PM6652 STMicroelectronics, PM6652 Datasheet - Page 36

• 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
36/53
Figure 37. Average current limit - recovery
If the current sourced by IMONFB pin is greater than I
average current limit fault is detected and the IC latches off: the MOS drivers are put in high
impedance and the internal discharge MOSFET is turned on (see
or SVCC toggle is required in order to restart the device.
Every time the IMONFB pin current becomes lower than IMAX, the internal timer is reset
(see
current limit fault is given by:
Equation 16
In order to set the right average current limit threshold, the PM6652 internal parameters and
also external components accuracy must be considered.
A complete equation for the average current limit threshold worst case variation is:
Equation 17
assuming δ R
V
attenuation (see
and δ G
resistors accuracy (see
and/or the current sensing filter resistors value is higher than the suggested one (as
explained it
modified in order to take account of DCR thermal drift and current sensing additional offset.
IMON,off
Figure 38
SNS
<1 mV the IMON maximum offset, G
δ
I
/G
AVCL
I
AVCL
Section 8.7: Current sensing on page 31
G
SNS
/R
); as a consequence the inductor current which can cause the average
,
WC
G
Equation 11
the thermal compensation network gain error, due to NTC and others
the accuracy of R
=
⎛ δ
⎜
⎜
⎝
R
R
Equation 25
G
G
⎞
⎟
⎟
⎠
+
), δ R
i
AVCL
Doc ID 16867 Rev 3
(
α
IMAX
SNS
=
). If the thermal compensation network is not used
G
I
)
OUT
/R
, α
+
⎛
⎜
⎜
⎝
SNS
Figure 38. Average current limit detected
IMAX
,
G
AVCL
SNS
the inductor DCR or precision resistor accuracy
<10% the internal current reference error,
SNS
V
−
⋅
IMON
R
Δ
SNS
I
L
the NTC thermal compensation network
,
≥
off
) the previous equation must be
⋅
I
I
MAX
MAX
AVCL
R
DCR
⋅
for more than 4 ms (typ.) the
R
⎞
⎟
⎟
⎠
+
G
⎛ δ
⎜
⎜
⎝
R
R
SNS
Figure 37
SNS
⎞
⎟
⎟
⎠
+
⎛ δ
⎜
⎜
⎝
G
). A COREON
G
SNS
SNS
⎞
⎟
⎟
⎠
PM6652