AIC1571 AIC [Analog Intergrations Corporation], AIC1571 Datasheet - Page 13

• Manufacturer Part Number: AIC1571
• Description: 5-bit DAC, Synchronous PWM Power Regulator with Dual Linear Controllers
• Manufacturer: AIC [Analog Intergrations Corporation]

component selection and tight layout of critical
components, and short, wide metal trace mini-
mize the voltage spike.
A multi-layer printed circuit board is recom-
mended. Figure 18 shows the connections of
the critical components in the converter. The
C
1) A ground plane should be used. Locate the
2) The connection between Q1, Q2 and out-
3) The output capacitor (C
4) The AIC1571 is best placed over a quiet
IN
input capacitors (C
switches. Minimize the loop formed by C
the upper MOSFET (Q1) and the lower
MOSFET (Q2) as possible. Connections
should be as wide as short as possible to
minimize loop inductance.
put inductor should be as wide as short as
practical. Since this connection has fast
voltage transitions will easily induce EMI.
cated as close the load as possible. Be-
cause minimize the transient load magni-
tude for high slew rate requires low induc-
tance and resistance in circuit board
ground plane area. The GND pin should be
and C
+3.3V
OUT
V
OUT2
IN
could each represent numerous
C
OUT2
V
OUT3
+
Q4
IN
C
OUT3
) close to the power
+
+12V
OUT
+
Fig. 18 Printed circuit board power planes and islands
Css
Q3
) should be lo-
VIN2
GATE3
GATE2
SS
VCC
+
IN
,
GND
Power Plane Layer
Circuit Plane Layer
Via Connection to Ground Plane
OCSET
UGATE
PHASE
LGATE
PGND
physical capacitors. Dedicate one solid layer for
a ground plane and make all critical component
ground connections with vias to this layer.
5) The wiring traces from the control IC to the
6) The Vcc pin should be decoupled directly to
connected to the groundside of the output
capacitors. Under no circumstances should
GND be returned to a ground inside the C
Q1, Q2 loop. The GND and PGND pins
should be shorted right at the IC. This help
to minimize internal ground disturbances in
the IC and prevents differences in ground
potential from disrupting internal circuit op-
eration.
MOSFET gate and source should be sized
to carry 1A current. Locate C
the AIC1571 IC.
GND by a 1uF ceramic capacitor, trace
lengths should be as short as possible.
Q2
Q1
+
C
L
IN
OUT
+5V
+
IN
C
OUT
V
OUT
AIC1571
OUT2
close to
13
IN
,