ETC FAN1537PA

www.fairchildsemi.com
FAN1537
Dual 1A Adjustable/Fixed Low Dropout
Linear Regulators
Features
Description
•
•
•
•
•
•
The FAN1537 provides 2 output voltages: 3.3V, and either
adjustable or 2.5V or 1.8V fixed with 1.0A each output
current capability. These devices have been optimized for
low voltage where transient response and minimum input
voltage are critical.
Low dropout voltage
Load regulation: 0.05% typical
On-chip thermal limiting
SO-8 and 5-lead SPAK and TO-252 DPAK packages
Fixed 3.3V, and adjustable or 2.5V or 1.8V fixed
Stable with low ESR output capacitors
Current limit features protect the outputs against short circuit
currents. On-chip thermal limiting provides protection
against any combination of overload and ambient temperature that would create excessive junction temperatures.
Applications
•
•
•
•
•
•
Hard Disk Drives, CD-ROMs, DVDs
High efficiency linear regulators
Post regulators for switching supplies
ADSL and Cable Modems
5V to 3.3V and 2.5V linear regulators
Motherboard with multiple supplies
The FAN1537 series regulators are available in SO-8 and
5-lead SPAK and TO-252 DPAK power packages.
Typical Applications
FAN1537A
V1
VIN = 5V
+
3.3V at 1.0A
VIN
10µF
NC GND
2.5V at 1.0A
V2
+
+
22µF
22µF
FAN1537B
V1
VIN = 5V
+
VIN
3.3V at 1.0A
1.8V at 1.0A
V2
+
10µF
GND
FB
R1
22µF
+
22µF
R2
REV. 1.0.7 8/17/01
FAN1537
PRODUCT SPECIFICATION
Pin Assignments
1 2 3
8-Lead Plastic SO-8
ΘJC=25°C/W
4 5
5-Lead SPAK
ΘJC=2°C/W
1
2
3
4
5
1
2
3
4
5
V2
1 2 3
V1
GND
GND
5
FB
4
VIN
V2
V2
GND
V1
6
NC
3
FAN1537DB
FRONT VIEW
GND
V1
FAN1537DA
FAN1537DC
FRONT VIEW
VIN
GND
4 5
V1
7
V2
2
FB
GND
NC
VIN
GND
V1
8
V2
1
VIN
VIN
FAN1537PB
FRONT VIEW
NC
GND
TOP VIEW
FAN1537PA
FAN1537PC
FRONT VIEW
5-Lead SPAK
ΘJC=2°C/W
5-Lead Plastic TO-252 DPAK
ΘJC=3°C/W Tab is GND
Pin Descriptions
Pin Name
SO-8
SPAK
DPAK
VIN
1
1
Pin Function
Input supply voltage
NC/FB
2
2
V1
3
4/5
Output #1
For V2 fixed, no connect. For V2 adjustable, feedback voltage.
V2
4
5/4
Output #2
GND
5, 6, 7, 8
3
Ground
Absolute Maximum Ratings
Parameter
Min.
Max.
10
V
0
150
°C
-65
150
°C
300
°C
VIN
Operating Junction Temperature Range
Storage Temperature Range
Lead Temperature (Soldering, 10 sec.)
2
Unit
REV. 1.0.7 8/17/01
PRODUCT SPECIFICATION
FAN1537
Electrical Characteristics (Operating Conditions: VIN ≤ 7V, TJ=25°C unless otherwise specified.)
The • denotes specifications which apply over the specified operating temperature range of 0°C to 125°C junction temperature.
Parameter
Conditions
Output Voltages
10mA ≤ IOUT ≤ 1A
4.75V ≤ VIN ≤ 7V
Min.
Typ.
Max.
•
1.764
1.742
2.450
2.420
3.234
3.200
1.8
1.8
2.500
2.500
3.300
3.300
1.836
1.858
2.550
2.580
3.366
3.400
•
3.2
1.225
1.210
V
•
•
Output Voltage
3.3V Output, VIN = 4.5V, IOUT = 1A
Units
Time to Output Voltages Valid
From VIN ≥ 4.75V
Reference Voltage
10mA ≤ IOUT ≤ 1A
4.75V ≤ VIN ≤ 7V
•
Line Regulation1,2
(both outputs)
4.75V ≤ VIN ≤ 7V, IOUT = 10mA
Load Regulation1,2
(both outputs)
V
5
msec
1.250
1.250
1.275
1.290
V
•
0.005
0.5
%
VIN = 4.75V, 10mA ≤ IOUT ≤ 1A
•
0.05
0.5
%
Dropout Voltage
(3.3V output)
∆VOUT = 1%, IOUT = 1A
•
1.100
1.300
V
Current Limit
(both outputs)
VIN = 5V
•
Minimum Load Current
(both outputs)
4.75V ≤ VIN ≤ 7V
•
Quiescent Current
VIN = 7V
•
Rejection3
Ripple
(both outputs)
f = 120Hz, COUT = 22µF Tantalum,
VIN = 5V, IOUT = 1A
Long-Term Stability
TA = 125°C, 1000 hrs.
RMS Output Noise (% of VOUT) TA = 25°C, 10Hz ≤ f ≤ 10kHz
Thermal Resistance, Junction to SO-8
Case
TO-252 DPAK
SPAK
Thermal Shutdown
Thermal Shutdown Hysteresis
Junction Temperature
1.3
1.5
A
10
mA
6
15
60
mA
dB
0.03
1.0
%
0.003
%
50
°C/W
3
°C/W
2
°C/W
155
°C
10
°C
Notes:
1. See thermal regulation specifications for changes in output voltage due to heating effects. Load and line regulation are
measured at a constant junction temperature by low duty cycle pulse testing.
2. Power dissipation is determined by input/output differential and the output current. Guaranteed maximum output power will
not be available over the full input/output voltage range.
3. ESR = 0.2Ω.
4. For adjust only, VOUT = VREF (1 + R1/R2)
REV. 1.0.7 8/17/01
3
FAN1537
PRODUCT SPECIFICATION
Application Hints
External Capacitors
Like any low-dropout regulator, the FAN1537 requires
external capacitors for stability.
Input Capacitor
An input capacitor of at least 0.47µF is required. The amount
of input capacitance can be increased without limit. This
capacitor must be located at a distance of no more than 0.5"
from the input pin of the device and returned to a clean
analog ground. Any good quality tantalum or ceramic low
ESR capacitor may be used at the input.
Output Capacitor
The FAN1537 is designed specifically to work with Ceramic
or Tantalum capacitors.
A value of 22µF is recommended on each output, but smaller
values can be used.
The value can be increased without limit for better performance such as transient response and noise.
When a Ceramic multilayer capacitor is used, the X7R
dielectric is recommended which holds the capacitance
within ±15%. The output capacitor should be located not
more than 0.5" from the output pins of the device and
returned to a clean analog ground.
4
REV. 1.0.7 8/17/01
PRODUCT SPECIFICATION
FAN1537
Mechanical Dimensions
8-Lead SOIC Package
Inches
Symbol
Millimeters
Min.
Max.
Min.
Max.
A
A1
B
C
D
.053
.004
.013
.0075
.189
.069
.010
1.35
0.10
0.33
0.20
4.80
1.75
0.25
E
e
H
h
L
N
α
ccc
.150
.158
.050 BSC
3.81
4.01
1.27 BSC
.228
.010
.016
5.79
0.25
0.40
.020
.010
.197
.244
.020
.050
8
0.51
0.25
5.00
6.20
0.50
1.27
8
0°
8°
0°
8°
—
.004
—
0.10
8
Notes:
Notes
1. Dimensioning and tolerancing per ANSI Y14.5M-1982.
2. "D" and "E" do not include mold flash. Mold flash or
protrusions shall not exceed .010 inch (0.25mm).
3. "L" is the length of terminal for soldering to a substrate.
4. Terminal numbers are shown for reference only.
5
2
2
5. "C" dimension does not include solder finish thickness.
6. Symbol "N" is the maximum number of terminals.
3
6
5
E
1
H
4
h x 45°
D
C
A1
A
SEATING
PLANE
e
B
REV. 1.0.7 8/17/01
–C–
LEAD COPLANARITY
α
L
ccc C
5
FAN1537
PRODUCT SPECIFICATION
Mechanical Dimensions
5-Lead SPAK
Inches
Symbol
Min.
Millimeters
Max.
Min.
Max.
A
B
b1
b2
0.350
0.360
0.220 NOM
0.268
0.025
0.031
8.89
9.14
5.59 NOM
6.81
0.63
0.79
C
c1
c2
D
E
e
L
L1
L2
L3
R
α
0.080
0.070
0.040
0.050
0.010 NOM
0.295 NOM
0.365
0.375
0.067
2.03
1.78
1.02
1.27
0.25 NOM
7.49 NOM
9.27
9.52
1.72
0.410
0.031
0.350
10.41
0.79
8.89
0.420
0.041
0.360
0.310
0.320
0.010 NOM
0°
8°
Notes:
1. All linear dimensions are in inches (millimeters).
2. This drawing is subject to change without notice.
3. The center lead is in electrical contact with the thermal tab.
4. Dimensions do not include mold protrusions, not to exceed 0.006 (0,15).
Notes
10.67
1.04
9.14
7.87
8.13
0.25 NOM
0°
8°
E
C
A
c1
B
c2
D
L3
L
1
L2
Thermal Ta b
(See Note 3)
5
Seating Plane
b2
e
b1
0.004 (0,10)
0.010 (0,25) M
0.005 (0.13)
0.001 (0.03)
R
L1
Gage Plane
3°–6°
6
REV. 1.0.7 8/17/01
FAN1537
PRODUCT SPECIFICATION
Mechanical Dimensions
5-Lead TO-252 Package
6.00 MIN
A
6.80
6.35
5.64
5.04
1.27
0.50
6.56 MIN
6.30
5.90
6.25
1.02
0.60
3.00 MIN
C
1
3
2
1
5
4
1.27
(0.44)
0.57±0.07
1.27
1.00
3.81
0.69±0.15
1.27
0.25 M A M C
LAND PATTERN RECOMMENDATION
5.08
B
2.40
2.18
0.60
0.40
(5.09)
(4.05)
10.42
9.20
SEE
DETAIL A
3
5
4
2
1
0.10 B
GAGE PLANE
0.60
0.40
0.51
(1.54)
NOTES: UNLESS OTHERWISE SPECIFIED
10°
0°
1.78
1.40
A) ALL DIMENSIONS ARE IN MILLIMETERS.
B) THIS PACKAGE CONFORMS TO JEDEC, TO-252,
ISSUE C, VARIATION AA, DATED NOV. 1999.
0.13 MAX
(2.90)
SEATING PLANE
DETAIL A
(ROTATED 90°)
SCALE: 2X
7
REV. 1.0.7 8/17/01
FAN1537
PRODUCT SPECIFICATION
Ordering Information
Example: FAN1537PA
FAN1537
P
M = SO-8
P = SPAK
D = TO-252 DPAK
A
Table 1
Table 1.
Suffix
V1
V2
A
3.3V
2.5V
B
3.3V
ADJ
C
3.3V
1.8V
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY
PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY
LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER
DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body,
or (b) support or sustain life, and (c) whose failure to
perform when properly used in accordance with
instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.
2. A critical component in any component of a life support
device or system whose failure to perform can be
reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
www.fairchildsemi.com
8/17/01 0.0m 004
Stock#DS30001537
 2001 Fairchild Semiconductor Corporation