lt3467aes67 Linear Technology Corporation, lt3467aes67 Datasheet - Page 5

• Manufacturer Part Number: lt3467aes67
• Description: 1.1a Step-up Dc/dc Converter With Integrated Soft-start
• Manufacturer: Linear Technology Corporation

BLOCK DIAGRA
PI FU CTIO S
(DFN/TSOT)
FB (Pin 1/Pin 3): Feedback Pin. Reference voltage is
1.255V. Connect resistive divider tap here. Minimize trace
area at FB. Set V
GND (Pins 2, 5, 9/Pin 2): Ground. Tie directly to local
ground plane.
SW (Pins 3, 4/Pin 1): Switch Pin. (Collector of internal
NPN power switch) Connect inductor/diode here and
minimize the metal trace area connected to this pin to
minimize EMI.
U
SHUTDOWN
U
V
SS
IN
OUT
V
OUT
R1 (EXTERNAL)
R2 (EXTERNAL)
SHDN
U
= 1.255V(1 + R1/R2).
FB
W
REFERENCE
1.255V
FB
–
+
A1
250k
Figure 1. Block Diagram
R
C
C
C
OSCILLATOR*
GENERATOR
1.3MHz
RAMP
V
bypassed.
SS (Pin 7/Pin 5): Soft-Start Pin. Place a soft-start capaci-
tor here. Upon start-up, 4μA of current charges the capaci-
tor to 1.255V. Use a larger capacitor for slower start-up.
Leave floating if not in use.
SHDN (Pin 8/Pin 4): Shutdown Pin. Tie to 2.4V or more to
enable device. Ground to shut down.
Σ
IN
(Pin 6/Pin 6): Input Supply Pin. Must be locally
–
+
*2.1MHz FOR LT3467A
COMPARATOR
A2
R
S
Q
LT3467/LT3467A
DRIVER
+
–
Q1
0.01Ω
3467 F01
SW
GND
3467afc
5