SC453_09 Datasheet, PDF (9/26 Pages) Semtech Corporation – Portable, VID Programmed Single Phase Power Supply Controller

SC453
POWER MANAGEMENT
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Pin#
Pin#
TSSOP-28 MLPQ-32
1
29
Pin
Name
DRN
Pin Function
This pin connects to the junction of the switching and synchronous MOSFETs.
2
30
TG Gate drive for the switching (high-side) MOSFET.
3
31
BST
Bootstrap pin. A capacitor is connected between BST and DRN pins to develop the
floating bootstrap voltage for the high-side MOSFET gate drive.
4
1
SLP Sleep logic input signal.
5
2
SLPV
Connect this pin to V_CCA to select VID Sleep Mode. Otherwise, SLPV Sleep Mode
is selected and the voltage on this pin sets the DAC output during sleep.
6
3
BOOTV The voltage on this pin sets the Boot-Up voltage.
7
4
PG# Start clock indicator open drain output — Active low
Core Comparator Hysteresis — Connect to ground through an external resistor. Hys-
8
5
HYS teresis current is established by the internal V_REF voltage, 1.7V, divided by the total
HYS resistance (R_HYS).
9
6
VID5 VID input, most significant bit of the voltage programming DAC input
10
7
VID4 VID input
11
8
VID3 VID input
12
9
VID2 VID input
13
10
VID1 VID input
14
11
VID0 VID input, least significant bit of the voltage programming DAC input
15
12
SS Soft-start — an external cap defines the soft-start ramp.
Delayed Power Good — open drain output. After the V_CORE output is within ± 14% of
16
13
PG_DEL the VID_DAC setting, and the t_{CPU_PWRGD} period has terminated, this internal pull-
down MOSFET opens and the pin is pulled high by an external resistor.
17
14
CORE
Feedback input for the V_CORE output. A small RC filter should be used to filter out
high frequency noise to prevent false or faulty trip conditions.
18
15
DAC Main controller digital-to-analog output
19
16
GND Analog ground
20
18
REFIN Core Comparator reference input pin — connect to DAC.
21
19
VCCA 5V supply for precision analog circuitry
22
20
CLRF Current limit reference input
23
21
CMP Core Comparator input
24
22
CL Current limit input
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