Linear Technology Analog Devices LT8708, Datasheet

Page: 56 / 64

LT8708
56
Rev 0
For more information www.analog.com
APPLICATIONS INFORMATION
Table of Operation Modes and Power Flow Directions
CONDITIONS RESULTS
V
BAT1
V
BAT2
DIR POWER FLOW CHIP OPERATES IN RVSOFF *
<V
BAT1_DEAD
–
–
No Power Flow
Shutdown
–
– <V
BAT2_DEAD
No Switching
<V
BAT1_UV
>V
BAT2_DEAD
Hi FHCM
>V
BAT1_UV
>14.5V
>V
BAT2_DEAD
and <14.5V
Power Flows from V
BAT1
to V
BAT2
(V
BAT2
Charging)
>V
BAT1_DEAD
>V
BAT2_DEAD
and <V
BAT2_UV
Lo
No Power Flow
RHCM
Lo
>14.6V >V
BAT2_UV
Hi
>V
BAT1_DEAD
and <14.6V >V
BAT2_UV
Power Flows from V
BAT2
to V
BAT1
(V
BAT1
Charging)
*For use with LT8708-1(s)
V
BAT1
Charge Voltage = 14.6V (FBIN in RHCM) V
BAT2_UV
to Stop Discharging = 10.5V (VOUTLOMON Falling) or 11.7V (VOUTLOMON Rising)
V
BAT2
Charge Voltage = 14.5V (FBOUT in FHCM) V
BAT1
Charging Current Limit = 15A (IMON_INN)
V
BAT1_DEAD
= 9V (Falling) or 9.4V (Rising) V
BAT2
Charging Current Limit = 15A (IMON_OP)
V
BAT2_DEAD
= 9.25V (Falling) or 9.4V (Rising) Frequency = 120kHz
V
BAT1_UV
to Stop Discharging = 10.5V (FBIN in FHCM)
Direction Change with
V
BAT1
= 13.5V and V
BAT2
= 13.5V
Direction Change with
V
BAT1
= 13.5V and V
BAT2
= 16V
Direction Change with
V
BAT1
= 16V and V
BAT2
= 13.5V
V
BAT1
Charging Lead Acid Battery V
BAT2
V
BAT2
Charging Lead Acid Battery V
BAT1
V
BAT2
I
OUT
CHARGING TIME (HOURS)
0 5 10 15
10
11
12
13
14
15
0
3
6
10
13
16
V
BA
T2
(V)
I
OUT
(A)
BAT2
8708 TA03g
V
BAT1
I
IN
CHARGING TIME (HOURS)
0 5 10 15
10
11
12
13
14
15
0
3
6
10
13
16
V
BA
T1
(V)
I
IN
(A)
BAT1
8708 TA03h
200ms/DIV
8708 TA03d
DIR
5V/DIV
I
L
25A/DIV
I
IN
25A/DIV
I
OUT
25A/DIV
200ms/DIV
8708 TA03e
DIR
5V/DIV
I
L
25A/DIV
I
OUT
25A/DIV
I
IN
25A/DIV
200ms/DIV
8708 TA03f
DIR
5V/DIV
I
L
25A/DIV
I
IN
25A/DIV
I
OUT
25A/DIV
12V Bidirectional Dual Battery System with FHCM & RHCM Details