PM6652 STMicroelectronics, PM6652 Datasheet - Page 32

• 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

Device description
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Figure 31.
The previous equation also shows the frequency dependence of the DCR current sensing
technique. During load variation the sensed DCR can also increase, if the time constant
matching is not adequate; in order to avoid this situation the following equation must be
verified:
Equation 10
Figure 31
whereas in
If a thermal compensation is required in order to compensate for the inductor's DCR
variation, due to temperature increase, RB is replaced by a complete network, based on a
NTC (negative temperature coefficient) thermistor (Rn).
NTC-based thermal compensation network (Rs, Rp and Rn). The resultant RB1 equivalent
resistance and NTC network attenuation are:
Equation 11
and the time constant due to CA capacitor can be computed as follows:
Equation 12
In PM6652 the CSNS and VOUT inputs are high-impedance pins so a very small leakage
current can be measured, in the range of 50 nA to 100 nA. This leakage current, sourced by
CSNS, is multiplied by the equivalent resistance measured across CA capacitor, i.e.
τ
L
>
τ
C
shows the VCORE load transient response when Equation 10 is not verified
Figure 32
the load transient response shows a better time constant matching.
Doc ID 16867 Rev 3
R
G
B
NTC
1
τ
(
A
) T
τ
A
=
=
Figure 32.
=
≥
C ⋅
R
R
A
B
R
S
R
1
DCR
L
+
B
(
+
R
1
R
R
A
A
P
=
//
//
R
τ
R
L
τ
B
L
1
N
)
( )
<
T
Figure 33
τ
C
shows an example of
PM6652