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DC143A-F

P1-P3P4-P6P7-P8
1
DEMO MANUAL DC143
DEMO MANUAL DC143
LTC1474/LTC1475
10µA I
Q
, High Efficiency,
Step-Down DC/DC
Converter
NO DESIGN SWITCHER
DESCRIPTIO
U
This demonstration circuit is a step-down (buck) regulator
using the LTC
®
1474/LTC1475. The exclusive use of surface
mount components and the LTC1474/LTC1475 in the tiny
MSOP package results in a highly efficient application in a
small board space. This demo board highlights the
capabilities of the LTC1474/LTC1475, which use a current
mode, constant off-time architecture to switch an internal
P-channel power MOSFET. This results in a power supply
that has low ripple and fast transient response. At low
output currents the LTC1474/LTC1475 automatically
switch to Burst Mode
TM
operation to maintain high operating
efficiencies and minimize supply current. At no load,only
10µA (typical) is required to regulate the output. The parts
can be shut down to further reduce the supply current to
6µA (typical). In dropout, the internal P-channel MOSFET
is turned on continuously (100% duty cycle), providing
low dropout operation with V
OUT
≅ V
IN
. An onboard low-
battery detector allows the user to monitor the input
supply through an external resistive divider. This board is
intended for applications such as cellular phones, GSM
systems, 4mA to 20mA current-loop pirate supplies or any
portable battery-powered application. Gerber files for this
circuit board are available. Call the LTC factory.
Demo Board D
DM143 DB D
DM143 DB A
LOAD CURRENT (mA)
EFFICIENCY (%)
100
90
80
70
60
50
0.03 3 30 300
DM143 TPC
0.3
V
IN
= 5V
V
IN
= 10V
V
IN
= 15V
L = 100µH
V
OUT
= 3.3V
R
SENSE
= 0Ω
, LTC and LT are registered trademarks of Linear Technology Corporation.
Burst Mode is a trademark of Linear Technology Corporation.
PERFORmANCE SU ARY
UW
WW
SYMBOL PARAMETER CONDITIONS BOARD SUFFIX VALUE
V
IN
Input Voltage Range V
OUT
= 3.3V A, B, D, E 3.3V to 18V
V
OUT
= 5V C, F 5V to 18V
V
OUT
Output Voltage LTC1474/LTC1475 A, D 3.3V ± 0.10V
LTC1474-3.3/LTC1475-3.3 B, E 3.3V ± 0.10V
LTC1474-5/LTC1475-5 C, F 5V ± 0.15V
I
OUT
Maximum Output Current R
SENSE
= 0Ω ALL 300mA
R
SENSE
= 0.25Ω ALL 150mA
I
Q
Typical Supply Current V
IN
= 10V, I
LOAD
= 0 A, B, C 10µA
V
IN
= 10V, I
LOAD
= 0 D, E, F 15µA
TYPICAL PERFOR A CE CHARACTERISTICS A D BOARD PHOTO
U
U
W
Board A, B, D, E Efficiency Demo Board A
2
DEMO MANUAL DC143
PERFORmANCE SU ARY
UW
WW
SYMBOL PARAMETER CONDITIONS BOARD SUFFIX VALUE
V
RIPPLE
Typical Output Ripple I
OUT
= 100mA All 50mV
∆V
OUT
Typical Line Regulation 4V < V
IN
< 18V, R
SENSE
= 0Ω, I
LOAD
= 100mA A, D 35mV
4V < V
IN
< 18V, R
SENSE
= 0.25Ω, I
LOAD
= 100mA 25mV
4V < V
IN
< 18V, R
SENSE
= 0Ω, I
LOAD
= 100mA B, E 20mV
4V < V
IN
< 18V, R
SENSE
= 0.25Ω, I
LOAD
= 100mA 10mV
6V < V
IN
< 18V, R
SENSE
= 0Ω, I
LOAD
= 100mA C, F 20mV
6V < V
IN
< 18V, R
SENSE
= 0.25Ω, I
LOAD
= 100mA 10mV
Typical Load Regulation 0 < I
LOAD
< 300mA, R
SENSE
= 0Ω, V
IN
= 10V All 10mV
0 < I
LOAD
< 150mA, R
SENSE
= 0.25Ω, V
IN
= 10V 10mV
V
LBI
Low-Battery Trip Threshold All 1.23V
DM143 F02
V
IN
GND
SENSE
LBI/OFF
LBI
ON
V
FB
LBO
LBO
SW
LTC1475
+
6
3
8
1
2
5
7
4
R7
100kRUN
SHDN
R5
C2
1000pF
C1
4.7µF
35V
C5
0.1µF
V
IN
4V* TO 18V
R4
R1
0.25Ω
R6
0Ω
R3
3.01M
R2
1M
*3.3V AT NO LOAD
C3
10pF
L1 
100µH
D1
MBR0530
+
C4
100µF
6.3V
THIS NETWORK
IS PRESENT IN
BOARD D ONLY
V
OUT
3.3V
300mA
Figure 2. LTC1475 Demo Board Schematic
PACKAGE A D SCHE ATIC DIAGRA SM
W UW
DM143 F01
V
IN
GND
SENSE
LBI
LBI
RUN
V
FB
LBO
LBO
SW
LTC1474
+
6
3
8
1
2
5
7
4
R7
100k
R5
JP1
RUN
C2
1000pF
C1
4.7µF
35V
C5
0.1µF
V
IN
4V* TO 18V
R4
R1
0.25Ω
R6
0Ω
*3.3V AT NO LOAD
C3
10pF
L1 
100µH
D1
MBR0530
+
C4
100µF
6.3V
THIS NETWORK
IS PRESENT IN
BOARD A ONLY
V
OUT
3.3V
300mA
Figure 1. LTC1474 Demo Board Schematic
1
2
3
4
V
OUT
(V
FB
*)
LBO
LBI
GND
8
7
6
5
RUN
V
IN
SENSE
SW
TOP VIEW
MS8 PACKAGE
8-LEAD PLASTIC MSOP
*ADJUSTABLE OUTPUT VERSION
1
2
3
4
V
OUT
(V
FB
*)
LBO
LBI/OFF
GND
8
7
6
5
ON
V
IN
SENSE
SW
TOP VIEW
MS8 PACKAGE
8-LEAD PLASTIC MSOP
*ADJUSTABLE OUTPUT VERSION
LTC1474CMS8
LTC1474CMS8-3.3
LTC1474CMS8-5
LTC1475CMS8
LTC1475CMS8-3.3
LTC1475CMS8-5
3
DEMO MANUAL DC143
REFERENCE
DESIGNATOR QUANTITY PART NUMBER DESCRIPTION VENDOR TELEPHONE
C1 1 TPSC475M035 4.7µF 35V 20% Tantalum Capacitor AVX (207) 282-5111
C2 1 080553102KAT2A 1000pF 25V 10% X7R Capacitor AVX (803) 946-0362
C3 1 08055310KAT1A 10pF 25V 10% NPO Capacitor (Boards B, C, E, F Only) AVX (803) 946-0362
C4 1 TPSC107M006R0150 100µF 6.3V 20% Tantalum Capacitor (Boards A, B, D, E) AVX (207) 282-5111
TPSC336M010R0375 33µF 6.3V 20% Tantalum Capacitor (Boards C, F)
C5 1 08053E104ZAT1A 0.1µF 25V +80% to –20% Y5V Capacitor AVX (803) 946-0362
D1 1 MBR0530 0.5A 30V Schottky Diode Motorola (602) 244-3576
E1 to E6 6 2501-02 Terminal Turret Mill Max (516) 922-6000
JP1 1 2802S-02-G2 Connector Pin Header (Boards A, B, C) Comm Con (818) 301-4200
L1 1 CDRH73-101 100µH Inductor Sumida (847) 956-0666
R1 1 LR1206 01 R250 F0 0.25Ω 0.25W 1% Resistor IRC (512) 992-7900
R2 1 CR21-105J-T 1M 0.1W 5% Resistor (Boards D, E, F Only) AVX (803) 946-0524
R3 1 CR21-225J-T 2.2M 0.1W 5% Resistor (Boards D, E, F Only) AVX (803) 946-0524
R4 1 WCR0805-1474-F-P-LT 1.47M 0.1W 1% Resistor (Boards B, C, E, F Only) IRC (512) 992-7900
R5 1 CJ21-000J-T 0805 Shunt Resistor (Boards B, C, E, F) AVX (803) 946-0524
WCR0805-2494-F-P-LT 2.49M 0.1W 1% Resistor (Boards A, D) IRC (512) 992-7900
R6 1 CJ21-000J-T 0805 Shunt Resistor AVX (803) 946-0524
R7 1 CR21-104J-T 100k 0.1W 5% Resistor AVX (803) 946-0524
S1, S2 2 EVQ PJS05K Momentary Switch (Boards D, E, F) Panasonic (201) 392-4511
U1 1 LTC1474CMS8 8-Pin MSOP IC, LTC1474 (Board A) LTC (408) 432-1900
LTC1474CMS8-3.3 8-Pin MSOP IC, LTC1474-3.3 (Board B)
LTC1474CMS8-5 8-Pin MSOP IC, LTC1474-5 (Board C)
LTC1475CMS8 8-Pin MSOP IC, LTC1475 (Board D)
LTC1475CMS8-3.3 8-Pin MSOP IC, LTC1475-3.3 (Board E)
LTC1475CMS8-5 8-Pin MSOP IC, LTC1475-5 (Board F)
PARTS LIST
Table 1. Demo Board Version Cross Reference
BOARD SUFFIX PART NUMBER OUTPUT VOLTAGE ON/OFF CONTROL
A LTC1474 3.3V (Adjustable) Jumper
B LTC1474-3.3 3.3V Jumper
C LTC1474-5 5V Jumper
D LTC1475 3.3V (Adjustable) Pushbutton
E LTC1475-3.3 3.3V Pushbutton
F LTC1475-5 5V Pushbutton
P1-P3P4-P6P7-P8

DC143A-F

Mfr. #:
Buy DC143A-F
Manufacturer:
Analog Devices Inc.
Description:
Power Management IC Development Tools LTC1475CMS8-5 - LOW Q-CURRENT HIGH EFFIC
Lifecycle:
New from this manufacturer.
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