Linear Technology DC2003A Demo Manual

Description
Demonstration circuit 2003A is a synchronous step-down
regulator using the power-saving
buck regulator in a compact 14-pin DFN (4mm × 3mm)
package. The DC2003A operates from an input voltage
range of 2.7V to 17V and provides dual 1A outputs with
an adjustable output voltage range from 1.2V to 5V. The
LTC3622 IC quiescent current can be as low as 5µA in
Burst Mode operation with both channels enabled and less
®
than 0.1µA in shutdown mode. The switching frequency is
fixed to 1MHz or 2.25MHz with a ±50% synchronization
range to an external clock. A user-selectable mode input
is provided to allow the user to trade off ripple noise for
performance summary
PARAMETER
Default IC
Default Switching Frequency
Default Operation Mode
Input Voltage Range
Onboard User Selectable Output Voltages
Default Output Voltage
Per Channel Maximum Continuous Output
Current
Efficiency, V (Burst Mode Operation)
OUT1
Efficiency, V (Burst Mode Operation)
OUT2
Output Voltage Ripple, V
Output Voltage Ripple, V
Load Transient Response, V
Load Transient Response, V
Thermal Image
Arrow.com.
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17V, Dual 1A, Synchronous Step-Down Regulator
LTC3622EDE
CONDITIONS
V = 2.7V to 17V, I
IN
(V ≤ V
OUT IN
V = 2.7V to 17V
IN
V = 12V, V
IN
V = 12V, V
IN
V = 12V, V
OUT1 IN
V = 12V, V
OUT2 IN
V = 12V, V
OUT1 IN
V = 12V, V
OUT2 IN
V = 12V, V
IN
DEMO MANUAL DC2003A
with Ultralow Quiescent Current
light load efficiency. Burst Mode operation provides the
monolithic highest efficiency at light loads, while pulse-skipping mode
provides the lowest ripple noise.
It is recommended to read the data sheet LTC3622 with
this demo manual prior to working on or making any
changes to DC2003A.
Design files for this circuit board are available at
http://www.linear.com/demo
L, LT, LTC, LTM, Linear Technology, Burst Mode 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
= I = 0A to 1A
OUT1 OUT2
)
= 3.3V, I = 1A
OUT1 OUT1
= 5.V, I = 1A
OUT2 OUT2
= 3.3V, I = 1A
OUT1 OUT1
= 5V, I = 1A
OUT2 OUT2
= 3.3V, I = 100mA to 1A
OUT1 OUT1
= 5V, I = 100mA to 1A
OUT2 OUT2
= 3.3V, V = 5V, I = I
OUT1 OUT2 OUT1
LTC3622EDE
VALUE
LTC3622EDE
1MHz
Burst Mode Operation
2.7V to 17V
V : 1.2V, 1.8V, 2.5V, 3.3V
OUT1
V : 1.5V, 1.8V, 3.3V, 5V
OUT2
V = 3.3V
OUT1
V = 5V
OUT2
I = I = 1A
OUT1 OUT2
88.2% (See Figure 3)
90.8% (See Figure 4)
<5.9mV (See Figure 5)
P-P
<7.8mV (See Figure 6)
P-P
See Figure 7
See Figure 8
= 1A See Figure 9
OUT2
dc2003af
1