LM2622MM-ADJ National Semiconductor, LM2622MM-ADJ Datasheet - Page 11

• Manufacturer Part Number: LM2622MM-ADJ
• Description: IC,SMPS CONTROLLER,CURRENT-MODE,TSSOP,8PIN,PLASTIC
• Manufacturer: National Semiconductor

Specifications of LM2622MM-ADJ

• Rohs Compliant: NO

Operation
gin can also be improved by adding C
in the section. The equation for A
additional equations required for the calculation:
(Continued)
mc ) 0.072fs (in V/s)
DC
C2
is given below with
as discussed earlier
11
where R
mum input voltage, g
tance found in the Electrical Characteristics table, and R
SON
the Typical Performance Characteristics section.
LAYOUT CONSIDERATIONS
The input bypass capacitor C
operating circuit, must be placed close to the IC. This will
reduce copper trace resistance which effects input voltage
ripple of the IC. For additional input voltage filtering, a 100nF
bypass capacitor can be placed in parallel with C
the V
output capacitor, C
IC. Any copper trace connections for the C
increase the series resistance, which directly effects output
voltage ripple. The feedback network, resistors R
R
inductor, to minimize copper trace connections that can in-
ject noise into the system. Trace connections made to the
inductor and schottky diode should be minimized to reduce
power dissipation and increase overall efficiency. For more
detail on switching power supply layout considerations see
Application Note AN-1149: Layout Guidelines for Switching
Power Supplies.
FB2
is the value chosen from the graph "R
, should be kept close to the FB pin, and away from the
IN
pin, to shunt any high frequency noise to ground. The
L
is the minimum load resistance, V
OUT
m
, should also be placed close to the
is the error amplifier transconduc-
IN
, as shown in the typical
OUT
DSON
IN
capacitor can
is the mini-
www.national.com
vs. V
IN
, close to
FB1
IN
and
" in
D -