MAX8688ALETG+ Maxim Integrated Products, MAX8688ALETG+ Datasheet - Page 10

• Manufacturer Part Number: MAX8688ALETG+
• Description: IC PWR SUPPLY CTRLR/MONTR 24TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX8688ALETG+

• 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

Digital Power-Supply Controller/Monitor
with PMBus Interface
Figure 2. System Application Showing Multiple MAX8688s Controlling POL Power Supplies
Figure 3 shows the typical manner in which the
MAX8688 is used in an application where the POL has a
reference input, REFIN, to which it regulates its output
voltage between the VO+ and VO- terminals. In the
REFIN application, the DACOUT of the MAX8688 is con-
nected to the REFIN input of the POL. The output voltage
of the POL is sensed using RS+ and RS-. The sensed
voltage is suitably filtered by an internal 200Ω resistor
and external capacitor connected to RS_C and is multi-
plexed to a 12-bit ADC that uses an accurate internal ref-
erence voltage. On receipt of either an OPERATION ON
command or a turn-on signal from A3/ONOFF, the
MAX8688 commences the startup operation that has
been programmed for the POL being controlled.
After the programmed t
open-drain ENOUT output goes active and the POL out-
put voltage is ramped up to its target VOUT_COMMAND
value precisely in the programmed t
facilitates easy implementation of tracking of multiple out-
10
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CONTROLLER
SYSTEM
MAX8688 Operating Modes
Reference Input (REFIN) Mode
SDA
SCL
RST
IRQ
ON_DELAY
time, the MAX8688
ON_RISE
time. This
SCL
SDA
FLT
RST
SCL
SDA
FLT
RST
SCL
SDA
FLT
RST
SCL
SDA
FLT
RST
A3/ONOFF A2/SDAE A1/SCLE
A3/ONOFF A2/SDAE A1/SCLE
A3/ONOFF A2/SDAE A1/SCLE
A3/ONOFF A2/SDAE A1/SCLE
MAX8688
MAX8688
MAX8688
MAX8688
put rails. On reaching the target output voltage, the
MAX8688 continuously monitors the POL output voltage
obtained at the RS+ and RS- inputs, and regulates it to
within ±0.2% for line, load, and temperature variations by
incrementing or decrementing the DACOUT output 1 LSB
(0.5mV) at a time. The MAX8688 output-voltage correc-
tion rate is programmable up to 10kHz by the
MFR_VOUT_CORRECTION_RATE parameter. Once the
requested target POL voltage is reached, it is possible to
easily margin up or down the POL voltage at a prepro-
grammed slew rate set by the parameter VOUT_TRANSI-
TION_RATE. To achieve this, the MAX8688 increments or
decrements the DACOUT output in a suitable number of
steps that depend on the programmed transition rate. In
addition,
VOUT_SCALE_LOOP parameter equal to any voltage-
divider ratio implemented on the POL from its output volt-
age node to the inverting input of its error amplifier. This
allows the MAX8688 to correctly calculate the number of
DACOUT steps and voltage increments/decrements per
step and thus achieves the programmed rise time and
transition time.
RS+
RS-
ISN+
ISN-
DACOUT
ENOUT
RS+
RS-
ISN+
ISN-
DACOUT
ENOUT
RS+
RS-
ISN+
ISN-
DACOUT
ENOUT
RS+
RS-
ISN+
ISN-
DACOUT
ENOUT
the
user
needs
VO+
VO-
IO+
IO-
FB
EN
VO+
VO-
IO+
IO-
FB
EN
VO+
VO-
IO+
IO-
FB
EN
VO+
VO-
IO+
IO-
FB
EN
POL N
POL 1
POL 2
POL 3
to
program
the