MIC38150 Evaluation Board
1.5A HELDO
®
High Efficiency
Low Dropout Regulator
General Description
The MIC38150 is a 1.5A step down converter and the
second device in a new generation of HELDO
TM
(High
Efficiency Low Dropout) regulators providing the benefits
of LDOs. They are easy to use, feature fast transient
performance, high PSRR and low noise while offering the
efficiency of a switching regulator.
3.
Enable the MIC38150.
The enable pin (J3) is
connected to V
IN
through a pull-up resistor R4. The output
of the MIC38150 turns on when V
IN
exceeds the UVLO
threshold at the V
IN
pin. MIC38150 may be turned off by
shorting the enable pin (J3) to ground or bringing the
enable pin below the enable threshold.
Output Voltage
The output voltage on the MIC38150 evaluation board is
adjustable. The output voltage is controlled by the
feedback resistors (R1 and R2) and can be calculated as
follows:
Requirements
The MIC38150 evaluation board requires an input power
supply able to provide greater than 1.5A at 3V.
Precautions
The evaluation board does not have reverse polarity
protection. Applying a negative voltage to the V
IN
(J1)
terminal may damage the device.
The MIC38150 evaluation board is tailored for a low
voltage input supply range. It should not exceed 5.5V on
the input.
V
OUT
= V
REF
× (1 +
R1
)
R2
Where V
REF
=1.0V.
The evaluation board is preset at 1.8V output, but can
easily be modified by removing R1 and replacing it with the
value that yields the desired output voltage.
Getting Started
1.
Connect an external supply to V
IN
terminal.
Apply
desired input voltage to the V
IN
(J1) and ground terminal
(J2) of the evaluation board, paying careful attention to
polarity and supply voltage (3.0V<V
IN
<5.5V). An ammeter
may be placed between the input supply and the V
IN
terminal to the evaluation board. Ensure the supply voltage
is monitored at the V
IN
terminal. The ammeter and/or
power lead resistance can reduce the voltage supplied to
the input.
2.
Connect the load to the V
OUT
and ground terminals.
The load can be either passive (resistive) or active (as in
an electronic load). An ammeter can be placed between
the load and the V
OUT
terminal (J5). Ensure the output
voltage is monitored at the VOUT terminal. The default
V
OUT
is set to 1.8V. This can be adjusted by changing the
feedback resistors. See “Output Voltage.”
R1
=
R2
×
(
V
OUT
−
1)
V
REF
V
OUT
−
1)
1.0 V
For V
REF
= 1.0V, this reduces to:
R1
=
R2
×
(
Ordering Information
Part Number
MIC38150HYHL
MIC38150HYHL EV
Description
IC
Evaluation Board
Package
28-Pin 4x6 MLF
®
28-Pin 4x6 MLF
®
HELDO is a registered trademark of Micrel, Inc.
MLF and
MicroLeadFrame
are registered trademark of Amkor Technology, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
September 2009
M9999-091109-A
Micrel, Inc.
MIC38150 Evaluation Board
Bill of Materials
Item
Part Number
0805ZD106MAT2A
C1, C3, C4, C14,
C23
LMK212BJ106KG-T
C2012X5R1A106K
GRM219R61A106KE44D
C2012X5R1A105K
C2
0805ZD105KAT2A
GRM219R61A105MA01D
R1
R2, R4
R3
U1
Notes:
1. AVX: www.avx.com
2. Taiyo Yuden: www.t-yuden.com
3. TDK: www.tdk.com
4. Murata: www.murata.com
5. Vishay: www.vishay.com
6. Micrel, Inc.: www.micrel.com
Manufacturer
AVX
(1)
Taiyo Yuden
(2)
TDK
(3)
Murata
(4)
TDK
(3)
AVX
(1)
Murata
(4)
Description
Qty
10uF, 10V, X5R, 0805 Ceramic Capacitor
5
1uF, 10V, X5R, 0805 Ceramic Capacitor
1
CRCW06038061FRT1
CRCW06031002KEYE3
CRCW06032492FRT1
MIC38150-HYHL
Vishay
(5)
Vishay
(5)
Vishay
(5)
Micrel, Inc.
(6)
8.06k, 1%, 1/10W, 0603
10k, 1%, 1/10W, 0603
24.9k, 1%, 1/10W, 0603
HELDO
®
1.5A High Efficiency Low Dropout
Regulator
1
2
1
1
September 2009
2
M9999-091109-A
Micrel, Inc.
MIC38150 Evaluation Board
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its
use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product
can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant
into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A
Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully
indemnify Micrel for any damages resulting from such use or sale.
© 2009 Micrel, Incorporated.
September 2009
5
M9999-091109-A
MEMS传感器
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
