LTC4040_15 Datasheet, PDF (7/26 Pages) Linear Technology – 2.5A Battery Backup Power Manager

LTC4040
Typical Performance Characteristics T_A = 25°C, unless otherwise noted.
Li–-IIoonn BBaatttteerryy CChhaarrggiinngg PPrrooffiile
4.20
1200
4.00
V_BAT
1000
3.80
800
3.60
600
I_BAT
3.40
V_SYS = 5V
R_PROG = 2k
400
F2 = F1 = F0 = 1
3.20
200
3.00
0
0123456
TIME (h)
4040 G10
Charge Current Reduction Due to
Input Current Limit Set by R_SS
2500
TOTAL INPUT CURRENT
2000
1500
V_SYS = 5V
R_PROG = 2k
R_S = 12 mΩ
I_BAT
1000
500
0
0
500 1000 1500 2000 2500
SYSTEM LOAD CURRENT (mA)
4040 G12
BBaacckkuupp ttoo NNoorrmmaall MMooddee
TTrraannssiittiioonn WWaavveeffoorrmm
6
6
5 ^VSYS
4
3
5
V_BAT = 3.7V
R_PROG = 2k
4
I_SYS = 1A
3
2
2
I_BAT
1
1
0
V_IN
ZERO
0
–1
–200–100 0
–1
100 200 300 400 500 600 700
TIME (ms)
4040 G14
LLiiFFeePPOO₄₄ BBaatttteerryy CChhaarrggiinngg PPrrooffiillee
3.7
1200
3.6
1000
3.5
800
3.4
600
3.3
V_SYS = 5V
R_PROG = 2k
400
F2 = 0, F1 = F0 = 1
3.2
200
3.1
0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
TIME (h)
4040 G11
NNoorrmmaall ttoo BBaacckkuupp MMooddee
TTrraannssiittiioonn WWaavveeffoorrmm ((LLii-–IoIonn))
6
12
V_SYS
5
10
4
V_IN
V_BAT = 3.6V
I_SYS = 1A
8
R_PROG = 2k
3
C_SYS = 100µF ₆
2
4
1
I_BAT
2
0
0
–1
–500 –250
0 250 500
TIME (µs)
–2
750 1000
4040 G13
PPRROOGG VVoollttaaggee TTrraannssiieennttRReessppoonnssee
btoy System Step Load
1.5
6
V_BAT = 3.7V
1.0
R_PROG = 2k
R_S = 12mΩ
V_PROG
5
0.5
4
0.0
3
I_SYS
–0.5
2
–1.0
I_BAT
1
–1.5
0
–2.0
0
–1
200 400 600 800 1000 1200
TIME (µs)
4040 G15
For more information www.linear.com/LTC4040
4040fa
7