Pin Description
Pin
Pin
Description
Name Number
1, 15,
16, 17
D
Drain- The Drain of the internal N-channel MOSFET, connect to the output load.
Source-The source of the internal N-channel MOSFET, connect to the input power source bus
voltage.
Positive Sense Input & Clamp: Connect SP pin to the S pin. The polarity of the voltage
difference between SP and SN provides an indication of current flow direction through the
MOSFET.
S
2, 3, 4, 5
6
SP
Fault State Output: This open collector pin pulls low when a fault occurs. Fault logic inputs
are VC Under-Voltage, Input Under-Voltage, Input Over-Voltage, Forward Over-Current, light
load, reverse current, and Over-Temperature. Leave this pin open if unused.
Blanking timer Input-Output: Connect a resistor from BK to GND to set the blanking time for
the Reverse Comparator function. To configure in slave mode, connect BK to VC. To
configure in master mode with the fastest turn-off response connect BK directly to GND.
Slave Input-Output: This pin is used for paralleling multiple PI2121 solutions in high power
applications. When the PI2121 is configured as the Master, this pin functions as an output
7
8
FT
BK
9
SL
capable of driving up to 10 SL pins of slaved PI2121 devices. It serves as an input when the
PI2121 is configured in slave mode.
Input Supply Pin: This pin is the supply pin for the control circuitry and gate driver. Connect
a 1μF capacitor between VC pin and the GND pin. Voltage on this pin is limited to 15.5V by
an internal shunt regulator in high auxiliary voltage applications. For high voltage auxiliary
supply applications connect a shunt resistor between VC and the auxiliary supply.
VC
10
11
GND
Ground: This pin is ground for the gate driver and control circuitry.
Input Over Voltage Input: The OV pin is used to detect an input source over-voltage
condition in ground referenced applications. When the OV pin voltage crosses the OV
OV
12
threshold, the FT pin pulls low indicating a fault condition. The input voltage OV threshold is
programmable through an external resistor divider. Connect OV to GND to disable this
function.
Input Under-Voltage Input: The UV pin is used to detect an input source under-voltage
condition in ground referenced applications. When the UV pin voltage drops below the UV
UV
SN
13
14
threshold, the FT pin pulls low indicating a fault condition. The input voltage UV threshold is
programmable through an external resistor divider. Connect UV to VC to disable this function.
Negative Sense Input & Clamp- Connect SN to D pin. The polarity of the voltage difference
between SP and SN provides an indication of current flow direction through the MOSFET.
Package Pin-out
17 Pin LGA (5mm x 7mm)
Top view
Picor Corporation • picorpower.com
PI2121
Rev. 1.0 Page 2 of 21
VICOR [ VICOR CORPORATION ]
