PM6652 STMicroelectronics, PM6652 Datasheet - Page 31

• Manufacturer Part Number: PM6652
• Description: IC CTLR STEPDOWN SMPS 32VFQFPN
• Manufacturer: STMicroelectronics

Specifications of PM6652

• Applications: Controller, Intel IMVP-6.5™, VR11
• Voltage - Input: 4.5 V ~ 36 V
• Number Of Outputs: 1
• Voltage - Output: 0.3 V ~ 1.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PM6652
8.7
Figure 29. Precision resistor current sensing
very high efficiency at light load.
inductor current waveform when the DPRSLPVR pin is asserted high or low.
When the DPRSLPVR control pin is still asserted high and the VDAC ramp-up transition is
requested, the render suspend fast exit is performed, by increasing VDAC output with a
minimum voltage slew-rate of 10 mV//µs (
If the DPRSLPVR signal is de-asserted before any VIDs change, the VDAC ramp-up
transition is performed with a minimum voltage slew-rate of 5 mV/µs (render suspend slow
exit).
In CPU IMVP6.5 and VR11 mode the minimum voltage slew-rate is fixed, as reported in
Table 8 on page 28
activate the pulse-skipping algorithm for higher light load efficiency.
Current sensing
As reported in
proportional to the output current. Two main techniques can be used: the precision RSNS
resistor and the inductor's DCR current sensing (
page 31
component must be selected; on the other side, the inductor's current sensing technique is
cheaper but it's based on the parasitic inductor resistance whose accuracy is hardly lower
than 10%. An R
inductor's DCR value is greater than the required DROOP an additional R
necessary. In this case, the sensed current as suggested by
Equation 9
). The first method is more precise and more expensive, since a dedicated precision
Equation 9
S
-C
, and the DPRSLPVR control signal, when asserted high, directly
S
filter matched with the inductor's time constant is also required. If the
C
τ
A
SNS
=
the voltage sensed between CSNS and VOUT pins must be
R
−
A
V
Doc ID 16867 Rev 3
//
OUT
R
Figure 8 on page 20
B
=
⋅
C
R
A
B
Figure 30. Inductor's DCR current sensing
R
+
Figure 26 on page 30
B
R
A
⋅
R
DCR
Figure 29 on page 31
⋅
I
and
LOAD
Figure 11 on page 21
⋅
1
1
Equation 9
+
+
).
R
s
sL
DCR
τ ⋅
A
and
Device description
becomes:
B
Figure 30 on
resistor is
show the
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