150mA SOT-23 Ultra Low Noise CMOS RF-LDO™ Regulator
Figure 8: Recommended application circuit schematic.
Figure 9: Recommended application circuit layout ( not drawn to scale)
Note, ground plane is bottom layer of PCB and connects to top layer ground
connections through vias.
Evaluation Board Parts List For Printed Circuit Board Shown Above
Pin Number
U1
J1
Cin
Cnoise
Cout
Pin Name
ILC7082AIM5-30
69190-405
GRM40 Y5V 105Z16
ECU-V1H103KBV
GRM42-6X5R475K10
Manufacturer
Impala Linear
Berg
muRata
Panasonic
muRata
Description
150mA RF LDO
TM
regulator
Connector, four position header
Ceramic capacitor, 1µF,16V,SMT
(size 0805)
Ceramic capacitor, 0.01µF,16V,SMT
(size 0603)
Ceramic capacitor, 4.7µF16V,SMT
(size 1206)
GROUNDING RECOMMENDATIONS
1. Connect C
IN
between V
IN
of the ILC7082 and the
“GROUND PLANE”.
2. Keep the ground side of C
OUT
and C
NOISE
connected to the
“LOCAL GROUND” and not directly to the “GROUND PLANE”.
3. On multilayer boards use component side copper for
grounding around the ILC7082 and connect back to a
“GROUND PLANE” using vias.
4. If using a DC-DC converter in your design, use a star
grounding system with separate traces for the power
ground and the control signals. The star should radiate from
where the power supply enters the PCB.
LAYOUT CONSIDERATIONS
1. Place all RF LDO related components; ILC7082, input
capacitor C
IN
, noise bypass capacitor C
NOISE
and output
capacitor C
OUT
as close together as possible.
2. Keep the output capacitor C
OUT
as close to the ILC7082
as possible with very short traces to the V
OUT
and GND pins.
3. The traces for the related components; ILC7082, input
capacitor C
IN
, noise bypass capacitor C
NOISE
and output
capacitor C
OUT
can be run with minimum trace widths close
to the LDO.
4. Maintain a separate “LOCAL GROUND” remote from the
“GROUND PLANE” to ensure a quiet ground near the LDO.
Figure 9 shows how this circuit can be translated into a
PCB layout.
Impala Linear Corporation
ILC7082 1.3
(408) 574-3939
www.impalalinear.com
April 1999
9
IMPALA [ Impala Linear Corporation ]
