Linear Technology LTM4612 Manual

FEATURES
Complete Low EMI Switch Mode Power Supply
n
EN55022 Class B Compliant
n
Wide Input Voltage Range: 5V to 36V
n
3.3V to 15V Output Voltage Range
n
5A DC, 7A Peak Output Current
n
Low Input and Output Referred Noise
n
Output Voltage Tracking and Margining
n
Power Good Tracks with Margining
n
PLL Frequency Synchronization
n
±1.5% Set Point Accuracy
n
Current Foldback Protection (Disabled at Start-Up)
n
Parallel/Current Sharing
n
Ultrafast Transient Response
n
Current Mode Control
n
Programmable Soft-Start
n
Output Overvoltage Protection
n
–55°C to 125°C Operating Temperature Range
n
(LTM4612MPV)
Small Surface Mount Footprint, Low Profile
n
(15mm × 15mm × 2.8mm) LGA Package
APPLICATIONS
Telecom and Networking Equipment
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Industrial and Avionic Equipment
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RF Systems
n
TYPICAL APPLICATION
5V/5A Ultralow Noise µModule with 7V to 36V Input
V
IN
7V
TO 36V
2M 100k
PGOOD
RUN
COMP
INTV
C
IN
DRV
f
SET
TRACK/SS
V
0.01µF
10µF
CLOCK SYNC
V PLLIN
IN
V
OUT
LTM4612
V
FB
CC
FCB
CC
MARG0
MARGIN
CONTROL
MARG1
D MPGM
392k
SGND PGND
5% MARGIN
4612 TA01
For more information
EN55022B Compliant
DC/DC µModule Regulator
DESCRIPTION
The LTM 4612 is a EN55022 Class B certified high voltage
®
input and output, 5A switching mode DC/DC power supply.
Included in the package are the switching controller, power
FETs, inductor and all support components. Operating
over an input voltage range of 5V to 36V, the LTM4612
supports an output voltage range of 3.3V to 15V, set by a
single resistor. Only bulk input and output capacitors are
needed to finish the design.
High switching frequency and an adaptive on-time current
mode architecture enables a very fast transient response
to line and load changes without sacrificing stability.
The onboard input filter and noise cancellation circuits
achieve low noise coupling, thus effectively reducing the
electromagnetic interference (EMI)—see Figures 4 and 8.
Furthermore, the DC/DC µModule
chronized with an external clock to reduce undesirable
frequency harmonics and allow PolyPhase
high load currents.
The LTM4612 is offered in a space saving and thermally
enhanced 15mm × 15mm × 2.8mm LGA package, which
enables utilization of unused space on the bottom of PC
boards for high density point-of-load regulation. The
LTM4612 is Pb-free and RoHS compliant.
L, LT, LTC, LTM, Linear Technology, the Linear logo, PolyPhase and µModule are registered
trademarks and LTpowerCAD is a trademark of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
Radiated Emission Scan at 24V
70
60
50
V
OUT
40
5V
5A
100pF
30
C
OUT
13.7k
20
10
0
–10
30
www.linear.com/LTM4612
LTM4612
36V , 15V
IN OUT
regulator can be syn-
®
, 5V
IN
EN55022 CLASS B LIMIT
226.2 422.4 618.6 814.8 1010
128.1 324.3 520.5 716.7 912.9
FREQUENCY (MHz)
4612 TA01b
, 5A,
operation for
®
/5A
OUT
4612fc
1