LTC4075HVXEDD LINER [Linear Technology], LTC4075HVXEDD Datasheet - Page 10

• Manufacturer Part Number: LTC4075HVXEDD
• Description: High Voltage Dual Input Li-Ion/Polymer Battery Charger
• Manufacturer: LINER [Linear Technology]

OPERATION
LTC4075HVX
Automatic Recharge
In standby mode, the charger sits idle and monitors the
battery voltage using a comparator with a 4.1ms fi lter time
(t
battery voltage falls below 4.075V (which corresponds to
approximately 80% to 90% battery capacity). This ensures
that the battery is kept at, or near, a fully charged condi-
tion and eliminates the need for periodic charge cycle
initiations.
If the battery is removed from the charger, a sawtooth
waveform appears at the battery output. This is caused
by the repeated cycling between termination and recharge
events. This cycling results in pulsing at the ⎯ C ⎯ H ⎯ R ⎯ G output;
an LED connected to this pin will exhibit a blinking pattern,
indicating to the user that a battery is not present. The
frequency of the sawtooth is dependent on the amount
of output capacitance.
Manual Shutdown
The ENABLE pin has a 2MΩ pull-down resistor to GND. The
defi nition of this pin depends on which source is supplying
power. When the wall adapter input is supplying power,
logic low enables the charger and logic high disables it
Table 1. Power Source Selection
V
V
6V > V
and V
50mV
22V > V
10
DCIN
DCIN
RECHRG
DCIN
< 4.15V or
< BAT + 50mV
ENABLE
DCIN
DCIN
> BAT +
). A charge cycle automatically restarts when the
> 4.15V
> 6V
No Charging.
⎯ P ⎯ W ⎯ R : Hi-Z
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : Hi-Z
No Charging.
⎯ P ⎯ W ⎯ R : Hi-Z
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : Hi-Z
No Charging.
⎯ P ⎯ W ⎯ R : Hi-Z
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : Hi-Z
HIGH
V
USBIN
V
USBIN
< BAT + 50mV
< 3.95V or
LOW or No Connect
No Charging.
⎯ P ⎯ W ⎯ R : Hi-Z
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : Hi-Z
Charging from DCIN
source.
⎯ P ⎯ W ⎯ R : LOW
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : LOW
No Charging.
⎯ P ⎯ W ⎯ R : Hi-Z
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : Hi-Z
Charging from
USBIN source.
⎯ P ⎯ W ⎯ R : LOW
USBPWR: Hi-Z
⎯ C ⎯ H ⎯ R ⎯ G : LOW
No Charging.
⎯ P ⎯ W ⎯ R : Hi-Z
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : Hi-Z
No Charging.
⎯ P ⎯ W ⎯ R : Hi-Z
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : Hi-Z
HIGH
6V > V
V
USBIN
(the internal pull-down resistor defaults the charger to the
charging state). The opposite is true when the USB input is
supplying power; logic low disables the charger and logic
high enables it (the default is the shutdown state).
The DCIN input draws 40μA when the charger is in shut-
down mode. The USBIN input draws 40μA during shutdown
if no voltage is applied to DCIN, but draws only 23μA when
V
Status Indicators
The charge status open drain output ( ⎯ C ⎯ H ⎯ R ⎯ G ) has two
states: pull-down and high impedance. The pull-down
state indicates that the LTC4075HVX is in a charge cycle.
Once the charge cycle has terminated or the LTC4075HVX
is disabled, the pin state becomes high impedance.
The power supply status open drain output ( ⎯ P ⎯ W ⎯ R ) has
two states: pull-down and high impedance. The pull-down
state indicates that power is present at either DCIN or
USBIN. This output is strong enough to drive an LED. If no
valid voltage is applied at either pin, the ⎯ P ⎯ W ⎯ R pin is high
impedance, indicating that the LTC4075HVX lacks valid
input voltage (see Table 1) to charge the battery.
DCIN
USBIN
> BAT + 50mV
provides valid voltage (see Table 1).
> 3.95V and
LOW or No Connect
No Charging.
⎯ P ⎯ W ⎯ R : Hi-Z
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : Hi-Z
Charging from DCIN
source.
⎯ P ⎯ W ⎯ R : LOW
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : LOW
No Charging.
⎯ P ⎯ W ⎯ R : Hi-Z
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : Hi-Z
No Charging.
⎯ P ⎯ W ⎯ R : Hi-Z
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : Hi-Z
No Charging.
⎯ P ⎯ W ⎯ R : Hi-Z
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : Hi-Z
No Charging.
⎯ P ⎯ W ⎯ R : Hi-Z
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : Hi-Z
HIGH
22V > V
USBIN
No Charging.
⎯ P ⎯ W ⎯ R : Hi-Z
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : Hi-Z
Charging from DCIN
source.
⎯ P ⎯ W ⎯ R : LOW
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : LOW
No Charging.
⎯ P ⎯ W ⎯ R : Hi-Z
USBPWR: LOW
⎯ C ⎯ H ⎯ R ⎯ G : Hi-Z
LOW or No Connect
> 6V
4075hvxf