900,000+ datasheet pdf search and download

Datasheet4U offers most rated semiconductors data sheet pdf




Linear Technology Electronic Components Datasheet

LT1572 Datasheet

100kHz/ 1.25A Switching Regulator with Catch Diode

No Preview Available !

FEATURES
s Catch Diode Included in Package
s Wide Input Voltage Range: 3V to 30V
s Low Quiescent Current: 6mA
s Internal 1.25A Switch
s Very Few External Parts Required
s Self-Protected Against Overloads
s Operates in Nearly All Switching Topologies
s Shutdown Mode Draws Only 50µA Typical Current
s Can Be Externally Synchronized
APPLICATI S
s 3.3V-to-5V and 5V-to-12V Boost Converters
s Negative-to-Positive Converter
s SEPIC Converter (Input Can Be Greater or
Less Than Output)
s Battery Charger
LT1572
100kHz, 1.25A Switching
Regulator with Catch Diode
DESCRIPTIO
The LT®1572 is a 1.25A 100kHz monolithic switching
regulator with on-board switch and catch diode included
in one package. It combines an LT1172 with a 1A Schottky
catch diode. The LT1572 can be operated in all standard
switching configurations, including boost, buck, SEPIC,
flyback, forward, inverting and “Cuk”. All necessary con-
trol, oscillator and protection circuitry is included on the
die with the high efficiency switch. This makes the part
extremely easy to use and provides “bustproof” operation
similar to that obtained with 3-pin linear regulators.
The LT1572 operates with supply voltages from 3V to 30V
and draws only 6mA quiescent current. It can deliver load
power up to 15W with no external power devices. By
utilizing a current mode switching technique, the LT1572
achieves excellent response to load and line transients.
The LT1572 has many unique features not found on the
more difficult to use control chips presently available. It
uses adaptive anti-sat switch drive to allow very wide
ranging load currents with no loss in efficiency. An exter-
nally activated shutdown mode reduces total supply cur-
rent to 50µA typical for standby operation. External syn-
chronizing of switching frequency is possible, with a range
of 120kHz to 160kHz.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATI
VIN
4.5V
TO 10V
5V-to-12V Boost Converter
+ C3
100µF
10V
L1*
50µH
*COILTRONICS CTX50-2
**AVX TPS OR SPRAGUE 593D
9
11 2 15
ALWAYS CONNECT BOTH ANODE (2, 15)
VIN VSW ANODE3 AND CATHODE (3, 14) PINS
CATHODE14
LT1572
FB
E1 E2 GND VC
10 12 4, 13 5
R3
1k
C1
1µF
R1
10.7k
1%
R2
1.24k
1%
12V
0.25A
+ C2**
100µF
16V
LT1572 • TA01
Boost Converter Efficiency
100
BOOST CONVERTER
VIN = 5V
90 VOUT = 12V
80
70
60
50
0
50 100 150 200
L0AD CURRENT (mA)
250
LT1572 • TA01
1


Linear Technology Electronic Components Datasheet

LT1572 Datasheet

100kHz/ 1.25A Switching Regulator with Catch Diode

No Preview Available !

LT1572
ABSOLUTE AXI U RATI GS
Supply Voltage (Note 4).......................................... 40V
Switch Output Voltage (Note 4) .............................. 60V
Feedback Pin Voltage (Transient, 1ms) ................ ±15V
Operating Junction Temperature Range
Operating .............................................. 0°C to 100°C
Short Circuit ......................................... 0°C to 125°C
Storage Temperature Range ............... – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
DIODE
Average Forward Current .......................................... 1A
Peak Repetitive Forward Current .............................. 2A
Peak Non-Repetitive Forward Current....................... 3A
Peak Repetitive Reverse Voltage............................. 20V
Continuous (Average) Reverse Voltage .................. 15V
Operating Junction Temperature ......................... 125°C
PACKAGE/ORDER I FOR ATIO
NC 1
ANODE* 2
CATHODE* 3
GND 4
VC 5
FB 6
NC 7
NC 8
TOP VIEW
16 NC
15 ANODE*
14 CATHODE*
13 GND
12 E2
11 VSW
10 E1
9 VIN
ORDER PART
NUMBER
LT1572CS
S PACKAGE
16-LEAD PLASTIC SO
*ALWAYS CONNECT BOTH ANODE
AND BOTH CATHODE PINS
TJMAX (REGULATOR) = 100°C
TJMAX (DIODE) = 125°C
SEE THERMAL MANAGEMENT SECTION FOR θJA
Consult factory for Industrial and Military grade parts.
Note 1: Minimum effective switch “on” time for the LT1572 (in current
limit only) is 0.6µs. This limits the maximum safe input voltage during
an output shorted condition. Buck mode and inverting mode input voltage
during an output shorted condition is limited to:
VIN (max, output shorted)
buck and inverting mode
=
15V
+
R
× IL
t×
+
f
Vf
R = Inductor DC resistance
IL = 2.5A
Vf = Output catch diode forward voltage at IL
t = 0.6µs, f = 100kHz switching frequency
Maximum input voltage can be increased by increasing R or Vf.
External current limiting such as that shown in AN19, Figure 39, will
provide protection up to the full supply voltage rating. C1 in Figure 39
should be reduced to 200pF.
Transformer designs will tolerate much higher input voltages because
leakage inductance limits rate of rise of current in the switch. These
designs must be evaluated individually to assure that current limit is well
controlled up to maximum input voltage.
Boost mode designs are never protected against output shorts because
the external catch diode and inductor connect input to output.
ELECTRICAL CHARACTERISTICS VIN = 15V, VC = 0.5V, VFB = VREF, output pin open, unless otherwise noted.
SYMBOL PARAMETER
VREF Reference Voltage
IB Feedback Input Current
gm Error Amplifier
Transconductance
Error Amplifier Source or
Sink Current
Error Amplifier Clamp
Voltage
Reference Voltage Line
Regulation
AV Error Amplifier Voltage Gain
Minimum Input Voltage (Note 3)
IQ Supply Current
CONDITIONS
Measured at Feedback Pin
VC = 0.8V
VFB = VREF
IC = ±25µA
VC = 1.5V
Hi Clamp, VFB = 1V
Lo Clamp, VFB = 1.5V
3V VIN 40V
VC = 0.8V
0.9V VC 1.4V
3V VIN 40V, VC = 0.6V
MIN TYP MAX UNITS
1.224 1.244 1.264
q 1.214 1.244 1.274
V
V
350 750
nA
q 1100 nA
3000 4400 6000 µmho
q 2400
7000 µmho
150 200 350
q 120
400
µA
µA
1.80 2.30
0.25 0.38 0.52
V
V
q 0.03 %/V
500 800
q 2.6 3.0
69
V/ V
V
mA
2


Part Number LT1572
Description 100kHz/ 1.25A Switching Regulator with Catch Diode
Maker Linear Technology
PDF Download

LT1572 Datasheet PDF





Similar Datasheet

1 LT1571 Constant-Current/ Constant-Voltage Battery Charger with Preset Voltage and Termination Flag
Linear Technology
2 LT1572 100kHz/ 1.25A Switching Regulator with Catch Diode
Linear Technology
3 LT1573 Low Dropout PNP Regulator Driver
Linear Technology
4 LT1575 Ultrafast Transient Response/ Low Dropout Regulators Adjustable and Fixed
Linear Technology
5 LT1576 1.5A/ 200kHz Step-Down Switching Regulator
Linear Technology
6 LT1576-5 1.5A/ 200kHz Step-Down Switching Regulator
Linear Technology
7 LT1577 Ultrafast Transient Response/ Low Dropout Regulators Adjustable and Fixed
Linear Technology
8 LT1578 1.5A/ 200kHz Step-Down Switching Regulator
Linear Technology
9 LT1578-2.5 1.5A/ 200kHz Step-Down Switching Regulator
Linear Technology





Part Number Start With

0    1    2    3    4    5    6    7    8    9    A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    Q    R    S    T    U    V    W    X    Y    Z

Site map

Webmaste! click here

Contact us

Buy Components

Privacy Policy