4
dc2043bfa
DEMO MANUAL DC2043B
QuicK start proceDure
Using short twisted pair leads for any power connections,
with all loads and power supplies off, refer to Figure 5 for
the proper measurement and equipment setup.
Follow the procedure below:
1. Before connecting PS1-PS5 to the DC2043B, the power
supplies must have its current limit set to 5A . For
most power supplies with a current-limit-adjustment
feature the procedure to set the current limit is as
follows. Turn the voltage and current adjustment to
minimum. Short the output terminals and turn the
voltage adjustment to maximum. Adjust the current
limit to 5A for PS1. Turn the voltage adjustment to
minimum and remove the short between the output
terminals. Repeat for PS2-PS5 The power supplies
are now current limited to 5A .
a. Initial Jumper and PS settings:
JP1(MODE)
= CONT
JP2 (EN)
= SD
JP3(TERM1)
= 1
JP4 (TERM2)
= 1
PS1
= Off
PS2
= Off
PS3
= OFF
PS4
= Off
PS5
= Off
PS6
= Off
2. Connect power supplies, load resistors and me-
ters as shown in Figure 5. Turn on PS1 and slowly
increase voltage to 2.0V while monitoring the input
current. If the current remains less than 200mA,
increase PS1 to 12.0V. Repeat for PS2-PS4.
3. Turn on PS5 and slowly increase voltage to 2.0V while
monitoring the input current. If the current remains less
than 200mA, increase PS5 to 11.8V. Turn on PS6 and
slowly increase voltage to 2.0V while monitoring the
input current. If the current remains less than 20mA,
increase PS6 to 5.0V.
4. Measure the voltage from the VREG turret to ground.
The voltage should read approximately 2.6V. Measure
the voltage from the BOOST test point to V4. The volt-
age should read approximately 0V. No LED should be
on.
5. Set JP2 to EN. Measure the voltage from the BOOST
test point to V4. The voltage should read approximately
8.5V.
6. Measure the voltage from the I
SET
test point to ground.
The voltage should read approximately 1.2V.
During some hot-plug events, the gate-to-source voltage
on some of the power FETs can approach the maximum
VGS rating of the FETs. Back-to-back Zener diodes (15V
nominal threshold) are included across all power-FET
gate-source pins.
Inrush current between the sense connections and capaci-
tors C6, C12–C15 is limited by resistors R107–R111. These
resistors are pulse-power-rated. The higher pulse-power
capability is a necessary requirement for these resistors.
These resistors are 5Ω, 1206 except for the resistor in
the BAT4_KF net which is 2Ω, 1206 because, while it
senses the voltage at the top of the battery stack, it also
sinks a small amount of current to power the internals of
the LTC3305.
TVS diodes D135 to D138 are listed as “OPT” on the sche-
matic, and are not included on the DC2043B. However, a
transient-voltage-suppressor diode is included across
the battery stack to protect the LTC3305 from transients
generated during hot plugging. The threshold voltage of
the part is specified to lie between 66.7V and 73.7V.
Fuses are present on each of the 14 connections to external
batteries. Seven power connections employ a 7A-rated
fuse. The sense connections (XXX_K) use 1A fuses. Note
that the protection circuits described above are placed on
the internal-to-the-board side of the fuses. This placement
ensures isolation and disconnection of the protection
circuits in the event of a steady-state fault condition.
operatinG principLe
