900,000+ datasheet pdf search and download

Datasheet4U offers most rated semiconductors data sheet pdf




Analog Devices Semiconductor Electronic Components Datasheet

LTC7804 Datasheet

Boost Controller

No Preview Available !

LTC7804
Low IQ Synchronous
Boost Controller
FEATURES
n Synchronous Operation for Highest Efficiency and
Reduced Heat Dissipation
n Wide VIN Range: 4.5V to 40V and Operates Down to
1V After Start-Up
n Output Voltage Up to 40V
n Low Operating IQ: 14μA
n Spread Spectrum Operation
n Pass-Thru/100% Duty Cycle Capability for
Synchronous MOSFET
n RSENSE or Inductor DCR Current Sensing
n Programmable Fixed Frequency (100kHz to 3MHz)
n Phase-Lockable Frequency (100kHz to 3MHz)
n Selectable Continuous, Pulse-Skipping, or Low
Ripple Burst Mode® Operation at Light Loads
n Low Shutdown IQ: 1.2μA
n Thermally Enhanced 16-Pin 3mm × 3mm QFN and
MSOP Packages
APPLICATIONS
n Automotive and Transportation
n Industrial
n Military/Avionics
n Telecommunications
DESCRIPTION
The LTC®7804 is a high performance synchronous boost
DC/DC switching regulator controller that drives an all
N-channel power MOSFET stage. Synchronous rectifica-
tion increases efficiency, reduces power losses and eases
thermal requirements. A constant frequency current mode
architecture allows a phase-lockable switching frequency
of up to 3MHz. The LTC7804 operates from a wide 4.5V
to 40V input supply range. When biased from the boost
converter output , the LTC7804 can operate from an input
supply as low as 1V after startup.
The very low no-load quiescent current extends operating
runtime in battery powered systems. OPTI-LOOP com-
pensation allows the transient response to be optimized
over a wide range of output capacitance and ESR values.
The MODE pin selects among Burst Mode operation,
pulse-skipping mode, or continuous inductor current
mode at light loads.
The LTC7804 additionally features spread spectrum oper-
ation which significantly reduces the peak radiated and
conducted noise on both the input and output supplies,
making it easier to comply with electromagnetic interfer-
ence (EMI) standards.
All registered trademarks and trademarks are the property of their respective owners. Protected
by U.S. patents, including 5481178, 5705919,5929620, 6144194, 6177787, 6580258.
TYPICAL APPLICATION
VIN
4.5V TO 38V
10µF RUN
8.06k
22nF
220pF
ITH
SS
0.1µF
VBIAS
SENSE+
SENSE
BG
LTC7804
TG
SW
BOOST
2mΩ 2µH
0.1µF
EXTVCC
FREQ
MODE
PLLIN/SPREAD
GND
INTVCC
VFB
7804 TA01a
4.7µF
10µF
×2
VOUT
24V
6A
150µF
VOUT FOLLOWS VIN
FOR VIN > 24V
604k
31.6k
Document Feedback
For more information www.analog.com
Efficiency and Power Loss
vs Output Current
100
10k
90
BURST EFFICIENCY
80
1k
70
60
100
BURST LOSS
50
40
10
30
20
10
0
0.00001 0.0001 0.001
VIN = 12V
VOUT = 24V
1
Burst Mode OPERATION
FIGURE 9 CIRCUIT
0.1
0.01 0.1 1 10
OUTPUT CURRENT (A)
7804 TA01b
Rev. 0
1


Analog Devices Semiconductor Electronic Components Datasheet

LTC7804 Datasheet

Boost Controller

No Preview Available !

LTC7804
TABLE OF CONTENTS
Features...................................................... 1
Applications................................................. 1
Typical Application ......................................... 1
Description.................................................. 1
Absolute Maximum Ratings............................... 3
Pin Configuration........................................... 3
Order Information........................................... 4
Electrical Characteristics.................................. 5
Typical Performance Characteristics.................... 7
Pin Functions............................................... 10
Block Diagram.............................................. 11
Operation................................................... 12
Main Control Loop................................................... 12
INTVCC/EXTVCC Power............................................. 12
Boost Supply and Dropout (BOOST and SW Pins).....12
Shutdown and Start-Up (RUN, SS Pins) .................12
Light Load Current Operation: Burst Mode
Operation, Pulse-Skipping or Forced Continuous
Mode (MODE Pin).................................................... 12
Frequency Selection, Spread Spectrum and Phase-
Locked-Loop (FREQ and PLLIN/SPREAD Pins).......13
Operation When VIN > VOUT............................................... 14
Operation at Low Input Voltage...............................14
BOOST Supply Refresh and Internal Charge Pump..14
Applications Information................................. 15
SENSE+ and SENSEPins........................................ 15
Low Value Resistor Current Sensing.......................16
Inductor DCR Sensing............................................. 16
Inductor Value Calculation.......................................17
Inductor Core Selection...........................................17
Power MOSFET Selection........................................18
CIN and COUT Selection............................................ 18
Setting Output Voltage............................................. 19
RUN Pin................................................................... 19
Soft-Start (SS Pin)................................................... 20
INTVCC Regulators................................................... 20
Topside MOSFET Driver Supply (CB, DB)................. 21
Phase-Locked Loop and Frequency
Synchronization ............................................... 21
Setting the Operating Frequency..............................22
Selecting the Light-Load Operating Mode................23
Minimum On-Time Considerations..........................23
Fault Conditions: Overtemperature Protection.........24
Efficiency Considerations.........................................24
Checking Transient Response..................................24
Design Example.......................................................25
PC Board Layout Checklist.......................................26
PC Board Layout Debugging.................................... 27
Typical Applications....................................... 28
Package Description...................................... 32
Typical Application........................................ 34
Related Parts............................................... 34
Rev. 0
2
For more information www.analog.com



Part Number LTC7804
Description Boost Controller
Maker Analog Devices
Total Page 3 Pages
PDF Download

LTC7804 Datasheet PDF





Similar Datasheet

1 LTC7800 High Frequency Synchronous Step-Down Controller
Analog Devices
2 LTC7801 Synchronous Step-Down DC/DC Controller
Linear Technology
3 LTC7804 Boost Controller
Analog Devices





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