LTC3407-3 Linear Technology, LTC3407-3 Datasheet - Page 13

• Manufacturer Part Number: LTC3407-3
• Description: Dual Synchronous 1.8V/0.8A and 3.3V/0.8A 2.25MHz Step-Down DC/DC Regulator
• Manufacturer: Linear Technology

APPLICATIO S I FOR ATIO
2. Are the C
C
3. The output feedback line should be routed away from
noisy components and traces, such as the SW line
(Pins 4 and 7), and its trace should be minimized.
4. Keep sensitive components away from the SW pins. The
input capacitor C
traces and the inductors.
TYPICAL APPLICATIO S
OUT
returns current to GND and the (–) plate of C
OUT
and L1 closely connected? The (–) plate of
IN
U
should be routed away from the SW
U
800mA
V
V
5V
OUT2
U
3.3V
IN
10µF
Low Ripple Buck Regulators Using Ceramic Capacitors
W
C3
C1, C2, C3: TAIYO YUDEN JMK316BJ106ML
L1, L2: SUMIDA CDRH2D18/HP-4R7NC
*IF C1 IS GREATER THAN 3" FROM POWER SOURCE,
ADDITIONAL CAPACITANCE MAY BE REQUIRED.
100
95
90
85
80
75
70
65
60
55
50
C1*
10µF
10
4.7µH
L2
V
OUT
Efficiency vs Load Current
U
= 3.3V
IN
MODE/SYNC
SW2
V
RUN2
OUT2
LOAD CURRENT (mA)
.
V
PULSE SKIP MODE
NO LOAD ON OTHER CHANNEL
IN
LTC3407-3
= 5V
GND
V
V
100
IN
OUT
= 1.8V
5. A ground plane is preferred, but if not available, keep the
signal and power grounds segregated with small signal
components returning to the GND pin at one point and
should not share the high current path of C
6. Flood all unused areas on all layers with copper.
Flooding with copper will reduce the temperature rise of
power components. These copper areas should be con-
nected to V
RUN1
V
SW1
POR
OUT1
34073 TA02b
4.7µH
L1
R5
100k
1000
IN
POWER-ON
RESET
or GND.
34073 TA03a
C2
10µF
V
1.8V
800mA
OUT1
www.DataSheet4U.com
LTC3407-3
IN
or C
13
OUT
34073fa
.