2
LTC1735-1
ABSOLUTE AXI U RATI GS
W
WW
U
PACKAGE/ORDER I FOR ATIO
UUW
(Note 1)
Input Supply Voltage (V
IN
)........................ 36V to –0.3V
Topside Driver Supply Voltage (BOOST)... 42V to –0.3V
Switch Voltage (SW) ................................... 36V to –5V
INTV
CC
, EXTV
CC
(BOOST, SW) Voltages..... 7V to –0.3V
SENSE
+
, SENSE
–
,
PGOOD Voltages................ 1.1(INTV
CC
+ 0.3V) to –0.3V
I
TH
, V
OSENSE
, C
OSC
Voltages .....................2.7V to –0.3V
RUN/SS Voltage ....................(INTV
CC
+ 0.3V) to –0.3V
Peak Driver Output Current <10µs (TG, BG) .............. 3A
INTV
CC
Output Current ......................................... 50mA
Operating Ambient Temperature Range
LTC1735C-1 ............................................ 0°C to 85°C
LTC1735I-1 ........................................ –40°C to 85°C
Junction Temperature (Note 2)............................. 125°C
Storage Temperature Range ................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)..................300°C
ELECTRICAL CHARACTERISTICS
ORDER PART
NUMBER
LTC1735CGN-1
LTC1735CS-1
LTC1735IGN-1
LTC1735IS-1
Consult factory for Military grade parts.
T
JMAX
= 125°C, θ
JA
= 130°C/W (GN)
T
JMAX
= 125°C, θ
JA
= 110°C/W (S)
TOP VIEW
S PACKAGE
16-LEAD PLASTIC SO
GN PACKAGE
16-LEAD PLASTIC SSOP
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
C
OSC
RUN/SS
I
TH
PGOOD
SENSE
–
SENSE
+
V
OSENSE
SGND
TG
BOOST
SW
V
IN
INTV
CC
BG
PGND
EXTV
CC
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 15V, V
RUN/SS
= 5V unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Control Loop
I
VOSENSE
Feedback Current (Note 3) –4 –25 nA
V
OSENSE
Feedback Voltage (Note 3) ● 0.792 0.8 0.808 V
∆V
LINEREG
Reference Voltage Line Regulation V
IN
= 3.6V to 30V (Note 3) 0.001 0.02 %/V
∆V
LOADREG
Output Voltage Load Regulation (Note 3)
Measured in Servo Loop; V
ITH
= 0.7V ● 0.1 0.3 %
Measured in Servo Loop; V
ITH
= 2V ● –0.1 –0.3 %
DF Max Maximum Duty Factor In Dropout 98 99.4 %
g
m
Transconductance Amplifier g
m
1.3 mmho
V
OVL
Feedback Overvoltage Lockout ● 0.84 0.86 0.88 V
I
Q
Input DC Supply Current (Note 5)
Normal Mode 3.6V < V
IN
< 30V 450 µA
Shutdown V
RUN/SS
= 0V 15 25 µA
V
RUN/SS
Run Pin Start Threshold V
RUN/SS
, Ramping Positive 1.0 1.5 1.9 V
Run Pin Begin Latchoff Threshold V
RUN/SS
, Ramping Positive 4.1 4.5 V
I
RUN/SS
Soft-Start Charge Current V
RUN/SS
= 0V –0.7 –1.2 µA
I
SCL
RUN/SS Discharge Current Soft Short Condition, V
OSENSE
= 0.5V, 0.5 2 4 µA
V
RUN/SS
= 4.5V
UVLO Undervoltage Lockout Measured at V
IN
Pin (Ramping Negative) ● 3.5 3.9 V
∆V
SENSE(MAX)
Maximum Current Sense Threshold V
OSENSE
= 0.7V ● 60 75 85 mV
I
SENSE
SENSE Pins Total Source Current V
SENSE
–
= V
SENSE
+
= 0V 60 80 µA
t
ON(MIN)
Minimum On-Time Tested with a Square Wave (Note 4) 160 200 ns
GN PART
MARKING
17351
1735I1
