Analog Devices LTC3315A Manual

DESCRIPTION
Demonstration Circuit DC3123A features the
dual 5V, 2A Synchronous Step-Down DC/DC regulators
operating at 2MHz. One regulator provides a 1.2V output
and the other provides 1.8V, both up to a 2A load. The
LTC3315A supports adjustable output voltages from 0.5V
to V , operating frequencies from 1MHz up to 3MHz. The
IN
LTC3315A is a compact, high efficiency, and high speed
synchronous monolithic step-down switching regulator.
Fast minimum on-time of 25ns enables high V
V conversion at high frequency.
OUT
The DC3123A operating mode may be selected as Burst
Mode operation, Skip mode or Forced Continuous (FC)
mode. Setting JP1 to the FC/SYNC position will allow
PERFORMANCE SUMMARY
PARAMETER
Input Supply Range (V )
IN
Internal Oscillator Frequency (f
SW
Top Switch On Time
V
OUT1
V
OUT2
V
IN
2.25V TO 5.5V
10µF 1µF
10µF 1µF
0.1µF
3.3V V , Dual 2A, 2MHz Buck Regulators at
IN
1.2V and 1.8V Outputs in a 74mm
LTC©3315A
IN
Specifications are at T
CONDITIONS
)
0 to 2A
0 to 2A
680nH
V SW1
IN
FB1
V
IN
LTC3315A
1µH
V
IN
SW2
FB2
EN1
EN2
MODE/SYNC
1M
PGOOD
GND
f = 2MHz dc3123a F01
SW
DEMO MANUAL DC3123A
the LTC3315A to sync to a clock frequency from 1MHz
to 3MHz. The LTC3315A operates in Forced Continuous
mode when syncing to an external clock.
The LTC3315A data sheet gives a complete description
of the device, operation and application information. The
data sheet must be read in conjunction with this demo.
The LTC3315A is assembled in a 1.6mm × 1.6mm WLCSP
package.
to low
The Efficiency vs Load graph shows the efficiency and
the power loss of the circuit with a 3.3V input in Burst
Mode operation.
Design files for this circuit board are
All registered trademarks and trademarks are the property of their respective owners.
= 25°C
A
V
OUT1
1.2V, 2A
3.3pF
140k
22µF
100k
V
OUT2
1.8V, 2A
3.3pF
261k
22µF
100k
V
IN
LTC3315A
2
Solution
available.
MIN TYP MAX
2.25 5.5
1.9 2.0 2.1
25
1.2
1.8
Efficiency vs Load Current Burst
Mode Operation
95
90
85
80
75
70
0.001 0.01 0.1
I (A)
OUT
UNITS
V
MHz
ns
V
V
V = 3.3V
IN
1.2 V
OUT
1.8 V
OUT
1 3
dc3123a TA01b
Rev. 0
1