Datasheet

7
4012fa
LTC4012/
LTC4012-1/LTC4012-2
typical perForMance characteristics
PWM Frequency vs Duty Cycle
Gate Drive Non-Overlap
Battery Shutdown Current
Charge Current Line Regulation
Input Current Limit
DCIN PIN VOLTAGE (V)
5
–0.5
CHARGE CURRENT ERROR (%)
–0.4
–0.2
–0.1
0
0.5
0.2
10
15
4012 G08
–0.3
0.3
0.4
0.1
20
25
I
CHG
= 1A
I
CHG
= 2A
I
CHG
= 3A
BAT = 6V
R
SENSE
= 33mΩ
R
IN
= 3.01k
Charge Current Load Regulation
BATTERY VOLTAGE (V)
11.0
CHARGE CURRENT (A)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
–0.5
12.6
4012 G09
11.4 11.8 12.2 13.0
I
CHG
= 3A
I
CHG
= 2A
I
CHG
= 1A
DCIN = 20V
R
SENSE
= 33mΩ
R
IN
= 3.01k
SYSTEM LOAD (A)
0
CURRENT (A)
0.5
1.0
1.5
1.5
2.5
4012 G10
0
–0.5
–1.0
0.5 1.0 2.0
2.0
2.5
3.0
I
IN
I
CHG
ICL STATE
2.5A BULK CHARGE
2.1A INPUT CURRENT LIMIT
PWM Soft-Start
I
CHG
2A/DIV
TIME (500µs/DIV)
4012 G11
ITH
1V/DIV
PROG
1V/DIV
SHDN
5V/DIV
TIME (80ns/DIV)
EXTERNAL FET DRIVE (1V/DIV)
4012 G12
TGATE
BGATE
DUTY CYCLE (%)
0
0
PWM FREQUENCY (kHz)
100
200
300
400
500
600
20 40 60 80
4012 G13
100
CLP = 6V
CLP = 12V
CLP = 20V
CLP = 25V
I
CHG
= 750mA
PWM Frequency
vs Charge Current
CHARGE CURRENT (A)
0
0
PWM FREQUENCY (kHz)
100
200
300
400
600
0.5
1.0 1.5 2.0
4012 G14
2.5 3.0
500
BAT = 14.5V
BAT = 12V
BAT = 5V
CLP = 15V
R
SENSE
= 33mΩ
R
IN
= 3.01k
BATTERY VOLTAGE (V)
0
0
BATTERY CURRENT (µA)
5
10
15
25
5 10 15
4012 G15
20 25
20
DC1256-CLASS
APPLICATION
DCIN = 0V
LTC4012,
ALL PINS
DCIN = 0V
LTC4012,
BAT PINS
DCIN = 20V
(T
A
= 25°C unless otherwise noted. L = IHLP-2525 6.8µH)
INFET Response Time to
DCIN Short to Ground
0A
V
GS =
0V
TIME (1µs/DIV)
DCIN = 15V
INFET = Si7423DN
I
OUT
= <50mA
V
OUT
= 12.3V
C
OUT
= 0.27F
4012 G16
PFET V
GS
(1V/DIV)
I
DCIN,
REVERSE
(5A/DIV)