12V, 8A 1.2MHz

Step-Down Regulator

10

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Detailed Description

The MAX8654 high-efficiency, voltage-mode switching

regulator is capable of delivering up to 8A of output

current. The MAX8654 provides output voltages from

ing them ideal for on-board point-of-load applications.

The output voltage accuracy is better than ±1% over

temperature.

The MAX8654 allows for all ceramic-capacitor designs

and faster transient responses. The device is available in

a 6mm x 6mm 36-pin TQFN-EP package. The SYNCOUT

function allows end users to operate two MAX8654s at

the same switching frequency with 180° out-of-phase

operation to minimize the input ripple current, conse-

quently reducing the input capacitance requirements.

The REFIN function makes the MAX8654 an ideal candi-

date for DDR and tracking power supplies. Using inter-

low-side switches maintains high efficiency at both heavy

load and high switching frequencies.

The MAX8654 uses voltage-mode control architecture

with a high-bandwidth (20MHz) error amplifier. The volt-

age-mode control architecture allows up to 1.2MHz

switching, reducing board area. The op-amp voltage

error amplifier works with type 3 compensation to fully

utilize the bandwidth of the high-frequency switching to

obtain fast transient response. Adjustable soft-start time

provides flexibility to minimize input startup inrush cur-

rent. The open-drain power-good (PWRGD) output

goes high impedance when the output reaches 90% of

its regulation point.

MAX8654

IN

VP

0.1

µF

3.57k

Ω

1

µF

2.2

µF

100k

Ω

75k

Ω

10

µF

1.0

µH

0.22

µF

2 x 22

µF

1nF

BST

VDL

INPUT

4.5V TO 14V

LX

EN

PGND

COMP

FB

SYNC

SYNCOUT

PWRGD

GND

VL

VL

ILIM

REFIN

SS

FREQ

10

µF

0.022

µF

IN

10nF

22pF

4.99k

Ω

100

Ω

20k

Ω

1.1k

Ω

VL

OUTPUT

3.3V, 8A

Figure 1. Typical Application Circuit, 3.3V, 8A, 500kHz