MAX16930 Datasheet, PDF (12/29 Pages) Maxim Integrated Products – 2MHz, 36V, Dual Buck with Preboost and 20μA Quiescent Current

MAX16930/MAX16931
2MHz, 36V, Dual Buck with Preboost and
20µA Quiescent Current
Pin Description (continued)
PIN
NAME
DESCRIPTION
Output Sense and Negative Current-Sense Input for Buck 2. When using the internal preset 3.3V
26
OUT2
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.
Positive Current-Sense Input for Buck 2. Connect CS2 to the positive terminal of the current-sense
27
CS2
resistor. See the Current Limiting and Current-Sense Inputs and Current-Sense Measurement
sections.
28
PGND2
Power Ground for Buck 2
29
DL2
Low-Side Gate Drive Output for Buck 2. DL2 output voltage swings from V_PGND2 to V_BIAS.
30
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.
31
DH2
High-Side Gate Drive Output for Buck 2. DH2 output voltage swings from V_LX2 to V_BST2.
Boost Capacitor Connection for High-Side Gate Voltage of Buck 2. Connect a high-voltage diode
32
BST2
between BIAS and BST2. Connect a ceramic capacitor between BST2 and LX2. See the High-Side
Gate-Driver Supply (BST_) section.
Frequency Select Pin for the Preboost. When pulled low, the preboost will have the same switching
33
FSELBST
frequency as buck 1. When pulled high, the preboost will have a switching frequency that is 1/5th
that of buck 1. FSELBST is only active for the MAX16930. FSELBST should be connected to ground
for the MAX16931.
Preboost On-Indicator Output. To obtain a logic signal, pull up BSTON with an external resistor
34
BSTON
connected to a positive voltage lower than 5.5V. BSTON goes high to indicate that the preboost
is on.
35
EN2
High-Voltage Tolerant, Active-High Digital Enable Input for Buck 2. Driving EN2 high enables
buck 2.
36
EN1
High-Voltage Tolerant, Active-High Digital Enable Input for Buck 1. Driving EN1 high enables
buck 1.
High-Voltage Tolerant, Active-High Digital Enable Input for Preboost. When EN3 is high, the external
37
EN3
preboost is enabled and begins switching if V_INS drops below V_INS,OLV and required conditions are
met (see the Preboost section).
Boost Capacitor Connection for High-Side Gate Voltage of Buck 1. Connect a high-voltage diode
39
BST1
between BIAS and BST1. Connect a ceramic capacitor between BST1 and LX1. See the High-Side
Gate-Driver Supply (BST_) section.
40
DH1
High-Side Gate-Drive Output for Buck 1. DH1 output voltage swings from V_LX1 to V_BST1.
Exposed Pad. Connect the exposed pad to ground. Connecting the exposed pad to ground does
—
EP
not remove the requirement for proper ground connections to PGND1, PGND2, PGND3, 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.
Maxim Integrated
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