Application Circuits
Typical Application Circuits
Single-Phase, 400kHz, 6A Operation
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High-Side Driver Supply. Connect a 0.1μF capacitor between LX and BST for proper operation.
BST
BST
IC Supply Input. Connect a 1μF or larger ceramic capacitor in parallel with a 4.7μF cap from SUP to PGND.
SUP
SUP
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
BUCK Switching Node. High impedance when part is off. Connect LX to the switched side of the appropriate inductor.
LX
LX
IC Supply Input. Connect a 1μF or larger ceramic capacitor in parallel with a 4.7μF cap from SUP to PGND.
SUP
SUP
Analog Ground
GND
GND
1.8V Internal BIAS Supply. Connect a minimum of 2μF ceramic capacitor to PGND.
BIAS
BIAS
Feedback Pin. Connect a resistor-divider from OUT to FB to GND for external adjustment of output voltage. Connect to BIAS for internal fixed voltages.
FB
FB
Buck Regulator Output Voltage-Sense Input. Bypass OUT to PGND with a minimum capacitor as for appropriate paragraph.
OUT
OUT
Internal Voltage Loop Error-Amplifier Output. Connect to VEA of the target for dual-phase operation. Leave unconnected for single-phase operation.
VEA
VEA
Open-Drain Reset Output. External pull-up required.
PGOOD
PGOOD
SYNC. If connected to GND, Skip-mode operation is enabled under light loads. If connected to BIAS, forced-PWM mode is enabled.
SYNC
SYNC
180-Degree Out-of-Phase Clock Output for Multiphase Operation. Leave SYNCOUT open for single-phase operation.
SYNCOUT
SYNCOUT
High-voltage-compatible input for circuit activation. If this pin is low, the part is off.
EN
EN
4.7µF
4.7µF
4.7µF
4.7µF
2.2µF
2.2µF
4.7µH
4.7µH
3x47µF
3x47µF
0.1µF
0.1µF
MAX20406
MAX20404
MAX20405
MAX20406
Single-Phase, 2.1MHz and 2.3MHz, 6A Operation
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High-Side Driver Supply. Connect a 0.1μF capacitor between LX and BST for proper operation.
BST
BST
IC Supply Input. Connect a 1μF or larger ceramic capacitor in parallel with a 4.7μF cap from SUP to PGND.
SUP
SUP
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
BUCK Switching Node. High impedance when part is off. Connect LX to the switched side of the appropriate inductor.
LX
LX
IC Supply Input. Connect a 1μF or larger ceramic capacitor in parallel with a 4.7μF cap from SUP to PGND.
SUP
SUP
Analog Ground
GND
GND
1.8V Internal BIAS Supply. Connect a minimum of 2μF ceramic capacitor to PGND.
BIAS
BIAS
Feedback Pin. Connect a resistor-divider from OUT to FB to GND for external adjustment of output voltage. Connect to BIAS for internal fixed voltages.
FB
FB
Buck Regulator Output Voltage-Sense Input. Bypass OUT to PGND with a minimum capacitor as for appropriate paragraph.
OUT
OUT
Internal Voltage Loop Error-Amplifier Output. Connect to VEA of the target for dual-phase operation. Leave unconnected for single-phase operation.
VEA
VEA
Open-Drain Reset Output. External pull-up required.
PGOOD
PGOOD
SYNC. If connected to GND, Skip-mode operation is enabled under light loads. If connected to BIAS, forced-PWM mode is enabled.
SYNC
SYNC
180-Degree Out-of-Phase Clock Output for Multiphase Operation. Leave SYNCOUT open for single-phase operation.
SYNCOUT
SYNCOUT
High-voltage-compatible input for circuit activation. If this pin is low, the part is off.
EN
EN
4.7µF
4.7µF
4.7µF
4.7µF
2.2µF
2.2µF
1µH
1µH
3x22µF
3x22µF
0.1µF
0.1µF
MAX20406
MAX20404
MAX20405
MAX20406
MAX20406E
Single-Phase, 3MHz, 6A Operation
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High-Side Driver Supply. Connect a 0.1μF capacitor between LX and BST for proper operation.
BST
BST
IC Supply Input. Connect a 1μF or larger ceramic capacitor in parallel with a 4.7μF cap from SUP to PGND.
SUP
SUP
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
BUCK Switching Node. High impedance when part is off. Connect LX to the switched side of the appropriate inductor.
LX
LX
IC Supply Input. Connect a 1μF or larger ceramic capacitor in parallel with a 4.7μF cap from SUP to PGND.
SUP
SUP
Analog Ground
GND
GND
1.8V Internal BIAS Supply. Connect a minimum of 2μF ceramic capacitor to PGND.
BIAS
BIAS
Feedback Pin. Connect a resistor-divider from OUT to FB to GND for external adjustment of output voltage. Connect to BIAS for internal fixed voltages.
FB
FB
Buck Regulator Output Voltage-Sense Input. Bypass OUT to PGND with a minimum capacitor as for appropriate paragraph.
OUT
OUT
Internal Voltage Loop Error-Amplifier Output. Connect to VEA of the target for dual-phase operation. Leave unconnected for single-phase operation.
VEA
VEA
Open-Drain Reset Output. External pull-up required.
PGOOD
PGOOD
SYNC. If connected to GND, Skip-mode operation is enabled under light loads. If connected to BIAS, forced-PWM mode is enabled.
SYNC
SYNC
180-Degree Out-of-Phase Clock Output for Multiphase Operation. Leave SYNCOUT open for single-phase operation.
SYNCOUT
SYNCOUT
High-voltage-compatible input for circuit activation. If this pin is low, the part is off.
EN
EN
4.7µF
4.7µF
4.7µF
4.7µF
2.2µF
2.2µF
0.68µH
0.68µH
2x22µF
2x22µF
0.1µF
0.1µF
MAX20406
MAX20404
MAX20405
MAX20406
Dual-Phase, Controller-Target 2.1MHz and 2.3MHz Operation
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High-Side Driver Supply. Connect a 0.1μF capacitor between LX and BST for proper operation.
BST
BST
IC Supply Input. Connect a 1μF or larger ceramic capacitor in parallel with a 4.7μF cap from SUP to PGND.
SUP
SUP
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
BUCK Switching Node. High impedance when part is off. Connect LX to the switched side of the appropriate inductor.
LX
LX
IC Supply Input. Connect a 1μF or larger ceramic capacitor in parallel with a 4.7μF cap from SUP to PGND.
SUP
SUP
Analog Ground
GND
GND
1.8V Internal BIAS Supply. Connect a minimum of 2μF ceramic capacitor to PGND.
BIAS
BIAS
Feedback Pin. Connect a resistor-divider from OUT to FB to GND for external adjustment of output voltage. Connect to BIAS for internal fixed voltages.
FB
FB
Buck Regulator Output Voltage-Sense Input. Bypass OUT to PGND with a minimum capacitor as for appropriate paragraph.
OUT
OUT
Internal Voltage Loop Error-Amplifier Output. Connect to VEA of the target for dual-phase operation. Leave unconnected for single-phase operation.
VEA
VEA
Open-Drain Reset Output. External pull-up required.
PGOOD
PGOOD
SYNC. If connected to GND, Skip-mode operation is enabled under light loads. If connected to BIAS, forced-PWM mode is enabled.
SYNC
SYNC
180-Degree Out-of-Phase Clock Output for Multiphase Operation. Leave SYNCOUT open for single-phase operation.
SYNCOUT
SYNCOUT
High-voltage-compatible input for circuit activation. If this pin is low, the part is off.
EN
EN
4.7µF
C
IN2
4.7µF
4.7µF
C
IN1
4.7µF
2.2µF
2.2µF
1µH
1µH
3x22µF
C
OUT1
3x22µF
CBST1
C
BST1
RPGOOD
R
PGOOD
High-Side Driver Supply. Connect a 0.1μF capacitor between LX and BST for proper operation.
BST
BST
IC Supply Input. Connect a 1μF or larger ceramic capacitor in parallel with a 4.7μF cap from SUP to PGND.
SUP
SUP
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
Power Ground. Connect all PGND pins together.
PGND
PGND
BUCK Switching Node. High impedance when part is off. Connect LX to the switched side of the appropriate inductor.
LX
LX
IC Supply Input. Connect a 1μF or larger ceramic capacitor in parallel with a 4.7μF cap from SUP to PGND.
SUP
SUP
Analog Ground
GND
GND
1.8V Internal BIAS Supply. Connect a minimum of 2μF ceramic capacitor to PGND.
BIAS
BIAS
Feedback Pin. Connect a resistor-divider from OUT to FB to GND for external adjustment of output voltage. Connect to BIAS for internal fixed voltages.
FB
FB
Buck Regulator Output Voltage-Sense Input. Bypass OUT to PGND with a minimum capacitor as for appropriate paragraph.
OUT
OUT
Internal Voltage Loop Error-Amplifier Output. Connect to VEA of the target for dual-phase operation. Leave unconnected for single-phase operation.
VEA
VEA
Open-Drain Reset Output. External pull-up required.
PGOOD
PGOOD
SYNC. If connected to GND, Skip-mode operation is enabled under light loads. If connected to BIAS, forced-PWM mode is enabled.
SYNC
SYNC
180-Degree Out-of-Phase Clock Output for Multiphase Operation. Leave SYNCOUT open for single-phase operation.
SYNCOUT
SYNCOUT
High-voltage-compatible input for circuit activation. If this pin is low, the part is off.
EN
EN
4.7µF
C
IN4
4.7µF
4.7µF
C
IN3
4.7µF
2.2µF
2.2µF
1µH
1µH
3x22µF
C
OUT2
3x22µF
CBST2
C
BST2
RPGOOD
R
PGOOD
MAX20404 MAX20405 MAX20406
MAX20404
MAX20405
MAX20406
MAX20406E
MAX20404 MAX20405 MAX20406
MAX20404
MAX20405
MAX20406
MAX20406E
