1.5A Low Dropout Voltage Regulator
Adjustable & Fixed Output
Fast Response
CLM2815
FEATURES
Adjustable Output . . . . . . . . . . . . . . . . . . . Down To 1.2V
Fixed Output Voltages. . . . . . . . . . . . . . 1.5, 2.5, 3.3, 5.0V
Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5A
Low Dropout Voltage. . . . . . . . . . . . . . . . . . . . . 1.1V Typ.
Extremely Tight Load And Line Regulation
Current & Thermal Limiting
Standard 3-Terminal Low Cost TO-220, TO-263 &
TO-252
Similar To Industry Standard LT1086/LT1586
APPLICATIONS
Powering VGA & Sound Card
Power PC
TM
TM
Supplies
SMPS Post-Regulator
High Efficiency "Green" Computer Systems
High Efficiency Linear Power Supplies
Portable Instrumentation
Constant Current Regulators
Adjustable Power Supplies
Battery charger
PRODUCT DESCRIPTION
Calogic's CLM2815 is a low power 1.5A adjustable and fixed
voltage regulator. The device requires 2 external resistors to
set the output for the adjustable version. The CLM2815 has
been designed for low voltage applications that require lower
dropout and faster transient responses. The device is well
suited to power a low voltage microprocessor that requires a
low dropout and a fast transient response to regulate from
+2.85V to 3.8V. The device is adjustable to 1.2 volts.
The product family offers full protection against over-current
faults, reversed input polarity, reversed load insertion, and
positive and negative transient voltage. On-chip trimming
adjusts the reference voltage to 1% while delivering 1.5A
output current.
Encapsulated in a 3-pin TO-220, TO-263 & TO-252 packages.
ORDERING INFORMATION
Part
Package
Temperature Range
CLM2815AU
TO-220
-45 to +125
o
C
CLM2815AAU
TO-220
-45 to +125
o
C
CLM2815AU-X
TO-220
-45 to +125
o
C
CLM2815AAU-X
TO-220
-45 to +125
o
C
CLM2815AT
TO-263 (DD)
-45 to +125
o
C
CLM2815AAT
TO-263 (DD)
-45 to +125
o
C
CLM2815AT-X
TO-263 (DD)
-45 to +125
o
C
CLM2815AAT-X
TO-263 (DD)
-45 to +125
o
C
CORPORATION
PIN CONNECTIONS
1E-30A
FRONT VIEW
V
IN
V
OUT
CL
M
2
815
PLASTIC TO-220 PACKAGE
V
ADJ/GND
1E-29A
PLASTIC TO-263 PACKAGE
FRONT VIEW
CLM2
8
1
5
3
2
1
V
ADJ/GND
V
OUT
V
IN
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
ABSOLUTE MAXIMUM RATINGS
Lead Temp. (Soldering, 10 Seconds) . . . . . . . . . . . . . . 300
o
C
Storage Temperature Range . . . . . . . . . . . . -65
o
C to +150
o
C
Operating Junction Temperature Range
CLM2815 Control Section . . . . . . . . . . . . . . -45
o
C +125
o
C
CLM2815 Power Transistor . . . . . . . . . . . . . . -45
o
C +150
o
C
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10V
Input to Output Voltage Differential . . . . . . . . . . . . . . . . . . 10V
Maximum Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . 2A
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
ELECTRICAL CHARACTERISTICS (Note 1) at I
OUT
= 10mA, T
A
= 25
o
C, unless otherwise specified.
PARAMETER
TYP
CLM2815A
CLM2815
UNITS
CONDITIONS
MIN
MAX
MIN
MAX
1.5V VERSION
Output Voltage (Note 2)
1.5
1.5
1.485
1.470
1.515
1.530
1.470
1.455
1.530
1.545
V
CLM2815-1.5V, 0
I
OUT
1.5A, 2.75V
V
IN
7V
2.5V VERSION
Output Voltage (Note 2)
2.5
2.5
2.475
2.450
2.525
2.550
2.450
2.425
2.550
2.575
V
CLM2815-2.5V, 0
I
OUT
1.5A, 3.5V
V
IN
7V
3.3V VERSION
Output Voltage (Note 2)
3.3
3.3
3.270
3.240
3.330
3.360
3.230
3.201
3.370
3.399
V
CLM2815-3.3V, 0
I
OUT
1.5A, 4.75V
V
IN
7V
5.0V VERSION
Output Voltage (Note 2)
5.0
5.0
4.95
4.90
5.05
5.10
4.900
4.850
5.100
5.150
V
CLM2815-5.0V, 0
I
OUT
1.5A, 5.5V
V
IN
7V
ALL VOLTAGE OPTIONS
Reference Voltage
(V
REF
)
1.250
1.225
1.270
1.225
1.270
V
V
IN
7V, P
P
MAX
1.5V
(V
IN
- V
OUT
)
5.75V, 10mA
I
OUT
I
OUT
5.75
Min. Load Current (Note 3)
5
10
10
mA
1.5V
(V
IN
- V
OUT
)
5.75V
Line Regulation
(
V
REF
(I
IN
))
0.005
0.2
0.2
%
2.75V
V
IN
7V, I
OUT
= 10mA, T
J
= 125
o
C (Note 3)
0.005
0.2
0.2
V
IN
7V, I
OUT
= 0mA, T
J
= 125
o
C (Note 2)
Load Regulation
(
V
REF
(I
OUT
))
0.05
0.3
0.3
%
10mA
I
OUT
1.5A, (V
IN
- V
OUT
) =
3V, T
J
= 25
o
C
0.05
0.3
0.3
0
I
OUT
1.5A, V
IN
= 7V, T
J
= 125
o
C (Note 2)
Dropout Voltage
1.1
1.2
1.2
V
V
REF
= 1%, I
OUT
= 1.5A (Note 3), I
OUT
1.5A (Note 2)
Current Limit
(I
OUT(MAX)
)
2.5
1.7
1.7
A
V
IN
= 7V
1.5A
1.4V
(V
IN
- V
OUT
)
(Note 3)
Long Term Stability
0.3
(Note 2)
1
1
%
T
A
= 125
o
C, 1000 Hrs.
Thermal Regulation
(
V
OUT
(PWR))
0.01
0.020
0.020
%/W
T
A
= 25
o
C, 20ms pulse
Temperature Stability
(
V
OUT
(T))
0.25
%
Output Noise, RMS
0.003
%V
O
10Hz to 10kHz, T
A
= 25
o
C
Thermal Resistance
3.0
60
3.0
60
3.0
60
3.0
60
3.0
60
3.0
60
o
C/W
TO-220
Junction to Tab
Junction to Ambient
DD Package
Junction to Tab
Junction to Ambient
The Bold specifications apply to the over full operating temperature range.
Note 1: Changes in output voltage due to heating effects are covered under the specification for thermal regulation.
Note 2: Fixed version only.
Note 3: Adustable version only.
CLM2815
CORPORATION
APPLICATION HINTS
The Calogic Semiconductor CLM2815 incorporates protection
against over-current faults, reversed load insertion, over
temperature operation, and positive and negative transient
voltage. However, the use of an output capacitor is required
in order to insure the stability and the performances.
Stability
The output capacitor is part of the regulator's frequency
compensation system. Either a 220
F aluminum electrolytic
capacitor or a 47
F solid tantalum capacitor between the
output terminal and ground guarantees stable operation for all
operating conditions.
However, in order to minimize overshoot and undershoot, and
therefore optimize the design, please refer to the section
'Ripple Rejection'.
Ripple Rejection
Ripple rejection can be improved by adding a capacitor
between the ADJ pin and ground. When ADJ pin bypassing is
used, the value of the output capacitor required increases to
its maximum (220
F for an aluminum electrolytic capacitor, or
47
F for a solid tantalum capacitor). If the ADJ pin is not
bypass, the value of the output capacitor can be lowered to
100
F for an electrolytic aluminum capacitor or 15
F for a
solid tantalum capacitor.
However the value of the ADJ-bypass capacitor should be
chosen with respect to the following equation:
C = 1 / ( 6.28
F
R
R
1
)
Where C = value of the capacitor in Farads (select an equal or
larger standard value),
F
R
= ripple frequency in Hz,
R
1
= value of resistor R
1
in Ohms.
If an ADJ-bypass capacitor is used, the amplitude of the
output ripple will be independent of the output voltage. If an
ADJ-bypass capacitor is not used, the output ripple will be
proportional to the ratio of the output voltage to the reference
voltage:
M = V
OUT
/ V
REF
Where M = multiplier for the ripple seen when the ADJ pin is
optimally bypassed.
V
REF
= Reference Voltage
Reducing parasitic resistance and inductance
One solution to minimize parasitic resistance and inductance
is to connect in parallel capacitors. This arrangement will
improve the transient response of the power supply if your
system requires rapidly changing current load condition.
Thermal Consideration
Although the CLM2815 offers some limiting circuitry for
overload conditions, it is necessary not to exceed the
maximum junction temperature, and therefore to be careful
about thermal resistance. The heat flow will follow the lowest
resistance path, which is the Junction-to-case thermal
resistance. In order to insure the best thermal flow of the
component, a proper mounting is required. Note that the case
of the device is electrically connected to the output. In case
the case has to be electrically isolated, a thermally conductive
spacer can be used. However do not forget to consider its
contribution to thermal resistance.
Assuming:
V
IN
= 10V, V
OUT
= 5V, I
OUT
= 1.5A, T
A
= 90
o
C,
CASE
= 1
o
C/W
(no external heat sink, no wind)
Power dissipation under these conditions
P
D
= (V
IN
- V
OUT
)
I
OUT
= 7.5W
Junction Temperature
T
J
= T
A
+ P
D
(
CASE
+
JC
)
For the Control Section
T
J
= 90
o
C + 7.5W
(1
o
C/W + 0.6
o
C/W) = 102
o
C
114
o
C T
JUNCTION MAX
for the control section.
For the Power Section
T
J
= 90
o
C + 7.5W
(1
o
C/W + 1.6
o
C/W) = 104.5
o
C
109.5
o
C T
JUNCTION MAX
for the power transistor.
In both cases reliable operation is insured by adequate
junction temperature.
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
CLM2815
CORPORATION
Output Voltage
Consider Figure 2. The resistance R
1
generates a constant
current flow, normally the specified load current of 10mA.
This current will go through the resistance R
2
to set the overall
output voltage. The current I
ADJ
is very small and constant.
Therefore its contribution to the overall output voltage is very
small and can generally be ignored.
Load Regulation
Parasitic line resistance can degrade load regulation. In order
not to affect the behavior of the regulator, it is best to connect
directly the R
1
resistance from the resistor divider to the case,
and not to the load. For the same reason, it is best to connect
the resistor R
2
to the Negative side of the load.
CORPORATION
CLM2815
CORPORATION
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
FIGURE 3. BASIC ADJUSTABLE REGULATOR
1U-24
CLM2815
R
1
R
2
V
OUT
R PARASITIC LINE
RESISTANCE
P
CONNECT R
TO CASE OF
REGULATOR
CONNECT
R TO
LOAD
1
2
R
L
FIGURE 2. BASIC ADJUSTABLE REGULATOR
1U-23
CLM2815
R
1
R
2
V
OUT
V
OUT
V
REF
I
ADJ
50
m
A
) + I
ADJ
(1 + R
1
/R
2
= V
REF
V
OUT
R
2
CLM2815
CORPORATION
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
TYPICAL APPLICATIONS
1E-37
CLM2815
OUT
ADJ
1.5A CURRENT OUTPUT REGULATOR
V
IN
R
1
C
1
IN
LOAD
1E-38
CLM2815
OUT
ADJ
TYPICAL ADJUSTABLE REGULATOR
OUT
) + I
ADJ
(1 + R
1
/R
2
= V
REF
V
OUT
V
IN
R
2
R
1
C
2
V
C
1
IN
R
2
1U-26
CLM2815
OUT
ADJ
5V REGULATOR WITH SHUTDOWN
OUT
V
IN
5V
IN
+
+
10
m
F
100
m
F
TTL
OUTPUT
1k
1k
121
9
1%
365
9
1%
(NOTE A)
V
IN (MIN)
= (INTENDED V
) + (V
DROPOUT (MAX)
)
NOTE A:
2N3904
1U-25
CLM2815
OUT
ADJ
IMPROVING RIPPLE REJECTION
OUT
V
IN
IN
+
10
m
F
150
m
F
121
9
1%
365
9
1%
(NOTE A)
V
IN (MIN)
= (INTENDED V
) + (V
DROPOUT (MAX)
)
NOTE A:
R
1
R
2
+
10
m
F
C
1
V
OUT
5V
*C IMPROVES RIPPLE REJECTION.
X SHOULD BE - R AT RIPPLE
FREQUENCY.
1
1
C
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