Linear Technology DC1830A-A Demo Manual

DESCRIPTION
Demonstration circuit 1830A is a battery charger controller
and PowerPath™ manager featuring the LTC
board should be connected to a front-end DC/DC power
supply for a complete charger solution.
The DC1830A is customizable to handle a wide variety
of applications with output voltages from 3V to 30V and
output currents up to 6.5A with the PFETs supplied, and up
to 60V and/or 13A with higher voltage rating and/or added
PFETs. The reference design provided with DC1830A is
targeted at 4-cell LiFePO
4
The DC1830A loop compensation values were proven with
the LTC3845A buck power converter shown and are typi-
cal for other applications. The output of this demo board
was specifically tailored for a Tenergy 10A-hour battery,
P/N 30207. Other voltages can be set by changing ROFB2
and RBFB2. The desired nominal voltage can be accurately
trimmed by using trim resistors ROFBX and RBFBX. For
example, for 14.4V battery float voltage, change ROFB2
and RBFB2 to 86.6k, and add 7.5M at ROFBX and RBFBX
for greater setpoint accuracy. Other parameters can be ad-
justed to suit specific applications with guidance provided
in the LTC4000 data sheet. Table 1 provides a summary
of parameter adjustments.
This circuit was designed to demonstrate the high levels
of performance and small solution size attainable using
PERFORMANCE SUMMARY
SYMBOL PARAMETER
V Input Supply Range
IN
I Input Current Limit
IN
V Battery Float Voltage
FLOAT
V Output Regulation
FLOAT
I Battery Charge Current
BAT
Battery Charge Current—Trickle
t Charge Termination Time
T
V System Output Voltage
OUT-SYS
I System Output Current Range
OUT-SYS
4000. This
®
(14.6V/5A) applications.
Specifications are at T
CONDITIONS/COMMENTS
This Is the Input Voltage of the Front-End DC/DC Supply
This Is the Input Current Limit Set by the LTC4000
Line and Load (20V to 60V, 0A to 4.5A)
V = V
BAT FLOAT
*Input Current Limited Below 35V
DEMO MANUAL
DC1830A-A/DC1830A-B
Battery Charger Controller
and PowerPath Manager
this IC to control a switch mode power converter to form
a battery charger, intelligent PowerPath manager, and
power supply system. It produces a regulated 5.0A/14.6V
battery charger output as well as a system output of up to
5.5A: suitable for a wide variety of portable applications
including instruments, industrial equipment, power tools
and computers.
The DC1830A-A provides a solution complete with both
battery charger control and PowerPath managment. It
includes a second PFET (Q2) between VOUT-SYS and
BAT to provide Instant-On functionality which keeps
VOUT-SYS within a narrow range regardless of battery
voltage, and disconnects the battery when it is fully charged
and power is available from the front-end DC/DC converter.
Thermal regulation circuitry is also provided to limit the
temperature of both PFETs. The DC1830A-B provides a
simple battery-charger-controller only solution without
the PowerPath manager. It deletes the second PFET and
thermal regulation circuitry. In this case, the battery is
always "online" and VOUT-SYS tracks the BAT Voltage.
Design files for this circuit board are available at
http://www.linear.com/demo
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
= 25°C
A
IN
LTC4000
MIN TYP MAX UNITS
20 60
3.0
14.4 14.6 14.8
±0.005
5.0
0.6
2.9 Hours
12.3 14.6 15.5
0 5.5*
dc1830af
1
V
A
V
%
A
A
V
A