MAX8688BHETG+ Maxim Integrated Products, MAX8688BHETG+ Datasheet - Page 25

• Manufacturer Part Number: MAX8688BHETG+
• Description: IC PWR SUPPLY CTRLR/MONTR 24TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX8688BHETG+

• Applications: Power Supply Controller/Monitor
• Voltage - Supply: 3 V ~ 3.6 V
• Current - Supply: 6.7mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-TQFN Exposed Pad
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 3 V
• Operating Temperature Range: - 40 C to + 85 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Input: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

To send a value, the host must use the equation below
to solve for Y:
where:
The following example demonstrates how the host can
send and retrieve values from the MAX8688.
From Table 4, the coefficients used in the following
parameters are:
If a host wants to request the POL to output a voltage of
3.0V, the corresponding VOUT_COMMAND value is:
Conversely, if the host received a value of 176Eh on a
READ_VOUT command, this is equivalent to:
which is within 0.0083% of 3.0V.
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 particu-
lar output is negative, if that is of interest to the system.
All output voltage-related commands use 2 data bytes.
Y is the 2-byte, two’s complement integer to be sent
to the unit;
m , the slope coefficient, is the 2-byte, two’s comple-
ment integer;
X is a real world value, in units such as amperes or
volts, to be converted for transmission;
b, the offset, is the 2-byte, two’s complement integer;
and
R, the exponent, is the decimal value equivalent to
the 1-byte, two’s complement integer.
VOUT_COMMAND:
READ_VOUT:
Y = (19995 x 3.0 + 0) x 10
= 176Eh (hex)
X =
Sending a DIRECT Format Value
= 59980/19995 = 2.999750
19995
X
Y = (mX + b) x 10
Y = (mX + b) x 10
______________________________________________________________________________________
1
=
Digital Power-Supply Controller/Monitor
m
1
(176Eh x 10
(
Y
×
10
m = 19995, b = 0, R = -1
m = 19995, b = 0, R = -1
−
-1
R
= 5998.5 (decimal)
−
b
-(-1)
R
R
)
- 0)
For reporting faults/warnings to the host on a real-time
basis, the MAX8688 asserts the open-drain FLT pin and
sets the appropriate bit in the STATUS_BYTE and
MFR_FAULT_STATUS registers, respectively. On
recognition of the FLT assertion, the host or system
manager is expected to poll multiple MAX8688s and
retrieves fault/warning information. The Manufacturer
Fault Status Register, MFR_FAULT_STATUS, provides
more detailed information on fault/warning. Faults/warn-
ings are cleared when any one of the following condi-
tions occurs:
The MAX8688 responds to fault conditions according to
the Manufacturer Fault Response command
(MFR_FAULT_RESPONSE). This command byte deter-
mines how the MAX8688 should respond to each par-
ticular fault.
error conditions.
1) If the internal reference fails to operate, FLT is
2) The MAX8688 responds to unsupported commands
3) When the host sends insufficient data (too few
4) When the host sends too much data (too many
When a read request is issued to a write-only com-
mand, the read operation is aborted and no warning is
issued.
In addition, the MAX8688 responds to the following
• A CLEAR_FAULTS command is received.
• ENOUT is commanded through the OPERATION
• A RST signal is asserted for longer than t
• Bias power to the MAX8688 is removed and then
with PMBus Interface
asserted. To clear this fault, the MAX8688 has to go
through a device reset.
with a NACK.
bytes), the MAX8688 sets the CML bit and asserts
FLT.
bytes), the MAX8688 sets the CML bit and asserts
FLT.
command or A3/ONOFF to turn off and then turn
on.
the MAX8688 is internally reset.
reapplied.
Fault Management and Reporting
RST
where
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