LTC4006 Datasheet, PDF (4/16 Pages) Linear Technology – 4A, High Efficiency, Standalone Li-Ion Battery Charger

LTC4006
ELECTRICAL CHARACTERISTICS The q denotes specifications which apply over the full operating
temperature range (Note 4), otherwise specifications are at T_A = 25°C. V_DCIN = 20V, V_BAT = 12V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Oscillator
f_OSC
Regulator Switching Frequency
f_MIN
Regulator Switching Frequency in Drop Out
DC_MAX Regulator Maximum Duty Cycle
Gate Drivers (TGATE, BGATE)
Duty Cycle ≥ 98%
V_CSP = V_BAT
255
300
345
kHz
20
25
kHz
98
99
%
TGTR
TGTF
BGTR
BGTF
V_TGATE High (V_CLN – V_TGATE)
V_BGATE High
V_TGATE Low (V_CLN – V_TGATE)
V_BGATE Low
TGATE Transition Time
TGATE Rise Time
TGATE Fall Time
BGATE Transition Time
BGATE Rise Time
BGATE Fall Time
V_TGATE at Shutdown (V_CLN – V_TGATE)
V_BGATE at Shutdown
I_TGATE = –1mA
C_LOAD = 3000pF
C_LOAD = 3000pF
I_BGATE = 1mA
C_LOAD = 3000pF, 10% to 90%
C_LOAD = 3000pF, 10% to 90%
C_LOAD = 3000pF, 10% to 90%
C_LOAD = 3000pF, 10% to 90%
I_TGATE = –1µA, DCIN = 0V, CLN = 12V
I_BGATE = 1µA, DCIN = 0V, CLN = 12V
50
mV
4.5
5.6
10
V
4.5
5.6
10
V
50
mV
50
110
ns
50
100
ns
40
90
ns
40
80
ns
100
mV
100
mV
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: See Test Circuit
Note 3: Does not include tolerance of current sense resistor.
Note 4: The LTC4006E is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
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-
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.
R_T (Pin 4): Timer Resistor. The timer period is set by
placing a resistor, R_RT , to GND.
The timer period is t_TIMER = (1hour • R_RT/154k)
If this resistor is not present, the charger will not start.
GND (Pin 5): Ground for Low Power Circuitry.
4
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