MAX17082GTL+ Maxim Integrated Products, MAX17082GTL+ Datasheet - Page 39

• Manufacturer Part Number: MAX17082GTL+
• Description: IC CTLR PWM DUAL IMVP-6.5 40TQFN
• Manufacturer: Maxim Integrated Products
• Series: Quick-PWM™r

Specifications of MAX17082GTL+

• Applications: Controller, Intel IMVP-6.5™
• Voltage - Input: 4.5 ~ 5.5 V
• Number Of Outputs: 1
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 40-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Lead Free Status / Rohs Status: Details

When SHDN goes low, the MAX17021/MAX17082/
MAX17482 enter low-power shutdown mode. PWRGD
is pulled low immediately, and the output voltage ramps
down at 1/8 the slew rate set by R
where dV
slew rate. Slowly discharging the output capacitors by
slewing the output over a long period of time keeps the
average negative inductor current low (damped
response), thereby eliminating the negative output-volt-
age excursion that occurs when the controller dis-
charges the output quickly by permanently turning on
the low-side MOSFET (underdamped response). This
eliminates the need for the Schottky diode normally
connected between the output and ground to clamp
the negative output-voltage excursion. After the con-
troller reaches the zero target, the MAX17021/
MAX17082/MAX17482 shut down completely—the dri-
vers are disabled (DL1 and DL2 driven low) and the
supply current drops below 1μA.
When a fault condition—output UVLO or thermal shut-
down—activates the shutdown sequence, the protection
circuitry sets the fault latch to prevent the controller from
restarting. To clear the fault latch and reactivate the con-
troller, toggle SHDN or cycle V
The MAX17082/MAX17482 includes a unidirectional
transconductance amplifier that sources current pro-
portional to the positive current-sense voltage. The
IMON output current is defined by:
where G
unidirectional (sources current out of IMON only) for
positive current-sense values. For negative current-
sense voltages, the IMON current is zero.
The current monitor allows the processor to accurately
monitor the CPU load and quickly calculate the power
dissipation to determine if the system is about to over-
heat before the significantly slower temperature sensor
signals an over-temperature alert.
Connect an external resistor between IMON and
VSS_SENSE to create the desired IMON gain based on
the following equation:
where IMAX is defined in the Current Monitor section of
the Intel IMVP-6.5 specification and based on discrete
R
IMON
m(IMON)
I
TARGET
IMON
IMVP-6+/IMVP-6.5 CPU Core Power Supplies
t
= 0.999V/(IMAX x R
TRAN SHDN
= G
/dt = 12.5mV/μs x 71.5kΩ/R
= 2.4mS (typ) and the IMON current is
(
______________________________________________________________________________________
(MAX17021/MAX17482 Only)
m(IMON)
Dual-Phase, Quick-PWM Controllers for
)
=
Current Monitor (IMON)
(
dV
x Σ (V
CC
TARGET
8
V
SENSE
OUT
power below 0.5V.
CSP_
TIME
dt
:
- V
x G
)
CSN_
m(IMON)
Shutdown
TIME
)
)
is the
increments (10A, 20A, 30A, 40A, etc.), R
typical effective value of the current-sense element
(sense resistor or inductor DCR) that is used to provide
the current-sense voltage, and G
transconductance amplifier gain as defined in the
Electrical Characteristics table.
The IMON voltage is internally clamped to a maximum
of 1.1V (typ), preventing the IMON output from exceed-
ing the IMON voltage rating even under overload or
short-circuit conditions. When the controller is disabled,
IMON is pulled to ground.
To filter the IMON signal, use an RC filter as shown in
Figure 2. The filter time constant is (R7 + R8) x C15.
The MAX17021/MAX17082/MAX17482 include a phase-
fault output that signals the system that one of the two
phases either has a fault condition or is not matched with
the other. Detection is done by identifying the need for a
large on-time difference between phases in order to
achieve or move towards current balance.
PHASEGD is high impedance when the controller oper-
ates in one-phase mode (DPRSLPVR high or PSI low
and DPRSLPVR low). On exit to two-phase mode,
PHASEGD is forced high impedance for 32 switching
cycles on DH2.
PHASEGD is low in shutdown. PHASEGD is forced high
impedance whenever the slew-rate controller is active
(output-voltage transitions).
The MAX17021/MAX17082/MAX17482 also feature an
independent comparator with an accurate threshold
(V
0.3V
dent of the V
tor- and thermistor-divider between V
generate a voltage-regulator over-temperature monitor.
Place the thermistor as close to the MOSFETs and
inductors as possible.
The overvoltage-protection (OVP) circuit is designed to
protect the CPU against a shorted high-side MOSFET
by drawing high current and blowing the battery fuse.
The MAX17021/MAX17082 continuously monitor the
output for an overvoltage fault. The controller detects
an OVP fault if the output voltage exceeds the set VID
DAC voltage by more than 300mV, regardless of the
operating state. During downward transitions in
HOT
CC
) that tracks the analog supply voltage (V
). This makes the thermal trip threshold indepen-
Temperature Comparator (VRHOT)
CC
supply voltage tolerance. Use a resis-
Fault Protection (Latched)
Output Overvoltage Protection
Phase Fault (PHASEGD)
(MAX17021/MAX17082 Only)
m(IMON)
CC
is the typical
SENSE
and GND to
HOT
is the
39
=