LM3671MF-1.8EV National Semiconductor, LM3671MF-1.8EV Datasheet

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LM3671MF-1.8EV

Manufacturer Part Number
LM3671MF-1.8EV
Description
BOARD EVALUATION LM3671MF-1.8
Manufacturer
National Semiconductor
Series
PowerWise®r
Datasheets

Specifications of LM3671MF-1.8EV

Main Purpose
DC/DC, Step Down
Outputs And Type
1, Non-Isolated
Voltage - Output
1.8V
Current - Output
600mA
Voltage - Input
2.7 ~ 5.5V
Regulator Topology
Buck
Frequency - Switching
2MHz
Board Type
Fully Populated
Utilized Ic / Part
LM3671
Lead Free Status / RoHS Status
Not applicable / Not applicable
Power - Output
-
© 2008 National Semiconductor Corporation
LM3671 Evaluation Board
Introduction
The LM3671 evaluation board is a working demonstration of
a step down DC-DC converter. This application note contains
information about the evaluation board. For further informa-
tion on buck converter topology, device electrical character-
istics, and component selection, please refer to the
datasheet.
General Description
The LM3671 converts high input voltages to lower output volt-
ages with high efficiency through an inductor-based switching
topology. Automatic intelligent switching between PWM low-
noise and PFM low-current mode offers improved system
control. LM3671 is available in both fixed output voltage op-
tions and adjustable voltage options range from 1.1V to 3.3V
in SOT23-5, micro SMD-5 package or 6-pin LLP packages.
The fixed output voltage options available in a SOT 23-5
Typical Application
FIGURE 2. Adjustable Output Voltage — Typical Application Circuit
FIGURE 1. Fixed Output Voltage — Typical Application Circuit
201647
National Semiconductor
Application Note 1395
Netnarin Joy Taylor and Vera Tsang
October 10, 2008
package are 1.2V, 1.25V, 1.375V, 1.5V, 1.6V, 1.8V, 1.875V,
2.5V, 2.8V, and 3.3V. The fixed output voltage options avail-
able in the micro SMD-5 package are 1.2V, 1.5V, 1.8V,
1.875V, 2.5V, 2.8V, and 3.3V. The fixed output voltage op-
tions available in the 6-pin LLP package are 1.2V, 1.3V, 1.6V
and 1.8V.
Operating Conditions
Recommended input voltage range:
V
V
V
where V
Recommended load current: 0 mA
Ambient temperature (T
Junction temperature (T
IN
IN
IN
= 2.7V to 4.5V for 1.1V
= 2.7V to 5.5V for 1.5V
= (V
OUT
DROPOUT
+ V
DROPOUT
= I
LOAD
) to 5.5V for 1.8V
A
* (R
J
) range: -30C to +125C
) range: -30C to +85C
20164716
20164715
DSON, PFET
V
V
OUT
OUT
< 1.5V
< 1.8V
I
OUT
+ R
INDUCTOR
www.national.com
V
600 mA
OUT
)
3.3V

Related parts for LM3671MF-1.8EV

LM3671MF-1.8EV Summary of contents

Page 1

... The fixed output voltage options available in a SOT 23-5 Typical Application FIGURE 1. Fixed Output Voltage — Typical Application Circuit FIGURE 2. Adjustable Output Voltage — Typical Application Circuit © 2008 National Semiconductor Corporation National Semiconductor Application Note 1395 Netnarin Joy Taylor and Vera Tsang October 10, 2008 package are 1 ...

Page 2

... Output Voltage Selection for LM3671MF-ADJ The output voltage of the adjustable parts can be pro- grammed through the resistor network connected from GND. The resistor from FB to GND (R 200 kΩ to keep the current drawn through this network well below 16 µA quiescent current level (PFM mode) but large enough that it is not susceptible to noise ...

Page 3

Powering the LM3671 for Bench Measurements When powering the LM3671 with a bench power supply recommended to place a 100 µF tantalum capacitor across the V and GND supply terminals of the bench power supply. IN This capacitor ...

Page 4

TABLE 3. Pin Descriptions (6–pin LLP) Pin# Name Description 1 EN Enable pin. The device is in shutdown mode when voltage to this pin is < 0.4V and enabled when > 1.0V. Do not leave this pin floating. 2 PGND ...

Page 5

Evaluation Board Layout FIGURE 6. Top Layer (SOT23-5) FIGURE 7. Top Layer (5-bump micro SMD) 5 20164731 20164721 www.national.com ...

Page 6

FIGURE 8. Bottom Layer (SOT23-5 and 5-bump micro SMD) www.national.com FIGURE 9. Top Layer (6–pin LLP) 6 20164723 20164717 ...

Page 7

FIGURE 10. Bottom Layer (6–pin LLP) 7 20164718 www.national.com ...

Page 8

... BOM For Common Configurations Manufacture LM3671MF/TL-1.5 FIXED, LM3671LC-1.6 FIXED C2 (input C) TDK C1 (output C) TDK L1 (inductor) Coilcraft Vishay OUT GND) None None OUT GND) None FB LM3671MF/TL - 1.8V ADJUSTABLE CIN (input C) TDK COUT (output C) TDK L1 (inductor) Coilcraft Vishay OUT GND) Vishay Vishay OUT GND) None FB COMMON TO ALL V ...

Page 9

Notes 9 www.national.com ...

Page 10

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