MAX17528GTJ+ Maxim Integrated Products, MAX17528GTJ+ Datasheet - Page 14

• Manufacturer Part Number: MAX17528GTJ+
• Description: IC PWM CTRLR STP-DWN 32TQFN-EP
• Manufacturer: Maxim Integrated Products
• Series: Quick-PWM™r

Specifications of MAX17528GTJ+

• Applications: Controller, Intel IMVP-6.5™ GMCH
• Voltage - Input: 4.5 ~ 5.5 V
• Number Of Outputs: 1
• Voltage - Output: 0.01 ~ 1.5 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 32-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

1-Phase Quick-PWM
Intel IMVP-6.5/GMCH Controllers
14
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PIN
1
2
3
4
5
6
NAME
GNDS
SLOW
IMON
CSN
CSP
FB
Current Monitor Output. The MAX17528 IMON output sources a current that is directly proportional
to the current-sense voltage as defined by:
where G
The IMON current is 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 VSS_SENSE to create the desired IMON gain
based on the following equation:
where IMAX is defined in the Current Monitor (IMON) section of the Intel IMVP-6.5 specification and
based on discrete increments (20A, 30A, 40A, etc.,), R
current-sense element (sense resistor or inductor DCR) that is used to provide the current-sense
voltage, and G
Characteristics table.
The IMON voltage is internally clamped to a maximum of 1.1V (typ).
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. IMON is pulled to ground when the MAX17528 is in shutdown.
Remote Ground-Sense Input. Connect directly to the CPU or GMCH V
or directly to the ground connection of the load. GNDS internally connects to a transconductance
amplifier that adjusts the feedback voltage, compensating for voltage drops between the
regulator’s ground and the processor’s ground.
Output of the Voltage-Positioning Transconductance Amplifier. Connect a resistor, R
FB and the positive side of the feedback remote sense to set the steady-state droop based on the
voltage-positioning gain requirement.
where R
value of the current-sense resistor that is used to provide the (CSP, CSN), current-sense voltage. If
lossless sensing is used, R
to minimize the temperature dependence of the voltage-positioning slope. Droop can be disabled
by shorting FB to the positive remote-sense point, but doing so increases the minimum ESR
requirement of the output capacitance for stability, and FB might therefore need to be driven by a
carefully designed feed-forward network. FB is high impedance in shutdown.
Negative Inductor Current-Sense Input. Connect CSN to the negative terminal of the inductor
current-sensing resistor or directly to the negative terminal of the inductor if the lossless DCR
sensing method is used (see Figure 4).
Under V
through a 10
Positive Inductor Current-Sense Input. Connect CSP to the positive terminal of the inductor current-
sensing resistor or directly to the positive terminal of the filtering capacitor used when the
lossless DCR sensing method is used (see Figure 4).
Active-Low Slew-Rate Select Input. This 1.0V logic input signal selects between the nominal and
slow (half of nominal rate) slew rates. When SLOW is forced high, the selected nominal slew rate is
set by the time resistance. When SLOW is forced low, the slew rate is reduced to half of the
nominal slew rate.
For IMVP-6.5 applications (CLKEN pullup to 3.3V with 1.9k ), the fast slew rate is not needed.
Connect SLOW to GND.
For GMCH 2009 applications (CLKEN = GND), connect to the system GFXDPRSLPVR signal.
CC
DROOP
m(IMON)
UVLO conditions and after soft-shutdown is completed, CSN is internally pulled to GND
m(IMON)
FET to discharge the output.
is the desired voltage-positioning slope, GMD = 600µS typ and R
= 5mS (typ).
is the typical transconductance amplifier gain as defined in the Electrical
R
IMON
SENSE
I
IMON
R
= 0.999V/(IMAX x R
FB
= R
= R
L
= G
. In this case, consider using a thermistor-resistor network
DROOP
m(IMON)
FUNCTION
/(R
x (V
SENSE
SENSE
SENSE
CSP
x GMD)
- V
x G
CSN
is the typical effective value of the
m(IMON)
)
SS
)
sense pin (ground sense)
Pin Description
SENSE
FB
, between
is the