Datasheet
2
LTC3728
3728fc
ORDER PART
NUMBER
LTC3728EG
Input Supply Voltage (V
IN
).........................36V to –0.3V
Top Side Driver Voltages
(BOOST1, BOOST2) ...................................42V to –0.3V
Switch Voltage (SW1, SW2) .........................36V to –5V
INTV
CC,
EXTV
CC
, RUN/SS1, RUN/SS2, (BOOST1-SW1),
(BOOST2-SW2), PGOOD .............................7V to – 0.3V
SENSE1
+
, SENSE2
+
, SENSE1
–
,
SENSE2
–
Voltages ........................ (1.1)INTV
CC
to –0.3V
T
JMAX
= 125°C, θ
JA
= 95°C/W
1
2
3
4
5
6
7
8
9
10
11
12
13
14
TOP VIEW
G PACKAGE
28-LEAD PLASTIC SSOP
28
27
26
25
24
23
22
21
20
19
18
17
16
15
RUN/SS1
SENSE1
+
SENSE1
–
V
OSENSE1
PLLFLTR
PLLIN
FCB
I
TH1
SGND
3.3V
OUT
I
TH2
V
OSENSE2
SENSE2
–
SENSE2
+
PGOOD
TG1
SW1
BOOST1
V
IN
BG1
EXTV
CC
INTV
CC
PGND
BG2
BOOST2
SW2
TG2
RUN/SS2
ABSOLUTE AXI U RATI GS
WWWU
PACKAGE/ORDER I FOR ATIO
UU
W
(Note 1)
PLLIN, PLLFLTR, FCB, Voltage ............ INTV
CC
to –0.3V
I
TH1,
I
TH2
, V
OSENSE1
, V
OSENSE2
Voltages ...2.7V to – 0.3V
Peak Output Current <10µs (TG1, TG2, BG1, BG2) ... 3A
INTV
CC
Peak Output Current ................................ 50mA
Operating Temperature Range (Note 7) ... –40°C to 85°C
Junction Temperature (Note 2)............................. 125°C
Storage Temperature Range ................. – 65°C to 125°C
Lead Temperature (Soldering, 10 sec)
(G Package Only) .................................................. 300°C
32
33
31 30 29 28 27 26 25
9 10 11 12 13
TOP VIEW
14 15 16
17
18
19
20
21
22
23
24
8
7
6
5
4
3
2
1V
OSENSE1
PLLFLTR
PLLIN
FCB
I
TH1
SGND
3.3V
OUT
I
TH2
BOOST1
V
IN
BG1
EXTV
CC
INTV
CC
PGND
BG2
BOOST2
NC
SENSE1
–
SENSE1
+
NC
RUN/SS1
PGOOD
TG1
SW1
V
OSENSE2
NC
SENSE2
–
SENSE2
+
RUN/SS2
TG2
SW2
NC
ORDER PART
NUMBER
LTC3728EUH
UH PACKAGE
32-LEAD (5mm × 5mm) PLASTIC QFN
T
JMAX
= 125°C, θ
JA
= 34°C/W
EXPOSED PAD IS SGND (MUST BE SOLDERED TO PCB)
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 15V, V
RUN/SS1, 2
= 5V unless otherwise noted.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Control Loops
V
OSENSE1, 2
Regulated Feedback Voltage (Note 3); I
TH1, 2
Voltage = 1.2V ● 0.792 0.800 0.808 V
I
VOSENSE1, 2
Feedback Current (Note 3) –5 – 50 nA
V
REFLNREG
Reference Voltage Line Regulation V
IN
= 3.6V to 30V (Note 3) 0.002 0.02 %/V
V
LOADREG
Output Voltage Load Regulation (Note 3)
Measured in Servo Loop; ∆I
TH
Voltage = 1.2V to 0.7V ● 0.1 0.5 %
Measured in Servo Loop; ∆I
TH
Voltage = 1.2V to 2.0V ● –0.1 –0.5 %
Consult LTC Marketing for parts specified with wider operating temperature ranges.
UH PART
MARKING
3728
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/