MAX17036 Maxim Integrated Products, MAX17036 Datasheet - Page 31

• Manufacturer Part Number: MAX17036
• Description: (MAX17030 / MAX17036) 1/2/3-Phase Quick-PWM IMVP-6.5 VID Controllers
• Manufacturer: Maxim Integrated Products

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Power-on reset (POR) occurs when V
approximately 2V, resetting the fault latch and prepar-
ing the controller for operation. The V
inhibits switching until V
troller powers up the reference once the system
enables the controller, V
driven high. With the reference in regulation, the con-
troller ramps the output voltage to the boot voltage
(1.1V) at 1/4 the slew rate set by R
where dV
slew rate. The soft-start circuitry does not use a variable
current limit, so full output current is available immedi-
ately. CLKEN is pulled low approximately 60µs after the
MAX17030/MAX17036 reach the boot voltage. At the
same time, the MAX17030/MAX17036 slew the output
to the voltage set at the VID inputs at the programmed
slew rate. PWRGD becomes high impedance approxi-
mately 5ms after CLKEN is pulled low. The MAX17030/
MAX17036 automatically operate in pulse-skipping
mode during soft-start, and use forced-PWM operation
during soft-shutdown, regardless of the DPRSLPVR and
PSI configuration.
If the V
assumes that there is not enough supply voltage to make
valid decisions, and shuts down immediately. DH and DL
are forced low, and CSNI 10Ω discharge FET is enabled.
When SHDN goes low, the MAX17030/MAX17036
enters low-power shutdown mode. PWRGD is pulled
low immediately, and the output voltage ramps down at
1/4 the slew rate set by R
where dV
slew rate. After the output voltage drops to 12.5mV, the
MAX17030/MAX17036 shut down completely—the dri-
vers are disabled (DL1 and DL2 driven low, PWM3 is
three-state, and DRSKP low), the reference turns off,
10Ω CSNI discharge FET is turned on, and the supply
current drops below 1µA.
When an undervoltage fault condition activates the shut-
down sequence, the protection circuitry sets the fault
latch to prevent the controller from restarting. To clear
the fault latch and reactivate the controller, toggle SHDN
or cycle V
CC
TARGET
TARGET
CC
voltage drops below 4.25V, the controller
t
t
TRAN START
power below 0.5V.
TRAN SHDN
/dt = 12.5mV/µs x 71.5kΩ/R
/dt = 12.5mV/µs x 71.5kΩ/R
(
______________________________________________________________________________________
(
CC
)
)
CC
TIME
=
=
rises above 4.25V. The con-
(
(
is above 4.25V, and SHDN
dV
dV
:
4
TARGET
TARGET
4
V
V
BOOT
TIME
OUT
CC
:
CC
dt
dt
UVLO circuitry
)
)
Shutdown
rises above
TIME
TIME
is the
is the
IMVP-6.5 VID Controllers
1/2/3-Phase Quick-PWM
The MAX17030/MAX17036 include 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.
Connect an external resistor between IMON and GNDS
to create the desired IMON gain based on the following
equation:
where I
the Intel IMVP-6.5 specification and based on discrete
increments (10A, 20A, 30A, 40A, etc.), R
the minimum effective value of the current-sense ele-
ment (sense resistor or inductor DCR) that is used to
provide the current-sense voltage, and G
is the minimum transconductance amplifier gain as
defined in the Electrical Characteristics .
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.
The transconductance amplifier and voltage clamp are
internally compensated, so IMON cannot directly drive
large capacitance values. To filter the IMON signal, use
an RC filter as shown in Figure 1.
The MAX17030/MAX17036 also feature an independent
comparator with an accurate threshold (V
tracks the analog supply voltage (V
makes the thermal trip threshold independent of the V
supply voltage tolerance. Use a resistor- and thermistor-
divider between V
regulator overtemperature 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 MAX17030/MAX17036 continuously monitor the
output for an overvoltage fault. An OVP fault is detected
if the output voltage exceeds the set VID DAC voltage
by more than 300mV, or the fixed 1.5V (typ) threshold
R
IMON
MAX
m(IMON)
= 0.9V/(I
I
IMON
Temperature Comparator ( VRHOT )
is defined in the Current Monitor section of
= G
= 1.6mS (typ) and the IMON current is
MAX
CC
m(IMON)
Fault Protection (Latched)
x R
and GND to generate a voltage-
Output Overvoltage Protection
SENSE(MIN)
Current Monitor (IMON)
x Σ(V
CSP
HOT
x G
- V
= 0.3V
m(IMON_MIN)
CSN
SENSE(MIN)
m(IMON_MIN)
)
HOT
CC
). This
) that
CC
31
)
is