MAX16064 Datasheet, PDF (37/52 Pages) Maxim Integrated Products – ±0.3% Accurate, Quad, Power-Supply Controller with Active-Voltage Output Control and PMBus Interface

±0.3% Accurate, Quad, Power-Supply Controller with
Active-Voltage Output Control and PMBus Interface
VOUT_MODE (20h)
The VOUT_MODE command is used to report the data
format of the device. The MAX16064 uses the direct for-
mat for all the voltage-related commands. The value
returned is 40h, indicating DIRECT data format. This
command is read only. See Table 4 for the m, b, and R
values for the various commands.
VOUT_COMMAND (21h)
The VOUT_COMMAND command loads the MAX16064
with the voltage to which the power-supply output is to
be changed when it is commanded to turn on using the
OPERATION command or A3/CONTROL transition
when enabled. Once the power supply is turned on,
changing the VOUT_COMMAND has no effect on the
power-supply output voltage. The MAX16064 only
adjusts the power supply to the new VOUT_COMMAND
voltage after receiving a new turn-on command.
The two data bytes are in DIRECT format. Valid values
are from 0 to 2.0V when the input range is 2.0V, and 0 to
5.5V when the input range is 5.5V. See the
MFR_MODE_OUTPUT (DEh) section for more information.
The default VOUT_COMMAND value is 00h.
VOUT_MARGIN_HIGH (25h)
The VOUT_MARGIN_HIGH command loads the
MAX16064 with the voltage to which the power-supply
output is to be changed when the OPERATION com-
mand is set to margin high. If the power supply is
already operating at margin high, changing
VOUT_MARGIN_HIGH has no effect on the output volt-
age. The MAX16064 only adjusts the power supply to
the new VOUT_MARGIN_HIGH voltage after receiving a
new margin high OPERATION command.
The two data bytes are in DIRECT format. Valid values
are the same as VOUT_COMMAND.
The default VOUT_MARGIN_HIGH value is 00h.
VOUT_MARGIN_LOW (26h)
The VOUT_MARGIN_LOW command loads the
MAX16064 with the voltage to which the power-supply
output is to be changed when the OPERATION com-
mand is set to margin low. If the power supply is
already operating at margin low, changing
VOUT_MARGIN_LOW has no effect on the output volt-
age. The MAX16064 only adjusts the power supply to
the new VOUT_MARGIN_LOW voltage after receiving a
new margin low OPERATION command.
The two data bytes are in DIRECT format. Valid values
are the same as VOUT_COMMAND.
The default VOUT_MARGIN_LOW value is 00h.
VOUT_TRANSITION_RATE (27h)
The VOUT_TRANSITION_RATE command sets the rate
in mV/µs at which the power-supply output voltage
should change when the power supply is commanded
to change among the margin high, margin low, and
margin off (ON) OPERATION mode. This commanded
rate of change does not apply when the power supply
is commanded to turn on or off. In that case, t_{ON_RISE}
and t_{OFF_FALL} apply.
The two data bytes are in DIRECT format. Valid values
are from 0 to 128mV/µs (FB mode) or 0.004 to 30mV/µs
(REFIN mode).
The default VOUT_TRANSITION_RATE value is 0.
When VOUT_TRANSITION_RATE is cleared to 0,
VOUT_TRANSITION_RATE is ignored and the voltage out-
put is not changed even when commanded by the
OPERATION command. When VOUT_TRANSITION_RATE
is set to 07FFFh, the voltage output is adjusted as quickly
as possible. If a VOUT_TRANSITION_RATE parameter
results in the DAC outputting an out of range value (valid
range 0 to 4090) during transition, the CML flag is set and
SMBALERT is asserted to issue a warning.
The VOUT_TRANSITION_RATE command applies to
REFIN mode only and is ignored in feedback mode.
VOUT_SCALE_LOOP (29h)
In applications where the V_OUT is not equal to the volt-
age at REFIN, VOUT_SCALE_LOOP is used. For exam-
ple, if REFIN expects a 0.6V input for a 3.3V output,
VOUT_SCALE_LOOP = 0.6V/3.3V = 0.182.
In applications where the power-supply output voltage is
greater than the MAX16064 input range, the output voltage
of the power supply is sensed through a resistive voltage-
divider, as illustrated in Figure 16. The resistive voltage-
divider reduces or scales the output voltage, V_OUT.
The PMBus commands specify the actual power-supply
output voltages and not the input voltage to the control
circuit. To allow the MAX16064 to map between the
commanded voltage (such as 3.3V), and the voltage at
the control circuit input (perhaps 3.3V divided down to
match a reference voltage of 2.0V), the
VOUT_SCALE_LOOP command is used.
VOUT _ SCALE _ LOOP = ^R2
R1+ R2
The two data bytes are in DIRECT format. Valid values
are from 0 to 1.0. Note that due to m, b, r representation
restriction, the supplied value is rounded off to multi-
ples of 1/128. Therefore, to ensure optimum operation,
circuit design should choose a value as close as possi-
ble to multiples of 1/128 to avoid rounding errors affect-
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