Q54SG Datasheet, PDF (12/26 Pages) Delta Electronics, Inc. – Industry standard, DOSA compliant pin out

FEATURES DESCRIPTIONS (CON.)
PMBus Data Format
The module receives and report date in LINEAR
format. The Exponent of the data words is fixed at a
reasonable value for the command; altering the
exponent is not supported. DIRECT format is not
supported by the module.
For commands that set or report any voltage
thresholds related to the output voltage, the module
supports the linear data format consisting of a two byte
value with a 16-bit, unsigned mantissa, and a fixed
exponent of -12. The format of the two data bytes is
shown below:
The equation can be written as:
Vout = Mantissa x 2^-12
For example, considering set Vout to 12V by
VOUT_COMMAND, the read/write data can be
calculated refer to below process:
1. Mantissa =Vout/2^-12= 12/2^-12=49152;
2. Converter the calculated Mantissa to hexadecimal
0xC000.
For commands that set or report all other thresholds,
including input voltages, output current, temperature,
time and frequency, the supported linear data format is
a two byte value with: an 11 bit, two’s complement
mantissa , and a 5 bit, two’s complement exponent
(scaling factor).The format of the two data bytes is
shown as in below.
The detail exponent and resolution of main parameter is
summarized as below:
Exponent Resolution
Vin
-3
0.125V
Vo
-12 0.244mV
Io
-4
62.5mA
Temperature
-2
/
Switching requency -2 0.25Khz
Time
-1
0.5ms
Supported PMBus Commands
The main PMBus commands described in the PMBus 1.2
specification are supported by the module. Partial PMBus
commands are fully supported; Partial PMBus commands
have difference with the definition in PMBus 1.2
specification. All the supported PMBus commands are
detail summarized in below table.
The equation can be written as:
Value = Mantissa x 2^exponent
For example, considering set the turn on threshold of
input under voltage lockout to 34V by VIN_ON
command; the read/write data can be calculated refer to
below process:
1. Get the exponent of Vin, -3; whose binary is 11101
2. Mantissa =Vin/2^-3=34/2^-3=272;
3. Converter the calculated Mantissa to hexadecimal
110, then converter to binary 00100010000;
4. Combine the exponent and the mantissa, 11101
and 00100010000;
5. Converter binary 1110100100010000 to
hexadecimal E910.
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DS_Q54SG12050_09092016