Datasheet

5
LTC4006
4006fa
nected and the CHG pin is forced into a high impedance
state. A pull-up resistor is required. The timer function is
defeated by forcing this pin below 1V (or connecting it to
GND).
ACP/SHDN (Pin 3): Open-Drain Output used to indicate if
the AC adapter voltage is adequate for charging. Active
high digital output. Internal 10µA pull-up to 3.5V. The
charger can also be inhibited by pulling this pin below 1V.
Reset the charger by pulsing the pin low for a minimum of
0.1µs.
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Disconnect/Reconnect Battery
(Load Dump)
Battery Leakage Current vs
Battery Voltage
4006 G04
LOAD CURRENT = 1A, 2A, 3A
DCIN = 20V
LTC4006-2
V
FLOAT
1V/(DIV)
LOAD
STATE
DISCONNECT
RECONNECT
1A STEP
3A STEP
3A STEP
1A STEP
BATTERY VOLTAGE (V)
0 5 10 15 20 25 30
BATTERY LEAKAGE CURRENT (µA)
4006 G05
40
35
30
25
20
15
10
5
0
VDCIN = 0V
Efficiency at 19VDC V
IN
LTC4006-2 Efficiency with
15VDC V
IN
CHARGING CURRENT (A)
1.000.50 1.50 2.00 2.50 3.00
EFFICIENCY (%)
4006 G07
LTC4006-4
LTC4006-2
100
95
90
85
80
75
CHARGING CURRENT (A)
1.000.50 1.50 2.00 2.50 3.00
EFFICIENCY (%)
4006 G08
100
95
90
85
80
75
UU
U
PI FU CTIO S
DCIN (Pin 1): External DC Power Source Input. Bypass
this pin with at least 0.01µF. See Applications Information
section.
CHG (Pin 2): Open-Drain Charge Status Output. When the
battery is being charged, the CHG pin is pulled low by an
internal N-channel MOSFET. When the charge current
drops below 10% of programmed current, the N-channel
MOSFET turns off and a 25µA current source is connected
from the CHG pin to GND. When the timer runs out or the
input supply is removed, the current source will be discon-