FAN54013_12 Datasheet, PDF (24/36 Pages) Fairchild Semiconductor – FAN54010 / FAN54011 / FAN54012 / FAN54013 / FAN54014

Special Charger
FAN54013, FAN54014 Only
The FAN54013 and FAN54014 have additional functionality
to limit input current in case a current-limited “special
charger” is supplying VBUS. These slowly increase the
charging current until either:
 I_INLIM or I_OCHARGE is reached
or
 V_BUS=V_SP.
If V_BUS collapses to V_SP when the current is ramping up, the
FAN54013 and FAN54014 charge with an input current that
keeps V_BUS=V_SP. When the V_SP control loop is limiting the
charge current, the SP bit (REG5[4]) is set.
Table 8. V_SP as Function of SP Bits (REG5[2:0])
SP (REG5[2:0])
DEC
BIN
HEX
V_SP
0
000
00
4.213
1
001
01
4.293
2
010
02
4.373
3
011
03
4.453
4
100
04
4.533
5
101
05
4.613
6
110
06
4.693
7
111
07
4.773
Safety Settings
FAN54013 and FAN54014 Only
The FAN54013 and FAN54014 contain a SAFETY register
(REG6) that prevents the values in OREG (REG2[7:2]) and
IOCHARGE (REG4[6:4]) from exceeding the values of the
VSAFE and ISAFE values.
After V_BAT exceeds V_SHORT, the SAFETY register is loaded
with its default value and may be written only before any
other register is written. After writing to any other register,
the SAFETY register is locked until V_BAT falls below V_SHORT.
The ISAFE (REG6[6:4]) and VSAFE (REG6[3:0]) registers
establish values that limit the maximum values of I_OCHARGE
and V_OREG used by the control logic. If the host attempts to
write a value higher than VSAFE or ISAFE to OREG or
IOCHARGE, respectively; the VSAFE, ISAFE value appears
as the OREG, IOCHARGE register value, respectively.
Table 9. I_SAFE (I_OCHARGE Limit) as Function of ISAFE
Bits (REG6[6:4])
ISAFE (REG6[6:4])
I_SAFE (mA)
DEC BIN HEX V_RSENSE (mV)
68 m 100 m
0
000 00
37.4
550
374
1
001 01
44.2
650
442
2
010 02
51.0
750
510
3
011 03
57.8
850
578
4 100 04
71.4
1050
714
5
101 05
78.2
1150
782
6
110 06
91.8
1350
918
7
111 07
98.6
1450
986
Table 10. V_SAFE (V_OREG Limit) as Function of VSAFE
Bits (REG6[3:0])
VSAFE (REG6[3:0])
DEC BIN HEX
Max. OREG
(REG2[7:2])
VOREG
Max.
0 0000 00
100011
4.20
1
0001 00
100100
4.22
2
0010 01
100101
4.24
3
0011 02
100110
4.26
4
0100 03
100111
4.28
5
0101 04
101000
4.30
6
0110 05
101001
4.32
7
0111 06
101010
4.34
8
1000 07
101011
4.36
9
1001 08
101100
4.38
10 1010 09
101101
4.40
11 1011 0A
101110
4.42
12 1100 0B
101111
4.44
13 1101 0C
110000
4.44
14 1110 0D
110001
4.44
15 1111 0E
110010
4.44
Thermal Regulation and Protection
When the IC’s junction temperature reaches T_CF (about
120°C), the charger reduces its output current to 550 mA to
prevent overheating. If the temperature increases beyond
T_SHUTDOWN; charging is suspended, the FAULT bits are set
to 101, and STAT is pulsed HIGH. In Suspend Mode, all
timers stop and the state of the IC’s logic is preserved.
Charging resumes at programmed current after the die
cools to about 120°C.
© 2011 Fairchild Semiconductor Corporation
FAN5401X Family • Rev. 1.0.4
24
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