lm25066apsqx National Semiconductor Corporation, lm25066apsqx Datasheet - Page 36

• Manufacturer Part Number: lm25066apsqx
• Description: Lm25066a System Power Management And Protection Ic With Pmbus
• Manufacturer: National Semiconductor Corporation

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(STATUS registers, DIAGNOSTIC_WORD) and the external
MOSFET gate control will still be active (VIN_OV_FAULT,
VIN_UV_FAULT,
MFR_SPECIFIC_09: DEVICE_SETUP
The DEVICE SETUP command may be used to override pin
settings to define operation of the LM25066A under host con-
trol. This command is accessed with the PMBus™ read / write
byte protocol.
In order to configure the Current Limit Setting via this register,
it is necessary to set the Current Limit Configuration bit (2) to
1 to enable the register to control the current limit function and
the Current Limit Setting bit (4) to select the desired setting.
Similarly, in order to control the Circuit Breaker via this regis-
ter, it is necessary to set the Circuit Breaker Configuration bit
(1) to 1 to enable the register to control the Circuit Breaker
Setting, and the Circuit Breaker / Current Limit Ratio bit (3) to
Bit
7:5
4
3
2
1
0
TABLE 30. DEVICE_SETUP Byte Format
Current limit setting
Circuit breaker
Configuration
Configuration
Retry setting
CB/CL Ratio
Current limit
Unused
BIT
Name
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
IIN/PFET_FAULT,
000 = Pin configured retries
1 = Use SMBus settings
1 = Use SMBus settings
1 = High setting (46mV)
0 = Low setting (25mV)
111 = Unlimited retries
1 = High setting (3.6x)
0 = Low setting (1.8x)
110 = Retry 16 times
0 = Use pin settings
0 = Use pin settings
101 = Retry 8 times
100 = Retry 4 times
011 = Retry 2 times
010 = Retry 1 time
001 = No retries
Meaning
TABLE 29. ALERT MASK Definitions
CML FAULT (Communications Fault)
VOUT UNDERVOLTAGE WARN
CB_FAULT,
OVERTEMPERATURE FAULT
VIN UNDERVOLTAGE FAULT
VIN UNDERVOLTAGE WARN
VIN OVERVOLTAGE FAULT
VIN OVERVOLTAGE WARN
OVERPOWER LIMIT WARN
CIRCUIT BREAKER FAULT
EXT_MOSFET_SHORTED
OVERTEMP WARN
IIN/PFET FAULT
IIN LIMIT Warn
PGOOD BAR
Not Used
Not Used
NAME
36
OT_FAULT). This register is accessed with the PMBus™
Read / Write Word protocol.
the desired value. If the respective Configuration bits are not
set, the Settings will be ignored and the pin set values used.
The Current Limit Configuration effects the coefficients used
for the Current and Power measurements and warning reg-
isters.
MFR_SPECIFIC_10: BLOCK_READ
The
DIAGNOSTIC_WORD with input and output telemetry infor-
mation (IIN, VOUT, VIN, PIN) as well as TEMPERATURE to
capture all of the operating information of the LM25066A in a
single SMBus transaction. The block is 12 bytes long with
telemetry information being sent out in the same manner as
if an individual READ_XXX command had been issued
(shown below). The contents of the block read register are
updated every clock cycle (85ns) as long as the SMBus in-
terface is idle. BLOCK_READ also guarantees that the VIN,
VOUT, IIN and PIN measurements are all time-aligned
whereas there is a chance they may not be if read with indi-
vidual PMBus™ commands.
The Block Read command is read via the PMBus™ block
read protocol.
MFR_SPECIFIC_11: SAMPLES_FOR_AVG
The SAMPLES_FOR AVERAGE is a manufacturer specific
command for setting the number of samples used in comput-
ing the average values for IIN, VIN, VOUT, PIN. The decimal
equivalent of the AVGN nibble is the power of 2 samples (e.g.
Byte Count (always 12)
DIAGNOSTIC WORD
VOUT_BLOCK
TEMP_BLOCK
VIN_BLOCK
PIN_BLOCK
IIN_BLOCK
BLOCK_READ
TABLE 31. BLOCK_READ Register Format
COMMAND
DEFAULT
(1 Word)
(1 Word)
(1 Word)
(1 Word)
(1 Word)
(1 Word)
(1 byte)
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
concatenates
the