ETC B1587D

Bay Linear
Inspire the Linear Power
B1587
4.0A Low Dropout Voltage Regulator
Adjustable & Fix Output
Description
Features
The Bay Linear B1587 is Monolithic low power 4.0A
Adjustable and fixed NPN voltage regulator that are easy to
use with minimum external components. It is suitable for
applications requiring a well-regulated positive output voltage
with low input-output differential voltage requirements and
output voltage 1.5V, 2.5V, 3.0V, 3.3V, or 5V.
The B1587 Outstanding features include full power usage up
to 4.0Amp of load current internal current limiting and thermal
shutdown. Other fixed versions are also available consult with
factory. The B1587 is offer in a new LPDD (Low Profile TO263) package from 4.47 mm (DD) thickness down to only 1.27
mm (LPDD) total thickness.
The B1587 is offered in a 3-pin TO-220, TO-263 & TO-252
packages compatible with other 3 terminal regulators. For 5A
Low dropout Regulator refer to the B1585 data sheet.
•
•
•
•
•
•
•
Adjustable Output Down to 1.2V
Fixed Output Voltages 2.5V, 3.0V 3.3V,
and 5.0V
Output Current of 4.0A
Low Dropout Voltage 1.1V Typ.
Current & Thermal Limiting
Standard 3-Terminal Low Cost TO-220,
D2, D Packages
Similar to industry Standard
LT1085/LT1587/LT1585
Applications
•
•
•
•
•
•
3.3V to 2.5V for Pentium Processor
SMPS Post Regulator
High Efficiency “Green” Computer
Systems
High Efficiency Linear Power Supplies
5V to 3.XXV for Pentium Processor
Battery Charger
Ordering Information
Pin Connection
Devices
B1587T
B1587S
B1587D
B1587J
TO-263-3 (S)
(
Package
Temp.
TO-220
TO-263
TO-252
LPDD
0 °C to 70 °C
0 °C to 70 °C
0 °C to 70 °C
0 °C to 70 °C
TO-252 (D)
Bay Linear
1
2
3
1
ADJ/
GND
Top View
Bay Linear, Inc
2
3
V OU VIN
T
Front View
LPDD (J)
2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
B1587
Absolute Maximum Rating
Parameter
Maximum Input Voltage
Power Dissipation
Thermal Resistance Junction to Case
Thermal Resistance Junction to
Ambient
Operating Junction
Temperature Range
Control Section
Power Transistor
Storage Temperature Range
Lead Temperature (Soldering 10
Sec.)
Symbol
Value
Unit
VIN
PO
θJC
θJA
7
Internally Limited
3
50
V
W
°C/W
°C
TJ
TSTG
TLEAD
0 to 125
0 to 150
-65 to 150
260
Electrical Characteristics
(VIN = 4.75V to 5.25V; IO = 10mA to 4.0Amp, unless otherwise specified)
Parameter
Symbol
Conditions
Output Voltage
VO
0<IOUT<4A, 3.3V<VIN<7V, T= 25 °C
0<IOUT<4A, 3.3V<VIN<7V, Over Temp.
0<IOUT<4A, 4.0V<VIN<7V, T= 25 °C
0<IOUT<4A, 4.0V<VIN<7V, Over Temp.
0<IOUT<4A, 4.5V<VIN<7V, T= 25 °C
0<IOUT<4A, 4.5V<VIN<7V, Over Temp.
0<IOUT<4A, 4.8V<VIN<7V, T= 25 °C
0<IOUT<4A, 4.8V<VIN<7V, Over Temp.
0<IOUT<4A, 6.5V<VIN<7V, T= 25 °C
0<IOUT<4A, 6.5V<VIN<7V, Over Temp.
VIN<7V, 1.5V<VIN<5.75, 10Ma<Iout<4Amp
MIN
TYP
MAX
UNIT
1.485
1.475
2.475
2.460
2.970
2.950
3.267
3.247
4.950
4.920
1.238
1.230
1.5
V
Reference Voltage
Vref
Line Regulation (1)
REG (line)
IO = 10mA, VIN =5V, T= 25 °C
0.04
1.515
1.525
2.525
2.540
3.030
3.050
3.333
3.353
5.050
5.080
1.262
1.270
0.2
Load Regulation (1)
REG (LOAD)
IO = 10mA, VIN =5V, T= 25 °C
0.08
0.40
T= 25 °C, IOUT=3A
T= 25 °C, IOUT=4A
1.0
1.1
5
5
5
0.5
0.003
75
3.0
60
3.0
60
1.1
1.3
10
Dropout Voltage
VD
Minimum load Current
Current Limit
Ground Pin Current
Temperature Stability
Thermal Regulation
Ripple Rejection
Thermal Resistance
Imin
IS
IQ
TS
RA
-
(Vin-Vout)=3V
VIN =5V
IO = 10mA, VIN =5V
T= 25 °C, 30ms pulse
T= 25 °C, VIN =5V
TO-220
Junction to Tab
Junction to Ambient
DD Package
Junction to Tab
Junction to Ambient
3
60
2.5
3.0
3.3
5.0
1.250
10
3.0
60
3.0
60
V
%
V
mA
A
mA
%
%/W
dB
°C/W
Note: Output Switch tests are performed under pulsed conditions to minimize power dissipation
Bay Linear, Inc
2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
B1587
APPLICATION HINTS
The Bay Linear B1587 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 220µF
aluminum electrolytic capacitor or a 47µF 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 (220µF
for an aluminum electrolytic capacitor, or 47µF for
a solid tantalum capacitor). If the ADJ pin is not
bypass, the value of the output capacitor can be
lowered to 100µF for an electrolytic aluminum
capacitor or 15µF 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 * FR * R1 )
Where C
= value of the capacitor in Farads
(select an equal or larger standard value),
FR = ripple frequency in Hz,
R1 = value of resistor R1 in Ohms.
If an ADJ-bypass capacitor is use, 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 = VOUT / VREF
Where M = multiplier for the ripple seen when
the ADJ pin is optimally bypassed.
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 B1587 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:
VIN = 10V, VOUT = 5V, IOUT = 4A, TA = 90°C, θCASE=
1°C/W (no external heat sink, no wind)
Power dissipation under these conditions
PD = (VIN – VOUT) * IOUT = 15W
Junction Temperature
TJ = TA + PD * (θCASE+ θJC)
For the Control Section
TJ = 90°C + 15W*(1°C/W + 0.6°C/W) = 114°C
114°C < TJUNCTION MAX for the control section.
For the Power Section
TJ = 90°C + 15W*(1°C/W + 1.6°C/W) = 129°C
129°C < TJUNCTION MAX for the power transistor.
In both case reliable operation is insured by adequate
junction temperature.
VREF = Reference Voltage
Bay Linear, Inc
2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
B1587
Basic Adjustable Regulator
BAY
B1587
V OU
T
V OU
T
V REF
I
R1
This current will go through the resistance R2 to set
the overall output voltage. The current IADJ is very
small and constant. Therefore its contribution to the
overall output voltage is very small and can generally
be ignored
Load Regulation
ADJ
50µA
R2
VOUT = V REF * ( 1 + R2/R1) + IADJ * R2
Fig.2 Basic Adjustable Regulator
Parasitic line resistance can degrade load regulation.
In order not to affect the behavior of the regulator, it
is best to connect directly the R1 resistance from the
resistor divider to the case,
and not to the load. For the same reason, it is best to
connect the resistor R2 to the Negative side of the
load.
Output Voltage Output Voltage
Output Voltage
VOUT
Consider Figure 2. The resistance R1 generates a
constant current flow, normally the specified load
current of 10mA
BAY
B1587
RP Parasitic Line
Resistance
Connect R1 to
Case of Regulator
R1
RL
R2
Connect R2 to Load
Fig.3 Basic Adjustable Regulator
Bay Linear, Inc
2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
B1587
VIN
BAY
B1587
IN
OUT
VIN
C1
BAY
B1587
IN
ADJ
VOUT
OUT
C2
C1
R1
ADJ
R1
LOAD
R2
VOUT = VREF (1 + R2) + IADJ R2
R1
Fig 5. Typical Adjustable Regulator
Fig.4 4A Current Output Regulator
(Note A)
VIN
IN
+
10µF
BAY
B1587
5V
OUT
VOUT
VIN
ADJ
BAY
B1587
R1
R2
+
121Ω
1%
+
+
10µF
150µF
365Ω
1%
5V
OUT
ADJ
121Ω
1%
*C1 improves ripple rejection. XC
should be ~ R1 at ripple frequency.
IN
(Note A)
C1
10µF*
TTL
Output
100µF
1k
2N3904
1k
365Ω
1%
Note A: VIN (MIN) = ( Intended VOUT ) + ( V DROPOUT (MAX) )
Note A: VIN (MIN) = ( Intended VOUT ) + ( V DROPOUT (MAX)
)
Fig. 6
Bay Linear, Inc
Improving Ripple Rejection
Fig.7
5V Regulator with Shutdown
2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
B1587
TYPICAL CHARACTERISTICS
Bay Linear, Inc
2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com
B1587
-B-
-A-
E
b2
A
A1
C1
L2
A
4
SEATING
PLANE
D
1
2
L3
L1
3
H
L
-C-
b
.010 M
A M
c
b1
3 PLCS
C
A
8
e
e1
NOTES
D1
1.
2.
3.
4.
Refer To Applicable Symbol List.
Dimensions And Tolerancing Per Ansi Y14.5m - 1982.
Lead Dimension Uncontrolled in 3L.
Tab Contour Optional Within Dim. 2b& L2 And E1 & D1
5. D1 & E1 Establishes A Minimum Mounting Surface for Terminal 4.
6. L is the Termal Length for Soldering.
7. Controlling Dimension: Inch
8. 2 Mils Suggested For Postive Contact At Mounting.
E1
TERM 4
BACK VIEW A-A
Bay Linear, Inc
S
Y
M
B
O
L
MIN
MAX
MIN
MAX
A
0.086
0.094
2.184
2.3876
A1
0.035
0.045
0.889
1.143
MM
INCHES
b
0.025
0.035
0.635
0.889
b1
0.300
0.045
7.620
1.143
b2
0.205
0.215
5.207
5.461
c
0.018
0.023
0.457
0.5842
c1
0.018
0.023
0.457
0.5842
D
0.235
0.245
5.969
6.223
D1
0.170
-
4.318
-
E
0.250
0.265
6.350
6.731
E1
0.170
-
4.318
-
e
0.098
e1
0.180
N
O
T
E
4
4,5
4,5
2.489
4.572
H
0.370
0.410
9.398
10.414
L
0.020
-
0.508
-
L1
0.025
0.040
0.635
1.016
L2
0.035
0.050
0.889
1.270
4
L3
0.045
0.060
1.143
1.524
3
2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
6
www.baylinear.com
B1587
0.405
(10.287
±
±
0.005
0.127)
0.176 ± 0.005 (4.470
0.050 ± 0.002 (1.270
0.055 (1.397)
0.356
(9.042
±
±
±
±
0.127)
0.051)
0.005
0.127)
0.600 +- 0.025
(15.24 ± 0.635)
0.100 ± 0.010
(2.540 ± 0.254)
0.103 BSC
(2.616)
0.050 (1.270)
0.032 +- 0.001
(0.813 +- 0.025)
0.015
(0.381
++-
0.003
0.074)
0° 8°
Advance Information- These data sheets contain descriptions of products that are in development. The specifications are based on the engineering calculations,
computer simulations and/ or initial prototype evaluation.
Preliminary Information- These data sheets contain minimum and maximum specifications that are based on the initial device characterizations. These limits are
subject to change upon the completion of the full characterization over the specified temperature and supply voltage ranges.
The application circuit examples are only to explain the representative applications of the devices and are not intended to guarantee any circuit
design or permit any industrial property right to other rights to execute. Bay Linear takes no responsibility for any problems related to any
industrial property right resulting from the use of the contents shown in the data book. Typical parameters can and do vary in different
applications. Customer’s technical experts must validate all operating parameters including “ Typical” for each customer application.
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Bay Linear products are not authorized for and should not be used within life support systems which are intended for surgical
implants into the body to support or sustain life, in aircraft, space equipment, submarine, or nuclear facility applications without
the specific written consent of Bay Linear President.
Bay Linear, Inc
2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556
www.baylinear.com