900,000+ datasheet pdf search and download

Datasheet4U offers most rated semiconductors data sheet pdf




Linear Technology Electronic Components Datasheet

LT1959 Datasheet

4.5A/ 500kHz Step-Down Switching Regulator

No Preview Available !

LT1959
4.5A, 500kHz Step-Down
Switching Regulator
FEATURES
s Operates with Input as Low as 4V
s Output Range Down to 1.21V
s Constant 500kHz Switching Frequency
s Uses All Surface Mount Components
s Inductor Size Reduced to 1.8µH
s Saturating Switch Design: 0.07
s Shutdown Current: 20µA
s Easily Synchronizable
s Cycle-by-Cycle Current Limiting
s 4.5A Switch
s Current Mode Control
U
APPLICATIO S
s Portable Computers
s Battery-Powered Systems
s Battery Chargers
s Distributed Power
s 5V to 3.3V Conversion
s 5V to 2.5V Conversion
s 5V to 1.8V Conversion
DESCRIPTIO
The LT®1959 is a 500kHz monolithic buck mode switching
regulator functionally identical to the LT1506 but optimized
for lower output voltage applications. It will operate down
to 1.21V output compared to 2.42V for the LT1506. A 4.5A
switch is included on the die along with all the necessary
oscillator, control and logic circuitry. High switching fre-
quency allows a considerable reduction in the size of ex-
ternal components. The topology is current mode for fast
transient response and good loop stability.
A special high speed bipolar process and new design tech-
niques achieve high efficiency at high switching frequency.
Efficiency is maintained over a wide output current range
by keeping quiescent supply current to 4mA and by utiliz-
ing a supply boost capacitor to saturate the power switch.
The LT1959 fits into standard 7-pin DD and fused lead
SO-8 packages. Full cycle-by-cycle short-circuit protection
and thermal shutdown are provided. Standard surface
mount external parts are used, including the inductor and
capacitors. There is the optional function of shutdown or
synchronization. A shutdown signal reduces supply current
to 20µA. Synchronization allows an external logic level sig-
nal to increase the internal oscillator from 580kHz to 1MHz.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
INPUT
5V
10µF
C3
TO
+
50µF
CERAMIC
5V to 1.8V Down Converter
D2
1N914
OPEN
OR
HIGH
= ON
BOOST
VIN VSW
LT1959
SHDN
FB
GND VC
CC
1.5nF
C2
0.68µF
L1
5µH
R1
1.21k
OUTPUT
1.8V
4A
R2 +
D1 2.49k
MBRS330T3
C1
100µF, 10V
SOLID
TANTALUM
1959 TA01
Efficiency vs Load Current
90
VOUT = 3.3V
VIN = 5V
L = 10µH
85
80
75
70
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
LOAD CURRENT (A)
1959 TA02
1


Linear Technology Electronic Components Datasheet

LT1959 Datasheet

4.5A/ 500kHz Step-Down Switching Regulator

No Preview Available !

LT1959
ABSOLUTE MAXIMUM RATINGS (Note 1)
Input Voltage .......................................................... 16V
BOOST Voltage ........................................................ 30V
BOOST Pin Above Input Voltage ............................. 15V
SHDN Pin Voltage ..................................................... 7V
FB Pin Voltage ....................................................... 3.5V
FB Pin Current ....................................................... 1mA
SYNC Pin Voltage ..................................................... 7V
Operating Junction Temperature Range
LT1959C ................................................ 0°C to 125°C
LT1959I ........................................... – 40°C to 125°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
PACKAGE/ORDER INFORMATION
FRONT VIEW
7 FB
6 BOOST
TAB 5 VIN
IS 4 GND
GND
3 VSW
2 SHDN
1 VC
R PACKAGE
7-LEAD PLASTIC DD
TJMAX = 150°C, θJA = 30°C/W
WITH PACKAGE SOLDERED TO 0.5 SQUARE INCH
COPPER AREA OVER BACKSIDE GROUND PLANE OR
INTERNAL POWER PLANE. θJA CAN VARY FROM 20°C/W
TO > 40°C/W DEPENDING ON MOUNTING TECHNIQUES
ORDER PART
NUMBER
LT1959CR
LT1959IR
TOP VIEW
VIN 1
BOOST 2
FB 3
GND** 4
8 VSW
7 SYNC
6 SHDN
5 VC
S8 PACKAGE
8-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 80°C/W
**WITH (FUSED GND) GROUND PIN
CONNECTED TO GROUND PLANE OR
LARGE LANDS
ORDER PART
NUMBER
LT1959CS8
LT1959IS8
S8 PART MARKING
1959
1959I
ELECTRICAL CHARACTERISTICS The q denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C, TJ = 25°C, VIN = 5V, VC = 1.5V, Boost = VIN + 5V, switch open, unless
otherwise noted.
PARAMETER
Feedback Voltage (Adjustable)
Reference Voltage Line Regulation
Feedback Input Bias Current
Error Amplifier Voltage Gain
Error Amplifier Transconductance
CONDITIONS
All Conditions
4.3V VIN 15V
(Note 2)
I (VC) = ±10µA
VC Pin to Switch Current Transconductance
Error Amplifier Source Current
Error Amplifier Sink Current
VC Pin Switching Threshold
VC Pin High Clamp
Switch Current Limit
Slope Compensation
VFB = 1.05V
VFB = 1.35V
Duty Cycle = 0
VC Open, VFB = 1.05V, DC 50%
DC = 80%
MIN TYP MAX
q 1.19 1.21 1.23
0.01 0.03
q –0.5 0 0.5
200 400
1500 2000 2700
q 1000
3100
5.3
q 140 225 320
q 140 225 320
0.9
2.1
q 4.5 6 8.5
0.8
UNITS
V
%/ V
µA
µMho
µMho
A/ V
µA
µA
V
V
A
A
2


Part Number LT1959
Description 4.5A/ 500kHz Step-Down Switching Regulator
Maker Linear Technology
PDF Download

LT1959 Datasheet PDF






Similar Datasheet

1 LT1950 Single Switch PWM Controller
Linear Technology
2 LT1952 Single Switch Synchronous Forward Controller
Linear Technology
3 LT1952-1 Single Switch Synchronous Forward Controller
Linear Technology
4 LT1956 High Voltage/ 1.5A/ 500kHz Step-Down Switching Regulators
Linear Technology
5 LT1956-5 High Voltage/ 1.5A/ 500kHz Step-Down Switching Regulators
Linear Technology
6 LT1959 4.5A/ 500kHz 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