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RS7300
600mA Adjustable & Fixed Voltage LDO Linear Regulator
General Description
The RS7300 series is a low‐dropout linear regulator that operates in the input voltage range from +2.4V to +7.0V and
delivers 600mA output current.
The RS7300 is available in two types, fixed output voltage type and adjustable output voltage type. The fixed output
voltage type is preset at an internally trimmed voltage 1.8V, 2.5V, or 3.3V. Other options 1.0V, 1.2V, 1.5V, 1.8V, 2.0V,
2.85V, 3.0V, 3.3V, 3.6V and 5.0V are available by special order only. The output voltage range of the adjustable type is from
1.25V to 5V.
The RS7300 (ADJ type) consists of a 1.25V bandgap reference, an error amplifier, and a P‐channel pass transistor. Other
features include short‐circuit protection and thermal shutdown protection.
The RS7300 (Fixed type) consists of a 0.95V bandgap reference, an error amplifier, and a P‐channel pass transistor. Other
features include short‐circuit protection and thermal shutdown protection. The RS7300 series devices are available in SOT‐
223, SOT‐89 and SOT‐23 packages.
Features
◎
Operating Voltage Range：+2.4V to +7.0V
◎
Output Voltages：+1.0V to +5.0V (0.1V Step) (Fixed),
+1.25V to +5.0V (ADJ Type)
◎
Dropout Voltage：500mV@600mA (Fixed)
◎
Fast Response in Power‐on (Fixed Voltage Only)
◎
Low Current Consumption：60μA (Typ.)
◎
±2% Output Voltage Accuracy (special ±1% highly
accurate), V
OUT
≧1.8V
◎
Low ESR Capacitor Compatible
◎
High Ripple Rejection：55dB (Typ.)
◎
Output Current Limit Protection：1.0A (Typ.)
◎
Short Circuit Protection：200mA (Typ.)
◎
Thermal Overload Shutdown Protection
◎
SOT‐223, SOT‐89 and SOT‐23 Packages
◎
RoHS Compliant and 100% Lead (Pb)‐Free and Green
(Halogen Free with Commercial Standard)
Applications
◎
◎
◎
◎
◎
◎
◎
◎
Battery‐Powered Equipments
Graphic Card, Peripheral Card
PCMCIA & New Card
Mini PCI & PCI‐Express Cards
Digital Still Camera
CDMA/GSM Cellular Handsets
Laptop, Palmtops, Notebook Computers
Portable Information Application
Application Circuits
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September, 2009
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This integrated circuit can be damaged by ESD. Orister Corporation recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more
susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
Pin Assignments
SOT‐23
SOT‐89
SOT‐223
PACKAGE
SOT‐23
PACKAGE
SOT‐89
PACKAGE
SOT‐223
PIN
1
2
3
PIN
1
2
3
PIN
1
2
3
SYMBOL
VIN
VOUT
GND/ADJ
SYMBOL
GND/ADJ
VIN
VOUT
SYMBOL
VOUT
GND/ADJ
VIN
DESCRIPTION
Regulator Input Pin
Regulator Output Pin
Ground Pin or ADJ Pin
DESCRIPTION
Ground Pin or ADJ Pin
Regulator Input Pin
Regulator Output Pin
DESCRIPTION
Regulator Output Pin
Ground Pin or ADJ Pin
Regulator Input Pin
Ordering Information
DEVICE
DEVICE CODE
XX is nominal output voltage (for example, AD=ADJ, 15 = 1.5V, 33 = 3.3V, 285 = 2.85V).
YY is package designator :
N : SOT‐23
M : SOT‐89
SJ : SOT‐223
Z is Lead Free designator :
P: Commercial Standard, Lead (Pb) Free and Phosphorous (P) Free Package
G: Green (Halogen Free with Commercial Standard)
RS7300‐XX YY Z
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September, 2009
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Block Diagram
Absolute Maximum Ratings
Parameter
Input Voltage V
IN
to GND
Output Current Limit, I
(LIMIT)
Junction Temperature
Thermal Resistance
SOT‐89
SOT‐223
SOT‐23
SOT‐89
SOT‐223
SOT‐23
Symbol
V
IN
I
LIMIT
T
J
θ
JA
Ratings
9.0
1.0
+155
180
155
260
550
900
400
‐40 ~ +85
‐55~+150
+260
Units
V
A
o
C
o
C/W
Power Dissipation
P
D
T
OPR
T
STG
‐
mW
o
o
Operating Ambient Temperature
Storage Temperature
Lead Temperature (soldering, 10sec)
C
C
o
C
NOTES：
1
The power dissipation values are based on the condition that junction temperature T
J
and ambient temperature T
A
difference is
100°C.
2
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress
ratings only, and function operation of the device at these or any other conditions beyond those indicated under “recommended
operating conditions” is not implied. Exposure to absolute‐maximum –rated conditions for extended periods may affect device
reliability.
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Electrical Characteristics
(T
A
=25°C, V
IN
=5.0V unless otherwise specified)
Conditions
Min.
Typ.
Max.
Unit
‐
2.4
‐
7.0
V
‐2%
+2%
V
V
IN
=V
OUT
+1.0V, I
OUT
=1mA, V
OUT
≧1.8V
Fixed
V
IN
=V
OUT
+1.0V, I
OUT
=1mA, V
OUT
＜1.8V,
Type
‐35
+35
mV
V
IN
＞2.4V
V
OUT
V
OUT
Output Voltage
‐2%
+2%
V
V
IN
=V
OUT
+1.2V, I
OUT
=1mA, V
OUT
≧1.8V
ADJ
V
IN
=V
OUT
+1.2V, I
OUT
=1mA, V
OUT
＜1.8V,
Type
‐50
+50
mV
V
IN
＞2.4V
I
MAX
Output Current (see NOTE)
600
‐
‐
mA
V
OUT
+1.0V≦V
IN
≦7.0V, V
OUT
≧2.4V
I
OUT
=100mA, V
OUT
>3.0V
‐
100
‐
Dropout Voltage (Fixed Type)
mV
V
DROP
I
OUT
=600mA, V
OUT
>3.0V
‐
500
‐
‐
900
‐
Dropout Voltage (ADJ Type)
I
OUT
=600mA, V
OUT
>3.0V
‐
0.2
0.3
V
OUT
+1.0V≦V
IN
≦7V, I
OUT
=1mA (Fixed Type)
ΔV
LINE
Line Regulation
%/V
‐
‐
0.2
V
OUT
+1.2V≦V
IN
≦5V, I
OUT
=1mA, V
IN
≧2.8V
ΔV
LOAD
Load Regulation
‐
0.01
0.02
%/mA
V
IN
=V
OUT
+1V, 1mA≦I
OUT
≦600mA
I
Q
Ground Pin Current
I
LOAD
=0mA to 600mA, V
IN
=V
OUT
+1.0V
‐
60
‐
uA
I
ADJ
ADJ Pin Current
I
LOAD
=0mA to 600mA, V
IN
=V
OUT
+1.0V
‐
60
‐
uA
PSRR
Ripple Rejection
I
OUT
=30mA, F=1KHz, C
OUT
=3.3uF
‐
55
‐
dB
e
N
Output Noise
I
OUT
=100mA , F=1KHz, C
OUT
=3.3uF
‐
40
‐
uV
(rms)
o
T
SD
Thermal Shutdown Temperature
‐
‐
150
‐
C
o
T
HYS
Thermal Shutdown Hysteresis
‐
‐
20
‐
C
NOTE：Measured using a double sided board with 1” x 2” square inches of copper area connected to the GND pins for “heat spreading”.
Symbol
V
IN
Parameter
Input Voltage
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Detail Description
The RS7300 is a low‐dropout linear regulator. The device provides preset 1.8V, 2.5V and 3.3V output voltages for output
current up to 600mA. Adjustable output voltage and other mask options for special output voltages are also available. As
illustrated in function block diagram, it consists of a 1.25V bandgap (Fixed voltage type is 0.95V) reference, an error amplifier,
a P‐channel pass transistor and an internal feedback voltage divider.
The bandgap reference for adjustable voltage type is connected to the error amplifier, which compares this reference with
the feedback voltage and amplifies the voltage difference. If the feedback voltage is lower than the reference voltage, the
pass transistor gate is pulled lower, which allows more current to pass to the output pin and increases the output voltage. If
the feedback voltage is too high, the pass transistor gate is pulled up to decrease the output voltage.
The output voltage is feed back through an internal resistive divider (or external resistive divider for adjustable output
voltage type) connected to V
OUT
pin. Additional blocks include an output current limiter, thermal sensor, and shutdown logic.
Internal P‐channel Pass Transistor
The RS7300 features a P‐channel MOSFET pass transistor. Unlike similar designs using PNP pass transistors, P‐channel
MOSFETs require no base drive, which reduces quiescent current. PNP‐based regulators also waste considerable current in
dropout when the pass transistor saturates, and use high base‐drive currents under large loads.
The RS7300 does not suffer from these problems and consumes only 60μA (Typ.) of current consumption under heavy loads
as well as in dropout conditions.
Output Voltage Selection
For fixed voltage type of RS7300, the output voltage is preset at an internally trimmed voltage. The first two digits of part
number suffix identify the output voltage (see Ordering Information). For example, the RS7300‐33 has a preset 3.3V output
voltage.
For adjustable voltage type of RS7300, the output voltage is set by comparing the feedback voltage at adjust terminal to the
internal bandgap reference voltage. The reference voltage V
REF
is 1.25V. The output voltage is given by the equation:
V
OUT
=V
REF
x (1+R2/R1)+I
ADJ
x R2
Current Limit
The RS7300 also includes a fold back current limiter. It monitors and controls the pass transistor’s gate voltage, estimates the
output current, and limits the output current within 1.0A.
Thermal Overload Protection
Thermal overload protection limits total power dissipation in the RS7300. When the junction temperature exceeds T
J
=+150°C,
a thermal sensor turns off the pass transistor, allowing the IC to cool down. The thermal sensor turns the pass transistor on
again after the junction temperature cools down by 20°C, resulting in a pulsed output during continuous thermal overload
conditions.
Thermal overload protection is designed to protect the RS7300 in the event of fault conditions. For continuous operation, the
absolute maximum operating junction temperature rating of T
J
=+125°C should not be exceeded.
Operating Region and Power Dissipation
Maximum power dissipation of the RS7300 depends on the thermal resistance of the case and circuit board, the temperature
difference between the die junction and ambient air, and the rate of airflow. The power dissipation across the devices is P =
I
OUT
x (V
IN
‐V
OUT
). The resulting maximum power dissipation is:
(
T
J
−
T
A
) (
T
J
−
T
A
)
P
MAX
=
=
θ
JC
+
θ
CA
θ
JA
Where (T
J
‐T
A
) is the temperature difference between the RS7300 die junction and the surrounding air,
θ
JC
is the thermal
resistance of the package chosen, and
θ
CA
is the thermal resistance through the printed circuit board, copper traces and
other materials to the surrounding air. For better heat‐sinking, the copper area should be equally shared between the V
IN
,
V
OUT
, and GND pins.
DS‐RS7300‐14
September, 2009
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