PM6652 STMicroelectronics, PM6652 Datasheet - Page 40

• 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
8.10.7
8.10.8
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Figure 42. Valley current limit detection
if the overload is not removed, the output capacitor keeps discharging until the UV fault is
detected.
In order to set the right valley current limit threshold, the PM6652 internal parameters and
also external components accuracy must be considered.
A complete computation of the valley current limit threshold worst case variation can be
found in
Equation 22
The “key parameter” is the low-side MOSFET on resistance,
of the maximum on-resistance value and its thermal drift. The other parameters, with the
exception of R
current reference variation and V
SVCC undervoltage protection
The PM6652 can detect an SVCC under voltage (threshold 3.9 V typ.). When this fault
occurs, the high-side MOSFET is turned-off and the low-side MOSFET is turned-on. The
device is turned-on again if the SVCC voltage is higher than 4.4 V (typ.). This fault protection
is always active.
Thermal protection
If the device internal temperature is greater than 150 °C the thermal shutdown is performed.
The internal discharge MOSFET is turned-on until VOUT is lower than about 100 mV, then
the low-side MOSFET is turned-on.
A COREON or SVCC toggle is required to turn-on again the device. This fault detection is
masked during VID transitions and, during soft-start, until the power good signal is released.
Equation 22
δ
ILIM
I
, L
I
, L
VALL
VALL
(typical accuracy 1%), are all internal parameters:
.
,
WC
>
⎛ δ
⎜ ⎜
⎝
R
R
Doc ID 16867 Rev 3
ILIM
ILIM
OFFSET
⎞
⎟ ⎟
⎠
+
⎛ δ
⎜ ⎜
⎝
I
<4 mV is the current limit comparator offset.
ILIIM
I
ILIIM
⎞
⎟ ⎟
⎠
+
⎛
⎜ ⎜
⎝
20
⋅
I
ILIM
V
OFFSET
⋅
R
ILIM
δ
R
⎞
⎟ ⎟
⎠
DS,ON
+
⎛ δ
⎜
⎜
⎝
R
δ
R
, which takes account
DS
I
DS
ILIM
,
ON
,
ON
<0.5 µA is the
⎞
⎟
⎟
⎠
PM6652