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Fault related commands, Clear_faults, Vout_ov_fault_limit – Maxim Integrated MAX15301 PMBus Command Set User Manual

Page 20

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MAX15301 PMBus Command Set User’s Guide

Rev 1

Page 20 of 53

Fault Related Commands

CLEAR_FAULTS

Reference:

Standard Command

Lockable:

Yes

Command Code:

0x03

Format:

N/A

Data Bytes:

0

Units:

N/A

Transfer:

Send Byte

Factory Value:

N/A

Description/Notes: See Section 15.1 of the PMBus Specification Part II.

If the MAX15301 has latched off for a fault condition, sending the CLEAR_FAULTS command will cause
a restart.

VOUT_OV_FAULT_LIMIT

Reference:

Standard Command

Lockable:

Yes

Command Code:

0x40

Format:

Unsigned integer mantissa

Data Bytes:

2

Units:

V

Transfer:

Read/Write Word

Factory Value:

0x0025 (see Description)

Description/Notes: See Section 15.2 of the PMBus Specification Part II.

VOUT_OV_FAULT_LIMIT mantissa data sent to and from the MAX15301 must be divided by 4096 to
determine the actual voltage value, according to the fixed value of

VOUT_MODE

.

In the MAX15301, there are seven possible output voltage ranges based on seven corresponding
internal feedback divider taps. The MAX15301 hardware has 8-bit resolution for the overvoltage fault
limit within each of these seven ranges.

The desired value of VOUT_OV_FAULT_LIMIT is retained in memory, regardless of limitations
imposed by the feedback divider range and the 8-bit fault limit resolution, but the read-back value is
based on actual hardware register settings.

The factory value of 0x0025 (9mV) will be overridden during initialization to

VOUT_COMMAND

x 1.15, unless a specific value has been written to the User Store.