Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.COM

X  

SC804EVB Datasheet(PDF) 8 Page - Semtech Corporation

Part # SC804EVB
Description  Fully Integrated Lithium-Ion Battery Charger System with Timer
Download  21 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  SEMTECH [Semtech Corporation]
Direct Link  http://www.semtech.com
Logo SEMTECH - Semtech Corporation

SC804EVB Datasheet(HTML) 8 Page - Semtech Corporation

Back Button SC804EVB Datasheet HTML 4Page - Semtech Corporation SC804EVB Datasheet HTML 5Page - Semtech Corporation SC804EVB Datasheet HTML 6Page - Semtech Corporation SC804EVB Datasheet HTML 7Page - Semtech Corporation SC804EVB Datasheet HTML 8Page - Semtech Corporation SC804EVB Datasheet HTML 9Page - Semtech Corporation SC804EVB Datasheet HTML 10Page - Semtech Corporation SC804EVB Datasheet HTML 11Page - Semtech Corporation SC804EVB Datasheet HTML 12Page - Semtech Corporation Next Button
Zoom Inzoom in Zoom Outzoom out
 8 / 21 page
background image
8
© 2007 Semtech Corp.
www.semtech.com
SC804
PRELIMINARY
POWER MANAGEMENT
Fast-Charge Mode (CC)
The fast-charge CC (Constant Current) mode is active when
the battery voltage is above VT
PreQ and less than VCV. The
fast-charge current can be set to a maximum of 1.5A and
is selected by the program resistor on the IPRGM pin. The
voltage on this pin will represent the current through the
battery, enabling a microprocessor via an analog-to-digital
converter (ADC) to monitor battery current by sensing the
voltage on the IPRGM pin. The equation to set the fast-
charge current is given by:
The superior fast-charge current accuracy of the SC804
is obtained by use of a patented* polarity-switched (i.e.,
chopped) current sense amplifier to nullify current mea-
surement offset errors.
Compliance with the absolute maximum output current
I
VOUTMAX, allowing for current regulation tolerance, requires
that R
IPRGM be no smaller than 1.05kΩ nominal.
R
IPRGM
can be as large as 11.5k
Ω, for a nominal FCI as small
as 130mA, but must exceed PCI by at least 80mA. Note
that for a given program resistor the current through
the battery in CV mode can be determined by replacing
V
IPRGM_Typ with the actual voltage on the IPRGM pin in the
above equation. The CC current can also be modified by
applying an analog voltage to the AFC pin as described
below.
Analog Fast Charge (AFC Pin)
Many applications require more than one current setting
for fast-charge. This behavior is obtained in the SC804
using the AFC function. When the AFC pin is connected
to VCC the device behaves as described in the previous
section. When the AFC pin is driven by an analog voltage
between 0V and (V
VCC-1.0)V, the SC804 automatically uses
this pin voltage to set the maximum fast-charge current
according to the following equation:
General Operation
The SC804 can be configured independently with respect
to fast-charge and termination current, output voltage,
and timing, depending on the application. A typical
charging cycle is described below. Details on alternative
applications and output programmability are covered in
the individual sections.
The charging cycle begins when the power adapter is
connected to the device. The SC804 performs glitch
filtering on the VCC input and initiates a charge cycle when
V
VCC is greater than the under-voltage lockout (UVLO) rising
threshold voltage. If the battery voltage is less than the
pre-charge threshold level, the SC804 will output the pre-
charge current. Once the pre-charge threshold voltage
is exceeded, the SC804 enters fast-charge constant
current (CC) mode. When the battery voltage reaches its
final value, the charger enters the constant voltage (CV)
mode. In this mode the output current decreases as the
battery continues to charge until the termination current
level is reached. The CHRGB output turns off when IOUT
drops below the termination current. If the charge timer
is active, the SC804 continues to hold the battery in CV
charge mode until the timer expires. When the timer
expires the charger enters the monitor mode where the
output remains off until the voltage at VOUT drops by
VT
ReQ. At this point a new charge cycle is initiated.
Pre-Charge Mode
Pre-charge mode is automatically enabled whenever
the battery voltage is below the pre-charge threshold
voltage, VT
PreQ. It is used to limit the power dissipation and
precondition the battery for fast charging. The pre-charge
current value is determined by the resistor on the ITERM
pin. The pre-charge current is programmable from 50mA
to 350mA. The equation to select the pre-charge current
is given by:
Where V
ITERM_Typ designates the typical value of VITERM. When
the timer is enabled there is also a maximum allowed pre-
charge duration. If the pre-charge time exceeds 25% of
the total charge cycle the charger will turn off due to a
pre-charge fault. This fault is cleared when VCC is toggled
or the output voltage rises above VT
PreQ.
PCI =
V
ITERM_Typ
× 100
R
ITERM
V
IPRGM_Typ
× 1000
FCI =
R
IPRGM
FCI =
V
AFC
× 1000
R
IPRGM
Applications Information
*US Patent 6,836,095.


Similar Part No. - SC804EVB

ManufacturerPart #DatasheetDescription
logo
Semtech Corporation
SC804EVB SEMTECH-SC804EVB Datasheet
539Kb / 21P
   Fully Integrated 4.4V Lithium-Ion Battery Charger System with Timer
More results

Similar Description - SC804EVB

ManufacturerPart #DatasheetDescription
logo
Semtech Corporation
SC802 SEMTECH-SC802 Datasheet
748Kb / 16P
   Fully Integrated Lithium-Ion Battery Charger System with Timer
SC802 SEMTECH-SC802_08 Datasheet
639Kb / 18P
   Fully Integrated Lithium-Ion Battery Charger System with Timer
SC804A SEMTECH-SC804A Datasheet
539Kb / 21P
   Fully Integrated 4.4V Lithium-Ion Battery Charger System with Timer
SC801 SEMTECH-SC801 Datasheet
360Kb / 17P
   Fully Integrated High Currnet Lithium-Ion Battery Charger System
SC801 SEMTECH-SC801_04 Datasheet
736Kb / 17P
   Fully Integrated High Current Lithium-Ion Battery Charger System
SC803 SEMTECH-SC803 Datasheet
737Kb / 17P
   Fully Integrated High Current Lithium-Ion Battery Charger System
logo
New Japan Radio
NJW4100 NJRC-NJW4100 Datasheet
280Kb / 19P
   Lithium-ion Battery Charger Controller IC with Timer
logo
Microchip Technology
TC3827 MICROCHIP-TC3827 Datasheet
142Kb / 10P
   Lithium-Ion Battery Charger
2001
logo
Shanghai awinic technol...
AW3210A AWINIC-AW3210A Datasheet
1Mb / 12P
   Lithium ion battery charger
logo
Analog Devices
ADP3820 AD-ADP3820 Datasheet
112Kb / 8P
   Lithium-Ion Battery Charger
REV. A
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21


Datasheet Download

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Link Exchange   |   Manufacturer List
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com