LT8705AE (Notes 3, 8)....................... –40°C to 125°C
LT8705AI (Notes 3, 8)........................ –40°C to 125°C
LT8705AH (Notes 3, 8) ...................... –40°C to 150°C
LT8705AMP (Notes 3, 8) ................... –55°C to 150°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)
FE Package ....................................................... 300°C
pin conFiguraTion
TOP VIEW
TOP VIEW
IMON_IN
INTV
CC
CSNIN
CSPIN
MODE
SWEN
V
IN
INTV
CC
MODE
IMON_IN
SHDN
31 CSPOUT
30 CSNOUT
29 EXTV
CC
28 SRVO_FBOUT
27 SRVO_IOUT
39
GND
26 SRVO_IIN
25 SRVO_FBIN
24 NC
23 BOOST1
22 TG1
21 SW1
20 NC
13 14 15 16 17 18 19
BG2
BOOST2
TG2
GATEV
CC
SW2
GND
BG1
CSN
CSP
LDO33
FBIN
FBOUT
1
2
3
4
5
6
7
8
9
39
GND
30
EXTV
CC
28
BOOST1
26
TG1
24
SW1
22
SW2
21
TG2
20
BOOST2
32
CSNOUT
34
CSPOUT
38
V
IN
37
CSPIN
36
CSNIN
38 37 36 35 34 33 32
SHDN
1
CSN 2
CSP 3
LDO33 4
FBIN 5
FBOUT 6
IMON_OUT 7
V
C
8
SS 9
CLKOUT 10
SYNC 11
RT 12
IMON_OUT
10
V
C
11
SS
12
CLKOUT
13
SYNC
14
RT
15
GND
16
BG1
17
GATEV
CC
18
BG2
19
UHF PACKAGE
38-LEAD (5mm
×
7mm) PLASTIC QFN
T
JMAX
= 125°C,
θ
JA
= 34°C/W
EXPOSED PAD (PIN 39) IS GND, MUST BE SOLDERED TO PCB
FE PACKAGE
VARIATION: FE38(31)
38-LEAD PLASTIC TSSOP
T
JMAX
= 125°C,
θ
JA
= 25°C/W
EXPOSED PAD (PIN 39) IS GND, MUST BE SOLDERED TO PCB
8705af
2
For more information
www.linear.com/LT8705A
LT8705A
orDer inForMaTion
LEAD FREE FINISH
LT8705AEUHF#PBF
LT8705AIUHF#PBF
LT8705AEFE#PBF
LT8705AIFE#PBF
LT8705AHFE#PBF
LT8705AMPFE#PBF
TAPE AND REEL
LT8705AEUHF#TRPBF
LT8705AIUHF#TRPBF
LT8705AEFE#TRPBF
LT8705AIFE#TRPBF
LT8705AHFE#TRPBF
LT8705AMPFE#TRPBF
http://www.linear.com/product/LT8705A#orderinfo
PART MARKING*
8705A
8705A
LT8705AFE
LT8705AFE
LT8705AFE
LT8705AFE
PACKAGE DESCRIPTION
38-Lead (5mm
×
7mm) Plastic QFN
38-Lead (5mm
×
7mm) Plastic QFN
38-Lead Plastic TSSOP
38-Lead Plastic TSSOP
38-Lead Plastic TSSOP
38-Lead Plastic TSSOP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
–55°C to 150°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/.
Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
elecTrical characTerisTics
PARAMETER
Voltage Supplies and Regulators
V
IN
Operating Voltage Range
V
IN
Quiescent Current
V
IN
Quiescent Current in Shutdown
EXTV
CC
Switchover Voltage
EXTV
CC
Switchover Hysteresis
INTV
CC
Current Limit
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V,
SHDN
= 3V unless otherwise noted. (Note 3)
CONDITIONS
EXTV
CC
= 0V
EXTV
CC
= 7.5V
Not Switching, V
EXTVCC
= 0
V
SHDN
= 0V
I
INTVCC
= 20mA, V
EXTVCC
Rising
l
l
l
MIN
5.5
2.8
TYP
MAX
80
80
UNITS
V
V
mA
µA
V
V
2.65
0
6.15
6.4
0.18
4.2
1
6.6
Maximum Current Draw from INTV
CC
and LDO33
Pins Combined. Regulated from V
IN
or EXTV
CC
(12V)
l
INTV
CC
= 5.25V
l
INTV
CC
= 4.5V
Regulated from V
IN
, I
INTVCC
= 20mA
Regulated from EXTV
CC
(12V), I
INTVCC
= 20mA
I
INTVCC
= 0mA to 50mA
INTV
CC
Falling, GATEV
CC
Connected to INTV
CC
GATEV
CC
Connected to INTV
CC
V
IN
-V
INTVCC
, I
INTVCC
= 20mA
5mA from LDO33 Pin
I
LDO33
= 0.1mA to 5mA
l
l
l
l
l
90
28
6.15
6.15
4.45
127
42
6.35
6.35
–0.5
4.65
160
245
165
55
6.55
6.55
–1.5
4.85
mA
mA
V
V
%
V
mV
mV
INTV
CC
Voltage
INTV
CC
Load Regulation
INTV
CC
, GATEV
CC
Undervoltage Lockout
INTV
CC
, GATEV
CC
Undervoltage Lockout Hysteresis
INTV
CC
Regulator Dropout Voltage
LDO33 Pin Voltage
LDO33 Pin Load Regulation
LDO33 Pin Current Limit
LDO33 Pin Undervoltage Lockout
LDO33 Pin Undervoltage Lockout Hysteresis
Switching Regulator Control
Maximum Current Sense Threshold (V
CSP
– V
CSN
)
Maximum Current Sense Threshold (V
CSN
– V
CSP
)
3.23
12
2.96
3.295
–0.25
17.25
3.04
35
3.35
–1
22
3.12
V
%
mA
V
mV
LDO33 Falling
Boost Mode, Minimum M3 Switch Duty Cycle
(LT8705AE, LT8705AI)
(LT8705AH, LT8705AMP)
Buck Mode, Minimum M2 Switch Duty Cycle
(LT8705AE, LT8705AI)
(LT8705AH, LT8705AMP)
l
l
l
l
102
100
69
67
117
117
86
86
132
134
102
104
mV
mV
mV
mV
8705af
For more information
www.linear.com/LT8705A
3
LT8705A
elecTrical characTerisTics
PARAMETER
Gain from V
C
to Maximum Current Sense Voltage
(V
CSP
-V
CSN
) (A5 in the Block Diagram)
SHDN
Input Voltage High
SHDN
Input Voltage High Hysteresis
SHDN
Input Voltage Low
Device Disabled, Low Quiescent Current
(LT8705AE, LT8705AI)
(LT8705AH, LT8705AMP)
V
SHDN
= 3V
V
SHDN
= 12V
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V,
SHDN
= 3V unless otherwise noted. (Note 3)
CONDITIONS
Boost Mode
Buck Mode
SHDN
Rising to Enable the Device
l
MIN
TYP
150
–150
MAX
UNITS
mV/V
mV/V
V
mV
1.184 1.234 1.284
50
0.35
0.3
0
11
22
1
22
V
V
µA
µA
V
mV
V
SHDN
Pin Bias Current
SWEN Rising Threshold Voltage (Note 5)
SWEN Threshold Voltage Hysteresis (Note 5)
MODE Pin Forced Continuous Mode Threshold
MODE Pin Burst Mode Range
MODE Pin Discontinuous Mode Threshold
Soft-Start Charging Current
Soft-Start Discharge Current
Regulation Voltage for FBOUT
Regulation Voltage for FBIN
Line Regulation for FBOUT and FBIN Error Amp Reference
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