LTC1778/LTC1778-1
ABSOLUTE
AXI U
RATI GS
Input Supply Voltage (V
IN
, I
ON
)................. 36V to – 0.3V
Boosted Topside Driver Supply Voltage
(BOOST) ................................................... 42V to – 0.3V
SW Voltage .................................................. 36V to – 5V
EXTV
CC
, (BOOST – SW), RUN/SS,
PGOOD Voltages ....................................... 7V to – 0.3V
FCB, V
ON
, V
RNG
Voltages .......... INTV
CC
+ 0.3V to – 0.3V
I
TH
, V
FB
Voltages...................................... 2.7V to – 0.3V
PACKAGE/ORDER I FOR ATIO
TOP VIEW
RUN/SS 1
PGOOD 2
V
RNG
3
FCB 4
I
TH
5
SGND 6
I
ON
7
V
FB
8
16 BOOST
15 TG
14 SW
13 PGND
12 BG
11 INTV
CC
10 V
IN
9
EXTV
CC
ORDER PART
NUMBER
LTC1778EGN
LTC1778IGN
GN PART MARKING
1778
1778I
GN PACKAGE
16-LEAD PLASTIC SSOP
T
JMAX
= 125°C,
θ
JA
= 130°C/ W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
SYMBOL
I
Q
PARAMETER
Input DC Supply Current
Normal
Shutdown Supply Current
Feedback Reference Voltage
Feedback Voltage Line Regulation
Feedback Voltage Load Regulation
Feedback Input Current
Error Amplifier Transconductance
Forced Continuous Threshold
Forced Continuous Pin Current
On-Time
Minimum On-Time
Main Control Loop
The
●
denotes specifications which apply over the full operating
temperature range, otherwise specifications are T
A
= 25°C. V
IN
= 15V unless otherwise noted.
CONDITIONS
MIN
TYP
MAX
UNITS
V
FB
∆V
FB(LINEREG)
∆V
FB(LOADREG)
I
FB
g
m(EA)
V
FCB
I
FCB
t
ON
t
ON(MIN)
I
TH
= 1.2V (Note 3) LTC1778E
I
TH
= 1.2V (Note 3) LTC1778I
V
IN
= 4V to 30V, I
TH
= 1.2V (Note 3)
I
TH
= 0.5V to 1.9V (Note 3)
V
FB
= 0.8V
I
TH
= 1.2V (Note 3)
V
FCB
= 0.8V
I
ON
= 30µA, V
ON
= 0V (LTC1778-1)
I
ON
= 15µA, V
ON
= 0V (LTC1778-1)
I
ON
= 180µA
2
U
U
W
W W
U
W
(Note 1)
TG, BG, INTV
CC
, EXTV
CC
Peak Currents .................... 2A
TG, BG, INTV
CC
, EXTV
CC
RMS Currents .............. 50mA
Operating Ambient Temperature Range (Note 4)
LTC1778E ........................................... – 40°C to 85°C
LTC1778I .......................................... – 40°C to 125°C
Junction Temperature (Note 2) ............................ 125°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
TOP VIEW
RUN/SS 1
V
ON
2
V
RNG
3
FCB 4
I
TH
5
SGND 6
I
ON
7
V
FB
8
16 BOOST
15 TG
14 SW
13 PGND
12 BG
11 INTV
CC
10 V
IN
9
EXTV
CC
ORDER PART
NUMBER
LTC1778EGN-1
GN PART MARKING
17781
GN PACKAGE
16-LEAD PLASTIC SSOP
T
JMAX
= 125°C,
θ
JA
= 130°C/ W
900
15
●
●
●
●
●
2000
30
0.808
0.812
– 0.3
±50
2
0.84
–2
268
536
100
µA
µA
V
V
%/V
%
nA
mS
V
µA
ns
ns
ns
1778fb
0.792
0.792
0.800
0.800
0.002
– 0.05
–5
1.4
0.76
198
396
1.7
0.8
–1
233
466
50
LINER [ LINEAR TECHNOLOGY ]
