LT1578IS8 Linear Technology, LT1578IS8 Datasheet - Page 2

• Manufacturer Part Number: LT1578IS8
• Description: IC BUCK SYNC ADJ 1.5A 8SOIC
• Manufacturer: Linear Technology
• Type: Step-Down (Buck)r

Specifications of LT1578IS8

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: Adj to 1.21V
• Current - Output: 1.5A
• Frequency - Switching: 200kHz
• Voltage - Input: 4 ~ 15 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -

LT1578/LT1578-2.5
ABSOLUTE
(Note 1)
Input Voltage .......................................................... 16V
BOOST Pin Above Input Voltage ............................. 10V
SHDN Pin Voltage ..................................................... 7V
SENSE Pin Voltage .................................................... 4V
FB Pin Voltage (Adjustable Part) ............................ 3.5V
FB Pin Current (Adjustable Part) ............................ 1mA
SYNC Pin Voltage ..................................................... 7V
Operating Junction Temperature Range
Storage Temperature Range ................ – 65 C to 150 C
Lead Temperature (Soldering, 10 sec)................. 300 C
ELECTRICAL CHARACTERISTICS
ture range, otherwise specifications are at T
PARAMETER
Feedback Voltage
Sense Voltage (Fixed 2.5)
Sense Pin Resistance
Reference Voltage Line Regulation
Feedback Input Bias Current
Error Amplifier Voltage Gain (Notes 2, 10)
Error Amplifier Transconductance (Note 10)
V
Error Amplifier Source Current
Error Amplifier Sink Current
V
V
Switch Current Limit
Slope Compensation (Note 8)
Switch On Resistance (Note 7)
Maximum Switch Duty Cycle
Minimum Switch Duty Cycle (Note 9)
Switch Frequency
Switch Frequency Line Regulation
Frequency Shifting Threshold on FB Pin
Minimum Input Voltage (Note 3)
Minimum Boost Voltage (Note 4)
2
C
C
C
Pin to Switch Current Transconductance
Pin Switching Threshold
Pin High Clamp
LT1578C ............................................... 0 C to 125 C
LT1578I ........................................... – 40 C to 125 C
W
MAXIMUM
W W
CONDITIONS
All Conditions
All Conditions
4.3V V
V
V
Duty Cycle = 0
V
DC = 80%
I
V
V
4.3V V
I
SW
SW
FB
FB
C
FB
C
I (V
f = 10kHz
RATINGS
Open, V
Set to Give 50% Duty Cycle
J
= 1.1V
= 1.4V
= 1.5A
= 1.1V
C
= 25 C. V
) = 10 A
1.5A
IN
IN
FB
U
15V
15V
= 1.1V, DC 50%
IN
= 5V, V
The
C
denotes specifications which apply over the full operating tempera-
= 1.5V, Boost = V
Consult factory for Military grade parts.
PACKAGE/ORDER
BOOST
CONNECTED TO GROUND PLANE OR
LARGE LANDS
JA
GND
V
V
SW
= 80 C/ W WITH FUSED GROUND PIN
IN
1
2
3
4
8-LEAD PLASTIC SO
S8 PACKAGE
TOP VIEW
IN
+ 5V, switch open, unless otherwise noted.
8
7
6
5
SYNC
SHDN
FB/SENSE
V
C
1.195
MIN
1.18
2.46
2.44
200
800
400
180
160
5.7
1.5
0.4
40
50
90
86
INFORMATION
U
S8 PART MARKING
1578
1578I
LT1578CS8
LT1578IS8
LT1578CS8-2.5
LT1578IS8-2.5
1050
1.21
0.01
0.74
TYP
400
110
130
200
2.5
9.5
0.5
1.5
0.8
2.1
0.3
0.2
4.0
2.3
94
94
ORDER PART
2
8
0
NUMBER
W
1.225
1300
1700
MAX
1.24
2.54
2.56
13.7
0.03
0.35
0.45
0.15
190
200
220
240
3.5
1.0
4.3
3.0
2
157825
578I25
UNITS
U
%/ V
Mho
Mho
%/V
A/ V
kHz
kHz
k
%
%
%
V
V
V
V
A
A
A
V
V
A
A
V
V
V