperature by using a 2ms current pulse.
Green Solution Technology Co.,LTD.
Rev.:1.51 6 Sep-15
Page 7
VIN Line Transient Response
V
OUT
=1.2V, I
OUT
=0
VIN Line Transient Response
V
OUT
=1.2V,I
OUT
=1A
VDD Line Transient Response
V
OUT
=1.2V,I
OUT
=0
VDD Line Transient Response
V
OUT
=1.2V,
IOUT
=1A
Load Transient Response
V
OUT
=1.2V, C
OUT
=22uF
Power On from VIN
VDD=5V, V
OUT
=1.6V, C
OUT
=(1000+10)uF, no load
2A Ultra Low Dropout Linear Regulator GS7105
Typical Characteristics
Green Solution Technology Co.,LTD.
Rev.:1.51 7 Sep-15
Page 8
Power On from VDD
VDD=5V, V
OUT
=1.6V, C
OUT
=(1000+10)uF, no load
Turn On from EN
VEN=5V, V
OUT
=1.6V, C
OUT
=(1000+10)uF, no load
Turn On from EN
VEN=5V, V
OUT
=1.6V, C
OUT
=10uF, I
load
=2A
Turn On from EN
VEN=5V, V
OUT
=1.6V, C
OUT
=10uF, R
load
=0.8Ω
Output Short Current
Output Short Current
2A Ultra Low Dropout Linear Regulator GS7105
Green Solution Technology Co.,LTD.
Rev.:1.51 8 Sep-15
Page 9
Dropout Voltage vs. Output Current
Shutdown Current vs. Input Voltage
Quiescent Current vs. Input Voltage
On Resistance vs. Temperature
Quiescent Current vs. Temperature
FB Voltage vs. Temperature
0
50
100
150
200
250
300
0 400 800 1200 1600 2000
Dropout Voltage (mV)
Output Current (mA)
2A Ultra Low Dropout Linear Regulator GS7105
Green Solution Technology Co.,LTD.
Rev.:1.51 9 Sep-15
Page 10
Cout
Rbottom
Ceramic
≥10uF
≥0.1KΩ
EL
1000uF
≥100KΩ
2A Ultra Low Dropout Linear Regulator GS7105
Application Information
Enable
The GS7105 has a dedicated enable pin(EN).
When the EN pin is in the logic low (VEN<0.6V),
the regulator will be turned off, reducing the
supply current to less than 1uA.
When the EN pin is in the logic high (VEN>1.4V),
the regulator will be turned on and undergoes a
new soft-start cycle. Left open, the EN pin is
pulled down by a internal resistor to shut down
the regulator.
Power-on-Reset
The GS7105 features a power-on-reset control
through monitor both input voltages to prevent
wrong operations. Only after the two supply
voltages exceed their rising POR threshold
Current Limit
The GS7105 contains a foldback over current
protection function. It allows the output current to
reach the maximum value of 3.5A. Then further
decreases in the load resistance reduce both the
load current and the load voltage. The main
advantage of foldback limiting is less power
dissipation in the pass transistor under shorted-
load conditions. During startup, the current limit
value is set to a high value, thus GS7105 can
operate in full load condition. After startup, the
current limit value is set to a normal value, so the
pass transistor can be protected well.
Thermal-Shutdown Protection
Thermal Shutdown protects GS7105 from ex-
voltages, the regulator is to be initiated and starts
up.
POK
The POK pin is an open-drain output, and can be
connects to V
or other rail through an external
OUT
pull-up resistor. As the output voltage arrives 92%
of normal output voltage, an internal delay
function starts to perform a delay time and then
output the POK pin high to indicate the output is
OK. As the output voltage falls below the falling
Power-OK threshold or one of the two supply
voltages falls below it’s falling POR threshold, the
POK pin will output low immediately without a
delay time.
Build-In Soft-Start
An internal soft-start function controls rise rate of
the output voltage to limit the current surge at
cessive power dissipation. If the die temperature
exceeds 160°C , the pass transistor is shut off.
50°C of hysteresis prevents the regulator from
turning on until the die temperature drops to
110°C .
Output Capacitor selection
The GS7105 is designed to employ ceramic
output capacitors as low as 10uF; if employ EL
output capacitor as large as 1000uF, feedback
resistance(Rbottom) should be larger than 100K
ohm(Table 2). Place the capacitors physically as
close as possible to the device with wide and
direct PCB traces. Capacitor ESR should be less
than 50mohm.
start-up. The typical soft-start interval is about
1.5mS.
Table 1 Cout capacitor vs. Rbottom resistance
Green Solution Technology Co.,LTD.
Rev.:1.51 10 Sep-15
Page 11
Vout
FB
R2
R1
Coption
Cout
Vout
GS7105
V
OUT
R1
C
OPTION
0.8V ~ 1.6V
0 ~ 10 KΩ
470pF~1nF
1.6V ~ 2.4V
10 KΩ ~ 20 KΩ
100pF~500pF
2.4V ~ 3.6V
20 KΩ ~ 30 KΩ
20pF~300pF
2A Ultra Low Dropout Linear Regulator GS7105
Feedback Network
Figure 3 shows the feedback network. The
suggested design procedure is to choose
R2=10KΩ and then calculate R2 using the
following formula: R1=(V
OUT
/V
-1)*R2.
REF
keep the junction temperature below the
maximum operation junction temperature 125°C
for maximum reliability.
The power dissipation definition in device is:
PD = (VIN − V
OUT
) x I
+ VDD x IQ
OUT
The maximum power dissipation can be
calculated as:
P
Where T
D(MAX)
= ( T
J(MAX)
− TA ) / θJA
J(MAX)
is the maximum operation junction
temperature 125°C, TA is the ambient
Figure 3. Feedback Network
C
can improve transient response, and
OPTION
recommend value as follow:
temperature and the θJA is the junction to ambient
thermal resistance.
The thermal resistance θJA for PSOP-8 package
is 75°C/W on the standard JEDEC 51-7 (4 layers,
2S2P) thermal test board. The copper thickness
is 2oz. The maximum power dissipation at TA =
Table 2 R1 vs. C
OPTION
Input Capacitor selection
Bypass VIN to ground with a 10uF or greater
capacitor. Bypass VDD to ground with a 1uF
capacitor for normal operation in most appli-
cations. Ceramic, tantalum or aluminum elec-
trolytic capacitors may be selected for input
capacitor. However ceramic capacitors are
recommended due to their significant cost and
space savings. Place the capacitors physically as
close as possible to the device with wide and
direct PCB traces.
Power Dissipation and Layout Considerations
Although internal thermal limiting function is
integrated in GS7105, continuously keeping the
junction near the thermal shutdown temperature
may possibly affect device reliability. For
continuous operation, it is highly recommended to
25°C can be calculated by following formula:
P
= (125°C − 25°C) / (75°C/W) = 1.33W
D(MAX)
(SOP-8 Exposed Pad on the minimum layout)
The thermal resistance θJA for TDFN10-3x3
package is 60°C/W on the standard JEDEC 51-7
(4 layers, 2S2P) thermal test board. The
maximum power dissipation at TA = 25°C can be
calculated by following formula:
P
= (125°C − 25°C) / (60°C/W) = 1.67W
D(MAX)
The thermal resistance θJA of PSOP-8 is
determined by the package design and the PCB
design. Copper plane under the exposed pad is
an effective heat sink and is useful for improving
thermal conductivity. As shown in Figure 3, the
amount of copper area to which the PSOP-8 is
mounted affects thermal performance. When
mounted to the standard PSOP-8 pad (Figure
3.a), θJA is 75°C/W. Adding copper area of pad
under the PSOP-8 Figure 3.b) reduces the θJA to
54°C/W. Even further, increasing the copper area
Green Solution Technology Co.,LTD.
Rev.:1.51 11 Sep-15
Page 12
T thermal Resistance
JA
(C/W)
0 10 20 30 40 50 60 70
Copper Area (mm 2)
90
80
70
60
50
40
0 25 50 75 100 125 150
Ambient Temperature (°C)
Power Dissipation (mW)
3500
3000
2500
2000
1500
1000
500
TDFN10-3x3
PSOP-8
2A Ultra Low Dropout Linear Regulator GS7105
of pad to 70mm2 (Figure 3.c) reduces the θJA to
49°C/W.
and thermal resistance JA. For GS7105
packages, the Figure 5 of derating curves allows
the designer to see the effect of rising ambient
temperature on the maximum power allowed.
Figure 3 (a). Minimum Footprint,
Figure 3 (b). Copper Area = 30mm2,
= 75C/W
JA
= 54C/W
JA
Figure 3 (c). Copper Area = 70mm2,
Figure 3. JA vs. Different Cooper Area Layout Design
= 49C/W
JA
And Figure 4 shows a curve for the θJA of the
PSOP-8 package for different copper area sizes
using a typical PCB with 2oz copper in still air.
Figure 5 Derating Curve for Packages
The maximum power dissipation depends on
operating ambient temperature or fixed T
Green Solution Technology Co.,LTD.
Rev.:1.51 12 Sep-15
Figure 4
vs. Copper Area
JA
J(MAX)
Page 13
2A Ultra Low Dropout Linear Regulator GS7105
Green Solution Technology Co.,LTD.
Rev.:1.51 13 Sep-15
Page 14
E1
c
DETAIL A
L
E
H
D1
b
e
D
A
A1
A3
DETAIL A
1
4
5
8
Symbol
Dimensions in
Millimeters
Min.
Max.
A
1.30
1.80
A1 - 0.15
A3
1.25
-
b
0.31
0.51
c
0.17
0.25
e
1.27 REF.
D
4.70
5.10
E
3.80
4.00
D1
3.1 REF.
E1
2.3 REF.
H
5.80
6.20
L
0.40
1.27
θ
0o
8o
2A Ultra Low Dropout Linear Regulator GS7105
Package Dimensions, PSOP-8(B)
Note:
1. Min.: Minimum dimension specified.
2. Max.: Maximum dimension specified.
3. REF.: Reference. Normal/Regular dimension specified for reference.
Green Solution Technology Co.,LTD.
Rev.:1.51 14 Sep-15
Page 15
A3
Top view
10
Bottom view
Pin #1 ID Options
Note:The configuration of the Pin#1 identifier is
optional,but must be located within the zone indicated.
A1
Side view
D
E
E1
D1
L
e
b
6
7
8
9
5
4
3
2
1
10
E1
D1
L
e
b
6
7
8
9
5
4
3
2
1
10
E1
D1
L
e
b
6
7
8
9
5
4
3
2
1
A
Symbol
Dimensions in
Millimeters
Min.
Max.
A
0.70
0.80
A1
0.00
0.05
A3
0.203 REF.
b
0.18
0.30
e
0.50 REF.
D
2.90
3.10
E
2.90
3.10
D1
2.30 REF.
E1
1.65 REF.
L
0.30
0.50
2A Ultra Low Dropout Linear Regulator GS7105
Package Dimensions, TDFN10-3x3
Note:
1. Min.: Minimum dimension specified.
2. Max.: Maximum dimension specified.
3. REF.: Reference. Normal/Regular dimension specified for reference.
Green Solution Technology Co.,LTD.
Rev.:1.51 15 Sep-15
Page 16
2A Ultra Low Dropout Linear Regulator GS7105
DISCLAIMERS
Please read the notice stated in this preamble carefully before Admission e accessing any contents of the
document attached. Admission of GStek’s statement therein is presumed once the document is released
to the receiver.
Notice:
Firstly, GREEN SOLUTION CO., LTD. (GStek) reserves the right to make corrections, modifications, enhancements, improvements, and
other changes to its information herein without notice.. And the aforesaid information does not form any part or parts of any quotation or
contract between GStek and the information receiver.
Further, no responsibility is assumed for the usage of the aforesaid information. GStek makes no representation that the interconnect
of its circuits as described herein will not infringe on exiting or future patent rights and other intellectual property rights, nor do the
descriptions contained herein express or imply that any licenses under any GStek patent right, copyright, mask work right, or other GStek
intellectual property right relating to any combination, machine, or process in which GStek products or services are used.
Besides, the product in this document is not designed for use in life support appliances, devices, or systems where malfunction of this
product can reasonably be expected to result in personal injury. GStek customers’ using or selling this product for use in such applications
shall do so at their own risk and agree to fully indemnify GStek for any damage resulting from such improper use or sale.
At last, the information furnished in this document is the property of GStek and shall be treated as highly confidentiality; any kind of
distribution, disclosure, copying, transformation or use of whole or parts of this document without duly authorization from GStek by prior
written consent is strictly prohibited. The receiver shall fully compensate GStek without any reservation for any losses thereof due to its
violation of GStek’s confidential request. The receiver is deemed to agree on GStek’s confidential request therein suppose that said receiver
receives this document without making any expressly opposition. In the condition that aforesaid opposition is made, the receiver shall
return this document to GStek immediately without any delay.
Green Solution Technology Co.,LTD.
Rev.:1.51 16 Sep-15
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