LX1918 E
VALUATION
B
OARD
U
SER
G
UIDE
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 6
Copyright
©
2004
Rev. 1.2, 2005-12-02
C
ONNECTIONS
The LX1918 Evaluation board has 4 test lead
attachment points for applying power and control
signals and for monitoring voltages. There are also 2
– 3 pin connections to select external synchronization
and operating mode. The E/S selector also has
shutdown capability
Function
Board Label
Connection
Input Power
VIN
Power Supply (2.70V ±6.0V)
Power Ground
GND
Common Power Supply Ground
External Sync / Shutdown
E/S
Connect to GND to disable LX1918. A PWM > 500KHz logic
PWM signal can also be applied
1
.
Output Voltage
VOUT
Test Point – Hook up load and monitor VOUT
Mode Select
Mode
High Efficiency = Pin 2 and 3. Low EMI = Pin 1 and 2.
1 – To use external synchroization feature the Mode Select must be in Lo EMI position.
B
ILL OF
M
ATERIALS
M I S C E L L A N E O U S C O M P O N E N T S
Line
Item
Part Description
Manufacturer & Part #
Case
Reference
Designators
Qty
1
1.5A Synchronous Buck Converter
M
ICROSEMI
LX1918CLD
LD U1
1
2
Inductor 1.8A Shielded SMD 3.3µH
C
OILCRAFT
MOS6020-332MX
L1
1
3
Header 3 Pin .100
P1, P2
2
4
Test Point – 0.045 diameter, Wire Loop
K
EY
S
TONE
5004_Term
4
5
PCB SGE # 3534 X1
C A P A C I T O R S
Line
Item
Part Description
Part Description
Case
Reference
Designators
Qty
1
Capacitor, 4.7µF, X5R, 10V, 20%
T
AIYO
Y
UDEN
CELDK212BJ475MG
0805 C1 1
2
Capacitor, 47µF, X5R, 6.3V, 20%
T
AIYO
Y
UDEN
JMK325BJ476MM
1210 C2 1
3
Capacitor, 0.1µF, X5R, 16V, 20%
T
AIYO
Y
UDEN
CEEMK107BJ104MA
0603 C3 1
R E S I S T O R S
Line
Item
Part Description
Part Description
Case
Reference
Designators
Qty
1
Resistor, 1.5K, 1/16W, 5%
P
ANASONIC
ERJ-3GSYJ152V
0603 R1 1
2
Resistor, 1K, 1/16W, 5%
P
ANASONIC
ERJ-3GSYJ102V
0603 R2 1
3
Resistor, 10K, 1/16W, 5%
P
ANASONIC
ERJ-3GSYJ103V
0603 R3,
R4 2
4
Resistor, 40.2, 1/10W, 1%
P
ANASONIC
ERJ-3EKF40R2
0603 R5 1
