Pin Description (continued)

PIN

NAME

DESCRIPTION

12

PGOOD1

Open-Drain Power-Good Output for Buck 1. PGOOD1 is low if OUT1 is more than 15% (typ) below

the normal regulation point. PGOOD1 asserts low during soft-start and in shutdown. PGOOD1

becomes high impedance when OUT1 is in regulation. To obtain a logic signal, pullup PGOOD1

withanexternalresistorconnectedtoapositivevoltagelowerthan5.5V.Placeaminimumof100Ω

13

PGOOD2

Open-Drain Power-Good Output for Buck 2. PGOOD2 is low if OUT2 is more than 15% (typ) below

the normal regulation point. PGOOD2 asserts low during soft-start and in shutdown. PGOOD2

becomes high impedance when OUT2 is in regulation. To obtain a logic signal, pullup PGOOD2 with

an external resistor connected to a positive voltage lower than 5.5V.

14

FSYNC

External Clock Synchronization Input. Synchronization to the controller operating frequency ratio is

operation. See the Switching Frequency/External Synchronization section.

15

FOSC

Frequency Setting Input. Connect a resistor from FOSC to AGND to set the switching frequency of

the DC-DC converters.

16

COMP2

Buck2ErrorAmplifierOutput.ConnectanRCnetworktoCOMP2tocompensatebuck2.

17

FB2

FeedbackInputforBuck2.ConnectFB2toBIASforthe3.3Vfixedoutputortoaresistivedivider

between OUT2 and GND to adjust the output voltage between 1V and 10V. In adjustable mode, FB2

regulates to 1V (typ). See the Setting the Output Voltage in Buck Converters section.

18

OUT2

Output Sense and Negative Current-Sense Input for Buck 2. When using the internal preset 3.3V

feedback-divider (FB2 = BIAS), the buck uses OUT2 to sense the output voltage. Connect OUT2 to

the negative terminal of the current-sense resistor. See the Current Limiting and Current-Sense Inputs

and Current-Sense Measurement sections.

19

CS2

Positive Current-Sense Input for Buck 2. Connect CS2 to the positive terminal of the current-sense

resistor. See the Current Limiting and Current-Sense Inputs and Current-Sense Measurement sections.

20

PGND2

Power Ground for Buck 2

21

DL2

22

LX2

Inductor Connection for Buck 2. Connect LX2 to the switched side of the inductor. LX2 serves as the

lower supply rail for the DH2 high-side gate drive.

23

DH2

24

BST2

Boost Capacitor Connection for High-Side Gate Voltage of Buck 2. Connect a high-voltage diode

between BIAS and BST2. Connect a ceramic capacitor between BST2 and LX2. See the High-Side

Gate-Driver Supply (BST_) section.

25

EN2

High-Voltage Tolerant, Active-High Digital Enable Input for Buck 2. Driving EN2 high enables buck 2.

26

EN1

High-Voltage Tolerant, Active-High Digital Enable Input for Buck 1. Driving EN1 high enables buck 1.

27

BST1

Boost Capacitor Connection for High-Side Gate Voltage of Buck 1. Connect a high-voltage diode

between BIAS and BST1. Connect a ceramic capacitor between BST1 and LX1. See the High-Side

Gate-Driver Supply (BST_) section.

28

DH1

—

EP

Exposed Pad. Connect the exposed pad to ground. Connecting the exposed pad to ground does not

remove the requirement for proper ground connections to PGND1, PGND2, and AGND. The exposed

pad is attached with epoxy to the substrate of the die, making it an excellent path to remove heat from

the IC.

MAX17232/MAX17233

3.5V–36V, 2.2MHz, Synchronous Dual Buck

Controller with 20µA Quiescent Current

www.maximintegrated.com

Maxim Integrated │ 11