Analog Devices DC2629A Demo Manual

DESCRIPTION
Demonstration Circuit DC2629A features the
10A, Low Voltage, Synchronous Step-Down Silent
Switcher 2 operating as a 2MHz 3.3V to 1.2V 10A buck
®
regulator. The LTC3310S supports output voltages from
0.5V to V with operating frequencies from 500kHz up
IN
to 5MHz. The LTC3310S is a compact, ultralow emission,
high efficiency, and high speed synchronous monolithic
step-down switching regulator. The integrated bypass
capacitors optimize all the fast current loops and make it
easier to minimize EMI/EMC emissions by reducing layout
sensitivity. Fast minimum on-time of 35ns enables high
V to low V conversion at high frequency.
IN OUT
DC2629A is set up to run in Forced Continuous Mode
with a 2MHz switching frequency but can be configured
to Pulse Skip Mode and different switching frequencies.
RT is connected to V which sets the MODE/SYNC pin
IN
as an input and allows the LTC3310S to sync from an
external clock. Connecting the MODE/SYNC pin to V
sets the mode to Forced Continuous Mode and connecting
the MODE/SYNC pin to GND sets the mode to Pulse Skip
Mode. The Efficiency vs. Load graph shows the efficiency
PERFORMANCE SUMMARY
SYMBOL PARAMETER
V /V EMI DC2629A Input Voltage Range
IN IN
V DC2629A V Voltage Range
OUT OUT
I DC2629A Output Current
OUT
f Switching Frequency
SW
EFF Efficiency
DEMO MANUAL DC2629A
5V, 10A Synchronous Step Down
Silent Switcher in 3mm x3mm LQFN
LTC 3310S and the power loss of the circuit with a 3.3V input in
®
forced continuous mode operation.
The DC2629A also has an EMI filter to reduce conducted
EMI. This EMI filter can be included by applying the input
voltage at the V
the board is shown in the EMI TEST RESULTS section.
The red lines in the EMI performance graphs illustrate
the CISPR25 Class 5 peak limits for the conducted and
radiated emission tests.
The LTC3310S data sheet gives a complete description of
the part, operation and application information. The data
sheet must be read in conjunction with this demo. The
LTC3310S is assembled in a 3mm x 3mm LQFN package
with exposed pads for low thermal resistance. The layout
recommendations for low EMI operation and maximum
thermal performance are available in the data sheet sec-
tion Low EMI PCB Layout.
IN
Design files for this circuit board are
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Specifications are at T
A
CONDITIONS
V = 3.3V, I = 5A
IN OUT
EMI terminal. The EMI performance of
IN
= 25°C
MIN
2.25
1.183
1.8
LTC3310S
available.
TYP MAX UNITS
5.5 V
1.2 1.217 V
10 A
2.2 MHz
91 %
Rev. 0
1