Datasheet
LTC3855
2
3855f
absoluTe MaxiMuM raTings
(Note 1)
pin conFiguraTion
Input Supply Voltage (V
IN
) .........................–0.3V to 40V
Top Side Driver Voltages
BOOST1, BOOST2 ..................................–0.3V to 46V
Switch Voltage (SW1, SW2) .........................–5V to 40V
INTV
CC
, RUN1, RUN2, PGOOD(s), EXTV
CC
,
(BOOST1-SW1), (BOOST2-SW2) .............–0.3V to 6V
SENSE1
+
, SENSE2
+
, SENSE1
–
,
SENSE2
–
Voltages .................................–0.3V to 13V
MODE/PLLIN, I
LIM1
, I
LIM2
, TK/SS1, TK/SS2, FREQ,
DIFFOUT, PHASMD Voltages ............. –0.3V to INTV
CC
DIFFP, DIFFN ..........................................–0.3V to INTV
CC
ITEMP1, ITEMP2 Voltages ....................–0.3V to INTV
CC
I
TH1
, I
TH2
, V
FB1
, V
FB2
Voltages ..............–0.3V to INTV
CC
INTV
CC
Peak Output Current (Note 8) ..................100mA
Operating Junction Temperature Range (Notes 2, 3)
LTC3855 .............................................–40°C to 125°C
Storage Temperature Range ...................–65°C to 125°C
Lead Temperature (Soldering, 10 sec)
(FE Package) ..................................................... 300°C
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
TOP VIEW
FE PACKAGE
38-LEAD PLASTIC SSOP
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
ITEMP2
ITEMP1
RUN1
SENSE1
+
SENSE1
–
TK/SS1
I
TH1
V
FB1
V
FB2
I
TH2
TK/SS2
SENSE2
+
SENSE2
–
DIFFP
DIFFN
DIFFOUT
RUN2
I
LIM1
I
LIM2
FREQ
MODE/PLLIN
PHASMD
CLKOUT
SW1
TG1
BOOST1
PGND1
BG1
V
IN
INTV
CC
EXTV
CC
BG2
PGND2
BOOST2
TG2
SW2
PGOOD2
PGOOD1
39
SGND
T
JMAX
= 125°C, θ
JA
= 25°C/W
EXPOSED PAD (PIN 39) IS SGND, MUST BE SOLDERED TO PCB
3940 38 37 36 35 34 33 32 31
11 20
12 13 14 15
TOP VIEW
41
SGND
UJ PACKAGE
40-LEAD (6mm s 6mm) PLASTIC QFN
16 17 18 19
22
23
24
25
26
27
28
29
9
8
7
6
5
4
3
2
TK/SS1
I
TH1
V
FB1
SGND
V
FB2
I
TH2
TK/SS2
SENSE2
+
SENSE2
–
DIFFP
TG1
BOOST1
PGND1
BG1
V
IN
INTV
CC
EXTV
CC
BG2
PGND2
BOOST2
SENSE1
–
SENSE1
+
RUN1
ITEMP1
ITEMP2
FREQ
MODE/PLLIN
PHASMD
CLKOUT
SW1
DIFFN
DIFFOUT
RUN2
I
LIM1
I
LIM2
PGOOD1
PGOOD2
NC
SW2
TG2
21
30
10
1
T
JMAX
= 125°C, θ
JA
= 33°C/W
EXPOSED PAD (PIN 41) IS SGND, MUST BE SOLDERED TO PCB