Linear Technology 1668B-C Demo Manual

Description
Demonstration circuit 1668B-C is a PolyPhase
ply featuring four
buck µModule regulators. The DC1668B-C input voltage
®
range is between 4.5V to 20V with a jumper programmable
output voltage from 0.6V to 3.3V. The demo circuit can
deliver up to 50A of load with excellent current-sharing.
Current derating may be necessary under certain operat-
ing conditions.
The LTM4627 can be synchronized to an external clock be-
tween 250kHz to 770kHz. The default switching frequency
for the DC1668B-C is set to 500kHz through the onboard
performance summary
PARAMETER
Maximum Input Voltage
Minimum Input Voltage
Output Voltage V
OUT
Maximum Continuous Output Current I
Default Operating Frequency
External Clock Synchronous Frequency Range
Output Voltage Ripple (Typical)
Efficiency
Load Transient
BoarD photo
Arrow.com.
Downloaded from
LTM 4627 high efficiency synchronous
®
CONDITIONS/NOTES
Remove V
Current Derating May Be Necessary for Certain V
OUT(MAX)
V , Frequency and Thermal Conditions
OUT
V = 12V, V
IN
V = 12V, V
IN
V = 12V, V
IN
Figure 1. LTM4627/DC1668B-C Demo Board
DEMO MANUAL DC1668B-C
High Efficiency PolyPhase
Step-Down Power Supply
power sup- LTC6902 clock generator. The external clock interleaves
®
the paralleled phases to minimize input and output ripple.
DC1668B-C demonstrates that paralleling LTM4627 mod-
ules is easy and reliable. These features and the availability
of the LTM4627 in a compact thermally enhanced 15mm
× 15mm × 4.32mm LGA package make the circuit ideal for
use in high density point of load regulation applications.
Design files for this circuit board are available at
http://www.linear.com/demo
L, LT, LTC, LTM, Linear Technology, PolyPhase, µModule and the Linear logo are registered
trademarks of Linear Technology Corporation. All other trademarks are the property of their
respective owners.
Specifications are at T = 25°C
A
SEL Jumper for V = 0.6V
OUT OUT
= 1.8V, 500kHz (20MHz BW)
OUT
= 1.8V, 500kHz
OUT
= 1.8V
OUT
LTM4627EV
0.6V
DC
,
IN
< 10mV at I
P-P
87.7% at I
DC1668bc F01
VALUE
20V
4.5V
, 1V , 1.2V , 1.5V ,
DC DC DC DC
1.8V , 2.5V , 3.3V
DC DC DC
50A
DC
500kHz
250kHz to 770kHz
= 50A, See Figure 6
OUT
= 50A, See Figure 3
OUT
See Figure 5
dc1668bcf
1