Linear Technology Analog Devices LT8708, Datasheet

Page: 62 / 64

LT8708
62
Rev 0
For more information www.analog.com
APPLICATIONS INFORMATION
Charging V
OUT
to 15V with 1A Current
Transient Behavior Upon V
IN
Dropout (I
LOAD
= 4A)
Supercapacitor Backup Supply Using CCM Detail
V
OUT
Charge Voltage = 15V (FBOUT) V
BACKUP
Overvoltage Rising Threshold in Backup Operation = 13.3V (VINHIMON Rising)
V
BACKUP
Regulation Voltage = 11V (FBIN) V
BACKUP
Overvoltage Falling Threshold in Backup Operation = 12.9V (VINHIMON Falling)
V
IN_MIN
= 5.42V (Falling) or 5.65V (Rising) V
OUT
Charging Current Limit = 1A (IMON_OP)
Frequency = 350kHz V
IN
Current Limit = 2A (IMON_INP)
Table of Operation Modes and Power Flow Directions
V
BACKUP
V
OUT
POWER FLOW CHIP OPERATES IN RVSOFF *
<V
IN_MIN
–
NO POWER FLOW
Shutdown –
>13.3V
>15V
CCM
Lo
<15V Power Flows from V
IN
to V
OUT
(V
OUT
Charging)
Fell Into (12.9V to 13.3V)
Range
>15V
No Power Flow
Rose Into (12.9V to 13.3V)
Range
<15V
Power Flows from V
OUT
to LOADS
(Backup Operation)
Hi
Power Flows from V
IN
to V
OUT
(V
OUT
Charging)
>11V and <12.9V >15V
Power Flows from V
OUT
to LOADS
(Backup Operation)
<11V and >V
IN_MIN
–
*For use with LT8708-1(s)
20s/DIV
8708 TA06d
V
IN
5V/DIV
V
OUT
5V/DIV
I
L
5A/DIV
3s/DIV
8708 TA06e
V
OUT
5V/DIV
V
BACKUP
5V/DIV
I
L
5A/DIV