LTC3408_15 Datasheet, PDF (12/12 Pages) Linear Technology – 1.5MHz, 600mA Synchronous Step-Down Regulator with Bypass Transistor

LTC3408
APPLICATIO S I FOR ATIO
Substituting V_OUT = 2.5V, V_IN = 4.2V, I_L = 120mA and
f = 1.5MHz in Equation (2) gives:
L
=
2.5V
1.5MHz (120mA)

1–
2.5V
4.2V

=
5.6µH
A 4.7µH inductor works well for this application. For best
efficiency choose a 660mA or greater inductor with less
than 0.2Ω series resistance.
C_IN will require an RMS current rating of at least 0.3A ≅
LOAD(MAX)/2 at temperature and C_OUT will require an
ESR of less than 0.25Ω. In most cases, a ceramic capaci-
tor will satisfy this requirement.
V_IN
2.7V
TO 5V _CIN†
10µF
CER
10k
DAC
1000pF
2, 7
V_IN
4 ^4.7µH*
SW
V_OUT
LTC3408
C_OUT**
4.7µF
5
RUN
1, 8
V_OUT
3403 F07
CER
6
REF
GND
3, 9
* _{MURATA LQH32CN4R7M11}
**
†
TAIYO
TAIYO
YUDEN
YUDEN
JMK212BJ475MG
JMK212BJ106MN
Figure 7
PACKAGE DESCRIPTIO
DD Package
8-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1698)
0.675 ±0.05
R = 0.115
TYP
5
0.38 ± 0.10
8
3.5 ±0.05
1.65 ±0.05
2.15 ±0.05 (2 SIDES)
PIN 1
PACKAGE ^{TOP MARK}
OUTLINE ^{(NOTE 6)}
0.25 ± 0.05
0.50
BSC
2.38 ±0.05
(2 SIDES)
0.200 REF
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-1)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
3.00 ±0.10
(4 SIDES)
1.65 ± 0.10
(2 SIDES)
0.75 ±0.05
0.00 – 0.05
4
0.25 ± 0.05
(DD8) DFN 1203
1
0.50 BSC
2.38 ±0.10
(2 SIDES)
BOTTOM VIEW—EXPOSED PAD
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON TOP AND BOTTOM OF PACKAGE
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LTC3403
LTC3405/LTC3405A-1.5/
LTC3405A-1.8
1.5MHz, 600mA Synchronous Step-Down Regulator
with Bypass Transistor
1.5MHz, 300mA (I_OUT) Synchronous
Monolithic Step-Down Regulators
Up to 96% Efficiency, V_IN: 2.5V to 5V, V_OUT: 0.3V to 3.5V,
I_Q = 20µA, I_SD < 1µA, DFN Package
Up to 95% Efficiency, V_IN: 2.5V to 5.5V, I_Q = 20µA,
Fixed Output Voltages Available, ThinSOT^TM Package
LTC3406B/LTC3406B-1.5/ 1.5MHz, 600mA, (I_OUT) Synchronous Monolithic
LTC3406B-1.8
Step-Down Regulators with Burst Mode Defeat
Up to 95% Efficiency, with Pulse Skipping Mode Enabled,
Fixed Output Voltages Available, ThinSOT Package
LTC3407/LTC3407-2
1.5MHz/2.25MHz, 600mA/800mA Dual (I_OUT) Synchronous Up to 91% Efficiency, V_IN: 2.5V to 5.5V, I_Q = 4µA,
Monolithic Step-Down Regulator
MS10 Package
LTC5505
ThinSOT RF Power Detector with Buffered Output
300MHz to 3GHz, Temperatrue Compensated,
and >40dB Dynamic Range
LTC5505-1: –28dBm to 18dBm,
LTC5505-2: –32dBm to 12dBm, V_CC = 2.7V to 6V
Burst Mode is a registered trademark of Linear Technology Corporaton. ThinSOT is a trademark of Linear Technology Corporation.
3408f
12 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
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 LINEAR TECHNOLOGY CORPORATION 2003