LTC1649 Linear Technology, LTC1649 Datasheet - Page 16

• Manufacturer Part Number: LTC1649
• Description: 3.3V Input High Power Step-Down Switching Regulator Controller
• Manufacturer: Linear Technology

RELATED PARTS
PART NUMBER
LTC1430
LTC1430A
LTC1435A
LTC1553
LTC1517-5
Pentium is a registered trademark of Intel Corporation.
LTC1649
TYPICAL APPLICATIO
16
CERAMIC
SHDN
10 F
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] FAX: [phone] www.linear-tech.com
Si9802 = SILICONIX
22
DESCRIPTION
High Power Step-Down Switching Regulator Controller
High Power Step-Down Switching Regulator Controller
High Efficiency, Low Noise, Synchronous Step-Down Converter
High Power Switching Regulator with Digital Output Voltage Control
Micropower, Regulated 5V Charge Pump in a 5-Pin SOT-23 Package
220pF
MBR0530
7.5k
0.01 F
U
0.1 F
0.1 F
CERAMIC
NC
1 F
4.7k
P
P
V
I
SHDN
COMP
SS
GND
MAX
VCC1
VCC2
CC
+
–
LTC1649
SSTL Logic Termination Supply
1/2 LT1211
2200pF
CP
OUT
V
I
G1
G2
FB
C
C
FB
IN
+
–
10k
MBR0530
10k
1 F
CERAMIC
+
10 F
+
–
10k
3.3V
V
IN
1/2 LT1211
Q1
1/2
Si9802
Q2
1/2
Si9802
50pF
COMMENTS
5V to 1.x – 3.x @10A
5V to 1.xV @10A, Maximum Duty cycle > 90% Permits
3.3V to 2.xV Conversion
16-Pin Narrow SO and SSOP
1.8V to 3.5V Supply for Pentium
Low Power 3.3V to 5V Step-Up Converter
R1
18.2k
R2
15k
1649 TA04
1.5 H
L
EXT
1649fs sn1649 LT/TP 1098 4K • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 1998
+
+
1500 F
1500 F
V
= 0.45V
= 1.48V AT V
OUT
®
II
IN
AT 5A
IN
= 3.3V