|
|
PDF LTC1473IGN Data sheet ( Hoja de datos )
| Número de pieza | LTC1473IGN | |
| Descripción | Dual PowerPathTM Switch Driver | |
| Fabricantes | Linear Technology | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LTC1473IGN (archivo pdf) en la parte inferior de esta página. Total 16 Páginas | ||
|
No Preview Available !
LTC1473
Dual PowerPathTM
Switch Driver
FEATURES
s Power Path Management for Systems with Multiple
DC Sources
s All N-Channel Switching to Reduce Power Losses and
System Cost
s Switches and Isolates Sources Up to 30V
s Adaptive High Voltage Step-Up Regulator for N-Channel
Gate Drive
s Capacitor Inrush and Short-Circuit Current Limited
s User-Programmable Timer to Limit Switch Dissipation
s Small Footprint: 16-Pin Narrow SSOP
U
APPLICATIO S
s Notebook Computers
s Portable Instruments
s Handi-Terminals
s Portable Medical Equipment
s Portable Industrial Control Equipment
DESCRIPTIO
The LTC®1473 provides a power management solution for
single and dual battery notebook computers and other
portable equipment. The LTC1473 drives two sets of back-
to-back N-channel MOSFET switches to route power to the
input of the main system switching regulator. An internal
boost regulator provides the voltage to fully enhance the
logic level N-channel MOSFET switches.
The LTC1473 senses current to limit surge currents both
into and out of the batteries and the system supply
capacitor during switch-over transitions or during fault
conditions. A user-programmable timer monitors the time
the MOSFET switches are in current limit and latches them
off when the programmed time is exceeded.
A unique “2-diode mode” logic ensures system start-up
regardless of which input receives power first.
, LTC and LT are registered trademarks of Linear Technology Corporation.
PowerPath is a trademark of Linear Technology Corporation.
TYPICAL APPLICATION
MBRD340
BAT1
DCIN
CTIMER
4700pF
MMBD2838LTI
1µF
1µF
FROM POWER
MANAGEMENT
µP
1mH*
MMBD914LTI
1 LTC1473
16
IN1 GA1
2
IN2
15
SAB1
3
DIODE
14
GB1
4
TIMER
SENSE+ 13
5 V+
SENSE– 12
6
VGG
11
GA2
7
SW
10
SAB2
8
GND
9
GB2
BAT2
*COILCRAFT 1812LS-105XKBC
Si9926DY
Si9926DY
RSENSE
0.04Ω
COUT
INPUT OF SYSTEM
HIGH EFFICIENCY DC/DC
SWITCHING REGULATOR
(LTC1735, ETC)
1473 TA01
1
1 page  
LTC1473
PIN FUNCTIONS
IN1 (Pin 1): Logic Input of Gate Drivers GA1 and GB1. IN1
is disabled when IN2 is high or DIODE is low.
IN2 (Pin 2): Logic Input of Gate Drivers GA2 and GB2. IN2
is disabled when IN1 is high or DIODE is low.
DIODE (Pin 3): “2-Diode Mode” Logic Input. DIODE over-
rides IN1 and IN2 by forcing the two back-to-back
external N-channel MOSFET switches to mimic two
diodes.
TIMER (Pin 4): Fault Timer. A capacitor connected from
this pin to GND programs the time the MOSFET switches
are allowed to be in current limit. To disable this function,
Pin 4 can be grounded.
V+ (Pin 5): Input Supply. Bypass this pin with at least a 1µF
capacitor.
VGG (Pin 6): Gate Driver Supply. This high voltage supply
is intended only for driving the internal micropower gate
drive circuitry. Do not load this pin with any external
circuitry. Bypass this pin with at least 1µF.
SW (Pin 7): Open Drain of an internal N-Channel MOSFET
Switch. This pin drives the bottom of the VGG switching
regulator inductor which is connected between this pin
and the V+ pin.
GND (Pin 8): Ground.
GA2, GB2 (Pins 11, 9): Switch Gate Drivers. GA2 and GB2
drive the gates of the second back-to-back external
N-channel switches.
SAB2 (Pin 10): Source Return. The SAB2 pin is connected
to the sources of SW A2 and SW B2. A small pull-down
current source returns this node to 0V when the switches
are turned off.
SENSE – (Pin 12): Inrush Current Input. This pin should be
connected directly to the bottom (output side) of the low
value current sense resistor in series with the two input
power selector switch pairs, SW A1/B1 and SW A2/B2, for
detecting and controlling the inrush current into and out of
the power supply sources and the output capacitor.
SENSE + (Pin 13): Inrush Current Input. This pin should be
connected directly to the top (switch side) of the low value
current sense resistor in series with the two input power
selector switch pairs, SW A1/B1 and SW A2/B2, for
detecting and controlling the inrush current into and out of
the power supply sources and the output capacitor. Cur-
rent limit is invoked when (VSENSE + – VSENSE–) exceeds
±0.2V.
GA1, GB1 (Pins 16, 14): Switch Gate Drivers. GA1 and
GB1 drive the gates of the first back-to-back external
N-channel switches.
SAB1 (Pin 15): Source Return. The SAB1 pin is connected
to the sources of SW A1 and SW B1. A small pull-down
current source returns this node to 0V when the switches
are turned off.
5
5 Page 
LTC1473
APPLICATIONS INFORMATION
VGG Regulator Inductor and Capacitors
The VGG regulator provides a power supply voltage 8.5V
higher than any of the three main power source voltages
to allow the control of N-channel MOSFET switches. This
micropower, step-up voltage regulator is powered by the
highest potential available from the three main power
sources for maximum regulator efficiency.
Three external components are required by the VGG regu-
lator: L1, C1 and C2, as shown in Figure 5.
L1 is a small, low current, 1mH surface mount inductor. C1
provides filtering at the top of the 1mH switched inductor
and should be at least 1µF to filter switching transients.
The VGG output capacitor, C2, provides storage and filter-
ing for the VGG output and should be at least 1µF and rated
for 50V operation. C1 and C2 can be ceramic capacitors.
LTC1473
DCIN BAT1 BAT2
V+
TO GATE
DRIVERS
(8.5V + V+)
VGG
SWITCHING
REGULATOR
L1*
1mH
VGG
SW
C1
1µF
50V
C2
1µF
50V
GND
*COILCRAFT 1812LS-105 XKBC. (708) 639-6400
1473 F05
Figure 5. VGG Step-Up Switching Regulator
11
11 Page | ||
| Páginas | Total 16 Páginas | |
| PDF Descargar | [ Datasheet LTC1473IGN.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LTC1473IGN | Dual PowerPathTM Switch Driver | Linear Technology |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |