LTC3404EMS8 Linear Technology, LTC3404EMS8 Datasheet - Page 14

• Manufacturer Part Number: LTC3404EMS8
• Description: IC REG STP-DWN SYNC HI-EFF 8MSOP
• Manufacturer: Linear Technology
• Type: Step-Down (Buck)r

Specifications of LTC3404EMS8

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 0.8 ~ 6 V
• Current - Output: 600mA
• Frequency - Switching: 1.4MHz
• Voltage - Input: 2.65 ~ 6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -

APPLICATIO S I FOR ATIO
Substituting V
f = 1.4MHz in equation (3) gives:
A 6.2μH inductor works well for this application. For best
efficiency choose a 1A inductor with less than 0.25Ω
series resistance.
C
temperature and C
LTC3404
TYPICAL APPLICATIO S
14
IN
L
will require an RMS current rating of at least 0.15A at
=
1 4
.
MHz
47pF
2 5
OUT
.
(
412k
120
V
1
2
3
4
47pF
= 2.5V, V
OUT
U
RUN
I
V
GND
mA
TH
FB
LTC3404
)
will require an ESR of less than
SYNC/MODE
887k
20pF
⎛
⎜
⎝
1
***
U
PLL LPF
**
Figure 8. Single Lithium-Ion to 2.5V/0.3A Regulator from Design Example
−
*
TOKO D52LC A914BYW-4R7M
TAIYO-YUDEN CERAMIC JMK325BJ226MM
TAIYO-YUDEN CERAMIC LMK325BJ106MN
IN
SW
2 5
4 2
V
1
2
3
4
IN
***
.
.
**
RUN
I
V
GND
= 4.2V, ΔI
*
TH
8
7
6
5
FB
V
V
TOKO D63LCB A920CY-6R2M
TAIYO-YUDEN CERAMIC JMK325BJ226MM
TAIYO-YUDEN CERAMIC LMK325BJ106MN
U
⎞
⎟ = μ
⎠
6.2μH*
W
LTC3404
SYNC/MODE
10μF***
22μF**
CER
CER
PLL LPF
6
H
SW
V
IN
L
Single Li-Ion to 2.5V/0.6A Regulator
=120mA and
8
7
6
5
Using All Ceramic Capacitors
3404 F08a
U
V
2.65V
TO 4.2V
V
2.5V
4.7μH*
IN
OUT
20pF
0.25Ω. In most applications, the requirements for these
capacitors are fairly similar.
For the feedback resistors, choose R1 = 412k. R2 can
then be calculated from equation (2) to be:
Figure 8 shows the complete circuit along with its effi-
ciency curve.
R
887k
412k
3404 TA03
2
=
⎛
⎜
⎝
V
0 8
C
22μF
CER
OUT
OUT
.
95
90
85
80
75
70
0.1
**
−
V
IN
V
2.5V
0.6A
1 1 875 5
OUT
= 4.2V
⎞
⎟
⎠
R
1.0
OUTPUT CURRENT (mA)
=
V
IN
C
10μF
CER
= 3.6V
IN
10
. ;
***
k use
V
3V TO 4.2V
IN
100
V
L = 6.2μH
OUT
V
8
IN
87k
= 2.5V
= 3V
3404 F8b
1000
3404fb