u2402b ETC-unknow, u2402b Datasheet - Page 5

• Manufacturer Part Number: u2402b
• Description: Fast Charge Controller Nicd/nimh Batteries
• Manufacturer: ETC-unknow

TELEFUNKEN Semiconductors
Rev. A3, 14-Nov-96
Flow Chart Explanation, f
(Figures 2, 3 and 4)
Battery pack insertion disables the voltage lock at battery
detection input Pin 10. All functions in the integrated
circuit are reset. For further description, DIP-pinning is
taken into consideration.
Battery Insertion and –dV Monitoring
The charging procedure will be carried out if battery
insertion is recognised. If the polarity of the inserted
battery is not according to the specification, the fast
charge rate will stop immediately. After the polarity test,
if positive, the defined fast charge rate, I
first 5 minutes according to –dV monitoring. After
5 minutes of charging, the first identification control is
executed.
If the inserted battery has a signal across its terminal of
less than 0.1 V, then the charging procedure is interrupted.
This means that the battery is defective i.e., it is not a
rechargeable battery – “shorted batteries ignored”.
Voltage and temperature measurements across the battery
are carried out during charge break interval (see figure 6),
i.e., currentless or idle measurements.
If the inserted battery is fully charged, the –dV control
will signal a charge stop after six measurements
(approximately 110 seconds). All the above mentioned
functions are recognised during the first 5 minutes
according to –dV method. During this time, +d
remains inactive. In this way the battery is protected from
unnecessary damage.
If there is no charge stop within the first 5 minutes after
battery insertion, then d
In this actual charge stage, all stop-charge criteria are
active.
When close to the battery’s capacity limit, the battery
voltage curve will typically rise. As long as the +d
stop-charging criteria are met, the device will stop the fast
charge activities.
d
2
V/dt
2
-Gradient
2
V/dt
2
monitoring will be active.
osc
O
, begins for the
= 800 Hz
2
2
V/dt
V/dt
2
2
Top-Off Charge Stage
By charge disconnection through the + d
device switches automatically to a defined protective
top-off charge with a pulse rate of 1/4 I
t
The top-off charge time is specified for a time of
20 minutes @ 800 Hz.
Trickle Charge Stage
When top-off charge is terminated, the device switches
automatically to trickle charge with 1/256 I
period = 1310.72 s). The trickle continues until the
battery pack is removed.
Basic Description
Power Supply, Figure 2
The charge controller allows the direct power supply of
8 to 26 V at Pin 15. Internal regulation limits higher input
voltages. Series resistance, R
current, I
resistance is recommended to suppress the noise signal,
even below 26 V limitation. It is calculated as follows:
R
R
where
I
V
I
I
I
p
tot
S
RB1
1
1min
1max
max,
= 5.12 s, period, T = 20.48 s).
= Current consumption (IC) without load
= Trigger current at Pin 1
= I
= Current through resistance, R
v
w
S
V
+ I
min
V
V
S
min
RB1
, to a maximum value of 25 mA. Series
max
25 mA
= Rectified voltage
I
– 8 V
–26 V
tot
+ I
1
1
, regulates the supply
U2402B
B1
2
V/dt
O
O
(pulse time,
(t
2
p
mode, the
= 5.12 s,
5 (17)