For the circuit schematic, bill of
materials, PCB layout files, and test results of an LMR664x0 implementation see the LMR66430-2EVM. As a quick-start guide, Table 8-1 and Table 8-4 provide typical component values for a range of the most common output
voltages.
Table 8-1 Typical External Component
Values for Adjustable Output LMR66430
ƒSW (kHz)(1) |
VOUT (V) |
L (µH) |
Nominal COUT (Rated Capacitance) |
Minimum COUT(Effective
Capacitance)(2) |
RFBT (kΩ)(3) |
RFBB (kΩ) |
CIN |
CBOOT |
CVCC |
CFF(4) |
400 |
3.3 |
10 |
3 × 22 µF |
60 µF |
33.2 |
14.3 |
4.7 µF |
100
nF |
1 µF |
100 pF |
2200 |
3.3 |
2.2 |
3 × 22 µF |
60 µF |
33.2 |
14.3 |
4.7 µF |
100
nF |
1 µF |
DNP |
400 |
5 |
10 |
3 × 22 µF |
60 µF |
49.9 |
12.4 |
4.7 µF |
100
nF |
1 µF |
100 pF |
2200 |
5 |
2.2 |
3 × 22 µF |
60 µF |
49.9 |
12.4 |
4.7 µF |
100
nF |
1 µF |
DNP |
(1) Inductor values are calculated based on typical VIN = 12
V.
(2) Minimum COUT values
take into account the effects of DC bias voltage and temperature on the actual
capacitance value.
Table 8-2 Typical External Component Values for Adjustable Output LMR66420
ƒSW (kHz)(1) |
VOUT (V) |
L (µH) |
Nominal COUT (Rated Capacitance) |
Minimum COUT(Effective
Capacitance)(2) |
RFBT (kΩ)(3) |
RFBB (kΩ) |
CIN |
CBOOT |
CVCC |
CFF(4) |
400 |
3.3 |
6.8 |
3 × 22 µF |
60 µF |
33.2 |
14.3 |
4.7 µF |
100
nF |
1 µF |
100 pF |
2200 |
3.3 |
2.2 |
2 × 22 µF |
40 µF |
33.2 |
14.3 |
4.7 µF |
100
nF |
1 µF |
DNP |
400 |
5 |
6.8 |
3 × 22 µF |
60 µF |
49.9 |
12.4 |
4.7 µF |
100
nF |
1 µF |
100 pF |
2200 |
5 |
2.2 |
2 × 22 µF |
40 µF |
49.9 |
12.4 |
4.7 µF |
100
nF |
1 µF |
DNP |
(1) Inductor values are calculated based on typical VIN = 12 V.
(2) Minimum COUT values take into account the effects of DC bias voltage
and temperature on the actual capacitance value.
Table 8-3 Typical External Component Values for Adjustable Output LMR66410
ƒSW (kHz)(1) |
VOUT (V) |
L (µH) |
Nominal COUT (Rated Capacitance) |
Minimum COUT(Effective
Capacitance)(2) |
RFBT (kΩ)(3) |
RFBB (kΩ) |
CIN |
CBOOT |
CVCC |
CFF(4) |
400 |
3.3 |
22 |
2 × 22 µF |
40 µF |
33.2 |
14.3 |
4.7 µF |
100
nF |
1 µF |
100 pF |
2200 |
3.3 |
4.7 |
1 × 22 µF |
20 µF |
33.2 |
14.3 |
4.7 µF |
100
nF |
1 µF |
DNP |
400 |
5 |
22 |
2 × 22 µF |
40 µF |
49.9 |
12.4 |
4.7 µF |
100
nF |
1 µF |
100 pF |
2200 |
5 |
4.7 |
1 × 22 µF |
20 µF |
49.9 |
12.4 |
4.7 µF |
100
nF |
1 µF |
DNP |
(1) Inductor values are calculated based on typical VIN = 12 V.
(2) Minimum COUT values take into account the effects of DC bias voltage
and temperature on the actual capacitance value.
Table 8-4 Typical External Component
Values for Fixed Output LMR66430
ƒSW (kHz)(1) |
VOUT (V) |
L (µH) |
Nominal COUT (Rated Capacitance) |
Minimum COUT(Effective
Capacitance)(2) |
RFBT (Ω) |
RFBB (Ω)(3) |
CIN |
CBOOT |
CVCC |
CFF |
400 |
3.3 |
10 |
3 × 22 µF |
60 µF |
0 |
DNP |
4.7 µF |
100
nF |
1 µF |
DNP |
2200 |
3.3 |
2.2 |
2 × 22 µF |
40 µF |
0 |
DNP |
4.7 µF |
100
nF |
1 µF |
DNP |
400 |
5 |
10 |
3 × 22 µF |
60 µF |
0 |
DNP |
4.7 µF |
100
nF |
1 µF |
DNP |
2200 |
5 |
2.2 |
2 × 22 µF |
40 µF |
0 |
DNP |
4.7 µF |
100
nF |
1 µF |
DNP |
(1) Inductor values are calculated based on typical VIN = 12
V.
(2) Minimum COUT values
take into account the effects of DC bias voltage and temperature on the actual
capacitance value.
(3) DNP = Do Not Populate.
Table 8-5 Typical External Component Values for Fixed Output LMR66420
ƒSW (kHz)(1) |
VOUT (V) |
L (µH) |
Nominal COUT (Rated Capacitance) |
Minimum COUT(Effective
Capacitance)(2) |
RFBT (kΩ) |
RFBB (kΩ)(3) |
CIN |
CBOOT |
CVCC |
CFF |
400 |
3.3 |
6.8 |
3 × 22 µF |
60 µF |
0 |
DNP |
4.7 µF |
100
nF |
1 µF |
DNP |
2200 |
3.3 |
2.2 |
2 × 22 µF |
40 µF |
0 |
DNP |
4.7 µF |
100
nF |
1 µF |
DNP |
400 |
5 |
6.8 |
3 × 22 µF |
60 µF |
0 |
DNP |
4.7 µF |
100
nF |
1 µF |
DNP |
2200 |
5 |
2.2 |
2 × 22 µF |
40 µF |
0 |
DNP |
4.7 µF |
100
nF |
1 µF |
DNP |
(1) Inductor values are calculated based on typical VIN = 12 V.
(2) Minimum COUT values take into account the effects of DC bias voltage
and temperature on the actual capacitance value.
(3) DNP = Do Not Populate.
Table 8-6 Typical External Component Values for Fixed Output LMR66410
ƒSW (kHz)(1) |
VOUT (V) |
L (µH) |
Nominal COUT (Rated Capacitance) |
Minimum COUT(Effective
Capacitance)(2) |
RFBT (kΩ) |
RFBB (kΩ)(3) |
CIN |
CBOOT |
CVCC |
CFF |
400 |
3.3 |
22 |
2 × 22 µF |
40 µF |
0 |
DNP |
4.7 µF |
100
nF |
1 µF |
DNP |
2200 |
3.3 |
4.7 |
1 × 22 µF |
20 µF |
0 |
DNP |
4.7 µF |
100
nF |
1 µF |
DNP |
400 |
5 |
22 |
2 × 22 µF |
40 µF |
0 |
DNP |
4.7 µF |
100
nF |
1 µF |
DNP |
2200 |
5 |
4.7 |
1 × 22 µF |
20 µF |
0 |
DNP |
4.7 µF |
100
nF |
1 µF |
DNP |
(1) Inductor values are calculated based on typical VIN = 12 V.
(2) Minimum COUT values take into account the effects of DC bias voltage
and temperature on the actual capacitance value.
(3) DNP = Do Not Populate.