MAX34440ETL+ Maxim Integrated Products, MAX34440ETL+ Datasheet - Page 20

• Manufacturer Part Number: MAX34440ETL+
• Description: Supervisory Circuits PMBUS 6-CH POW SUPPLY MANAGER
• Manufacturer: Maxim Integrated Products

Specifications of MAX34440ETL+

• Minimum Operating Temperature: - 40 C
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Supply Current (typ): 2.5 mA
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 85 C
• Package / Case: TQFN-40
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PMBus 6-Channel Power-Supply Manager
Table 3. PMBus Command Code Coefficients
To send a value, the host must use the below equation
to solve for Y:
where Y is the 2-byte, two’s complement integer to be
sent to the unit; m is the slope coefficient; X is the real
world value, in units such as volts, to be converted for
transmission; b is the offset; and R is the exponent.
The following example demonstrates how the host can
send and retrieve values from the device. Table 4 shows
the coefficients used in the following parameters.
Table 4. Coefficients for DIRECT Format
Value
20
COMMAND
Voltage Scaling
Current Scaling
PARAMETER
Temperature
CODE
8Bh
25h
Voltage
Current
Timing
VOUT_MARGIN_HIGH
READ_VOUT
Sending a DIRECT Format Value
COMMAND NAME
Y = (mX + b) x 10
VOUT_MARGIN_HIGH
VOUT_MARGIN_LOW
VOUT_OV_FAULT_LIMIT
VOUT_OV_WARN_LIMIT
VOUT_UV_WARN_LIMIT
VOUT_UV_FAULT_LIMIT
POWER_GOOD_ON
POWER_GOOD_OFF
READ_VOUT
MFR_VOUT_PEAK
MFR_VOUT_MIN
VOUT_SCALE_MONITOR
IOUT_OC_WARN_LIMIT
IOUT_OC_FAULT_LIMIT
READ_IOUT
MFR_IOUT_PEAK
IOUT_CAL_GAIN
OT_FAULT_LIMIT
OT_WARN_LIMIT
READ_TEMPERATURE_1
MFR_TEMPERATURE_PEAK
TON_DELAY
TON_MAX_FAULT_LIMIT
TOFF_DELAY
MFR_FAULT_RETRY
COMMANDS
R
m
1
1
b
0
0
R
0
0
UNITS
mI
mV
mA
ms
NC
—
If a host wants to set the device to change the power-
supply output voltage to 3.465V (or 3465mV), the cor-
responding VOUT_MARGIN_HIGH value is:
Conversely, if the host received a value of 0D89h on a
READ_VOUT command, this is equivalent to:
Power supplies and power converters generally have
no way of knowing how their outputs are connected to
ground. Within the power supply, all output voltages are
most commonly treated as positive. Accordingly, all out-
put voltages and output voltage-related parameters of
PMBus devices are commanded and reported as posi-
tive values. It is up to the system to know that a particular
output is negative if that is of interest to the system. All
output-voltage-related commands use 2 data bytes.
Y = (1 x 3465 + 0) x 10
X = (1/1) x (0D89h x 10
RESOLUTION
1/32,767
0.01
0.1
1
1
1
0
32,767
32,767
3276.7
327.67
32,767
= 3465 (decimal) = 0D89h (hex)
MAX
-(-0)
1
- 0) = 3465mV = 3.465V
32,767
m
1
1
1
1
1
b
0
0
0
0
0
0
R
0
0
0
1
2
0