ISL6293 Просмотр технического описания (PDF) - Renesas Electronics
Номер в каталоге
Компоненты Описание
производитель
ISL6293 Datasheet PDF : 8 Pages
| |||
ISL6293
Description
The ISL6293 is designed for a single-cell Li-ion or Li-polymer
battery charging circuit that accepts both a USB port and a
desktop cradle as its power source. The charge current from
each power source is independently programmable but only
one of the two sources charges the battery. The following
describes the operation of the charger.
Input Auto Selection
When both input sources are present, the charger selects
only one power source to charge the battery. When the
CRDL input is higher than both the POR threshold and the
battery voltage, CRDL is selected as the power source.
Otherwise the USB input is selected. If the CRDL input
voltage is below the battery voltage but the USB input
voltage is higher than the battery voltage, then the USB input
is used to charge the battery. The control circuit always
breaks both internal power devices before switching in one
power source to avoid any simultaneous conduction of both
power MOSFETs.
When the BAT pin voltage is below 1.7V, the charger selects
the CRDL input as the power source. Hence, if the USB
input is powered, the charger will not charge the battery.
USB Charge Current
When the USB port is selected as the power source, the
charge current is programmed by the logic input USBP pin.
With the RIUSB selected at 80k, when the USBP is driven
to logic LOW, the charge current is set to 90mA. When the
USBP is driven to logic HIGH, the charge current is set to
450mA. The USBP is equivalent to a logic LOW when left
floating. Typically the P-channel MOSFET for the USB input
has an rDS(ON) of 700m at room temperature, thus with a
500mA charge current, the typical head room is 350mV. If
the input voltage drops to a level that the voltage different
between the USB pin and the BAT pin is less than 350mV,
the rDS(ON) becomes a limiting factor of the charge current
and the charge current drops out the constant current
regulation.
Cradle Charge Current
The cradle charge current is programmed with the external
resistor connected between the ICDL pin and the GND pin.
The current can be calculated with the equation given in the
ICDL pin description. The typical rDS(ON) value of the
P-channel MOSFET for the CRDL input is 700m at room
temperature, thus when the head room between the input and
output voltages is small, the actual charge current, similar to
the USB case, could be limited by the rDS(ON). On the other
hand, if the head room between the input and output voltages
is large, the charge current maybe limited by the thermal
foldback threshold due to the increased power dissipation.
Floating Charge Voltage
The floating voltage during the constant voltage phase is
4.2V. The floating voltage has an 1% accuracy over the
ambient temperature range of -40°C to 70°C.
Trickle Charge Current
When the battery voltage is below the minimum battery
voltage VMIN given in the electrical specification, the charger
operates in a trickle/preconditioning mode. If power comes
from the cradle, the trickle mode current is
ITRICKLE= -R1----.I-2-C---0-D--V--L-- 100
A
The trickle current is 45mA if the power comes from the USB
port with RIUSB = 80k.
End-of-Charge Indication
The CHG pin outputs a logic HIGH by turning off the internal
open-drain MOSFET when the charge current falls below
8% of the constant current mode current for the cradle input
or 10% for the USB input when RIUSB is 80k. The charger,
however, does not turn off as long as an input power source
is attached.
Power Presence Indication
When either the USB or the cradle input voltage is above the
POR level, the PPR pin outputs a logic LOW signal to
indicate the presence of input power.
© Copyright Intersil Americas LLC 2004-2006. All Rights Reserved.
All trademarks and registered trademarks are the property of their respective owners.
For additional products, see www.intersil.com/en/products.html
Intersil products are manufactured, assembled and tested utilizing ISO9001 quality systems as noted
in the quality certifications found at www.intersil.com/en/support/qualandreliability.html
Intersil products are sold by description only. Intersil may modify the circuit design and/or specifications of products at any time without notice, provided that such
modification does not, in Intersil's sole judgment, affect the form, fit or function of the product. Accordingly, the reader is cautioned to verify that datasheets are
current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its
subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
FN9180 Rev.1.00
January 4, 2006
Page 7 of 8
Share Link: 