DESCRIPTION
Demonstration circuit DC1259A is a single-battery battery-
backup controller featuring the LTC4110. The
LTC4110 controller provides all the features and functions
to offer a complete standalone battery-backup system.
The LTC4110 is scalable with other LTC4110s to
allow a larger battery array for increased capacity and/or
redundancy.
A SMBus interface is offered to allow host communications
in control and status and/or support Smart Batteries.
However, no host is required to use the LTC4110.
An on-board LTC1694 SMBus accelerator is used to
provide 3.3V pull-up power and fast rise times of the
bus for maximum speed and reliability.
From the factory, the DC1259A is configured for a 12.6V
Li-ion Smart Battery in charge and discharge. The battery
is connected to the BAT terminal. However, the Demoboard
can be easily configured for a Standard Battery
as well. Set JP1 to INT to allow batteries without a
thermistor pin to be charged.
Note: If you use a standard battery, it is strongly recommended
you have the final production version of the
battery provide an extra pin to support the
NTC/thermistor pin. This will allow the LTC4110 to:
1) Detect the physical presence of the battery and optionally
report it to a host.
2) Start a complete charge cycle from the beginning including
safe recovery of an over-discharged battery.
3) Allow the battery terminals to be 0V when no battery
is present.
All the pin does inside the battery is connect a 300 ohm
resistor (Li-ion) or a 10K NTC to Battery (B-) per the
Smart Battery Standards. For more information, contact
the factory.
Smart Batteries offer an integrated, high-accuracy gas
gauge report allowing the host system to know exactly
the state of charge of the battery at all times. Smart Batteries
are the battery packs found on all mainstream
notebooks made today. If you wish to try an industry
standard Smart Battery that plugs-and-plays with the
Demoboard, we recommend you contact Inspired Energy:
http://www.inspired-energy.com/
If the battery you’re using is not 12.6V Li-ion, the Demoboard
provides jumper options to support other
chemistries and cell stack voltages. Consult the Schematic
and Datasheet for more information.
Power input is connected to the DCIN terminal. The
recommended input power is 12V± 5% at 1.4A minimum
up to 7A maximum as required to power the load.
To successfully perform a calibration test, a 1.7A load
on the VSYS or DCOUT terminals must be connected
and turned on.
The battery backed load is to be connected to the
DCOUT terminal. The VSYS terminal is optional and intended
for loads that are NOT battery backed up. Why a
VSYS connection? R1 exist as part of the Calibration
protection system that looks for insufficient load current
to support calibration safely. See datasheet for more
information.
The Calibration feature of the LTC4110 allows one to test
load the battery without generating any heat. The Flyback
converter is used in reverse as a current source
dumping current back into the DCIN supply. The DCIN
supply simply sees a reduction in load current.
The 3 GPIO pins are initially defined to be STATUS pins
on power up. JP4 can be used to change them to be Hi-
Z state on power up until programmed by the host.
The optional DC1223A-B SMBUS to USB port adapter
along with the associated “QuickEval” software is used
to automatically download IDs over the internet to program
the LTC4110. The software will allow one to control,
monitor and data-log the system and battery status
for demonstration purposes only. You DO NOT need this
software to run the DC1259A. Contact your LT representative
for ordering a DC1223A-B.