Fault-related commands, Clear_faults, Vout_ov_fault_limit – Maxim Integrated MAX15303 PMBus Command Set User Manual
Page 19: Vout_ov_fault_response
MAX15303 PMBus Command Set User’s Guide
Page 19 of 52
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 MAX15303 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:
0x170A (1.440V)
Description/Notes: See Section 15.2 of the PMBus Specification Part II.
VOUT_OV_FAULT_LIMIT mantissa data sent to and from the MAX15303 must be divided by 4096 to
determine the actual voltage value, according to the fixed value of
In the MAX15303, there are seven possible output voltage ranges based on seven corresponding
internal feedback divider taps. The MAX15303 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 0x170A (1.440V) will be overridden during initialization to
x 1.15, unless a specific value has been written to the User Store.
VOUT_OV_FAULT_RESPONSE
Reference:
Standard Command
Lockable:
Yes
Command Code:
0x41
Format:
Bit field
Data Bytes:
1
Units:
N/A
Transfer:
Read/Write Byte
Factory Value:
0x80 (Stop regulating and remain off)
Description/Notes: See Sections 10.5.1 and 15.3 of the PMBus Specification Part II.
Note that the MAX15303 does not support finite, non-zero restart-attempt counts. (Continuous
restart attempts are supported.)
The VOUT_OV_FAULT_RESPONSE command data comprises three bit-fields:
Bits [7:6] determine the basic fault-response mode. The MAX15303 supports the following modes:
00
Ignore the fault condition.
01
Continue operating and wait for the fault to abate for time specified in bits [2:0]. If the