PI2211
Positive Low Voltage (0.9V to 14V) Hot Swap Controller and Circuit Breaker with True-SOA
Description: Features:
The PI2211 hot swap controller and circuit breaker ensures Operating range: +0.9 to +14V
safe system operation during circuit card insertion by limiting
Programmable inrush current limiting
the start-up or in-rush current to the load and eliminating the
Programmable MOSFET True-SOA Protection
electrical disturbance or possible voltage sag imposed on a
Programmable circuit breaker with Glitch-Catcher
backplane power supply. During steady state operation, the
voltage suppression
PI2211 acts as a circuit breaker disconnecting from the
100nS circuit breaker fault detection time
backplane power source if a overcurrent condition arises.
Adjustable Input Under-voltage Lockout (UVLO) with
The PI2211 uses an external N-channel MOSFET and employs
hysteresis
the MOSFETs transient thermal characteristics (supplied by
Adjustable Input Over-voltage Lockout (OVLO) with
the MOSFET supplier) to ensure operation within the
hysteresis
MOSFETs dynamic safe operating area (SOA).
Power good status indicator
o o
Wide operation temperature from -40 C to 125 C
The PI2211, with True-SOA, continuously monitors MOSFET
power to calculate the MOSFET junction temperature rise and
Applications
determines proper operation regardless of load conditions.
Base Station Power Distribution Systems
The PI2211 limits the MOSFET junction temperature rise to a
Server Backplanes Systems
maximum of 60C preventing overheating (hot spotting) by
Live Board Insertion / Removal
cycling the MOSFET on/off and allowing it to cool for a period
Circuit Breaker with Voltage Clamp
determined by the programmed MOSFET package thermal
properties. Emulation and protection based on the specific
Package
MOSFETs transient thermal performance optimizes the safe
operating limits and allows designers to take advantage of 24-Pin QFN
the latest power MOSFET technologies.
During a circuit breaker fault, the PI2211 internal Glitch-
Catcher circuit acts as an active snubber, passing inductive
bus energy through the MOSFET mitigating the need for
additional BUS input transient protection and protects
against MOSFET avalanching.
Typical Application:
Figure 1 Typical PI2211 application schematic.
Picor Corporation picorpower.com PI2211 Rev 1.1, Page 1 of 26
PI2211
Pin Descriptions
Pin
Pin Name Description
Number
BUS 7 Bus input power.
VCC 6 Positive supply input. Derived internally from BUS for voltages > 4.5Vdc, externally from VAUX for
lower BUS voltages.
UV/EN 20 BUS voltage sense for under-voltage fault. An enable or disable for the controller.
OV 19 BUS voltage sense for over-voltage fault.
CSP 8 Current sense positive location input.
CSN 10 Current sense negative location input.
DRN 9 MOSFET drain sense .
SRC 12 MOSFET source sense.
GDR 11 MOSFET gate drive.
PWRGD 21 Power good indicator.
GND 13, 14, 15 Controller ground reference.
SEL 16 Programming option for SOA programming with external resistors.
RACC 24 Internal current programming resistor.
TIMER 23 Programmable delay timer to inhibit the start of the controller.
SOAS 22 SOA current programming resistor.
SOAR 4 SOA thermal programming resistor.
SOAT 3 SOA transient response programming resistor.
- 1, 2, 5, 17, No connects, pins are to be left floating.
18
TAB TAB No electrical connection; receiving footprint is required to achieve a R of 46C/W. Can be
J-A
electrically connected to PI2211 GND only.
Ordering Information
Part Number Description
PI2211-00-QAIG 24 lead QFN package
Picor Corporation picorpower.com PI2211 Rev 1.1, Page 2 of 26