LTM4608 LINER [Linear Technology], LTM4608 Datasheet - Page 9

• Manufacturer Part Number: LTM4608
• Description: Low VIN, 8A DC/DC ?ModuleTM with Tracking, Margining, and Frequency Synchronization
• Manufacturer: LINER [Linear Technology]

Table 1. Decoupling Requirements. T
SYMBOL
C
C
OPERATION
SIMPLIFIED BLOCK DIAGRAM
The LTM4608 is a standalone nonisolated switch mode
DC/DC power supply. It can deliver up to 8A of DC output
current with few external input and output capacitors.
This module provides precisely regulated output voltage
programmable via one external resistor from 0.6V DC to
5.0V DC over a 2.375V to 5.5V input voltage. The typical
application schematic is shown in Figure 18.
The LTM4608 has an integrated constant frequency current
mode regulator and built-in power MOSFET devices with
fast switching speed. The typical switching frequency is
IN
OUT
PHMODE
CLKOUT
PGOOD
PLLLPF
TRACK
MODE
CLKIN
SGND
BSEL
MGN
SV
I
RUN
THM
I
TH
IN
PARAMETER
External Input Capacitor Requirement
(V
External Output Capacitor Requirement
(V
IN
IN
= 2.375V to 5.5V, V
= 2.375V to 5.5V, V
INTERNAL
COMP
INTERNAL
FILTER
A
= 25°C, Block Diagram Confi guration.
OUT
OUT
= 1.5V)
= 1.5V)
Figure 1. Simplifi ed LTM4608 Block Diagram
INTERNAL
CONTROL
POWER
FILTER
CONDITIONS
I
I
OUT
OUT
= 8A
= 8A
1.5MHz. For switching noise sensitive applications, it can
be externally synchronized from 0.75MHz to 2.25MHz.
Even spread spectrum switching can be implemented in
the design to reduce noise.
With current mode control and internal feedback loop
compensation, the LTM4608 module has suffi cient stabil-
ity margins and good transient performance with a wide
range of output capacitors, even with all ceramic output
capacitors.
M1
M2
L
10μF
22μF
10μF
10k
MIN
10
10μF
22pF
V
SW
V
GND
FB
4608 BD
TYP
100
IN
OUT
+
LTM4608
R
6.65k
FB
C
IN
C
OUT
MAX
V
2.375 TO 5.5V
V
1.5V
8A
IN
OUT
UNITS
9
4608f
μF
μF