LTC3410-1.875
2.25MHz, 300mA
Synchronous Step-Down
Regulator in SC70
U FEATURES DESCRIPTIO ■ The LTC ®3410-1.875 is a high efficiency monolithic synchronous buck regulator using a constant frequency,
current mode architecture. Supply current during operation is only 26µA, dropping to 1µF) supply bypass capacitors. The discharged bypass capacitors are effectively put in parallel
with COUT, causing a rapid drop in VOUT. No regulator can
deliver enough current to prevent this problem if the load
switch resistance is low and it is driven quickly. The only
solution is to limit the rise time of the switch drive so that
the load rise time is limited to approximately (25 • CLOAD).
Thus, a 10µF capacitor charging to 3.3V would require a
250µs rise time, limiting the charging current to about
130mA. Therefore, power dissipated by the part is:
PD = ILOAD2 • RDS(ON) = 86.4mW 34101875f 11 LTC3410-1.875 U W U U APPLICATIO S I FOR ATIO
PC Board Layout Checklist When laying out the printed circuit board, the following
checklist should be used to ensure proper operation of the
LTC3410-1.875. These items are also illustrated graphically in Figures 3 and 4. Check the following in your layout:
1. The power traces, consisting of the GND trace, the SW
trace and the VIN trace should be kept short, direct and
wide.
2. Does the (+) plate of CIN connect to VIN as closely as
possible? This capacitor provides the AC current to the …