LT1777 Linear Technology, LT1777 Datasheet - Page 2

• Manufacturer Part Number: LT1777
• Description: Low Noise Step-Down Switching Regulator
• Manufacturer: Linear Technology

ABSOLUTE
LT1777
ELECTRICAL CHARACTERISTICS
The
V
SYMBOL
Power Supplies
V
I
I
V
Feedback Amplifier
V
I
g
I
V
(Note 1)
Supply Voltage ....................................................... 48V
Switch Voltage (V
SHDN, SYNC Pin Voltage .......................................... 7V
V
FB Pin Voltage ........................................................ 3.0V
Operating Junction Temperature Range
Storage Temperature Range ................ – 65 C to 150 C
Lead Temperature (Soldering, 10 sec)................. 300 C
2
VIN
VCC
IN
SRC
m
IN(MIN)
VCC
REF
CL
IN
CC
LT1777C ............................................... 0 C to 125 C
LT1777I ........................................... – 40 C to 125 C
= 24V, V
, I
Pin Voltage ...................................................... 30V
SNK
denotes specifications which apply over the full operating temperature range, otherwise specifications are at T
PARAMETER
Minimum Input Voltage
V
V
V
Shutdown Mode I
Reference Voltage
FB Pin Input Bias Current
Feedback Amplifier Transconductance
Feedback Amplifier Source or Sink Current
Feedback Amplifier Clamp Voltage
Reference Voltage Line Regulation
Voltage Gain
SW
IN
CC
CC
Supply Current
Supply Current
Dropout Voltage
Open, V
IN
W
MAXIMUM
– V
CC
= 5V, V
VIN
SW
) (Note 4) ...................... 51V
W W
C
= 1.4V unless otherwise noted.
RATINGS
U
CONDITIONS
V
V
(Note 2)
V
12V V
C
C
SHDN
I
C
= 0V
= 0V
= 10 A
= 0V
IN
48V
PACKAGE/ORDER I FOR ATIO
Consult factory for Military grade parts.
SHDN
SGND
GND*
GND*
V
V
NC
SW
V
CC
T
D
JMAX
1
2
3
4
5
6
7
8
16-LEAD PLASTIC SO
= 125 C,
S PACKAGE
TOP VIEW
JA
= 50 C/W*
16
15
14
13
12
11
10
9
GND*
NC
V
FB
SYNC
NC
V
GND*
1.225
1.215
MIN
C
IN
400
200
200
60
45
U
1.240
TYP
620
600
650
100
600
6.7
2.5
2.8
2.0
*FOUR CORNER PINS ARE
30
FUSED TO INTERNAL DIE
ATTACH PADDLE FOR HEAT
SINKING. CONNECT THESE
FOUR PINS TO EXPANDED PC
LANDS FOR PROPER HEAT
SINKING.
ORDER PART
LT1777CS
LT1777IS
NUMBER
W
J
1.255
1.265
1500
1000
1500
= 25 C.
MAX
0.01
800
900
170
220
7.0
7.4
3.5
4.5
3.1
50
75
UNITS
U
mho
mho
%/V
V/V
mA
mA
nA
V
V
A
A
V
A
A
V
V
A
A
V