FOSLINK FSP3122DE 150khz 3a pwm buck dc/dc converter Datasheet

150KHZ 3A PWM BUCK DC/DC CONVERTER
FSP3122
„
FEATURES
„
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Output voltage: 3.3V, 5.0V, 12V, and adjustable
output version
Adjustable version output voltage range:1.23V to
37V±4%
150KHz±15% fixed switching frequency
Voltage mode non-synchronous PWM control
Thermal-shutdown and current-limit protection
ON/OFF shutdown control input
Operating voltage can be up to 40V
Output load current: 3A
Low power standby mode
Built-in switching transistor on chip
TO220-5L,TO252-5L and TO263-5L packages
„
APPLICATIONS
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Simple High-efficiency step-down regulator
On-card switching regulators
Positive to negative converter
„
PIN CONFIGURATION
The FSP3122 series are monolithic IC that design for
a step-down DC/DC converter, and own the ability of
driving a 3A load without additional transistor
component. Due to reducing the number of external
component, the board space can be saved easily.
The external shutdown function can be controlled by
logic level and then come into standby mode. The
internal compensation makes feedback control have
good line and load regulation without external design.
Regarding protected function, thermal shutdown is to
prevent over temperature operating from damage,
and current limit is against over current operating of
the output switch. The FSP3122 series operates at a
switching frequency of 150 KHz thus allowing smaller
sized filter components than what would be needed
with lower frequency switching regulators. Other
features include a guaranteed ±4% tolerance on
output voltage under specified input voltage and
output load conditions, and ±15% on the oscillator
frequency. The output version included fixed 3.3V,
5V, 12V, and an adjustable type. The packages are
available in a standard 5-lead TO-220 package,
5-lead TO252 package
and a 5-lead TO-263
package.
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(1) TO220-5L
GENERAL DESCRIPTION
(2) TO252-5L
(Top View)
(Top View)
5 SD
5
SD
4 FB
4
FB
3 GND
3
GND
2 OUTPUT
2
OUTPUT
1 VIN
1
VIN
Metal Tab GND
Metal Tab Gnd
(3) TO263-5L
(Top View)
5
SD
4
FB
3
GND
2
OUTPUT
1
VIN
Symbol
1
2
3
4
5
Name
Vin
Output
Gnd
FB
SD
Descriptions
Operating Voltage Input
Switching Output
Ground
Output Voltage Feedback Control
ON/OFF Shutdown
Metal Tab Gnd
1/10
2007-6-12
150KHZ 3A PWM BUCK DC/DC CONVERTER
FSP3122
„
BLOCK DIAGRAM
SD
5
1 VIN
220mV
1.235V
Reference
2.5V
Regulator
Start up
+
Current
Source
bias
220mV
Comp
-
Comp
+
+
Amp
FB 4
-
Frequency
compensation
-
3A
Sw itch
Pre-driver
Comp
+
2 OUTPUT
150KHz
OSC.
„
3 GND
ABSOLUTE MAXIMUM RATINGS
Symbol
VCC
VSD
VFB
VOUT
PD
TST
TOP
VOP
2/10
Thermal
Limit
Paramrter
Supply Voltage
ON/OFF Pin input Voltage
Feedback Pin Voltage
Output Voltage to Ground
Power Dissipation
Storage Temperature
Operating Temperature
Operating Voltage
Rating
+45
-0.3 to +25
-0.3 to +25
-1
Internally Limited
-65 to +150
-40 to +125
+4.5 to +40
Unit
V
V
V
V
W
℃
℃
V
2007-6-12
150KHZ 3A PWM BUCK DC/DC CONVERTER
FSP3122
„
ELECTRICAL CHARACTERISTICS (ALL OUTPUT VOLTAGE VERSIONS)
Unless otherwise specified, VIN=12V for 3.3V,5V, adjustable version and VIN=24V for the 12V version. ILOAD=0.5A
Symbol
Paramrter
Conditions
Min.
Typ.
Max.
Unit
VFB=1.3V(Adjustable
50
40
nA
IB
Feedback bias current
version only)
100
127
150
173
FOSC
Oscillator frequency
KHz
110
173
IOUT=3A
1.16
1.4
V
VSAT
Saturation voltage
no outside circuit
VFB=0V force driver on
Max.Duty Cycle(ON)
VFB=0V force driver on
100
%
DC
0
Min.Duty Cycle(OFF)
VFB=12V force driver off
Peak current
3.6
6.9
A
ICL
Current limit
no outside circuit
VFB=0V force driver on
no outside circuit
Output
50
µA
Output=0
VFB=12V force driver off
IL
leakage
current
Output=-1
VIN=40V
5
30
mA
IQ
Quiescent Current
VFB=12V force driver off
7.8
10
mA
Standby Quiesient
ON/OFF Pin=5V
ISTBY
85
200
µA
Current
VIN=40V
VIL
VIH
IH
IL
θJC
θJA
„
ON/OFF pin logic input
threshold voltage
ON/OFF pin logic input
current
ON/OFF pin input
current
Thermal Resistence
Thermal Resistence
With copper area of
approximately 3 in2
Low(regultaor ON)
1.4
High(regultaor OFF)
6
15
0.02
5
µA
VLOGIC=0.5V(ON)
TO220-5L
TO263-5L
10
2.5
3.5
30
Junction
to case
Junction
to ambient
℃/W
℃/W
28
30
ELECTRICAL CHARACTERISTICS (CONTINUED)
FSP3122-ADJ
FSP3122-3.3V
FSP3122-5V
FSP3122-12V
Symbol
Parameter
VFB
Output Feedback
η
Efficiency
VOUT
Output voltage
η
Efficiency
VOUT
Output voltage
η
Efficiency
VOUT
Output voltage
Conditions
4.5V≤VIN≤40V
0.2A≤ILOAD≤3A
VOUT programmed for
3V
VIN =12V, ILOAD =3A
5V≤VIN≤40V
0.2A≤ILOAD≤3A
VIN =12V,
ILOAD =3A
7V≤VIN≤40V
0.2A≤ILOAD≤3A
VIN =12V,
ILOAD =3A
15V≤VIN≤40V
0.2A≤ILOAD≤3A
Typ.
Limit
Unit
1.23
1.193/1.18
1.267/1.28
V
VMIN
VMAX
72
3.3
3.168/3.135
3.432/3.465
72
5
4.8/4.75
5.2/5.25
79
12
11.52/11.4
12.48/12.6
90
η
Efficiency
VIN =15V, ILOAD =3A
Specifications with boldface type are for full operating temperature range, the other type are for TJ=25ºC.
3/10
V
2.0
VLOGIC=2.5V(OFF)
TO252-5L
TO220-5L
TO263-5L
TO252-5L
0.6
2007-6-12
%
V
VMIN
VMAX
%
V
VMIN
VMAX
%
V
VMIN
VMAX
%
150KHZ 3A PWM BUCK DC/DC CONVERTER
FSP3122
„
TYPICAL PERFORMANCE CHARACTERISTICS
Normalized Output Voltage
Switch Saturation Voltage
VIN=20V
1.0
ILOAD=3A
Normalixed at TJ=25℃
0.5
0
-0.5
-1.0
SATURATION VOLTAGE(V)
OUTPUT VOLTAGE CHANGE(%)
1.5
1.60
1.40
1.00
1
0.80
2
0.60
3
0.5
0 25 50 75 100 125
-50 -25
JUNCTION TEMPERATURE(℃)
ILOAD=3A
1.2
1.0
0.8
ILOAD=1A
155
150
145
140
135
130
0.6
50 75 100 125
0 25
-50 -25
JUNCTION TEMPERATURE(℃)
4/10
3
160
L=33µH RIND=0.04O
VOUT=VREG-50mV
1.4
1
2
SWITCH CURRENT(A)
Switching Frequency
FREQUENCY (KHz)
INPUT-OUTPUT DIFFERENTIAL (V)
Dropout Voltage
1.6
VIN=12V
1.20
-1.5
1.8
1:-40℃
2:25℃
3:125℃
-50 -25
0
25
50 75 100 125
JUNCTION TEMPERATURE(℃)
2007-6-12
150KHZ 3A PWM BUCK DC/DC CONVERTER
FSP3122
2.0
1.5
1.0
ON
0.5
0.0
„
OFF
-50 -25 0 25 50 75 100 125
JUNCTION TEMPERATURE(℃)
Switch Current Limit
SWITCH CURRENT LIMIT(A)
THRESHOLD VOLTAGE(V)
ON/OFF Threshold Voltage
2.5
5.50
VIN=12V
Vout=5V
5.00
4.50
4.00
3.50
-50 -25 0 25
50 75 100 125
JUNCTION TEMPERATURE(℃)
TYPICAL APPLICATION CIRCUITS
(1) Fixed Output Circuit
(2) Adjustable Output Circuit
5/10
2007-6-12
150KHZ 3A PWM BUCK DC/DC CONVERTER
FSP3122
„
FUNCTION DESCRIPTION
Pin Function
VIN
This is the positive input supply for the IC switching regulator. A suitable input bypass capacitor must be present at
this pin to minimize voltage transients and to supply the switching currents needed by the regulator.
Ground
Circuit ground.
Output
Internal switch. The voltage at this pin switches between (VIN – VSAT ) and approximately – 0.5V, with a duty cycle
of approximately VOUT / VIN. To minimize coupling to sensitive circuitry, the PC board copper area connected to
this pin should be kept a minimum.
Feedback
Senses the regulated output voltage to complete the feedback loop.
ON/OFF
Allows the switching regulator circuit to be shutdown using logic level signals thus dropping the total input supply
current to approximately 150uA. Pulling this pin below a threshold voltage of approximately 1.3V turns the
regulator on, and pulling this pin above 1.3V (up to a maximum of 25V) shuts the regulator down. If this shutdown
feature is not needed, the ON/OFF pin can be wired to the ground pin or it can be left open, in either case the
regulator will be in the ON condition.
Thermal Considerations
The FSP3122 is available in three packages, a 5-pin TO-220, 5-pin TO252 and a 5-pin surface mount TO-263.
The TO-220 package needs a heat sink under most conditions. The size of the heat sink depends on the input
voltage, the output voltage, the load current and the ambient temperature. The FSP3122 junction temperature
rises above ambient temperature for a 3A load and different input and output voltages. The data for these curves
was taken with the FSP3122 (TO-220 package) operating as a buck switching regulator in an ambient
temperature of 25oC (still air). These temperature rise numbers are all approximate and there are many factors that
can affect these temperatures. Higher ambient temperatures require more heat sinking.
The TO-263 surface mount package tab is designed to be soldered to the copper on a printed circuit board. The
copper and the board are the heat sink for this package and the other heat producing components, such as the
catch diode and inductor. The PC board copper area that the package is soldered to should be at least 0.4 in 2,
and ideally should have 2 or more square inches of 2 oz. Additional copper area improves the thermal
characteristics, but with copper areas greater than approximately 6 in2, only small improvements in heat
dissipation are realized. If further thermal improvements are needed, double sided, multilayer PC board with large
copper areas and/or airflow are recommended.
The FSP3122 (TO-263 package) junction temperature rise above ambient temperature with a 2A load for
various input and output voltages. This data was taken with the circuit operating as a buck switching regulator
with all components mounted on a PC board to simulate the junction temperature under actual operating
conditions. This curve can be used for a quick check for the approximate junction temperature for various
conditions, but be aware that there are many factors that can affect the junction temperature. When load
currents higher than 2A are used, double sided or multilayer PC boards with large copper areas and/or airflow
might be needed, especially for high ambient temperatures and high output voltages.
For the best thermal performance, wide copper traces and generous amounts of printed circuit board copper
should be used in the board layout. (Once exception to this is the output (switch) pin, which should not have
large areas of copper.) Large areas of copper provide the best transfer of heat (lower thermal resistance) to the
surrounding air, and moving air lowers the thermal resistance even further.
Package thermal resistance and junction temperature rise numbers are all approximate, and there are many
factors that will affect these numbers. Some of these factors include board size, shape, thickness, position,
location, and even board temperature. Other factors are, trace width, total printed circuit copper area, copper
thickness, single or double-sided, multilayer board and the amount of solder on the board. The effectiveness of
the PC board to dissipate heat also depends on the size, quantity and spacing of other components on the board,
as well as whether the surrounding air is still or moving. Furthermore, some of these components such as the
catch diode will add heat to the PC board and the heat can vary as the input voltage changes. For the inductor,
depending on the physical size, type of core material and the DC resistance, it could either act as a heat sink
taking heat away from the board, or it could add heat to the board.
6/10
2007-6-12
150KHZ 3A PWM BUCK DC/DC CONVERTER
FSP3122
„
ORDERING INFORMATION
FSP3122XXXX
Package:
T: TO220-5L
K: TO263-5L
D: TO252-5L
„
Temperature Grade:
Output Voltage: Packing:
Blank: Tube or Bulk E: -40~125℃
Blank: ADJ
A: Tape & Reel
33: 3.3V
50: 5.0V
12: 12V
MARKING INFORMATION
1) TO220-5L
2) TO263-5L
Logo
3122-VV
YYWWXX
Part Number:
3122-ADJ: ADJ
3122-33: 3.3V
3122-50: 5.0V
3122-12: 12V
Internal Code
Date Code:
YY: Year (01=2001)
WW: Nth week (01~52)
Logo
3122-VV
YYWWXX
Part Number:
3122-ADJ: ADJ
3122-33: 3.3V
3122-50: 5.0V
3122-12: 12V
Internal Code
Date Code:
YY: Year (01=2001)
WW: Nth week (01~52)
(3) TO252-5L
Logo
3122-VV
YYWWXX
Part Number:
3122-ADJ: ADJ
3122-33: 3.3V
3122-50: 5.0V
3122-12: 12V
Internal Code
Date Code:
YY: Year (01=2001)
WW: Nth week (01~52)
7/10
2007-6-12
150KHZ 3A PWM BUCK DC/DC CONVERTER
„
FSP3122
PACKAGE INFORMATION
1) TO220-5L
E
A
P
L
D
H1
Q
F
e
C
b
J1
e1
Symbol
A
b
C
D
E
e
e1
F
H1
J1
L
P
Q
8/10
Min.
4.07
0.76
0.36
14.22
9.78
1.57
6.68
1.14
5.46
2.29
13.21
3.68
2.54
Dimensions In Millimeters
Nom.
Max.
4.45
4.82
0.89
1.02
0.50
0.64
14.86
15.50
10.16
10.54
1.71
1.85
6.81
6.93
1.27
1.40
6.16
6.86
2.74
3.18
13.97
14.73
3.81
3.94
2.73
2.92
Min.
0.160
0.030
0.014
0.560
0.385
0.062
0.263
0.045
0.215
0.090
0.520
0.145
0.100
Dimensions In Inches
Nom.
0.175
0.035
0.020
0.585
0.400
0.067
0.268
0.050
0.243
0.108
0.550
0.150
0.107
2007-6-12
Max.
0.190
0.040
0.025
0.610
0.415
0.073
0.273
0.055
0.270
0.125
0.580
0.155
0.115
150KHZ 3A PWM BUCK DC/DC CONVERTER
FSP3122
2) TO263-5L
E
10.90
9.10
L2
D
15.70
L
2.50
e
1.00
B
1.70
Land Pattern Recommendation (Unit: mm)
A
C2
C
L1
Symbol
A
B
C
C2
D
E
e
L
L1
L2
9/10
Min.
4.07
0.51
0.36
1.14
8.20
9.65
1.57
14.45
1.78
Dimensions In Millimeters
Nom.
Max.
4.46
4.85
0.84
1.02
0.50
0.74
1.27
1.65
9.15
9.65
10.16
10.67
1.71
1.85
15.24
15.88
2.54
2.79
2.92
Min.
0.163
0.020
0.014
0.046
0.328
0.386
0.063
0.578
0.071
Dimensions In Inches
Nom.
0.176
0.033
0.020
0.050
0.360
0.400
0.068
0.600
0.100
2007-6-12
Max.
0.194
0.041
0.030
0.066
0.380
0.427
0.074
0.635
0.110
0.115
150KHZ 3A PWM BUCK DC/DC CONVERTER
FSP3122
(3) TO252-5L
D
A
D1
L2
V
L3
L1
A1
E
c1
e
b
c
e1
Symbol
A
A1
b
c
c1
D
D1
E
e
e1
L1
L2
L3
V
10/10
Dimensions In Millimeters
Min.
Max.
2.200
2.400
0.000
0.127
0.400
0.600
0.430
0.580
0.430
0.580
6.350
6.650
5.200
5.400
5.400
5.700
1.270TYP.
2.540TYP.
9.500
9.900
1.400
1.780
2.550
2.900
3.800REF
Dimensions In Inches
Min.
Max.
0.087
0.094
0.000
0.005
0.016
0.024
0.017
0.023
0.017
0.023
0.250
0.262
0.205
0.213
0.213
0.224
0.050TYP.
1.000TYP.
0.374
0.390
0.055
0.070
0.100
0.114
0.150REF
2007-6-12
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