Datasheet

MAX16932/MAX16933
2.2MHz, 36V, Dual Buck
with 20µA Quiescent Current
10Maxim Integrated
Pin Description (continued)
PIN NAME DESCRIPTION
10 EXTVCC 3.1V to 5.2V Input to the Switchover Comparator
11 IN Supply Input. Bypass IN with sufficient capacitance to supply the two out-of-phase buck converters.
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
with an external resistor connected to a positive voltage lower than 5.5V. Place a minimum of 100Ω
(R
PGOOD1
) in series with PGOOD1. See the Voltage Monitoring section for details.
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
1. Keep f
SYNC
a minimum of 10% greater than the maximum internal switching frequency for stable
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 Buck 2 Error Amplifier Output. Connect an RC network to COMP2 to compensate buck 2.
17 FB2
Feedback Input for Buck 2. Connect FB2 to BIAS for the 3.3V fixed output or to a resistive divider
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 Low-Side Gate Drive Output for Buck 2. DL2 output voltage swings from V
PGND2
to V
BIAS
.
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 High-Side Gate Drive Output for Buck 2. DH2 output voltage swings from V
LX2
to V
BST2
.
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.