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
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
safe system operation during circuit card insertion by limiting
the start-up or in-rush current to the load and eliminating the
electrical disturbance or possible voltage sag imposed on a
backplane power supply. During steady state operation, the
PI2211 acts as a circuit breaker disconnecting from the
backplane power source if a overcurrent condition arises.
The PI2211 uses an external N-channel MOSFET and employs
the MOSFET’s transient thermal characteristics (supplied by
the MOSFET supplier) to ensure operation within the
MOSFET’s dynamic safe operating area (SOA).

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The PI2211, with True-SOA™, continuously monitors MOSFET
power to calculate the MOSFET junction temperature rise and
determines proper operation regardless of load conditions.
The PI211 limits the MOSFET junction temperature rise to a
maximum of 60°C preventing overheating (hot spotting) by
cycling the MOSFET on/off and allowing it to cool for a period
determined by the programmed MOSFET package thermal
properties. Emulation and protection based on the specific
MOSFET’s transient thermal performance optimizes the safe
operating limits and allows designers to take advantage of
the latest power MOSFET technologies.
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Operating range: +0.9 to +14V
Programmable inrush current limiting
Programmable MOSFET True-SOA™ Protection
Programmable circuit breaker with Glitch-Catcher™
voltage suppression
100nS circuit breaker fault detection time
Adjustable Input Under-voltage Lockout (UVLO) with
hysteresis
Adjustable Input Over-voltage Lockout (OVLO) with
hysteresis
Power good status indicator
o
o
Wide operation temperature from -40 C to 125 C
Applications
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
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Base Station Power Distribution Systems
Server Backplanes Systems
Live Board Insertion / Removal
Circuit Breaker with Voltage Clamp
Package

24-Pin QFN
During a circuit breaker fault, the PI2211 internal GlitchCatcher™ 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 1.0, Page 1 of 26
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PI2211
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Pin Descriptions
Pin Name
BUS
VCC
UV/EN
OV
CSP
CSN
DRN
SRC
GDR
PWRGD
GND
SEL
RACC
TIMER
SOAS
SOAR
SOAT
TAB
Pin
Number
7
6
20
19
8
10
9
12
11
21
13, 14, 15
16
24
23
22
4
3
1, 2, 5, 17,
18
TAB
Description
Bus input power.
Positive supply input. Derived internally from BUS for voltages > 4.5Vdc, externally from VAUX for
lower BUS voltages.
BUS voltage sense for under-voltage fault. An enable or disable for the controller.
BUS voltage sense for over-voltage fault.
Current sense positive location input.
Current sense negative location input.
MOSFET drain sense .
MOSFET source sense.
MOSFET gate drive.
Power good indicator.
Controller ground reference.
Programming option for SOA programming with external resistors.
Internal current programming resistor.
Programmable delay timer to inhibit the start of the controller.
SOA current programming resistor.
SOA thermal programming resistor.
SOA transient response programming resistor.
No connects, pins are to be left floating.
No electrical connection; receiving footprint is required to achieve a RθJ-A of 46°C/W. Can be
electrically connected to PI2211 GND only.
Ordering Information
Part Number
Description
PI2211-00-QAIG
24 lead QFN package
Picor Corporation · picorpower.com
PI2211
Rev 1.0, Page 2 of 26

PI2211
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
Absolute Maximum Ratings – Exceeding these parameters may result in permanent damage to the product.
CSP, CSN, GDR, SRC, PWRGD, DRN
BUS
SOAT, SOAR, SOAS, Timer, RACC, UV, OV
VCC
Storage Temperature
Operating Temperature - TA
Reflow temperature, 20 s exposure
ESD, Human body model (HBM)
MSL
Recommended Electrical Specifications
Parameter
Junction Temperature
SRC, DRN, CSP, CSN
BUS
VCC capacitor
VCC bypass capacitor
Notes
Min
-40
-0.3 to 21 Vdc
-0.3 to 21 Vdc, 20 mA
-0.3 to 6 Vdc, 10 mA
-0.3 to 6 Vdc, 20 mA
-65 to 150 °C
-40 to 125 °C
260 °C
-2000 to 2000 V
Level 1
Typ
0.9
1
Max
125
14
14
10
Units
°C
Vdc
Vdc
µF
Electrical Specifications
Unless otherwise specified: -40C < TJ < 125C, BUS > 4.5 to 14 Volts (No Auxiliary Supply at VCC), BUS = 0.9 to 4.5 Volts ( 3.8 V < VCC
< VCC Clamp). RACC = 20.0k
Parameter
Min
Typ
Max
Units
Conditions
4.5
14.0
V
Operating Icc
7
13
mA
UV/EN pin enabled
Standby Icc
6
12
mA
UV/EN pin disabled
Vcc Clamp
4.5
5.2
V
Operating ICC range
8
mA
UV/EN pin enabled
100
uA
UV/EN pin disabled
3.2
V
4.3
V
Operating ICC range, UV/EN pin
enabled.
V
200us delay after UVLO low trip
(1)
VCC Supplied from VAUX using RAUX .
(BUS = 0.9 to 4.5 V)
VAUX Range (with series RAUX)
Required for BUS = 0.9 to 4.5V
VCC derived from BUS
(BUS = 4.5 to 14 Volts, No VAUX Supply)
Operating ICC from BUS pin
Standby ICC from BUS pin
40
POR (VCC derived)
VCC Regulation
3.8
UV/EN and OV
Disable Threshold (pin UV/EN)
0.375
Enable Threshold (pin UV/EN)
Enable Pin Blanking Filter (pin UV/EN)
100
Threshold Hysteresis (pin UV/EN)
UVLO Threshold (Low to High Transition of VIN)
UVLO Hysteresis
0.575
V
300
us
50
mV
0.725
0.75
0.775
V
50
75
100
mV
UVLO De-asserted
Note 1: VAUX is defined on Page 11 and is shown in Figure 6.
Picor Corporation · picorpower.com
PI2211
Rev 1.0, Page 3 of 26
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PI2211
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Electrical Specifications(Continued)
Unless otherwise specified: -40C < TJ < 125C, BUS = 4.5 to 14 Volts (No Auxiliary Supply at VCC), BUS = 0.9 to 4.5 Volts ( 3.8 V < VCC
< VCC Clamp). RACC = 20.0k
Parameter
Min
Typ
Max
Units
0.650
0.675
0.700
V
OVLO Hysteresis
50
75
100
mV
UVLO Blanking Filter
100
300
us
OVLO Blanking Filter
5
15
us
OVLO Threshold (High to Low Transition of VIN)
10
UVLO/OVLO Holdoff Time
100
300
us
OV Current
-0.3
0.3
uA
UV Current
-0.3
0.3
uA
Gate Drive
(VGATE @ GDR pin to GND, VGS @ GDR pin to SRC pin). Operation is not in Current Limit.
VBUS +
VBUS +
VGATE High
V
4.65
6.5
Conditions
OVLO De-asserted
Ensures gate is maintained low.
Not to exceed 21V.
Gate Drive Operating Range (VGS)
4.65
6.5
V
VGS Current Limit Disable Threshold
4.2
4.6
V
Power Good
VGS Current Limit Enable Threshold
0
1
V
Start-up
Gate Current (Sourcing Mode)
10
40
uA
VGS = 0 to 4.6 V
VGS = 0.3 to Gate Drive Operating
Range.
VDRAIN > Drain Low-Threshold
VGATE = 14 V.
VDRAIN < Drain High-Threshold
Gate Current (Sinking Mode)
(2)
0.18
0.25
0.33
mA
Gate Current (Sinking Mode)
(2)
4
8
16
mA
30
Ohm
2.5
uA
27
mV
120
us
Settling to within 5%
10
%
Closed loop, shorted load, MOSFET
transconductance 20 to 200 A / V
OFF State Gate Discharge Path to GND (Gate Pull
Down)
SRC Pin Current
-2
@ 50 mA
@ 14 Volts. Positive Current into pin.
Current Limit & Sense
(CSP to CSN)
Differential Current Limit Sense Voltage
21
Current Ramp Time to Current Limit Level (GBD)
30
25
Current Limit Overshoot (GBD)
CSP Pin Current
-10
10
uA
CSN Pin Current
-10
10
uA
Note 2: This current is the gate discharge current for all shutdown conditions except circuit breaker (short circuit). This includes UV,
Disable (UV/EN pin), OV, SOA.
Picor Corporation · picorpower.com
PI2211
Rev 1.0, Page 4 of 26
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PI2211
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Electrical Specifications(Continued)
Unless otherwise specified: -40C < TJ < 125C, BUS = 4.5 to 14 Volts (No Auxiliary Supply at VCC), BUS = 0.9 to 4.5 Volts ( 3.8 V < VCC
< VCC Clamp). RACC = 20.0k
Parameter
Min
Typ
Max
Units
Conditions
Circuit Breaker (CB)
(CSP to CSN), Refer to Figure 9 Timing Diagram
Differential Circuit Breaker Trip Sense Threshold
(3)
52
Differential Circuit Breaker Trip Sense Threshold
Accuracy
-8
Circuit Breaker Sense CMRR
65
Circuit Breaker Detection Delay
mV
8
80
%
dB
50KHz
100
150
ns
CB event to 99% VGS. 3 mV overdrive
(above trip point).
VGATE = 14 V
Gate High Discharge Current (Stage 1 shutdown)
40
80
160
mA
Gate Intermediate Discharge Current (Stage 2
shutdown)
4
8
16
mA
0.18
0.25
0.33
mA
16
V
Gate Low Discharge Current (Stage 3 shutdown)
Drain Low-Threshold (ΔVDRN)
Drain High-Threshold (VDRN)
2
14
Drain High-Threshold Hysteresis
15
0.9
V
Response Time 1
5
ns
Response Time 2
30
ns
Circuit Breaker Trip Hold Time
Note 2
100
300
us
VGATE = 14 V
VDRAIN < Drain High-Threshold
VGS = 0.3 to Gate Drive Operating
Range.
VDRAIN > Drain High-Threshold
Positive differential change in VDRN
during CB shut-down. Discharge goes
from Stage 1 to Stage 2.
Positive going drain voltage threshold
(gate discharge transitions from
Intermediate to Low Current)
Negative going drain voltage threshold
minus Positive going threshold
Drain Low-Threshold to Gate
Intermediate Discharge Current (settled
within 5%)
Drain High-Threshold to Gate Low
Discharge Current (settled within 5%)
Gate maintained low
Note 3: The Circuit Breaker fault is enabled only when no other fault has occurred prior to exceeding the 52mV threshold. If another
shutdown event occurs first (SOA shutdown, UV shutdown, OV shutdown, Disable shutdown) then circuit breaker fault
sensing is disabled and held disabled until the gate is fully discharged and the trip hold time has passed. See Figure 9 for
details.
Picor Corporation · picorpower.com
PI2211
Rev 1.0, Page 5 of 26

PI2211
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
Electrical Specifications
Unless otherwise specified: -40C < TJ < 125C, BUS = 4.5 to 14 Volts (No Auxiliary Supply at VCC), BUS = 0.9 to 4.5 Volts ( 4.2 V < VCC
< VCC Clamp). RACC = 20.0k
Parameter
Min
Typ
Max
Units
80
mV
Conditions
SOA
Differential Current Sense Level Range for SOA (CSP
to CSN)
0
SOAS
SOAS Current Scaling Factor (RSENSE * RSOAS )
RSOAS Resistor Range
VDS range (CSN to SRC), Active SOA
Minimum VDS Sense Level to enable SOA Shutdown
Ω
This is the means to scale current for
SOA.
RACC resistor 20 K.
2
10
1
20
kΩ
VDS min
VBUS
V
23
33
mV
Below this level SOA shutdown is
disabled.
0.38
7.5
C/W
Range for exposed pad MOSFETs
SOAR
Rthjc Range
SOAR to Rthjc Conversion Factor
RSOAR Resistor Range (programs Rthjc)
Rthca
o
0.38
1
60
o
C/(W∙kΩ)
RACC resistor 20 K.
kΩ
RACC resistor 20 K.
C/W
Value Fixed Digitally
20
60
60
o
o
SOA Shaper 2 Input Range (VDS * I * Rthca),
4800
SOA Update Rate (Time from A/D Acquisition of VDS
& I to Update of Digital Filter)
13.5
Units
15
16.5
us
19.27
ms
One unit = 1 V * 1 A *1 C/W, SOA Note
1
Includes all A/D conversions, and all
multiplications.
SOAT
SOA Shaper 1: Tau p Range
0.96
SOAT to Tau p Conversion Factor
19.27
kΩ ∙ ms
RSOAT Resistor Range
1.3
20
SOA Shaper 1: (Tau z / Tau p) Ratio
1/8
1/8
1/8
SOA Shaper 2: Tau
1.8
2
2.2
sec
A/D Anti-Aliasing Filter 3 dB
3.3
13
KHz
1.19
°C
SOA Comparator Input Resolution
SOA Note 1
RACC resistor 20 K.
kΩ
SOA Note 1
SOA Note 1
SOA Comparator Hi Threshold
60
°C
All SOA cycles
SOA Comparator Lo Threshold
21
°C
First 16 SOA cycles.
SOA Comparator Lo Threshold
3
°C
Beyond 16 SOA cycles.
SOA Note 1: SOA Shaper 1 has a function that is represented by a normalized step response of the form:
SOA Shaper 2 is represented by a normalized step response of the form:
See "Junction to Case Thermal Response" section for further details.
Picor Corporation · picorpower.com
PI2211
Rev 1.0, Page 6 of 26
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PI2211
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
Electrical Specifications
Unless otherwise specified: -40C < TJ < 125C, BUS = 4.5 to 14 Volts (No Auxiliary Supply at VCC), BUS = 0.9 to 4.5 Volts ( 3.8 V < VCC
< VCC Clamp). RACC = 20.0k
Parameter
Min
Typ
Max
Units
0.4
V
Conditions
Power Good (PWRGD)
PWRGD Voltage (Output De-asserted)
PWRGD Current (Output Asserted)
0
2
uA
PWRGD Current (Output Asserted)
0
2
uA
0.4
V
VGS CLDT Event to PWRGD High Prop Delay
1
us
VGS CLET Event to PWRGD Low Prop Delay
1
us
20
k
PWRGD during Power Up (GDR Off)
@5mA
@ V = 14 Volts, VBUS = 0.9 to 14
Volts
@ V= 0.9 Volts, VBUS=0.9 to 14
Volts
@ 2 mA
Timer
Rtimer Resistance Range
1
Rtimer to Time Conversion Factor
Hot Swap Initialization Time
Hot Swap Initialization Time Error
5
Resistance at Timer Pin. RACC
resistor 20 K.
ms / k
RACC resistor 20 K.
RACC resistor 20 K.
5
100
ms
-25
25
%
46
°C/W
RTimer resistor 1.25 K to 20 K.
Thermal Resistance
RθJ-A
Picor Corporation · picorpower.com
PI2211
TAB connected to copper PCB trace.
Rev 1.0, Page 7 of 26
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PI2211
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PI2211 Introduction
The PI2211 limits the start-up current to a load, eliminating
the electrical disturbance or possible voltage sag imposed on
a backplane power supply. The PI2211 performs hot swap
protection during power-up or insertion and acts as a circuit
breaker during steady state operation. The PI2211 performs
these protection functions by controlling an external MOSFET
and limiting the MOSFET junction temperature rise to a safe
level, a key requirement for hot swap power managers
expected to operate over wide dynamic conditions.
True-SOA™
Upon insertion, the PI2211 initiates a user programmable
turn-on delay where the gate of the MOSFET is held "off",
providing input BUS de-bounce. The PI2211 then turns "on"
the MOSFET pass element in a controlled manner, limiting
the current to a pre-defined level based on the value of a user
selected sense resistor. The PI2211 circuit breaker threshold
protects against over-current by comparing the voltage drop
across this sense resistor with a fixed internal reference
voltage. Once the load voltage has reached its steady-state
value, the Power-good pin is asserted "high" and the start-up
current limit is disabled. Under voltage (UV) and Over Voltage
(OV) trip points (user settable) ensure operation within a
defined operating range in addition to a Enable/Disable
feature shared with the UV input.
With Power-good established, the load current is
continuously monitored by the PI2211 with the MOSFET
operating in the low loss RDSON region. In this steady state
operation, the PI2211 now acts primarily as a circuit breaker.
An over-current threshold is fixed to be twice the start-up
current limit and sets an upper current boundary that
determines when a gross fault has occurred. Exceeding this
boundary will initiate the PI2211 Glitch-Catcher™ circuitry
and assert the power good pin low.
Glitch-Catcher™
The Glitch-Catcher™ feature of the PI2211 prevents
overvoltage events caused by the energy stored in the
parasitic inductance of the input power path in response to a
rapid interruption of the forward current during an
overcurrent fault event. Acting as an active snubber, this
circuitry mitigates the need for large external protection
components by shunting the energy through the MOSFET to
the low impedance load.
Picor Corporation · picorpower.com
PI2211
The Picor PI2211 ensures efficient operation within the
MOSFET SOA by emulating the MOSFET junction temperature
rise via a internal digital processor. The PI2211, with TrueSOA™, constantly monitors MOSFET power to calculate the
MOSFET junction temperature rise and determine the proper
operation regardless of load conditions. The amount of time
that the PI2211 will turn a MOSFET on during SOA is
dependent on the calculated temperature rise, not a fixed
time, making the pulse width dynamic with varying line
voltages. The PI2211 will keep the MOSFET on until it predicts
an absolute 60°C junction temperature rise. Selecting 60°C as
the maximum junction temperature rise allows for the use of
the MOSFET at ambient temperatures approaching 90°C and
prevents exceeding the MOSFET’s maximum junction
temperature, typically 150°C.
Once the junction temperature rise has been calculated to be
60°C, the PI2211 will shut down the MOSFET and allow for
thermal cooling. While in True-SOA™ protection mode, the
PI2211 will attempt to start the MOSFET when the TrueSOA™ emulator has calculated that the junction temperature
has dropped by 39°C. The 39°C thermal cycling range will
retry start-up for a total of 16 pulses before the range is
extended to 57°C, where the thermal cycling will go on
indefinitely or until the low impedance load is removed.
The PI2211 can also protect the MOSFET when it is operating
at a higher than anticipated load current, but still below the
circuit breaker threshold. True-SOA™ constantly calculates
junction temperature rise as a function of power dissipation
and can shut down the MOSFET preventing damage. A typical
hot-swap controller will only fault when a threshold is
exceeded and cannot continuously protect the MOSFET
during operation.
Emulation of the MOSFET thermal performance is possible
with the use of the MOSFET manufacturers’ transient thermal
impedance curves. The Picor True-SOA™ digital algorithm
ensures maintaining a MOSFET within the actual SOA of the
device, optimizing the size of the device without the need to
oversize the MOSFET. The PI2211 True-SOA™ is programmed
for specific MOSFET thermal characteristics by the setting of
three resistors. The SOAS resistor determines the magnitude
and scaling of the current through the MOSFET. The SOAR
and SOAT resistors program the transient thermal parameters
of the MOSFET's junction to case characteristics. By
programming the MOSFET thermal characteristics, the PI2211
adapts its control and start-up or thermal cycling to that
specific MOSFET as shown in Figure 5.
Rev 1.0, Page 8 of 26

PI2211
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PI2211 Application/Theory of Operation
Maintaining a MOSFET within its SOA boundary:
The PI2211 has a programmable digital model of a MOSFET
thermal response to transient and static loads that it uses to
predict a junction temperature rise, as a function of power,
for a given MOSFET. The equivalent analog model is shown in
Figure 2. It consists of two RC stages to emulate the total
thermal equivalent of the junction-to-case and case-toambient characteristics of the MOSFET and its package. In the
model, the case-to-ambient characteristics are fixed while the
junction-to-case can be tuned to match the published data
for a specific MOSFET by two programming resistors; RSOAT
and RSOAR.
The RSOAT resistor controls the time constant (TauP) of the SOA
junction-to-case model. This resistor programs the model to
adhere to the manufacturer’s transient thermal impedance
graph of the junction-to-case response to "single pulse"
power changes, as well as the extended SOA curves beyond
the DC area limit. This instantaneous power calculation
refreshes in less than 50µs and predicts junction temperature
rise within the 1ms extended SOA MOSFET curves so the
PI2211 will protect the MOSFET from prolonged heating with
excessive static loads and hot-spotting from transient loads.
The RSOAR resistor programs the model with the RJ-C of the
MOSFET. Scaled by the ratio of the junction-to-case/case-toambient thermal impedances (RJ-C/RC-A), referenced on the
fixed internal 60°C/W RC-A of the PI2211.
The RSOAS resistor programs the magnitude of the calculated
current through the MOSFET and the power it is dissipating.
All three of these resistors have a maximum value 20kΩ. RSOAR
and RSOAs have a 1kΩ minimum value, the RSOAT has a
minimum of 1.30kΩ. Values outside of these ranges will not
stop the PI2211 from working, but will force the internal
references to either their minimum or maximum values. See
the Recommended Design Steps section for more details on
calculating the required SOA programming resistors.
Figure 2 - Simplified representation of the PI2211 thermal
model.
10
RθJ-C =
7.5°C/W
Tau= 1ms
Tau= 15ms
1
RthJ-C
RθJ-C =
0.5°C/W
Tau= 1ms
Tau= 15ms
0.1
0.01
1E-05
0.0001
.5°C/W, Tau = 1ms
0.001
Time
.5°C/W, Tau = 15ms
0.01
7.5°C/W, Tau = 1ms
0.1
7.5°C/W, Tau = 15ms
Figure 3 - The range of PI2211 RθJ-C thermal impedance adjustment at 1W.
Picor Corporation · picorpower.com
PI2211
Rev 1.0, Page 9 of 26
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PI2211
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
Junction-to-Case Thermal Response:
The magnitude of the MOSFET junction-to-case temperature
rise is the product of the MOSFET junction-to-case thermal
resistance (RJ-C), the sampled instantaneous power
dissipated in the MOSFET and the duration of the power
dissipation. The PI2211 internal model of RJ-C includes both a
“pole” and a “zero” in the transfer function as an electrical
equivalent of the thermal resistance and storage components
of the MOSFET in the thermal model. The pole, Tau P, has a
slower response to the dissipated power than the zero TauZ
does. TauZ is internally calculated to be 1/8th of TauP. RJ-C
and TauP are derived directly from the manufacturer’s
datasheet, and is further explained in the Recommended
Design Steps section.
The PI2211 junction-to-case thermal response is shown in
Figure 3; bounded by the internal allowed ranges of Tau P and
RJ-C. The range of TauP is 1ms to 15ms, the range of RJ-C is
0.5°C/W to 7.5°C/W, and the minimum pulse width is 50us.
The "Power" term is the calculated power based on the value
of RSOAS, which may be scaled from the true power. The
response of the PI2211 junction-to-case model is based on
the following equation:


The calculated minimum RJ-C is 1/8th of its nominal (steadystate) value, meaning that the PI2211 will predict a higher
junction temperature rise than what the manufacturer's
curves would suggest for shorter pulse widths. This helps to
protect against transient hot-spotting in the MOSFET.
Case-to-Ambient Thermal Response:
The magnitude of the MOSFET case-to-ambient temperature
rise is a function of the MOSFET case-to-ambient thermal
resistance (RC-A) and the instantaneous calculated power
dissipated in the MOSFET. The internal model has a “pole”
with a fixed thermal time constant (Tau) of 2 seconds and a
fixed RC-A of 60°C/W. A 2 second Tau will shut off the
MOSFET quickly at power levels that would typically require
100's of seconds to achieve an actual 60°C temperature rise,
protecting the MOSFET from thermal stress. 60°C/W is a
typical value of RC-A for packages with thermal tabs.
Junction-to-Ambient Thermal Response:
The over-all range of the junction-to-ambient thermal
impedance response of the PI2211 is shown in Figure 4. This
represents the entire adjustable range of the dynamic RJ-C
and the fixed RC-A summed together.
Using the ratios of TauP to TauZ, the equation simplifies to:
100
RthJ-A
10
1
0.1
0.01
1E-05
0.0001
0.001
0.01
0.1
1
Time
7.5°C/W, Tau = 1ms
.5°C/W, Tau = 15ms
Figure 4 - PI2211 J-A Thermal Impedance range of adjustment at 1W.
Picor Corporation · picorpower.com
PI2211
Rev 1.0, Page 10 of 26
10


SOA Thermal Cycling:
The PI2211 continuously monitors the power dissipation in
the MOSFET by measuring the voltage drop across the
MOSFET (VDS) and the calculated current through the sense
resistor (IDRAIN).
As previously described the power
information is processed through two equivalent internal
networks whose individual responses emulate the MOSFET
RJ-C and RC-A thermal characteristics. These two responses
are summed together to create an accurate RJ-A thermal
response.
PI2211

a series current limiting resistor (RAUX), as is shown in Figure
6, to protect the internal clamp of the VCC pin. The RAUX
limiting resistor is calculated as: RAUX = (VAUX - 3.8V)/10mA.
Though the BUS pin is not used to generate VCC, it still must
be connected to the BUS supply for proper operation.
When the computed junction temperature rise in the
MOSFET is 60°C, the MOSFET is turned off and, while still
being continuously monitored, allowed to cool to a calculated
junction temperature rise of 21°C (an estimated drop of
39°C). The MOSFET is once again turned on and monitored.
The PI2211 will continue the thermal cycling of the MOSFET
16 times with this temperature hysteresis range before
dropping the cool down temperature to 3°C rise. Once at
3°C, the PI2211 will continue the thermal cycling indefinitely
with a 57°C temperature hysteresis range resulting in a long
cool down period. An example of this SOA thermal cycling is
shown below in Figure 5 and in Figure 11.
Figure 6 - External VAUX connection for lower BUS voltages.
The PI2211 has an internal charge pump that requires no
external components and is designed to be used with
MOSFET that can operate with a gate drive of 4.5Vdc.
Figure 5 - SOA Thermal Cycling
Figure 5 shows the initial string of 16 SOA pulses. The V GS is
displayed on Ch1 (blue), the start-up current is shown on Ch3
(purple) and the BUS voltage is shown on Ch4 (green). Power
-good is shown on Ch2 (light blue), which is low during SOA.
VAUX Supply/Gate Drive:
The PI2211 is designed to be used in systems where the BUS
voltage range is from 0.9Vdc to 14Vdc. When using a BUS
voltage of 4.5Vdc or greater, the PI2211 internal LDO
regulator creates a VCC voltage of 4Vdc to bias the IC.
Figure 7 - Enable, UV and OV thresholds.
When using a BUS of less than 4.5Vdc, an external supply
(VAUX) is required to drive VCC; typically 5Vdc or greater with
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PI2211
Rev 1.0, Page 11 of 26
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PI2211


UV/EN and OV:
Figure 7 depicts the divided down BUS voltage, monitored on
the UV/EN and OV pins respectively and the "fault" state of
the PI2211. The over-voltage (OV) pin will disable (fault) the
PI2211 once the voltage on the OV pin reaches 0.750Vdc. It
will re-enable (fault clear) the controller once the voltage
drops below 0.675Vdc.
discharged rapidly, then in a slower controlled discharged to
a full "off" state. This allows the stored energy to pass
through the MOSFET into the low impedance load, keeping
the BUS voltage ringing to a controlled maximum value, well
below the avalanche voltage rating of the MOSFET. Acting as
an active snubber this provides the same protection as having
a voltage suppressor on the BUS. Figure 8 shows a simplified
block diagram of the Glitch-Catcher™ circuit.
The UV/EN pin monitors for under-voltage faults and also
provides a means of disabling the part via an external control.
The part becomes enabled once the voltage on the UV/EN pin
exceeds 0.575Vdc. To disable the part, the voltage on the
UV/EN pin must be below 0.375Vdc. A UV fault occurs when
the voltage on the UV/EN pin drops below 0.675Vdc,
disabling the controller. The fault is cleared and the controller
re-enabled, when the UV/EN pin’s voltage exceeds 0.75Vdc.
Glitch-less Turn-off: Transient Turnoff Glitch-Catcher™
During a circuit breaker event, uncontrolled turn off of the
series MOSFET can cause voltage ringing on the BUS due to
the stored energy in components and copper traces. To
maintain BUS voltage stability the PI2211 uses a glitch-less
turn-off mechanism whereby the MOSFET gate is initially
Figure 8 - Glitch-Catcher™ Over-current fault detection circuit.
Figure 9 - Circuit Breaker (CB) and Glitch-Catcher™ waveforms.
Figure 9 represents the typical response waveforms of the
PI2211 Glitch-Catcher™ to a circuit breaker (CB) event. After
the CB detection delay, the MOSFET gate gets discharged
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PI2211
with an 80mA discharge current until there is a positive dv/dt
on the drain. The discharge current is reduced to 8mA which
slows the drain voltage over-shoot until the drain - high
Rev 1.0, Page 12 of 26
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
threshold limit is passed. The discharge current is again
reduced to 250uA to slowly discharge the MOSFET gate. As
the drain voltage falls below the hysteresis threshold of the
drain-high threshold, the discharge current is increased to
8mA. This hysteretic cycling of discharge currents continues
until the gate is completely discharged.
PI2211

The start-up current level is set to approximately half the
circuit breaker threshold; (0.025V/0.052V) * circuit breaker
current. The start-up current limit is only in effect during
start-up, while the power-good signal is low, and acts to limit
the amount of current that the load can draw.
When start-up is completed, and power good is asserted
high, the current limit is no longer enabled and the circuit will
be allowed to draw current up to the circuit breaker
threshold or until an SOA fault is calculated. The circuit
breaker threshold is always enabled.
Another current threshold to consider is the maximum
operating current, IDCMAX. IDCMAX is calculated based on the
maximum rated junction temperature and the thermal and
resistive properties of the MOSFET. See the IDCMAX equation
in the Recommended Design Steps section for more details.
Operating above this current will result in an SOA shut down
and thermal cycling of the MOSFET when the PI2211 is
properly programmed.
Figure 10 - Glitch-Catcher response to shorted output.
Figure 10 shows the Glitch-Catcher™ responding to a hard
short-circuit applied to its output. The BUS voltage (blue, Ch1)
starts to drop as the current though the FET (green, Ch4)
rises. The source voltage (purple, Ch3) separates from the
BUS voltage as the voltage drop across the sense resistor and
the FET increases. The gate voltage (cyan, Ch2) tracks the BUS
voltage until the over-current threshold is exceeded, which
starts the Glitch-Catcher™ controlled gate discharge circuitry.
Current Limit:
The PI2211 has a start-up current limit and a circuit breaker
threshold, as shown in Figure 11. The designer’s MOSFET
selection can be determined by the maximum load current,
acceptable power loss at max current and the maximum
ambient temperature.
The PI2211 has a current sense amplifier that uses an
external current sense resistor to monitor MOSFET current.
The circuit breaker current threshold is determined by
dividing the internal 52mV reference voltage by the desired
over-current threshold. Exceeding this threshold will initiate
the Glitch-Catcher™ shut-down function, but the current is
not restricted. Since sense resistor value increments are
limited an additional resistor divider might be needed to
adjust for
the desired circuit breaker threshold.
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PI2211
The waveforms in Figure 11 are representative of a typical
start-up sequence, followed by an over-current event, and
then a re-start into a shorted load, leading to SOA thermal
cycling.
As the BUS supply rises and clears the VCC POR and UV fault
thresholds, the programmable insertion delay timer starts.
After the insertion delay, the series MOSFET gate is charged
with a 25uA current, allowing the input current to gradually
increase until it reaches the start-up current threshold. The
gate will be regulated to maintain the start-up current until
either the output reaches the BUS voltage or the MOSFET is
turned off due to SOA. Here, the output voltage reaches the
BUS voltage and the current drops below the start-up current
threshold, stopping the regulation of the MOSFET VGS and
allowing it to increase to the full charge pump voltage level of
about 5V. The power good pin is de-asserted and allowed to
float once the VGS is above 4.4V.
Sometime after the normal start-up an over-current event
occurs, triggering the Glitch-Catcher™ turn-off of the MOSFET
and the low assertion of the power good pin. See Figure 9 for
further details.
Rev 1.0, Page 13 of 26

PI2211


Figure 11 - Start-up, Over-Current, and SOA shut-down waveforms.
The MOSFET is held off for 200us before attempting to restart. Again, the MOSFET will be regulated to the start-up
current level, but now turns off due to an SOA shut-down.
The True-SOA™ protection has determined that the junction
temperature of the MOSFET has risen by 60°C and has shut it
down to cool. When the SOA monitoring has determined that
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the junction temperature has dropped by 39°C the MOSFET
will again turn on. The 39°C thermal cycling range will
continue for a total of 16 pulses before the range is extended
to 57°C, where the thermal cycling will go on indefinitely until
the low impedance load is removed.
PI2211
Rev 1.0, Page 14 of 26
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
PI2211

Figure 12 - PI2211 Block Diagram.
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PI2211
Rev 1.0, Page 15 of 26

PI2211


PI2211: Recommended Design Steps
There are two options to designing a hot swap solution with the PI2211:
 Utilize PICOR's PI2211 reference design with pre-selected components
 Follow PICOR's design guidelines and use the "Picor Calculator Tool" available from Picor's website
Either of these approaches will yield a suitable and reliable hot swap design solution.
PICOR PI2211 Reference Design:
Figure 13 - Final Design Schematic
For this design example we'll define our system requirements as follows:
 Nominal BUS voltage (VBUS) = 12V
 High BUS voltage where controller must be enabled (V BUSHIGH) = 12.5V
 Low BUS voltage where controller must be enabled (V BUSLOW) = 11.5V
 Maximum Operating Current (IMAX) = 10A
 Circuit Breaker Threshold (ICB) = 13A
 Hot-Swap Efficiency > 99%
 Schottky Diode is 40V, 1A; required to protect the SCR pin from negative voltage transients that can damage the controller.
The 100Ω series resistor is used to limit current.
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PI2211
Rev 1.0, Page 16 of 26

PI2211


Design Example FET Table:
In the preceding design Vishay's SiR890DP was used for the series MOSFET. The following table lists suitable MOSFETs and their
associated component values for use in various design configurations.
VBUS
IMAX
ICB
22A
26A
10A
13A
10A
13A
5A
6.5A
12V
5V
RSENSE
MOSFET
Manufacturer
RSOAR
RSOAS
IRFH5300PbF
IR
2.32k
2.67k
0.002Ω
IRFH6200PbF
IR
2.32k
2.67k
BSC019N02KSG
Infineon
4.32k
1.69k
FDMS7570S
Fairchild
4.87k
1.87k
0.004Ω
SiR890DP
Vishay
5.90k
2.61k
IRFH5300PbF
IR
2.32k
1.33k
BSC019N02KSG
Infineon
4.32k
1.69k
SiR890DP
Vishay
5.90k
2.61k
0.004Ω
IRFH5304PbF
IR
13.3k
1.24k
SiR890DP
Vishay
5.90k
1.30k
SiR802DP
Vishay
10.7k
1.24k
BSC046N02KSG
Infineon
9.76k
1.00k
0.008Ω
FDMS7580S
Fairchild
15.8k
1.00k
IRFH5304PbF
IR
13.3k
1.00k
Table 1 - Reference Design Variations and Associated Components
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PI2211
RSOAT
1.74k
2.26k
1.74k
2.15k
2.37k
2.74k
2.05k
1.96k
1.87k
4.02k
1.43k
2.26k
1.96k
1.58k
Rev 1.0, Page 17 of 26
PULSE
8ms
7ms
8ms
5ms
2ms
22ms
41ms
10ms
11ms
49ms
20ms
38ms
12ms
20ms


PI2211

PI2211 Design Guidelines
Table 1 lists some typical system configurations; their NMOSFETs and associated PI2211 programming resistors.
There are 9 different MOSFETs listed from various
manufacturers; all in the 5 x 6mm power tabbed package.
When designing a system that is not captured by the
reference designs listed in Table 1, the recommended design
steps are as follows:
1) Determine the value and power rating of the current
sense resistor (RSENSE) based on the maximum
allowed current where a circuit breaker fault event
will be set.
2) Determine the maximum RDSON and RθJ-A that the
system can tolerate for a 60°C delta rise in junction
temperature to chose an appropriate MOSFET.
3) Calculate the required programming resistors of the
PI2211 based on the system requirements and the
selected MOSFET.
4) Calculate the under and over-voltage resistors,
based on the required window of operation of the
BUS voltage.
Component values for the PI2211 can be taken directly from
the reference design examples, by using the equations in this
datasheet, or by using the Windows® based component
calculator software for the PI2211.
1) Sense Resistor Calculation:
The value of the current sense resistor, RSENSE, determines the
start-up current limit and circuit breaker threshold. During
start-up, the PI2211 will actively regulate at the start-up
current limit, which is calculated as follows:
Where; 0.025V is the internal reference voltage for the startup current to the sense comparator.
The circuit breaker threshold, ICB, is approximately twice the
ISTART-UP current. When designing a system using the PI2211, it
is often better to determine the maximum over-current
threshold that the design can tolerate rather than the startup current, since during start-up the MOSFET is protected by
the PI2211 SOA capabilities.
Where; 0.052V is the internal reference voltage for circuit
breaker threshold to the sense comparator.
The power rating of RSENSE should calculated to be about
double that of the power dissipated at the over-current level.
2) Maximum RDSON and RθJ-A Calculation:
The product of the constant power across the MOSFET and
the junction to ambient thermal resistance (RθJ-A) must be
less than 60°C. The power across the MOSFET is the product
of the square of the maximum operating current and the
RDSON, multiplied by the RDSON thermal scalar at 150°C, which
is typically about 1.6.
Figure 14 - Examples of an RDSON (left) and a RDSSCALAR thermal scalar (right) graphs.
RDSON and RDSSCALAR
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PI2211
Rev 1.0, Page 18 of 26

Using the VGS @ 4.5V trace, the RDSON can be taken from the
graph on the left in
Figure 14, using the desired operating current as an X
intercept. Once that value is chosen, the graph on the right
will determine the scalar of the RDSON value at the maximum
junction temperature. In this example it is about 1.58X, also
taken using the VGS @ 4.5V trace.
IDCMAX is the DC operating current that will heat the MOSFET
to its maximum junction temperature TJMAX when the
surrounding environment is at some maximum ambient
temperature. It is found by taking the maximum allowed
temperature rise of the MOSFET, based on the difference
between the maximum MOSFET junction temperature and
the maximum ambient temperature, and dividing this by the
thermal resistance of the MOSFET, RJ-A. The results will be
the maximum wattage (power) of the MOSFET. Dividing this
wattage by the RDSON of the MOSFET, at its maximum
junction temperature, will yield the maximum operating
current squared. IDCMAX is calculated as 90% of this value.
PI2211


3) PI2211 Resistor Calculations:
RACC is the resistor used to program the internal current
source. Its value is always 20.0k and should be set using a 1%
tolerance resistor. The power through the resistor is about
30µW.
RTIMER is the resistor that programs the start-up delay timer
after board insertion; DELAY is in the range of 5ms to 100ms.
For a 25ms delay:
SOA Programming Components:
Every MOSFET has its own unique thermal characteristics,
due to die size, lead frame, packaging, etc., and these
characteristics need to be "programmed" into the PI2211
digital model for it to accurately emulate and predict the
junction temperature rise for any given MOSFET. The model
needs to know the MOSFET junction-to-case and junction-toambient thermal impedances, as well as the power through
the MOSFET, in order to accurately predict the MOSFET
junction temperature rise.
These unique MOSFET
characteristics are used in conjunction with some built-in
default model parameters to accurately model a MOSFET in
the end user's application.
Where; TJMAX = Maximum allowed junction temperature
TAMBMAX = Maximum ambient temperature
RDSON = The MOSFET "On" resistance @ room
temperature.
RDSSCALAR = The MOSFET "On" resistance multiplier @
the maximum junction temperature.
RJA = The MOSFET thermal resistance, junction to
ambient.
Recommended MOSFETs:
The ability to program the PI2211 to maintain a MOSFET in its
thermal SOA region allows for a wider selection of MOSFETs
to be used in a hot-swap application.
When selecting a MOSFET, the key features to look for are:
 low RDSON at 4.5VGS
 a minimum VDS voltage rating of 20V
 a RθJ-C between 0.5°C/W and 7.5°C/W
 the peak pulsed current rating
 packages with metal thermal tabs
Figure 15 - MOSFET Power measurements.
RSOAS
The PI2211 determines the power across the MOSFET by
measuring the voltage drops across the MOSFET and the
sense resistor, as is shown in Figure 15. The RSOAS resistor is
used to program the PI2211 with the sense resistor's value.
The value range of this programming resistor is 1k minimum,
to 20k maximum.
The equation for calculating RSOAS is:
The PI2211 is designed to be used with a wide range of
MOSFETs in various packages, but to realize the greatest
efficiency Picor recommends the use of surface mount
MOSFETs with a metal drain tab for the best thermal and
2
Where; 10Ω is the SOAS current scaling factor,
RDSon performance. Packages such as Vishay's PowerPAK SO8
the default case-to-ambient, RΘCA-DEFAULT, is 60°C/W,
and 1212-8, Infineon's PG-TDSON-8 and PG-TSDSON-8, IR's 5
the default temperature rise, ΔTDEFAULT, is 60°C,
x 6 mm and 3 x 3 mm PQFN, and other similar tabbed
the difference between the max junction and the max
packages offer MOSFETs with high current ratings, better RθJambient temperatures is ΔTUSER .
C thermal transfer properties and lower RDS on resistances.
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PI2211
Rev 1.0, Page 19 of 26

PI2211


The additional terms for temperature rise and case-toambient ratios will scale the RSOAS resistor value, allowing
for the fine tuning of the PI2211 digital model to the MOSFET.
For example, if the steady-state RθC-A of the MOSFET is less
than the default 60°C/W of the model, the value of RSOAS
would be scaled down by this ratio. This would make the
value of the sense resistor appear to be larger to the PI2211.
For a given voltage drop across the sense resistor, a larger
sense resistor value would mean less apparent current
flowing through it and therefore the calculated power across
the MOSFET is less. By scaling the apparent power a wide
range of MOSFETs can be accurately emulated by the digital
thermal model.
Similarly, if the user has a lower ΔT than the default, the net
result is that the value of the sense resistor appears to be
lower, therefore the current flowing through it appears to be
greater to the SOA model and it will calculate more power
across the MOSFET.
RSOAR programs the PI2211 with the junction-to-case (RθJ-C)
thermal impedance of the selected MOSFET. The ratio of the
internal RθC-A (60°C/W) and the user's RθC-A is used to scale
the MOSFET RθJ-C in order to maintain the correct RθJ-C to RθCA ratio.
Where; 0.38 °C/(W∙k) is the SOAR to RθJ-C scaling factor,
the default case-to-ambient, RθCA-DEFAULT, is 60°C/W,
RθJA-USER is the steady-state junction-to-ambient value
of the MOSFET, taken from the manufacturer's
datasheet,
RθJC-USER is the maximum junction-to-case value of the
MOSFET, taken from the manufacturer's datasheet.
RSOAT programs the PI2211 with the TauP (time constant) of
the MOSFET RθJ-C and its value can be calculated after first
determining the pulse width that will cause a 60°C
temperature rise of the MOSFET junction. This can typically
be done using RθJ-C transient thermal impedance curves
provided by the FET manufacturer.
The scaled value of current used to determine RSOAS is used to
calculate the power across the MOSFET when calculating TauP
and in determining the value of RSOAT.
RSOAT , RSOAR
The PI2211 thermal model has a default case-to-ambient
thermal impedance of 60°C/W, and a Tau of 2 seconds. The
junction-to-case thermal impedance and TauP are
programmed by the RSOAT and RSOAR resistors. RSOAT has a
minimum resistor value of 1.30k, the RSOAR a minimum of 1k.
The maximum for both is 20k.
The power used for determining the pulse width is the
product of the BUS voltage and the start-up current.
Multiplying this power by RθJ-C results in a temperature rise.
Setting the maximum temperature rise to 60°C for the same
power means that the RθJ-C will have to be scaled down. Using
this scaling factor and the RθJ-C thermal impedance curves for
a single pulse, the pulse width can determined. An example
of normalized RθJ-C thermal impedance curves is shown in
Figure 16.
Figure 16 - Determining the pulse width.
For example: A MOSFET with a RθJ-C of 2.5°C/W, a BUS
voltage of 12V, and a start-up current limit of 6.25A will yield
the following RθJ-C scaling factor:
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PI2211
Rev 1.0, Page 20 of 26


PI2211

4) Under and Over-Voltage Programming:
Using the thermal impedance curves shown in Figure 16 and
a RθJ-C scalar of 0.32, the intersection with the single pulse
curve produces a pulse width of 1.4ms. To summarize, a
1.4ms pulse of 75W across this particular MOSFET should
raise the junction to case temperature by 60°C.
As is shown in Figure 7, there is a programmable window of
BUS voltage range where the PI2211 is guaranteed to be
operational. This window is defined by the OV pin voltage
being ≤ 0.675Vdc and the UV/EN pin voltage being ≥
0.750Vdc. The user should be aware that VBUSMAX , when
calculated using the following equations, is the maximum
voltage where the controller is guaranteed to be operational,
not the maximum voltage where the controller faults.
Knowing the pulse width, TauP can be calculated using the
equation below:
Where; PULSE is the pulse width taken from the RθJ-C thermal
impedance curves,
RθC-A is the default junction to case thermal
impedance of 60°C/W,
RθJ-C is the maximum junction-to-case value of the
MOSFET scaled by the ratio of the FET's RθC-A and the
default RθC-A .
Power is the nominal BUS voltage multiplied by the
current programmed via RSOAS.
Power = BUS * RSOAS * .0025
Figure 17 - Resistor divider options for UV and OV threshold
programming.
To calculate the OV and UV resistor divider ratios for separate
networks:
The power across the MOSFET is calculated by the PI2211 as
the product of the BUS voltage and the programmed current
as determined by RSOAS.
Knowing TauP, RSOAT can be calculated using the equation
below:
Using a three resistor string (RHI, RMID, RLO); when VBUSMIN the
voltage on UV is 0.75V, when VBUSMAX the voltage on OV is
0.675V. The ratio of the RMID to RLOW can be determined once
the ratio of VBUSMAX to VBUSMIN is set.
Using junction-to-case thermal impedance curves is a good
method to determine the duration of the power pulse since
the junction-to-case heats up much faster than the case-toambient and they are typically the most accurate thermal
curves published.
The MOSFET in Figure 16 reaches its normalized RθJ-C value at
about 50ms. MOSFETs with larger die sizes can take much
longer to reach their normalized value, even though they
might be in the same package. As this single pulse time
increases, then effect of the RθJ-A will become more dominate
and the RθJ-A single-pulse thermal impedance curve should be
used to determine the pulse width for a 60°C junction rise.
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PI2211
Once the max and min BUS voltage has been selected,
plugging their values into these three equations will provide
the resistance ratios of the three resistors.
Rev 1.0, Page 21 of 26

PI2211


pulse is considered to be the average current, then the peak
energy is twice this amount. The capacitive load can be
calculated as:
Optional: Max Load Capacitance
Knowing the duration of the power pulse, the user can
calculate the available energy during start-up. Knowing this
energy, a rough calculation of the amount of load capacitance
that can be charged during the initial start-up pulse can be
calculated. This calculation takes no tolerances into account.
The energy provided to the load during an SOA pulse is:
When charging the capacitive load, the required energy peaks
at the start of the charging and reduces to zero when the
charging is complete. If the energy calculated during the SOA
PI2211 Design Calculator
The PI2211 component calculator program is designed to calculate the required programming resistors of the PI2211 controller;
requiring the designed to enter just a few key thermal MOSFET parameters taken from the manufacturer’s datasheet. It is capable of
calculating both an under-voltage/over-voltage divider as well as a current sense divider. It can also derive a usable pulse width
when a MOSFET's RθJ-C curves are not given. Please read the PI2211 Component Calculator user guide for instructions on use and
available features.
Figure 18 - PICOR's Windows™ based PI2211 Design Calculator
Picor Corporation · picorpower.com
PI2211
Rev 1.0, Page 22 of 26


PI2211

Mechanicals
Figure 19 - 24 lead QFN package mechanicals.
Picor Corporation · picorpower.com
PI2211
Rev 1.0, Page 23 of 26

PI2211


Receiving Pad Definition:
Figure 20 - Bottom view of QFN with package outline reference. (All dimensions are in mm.)
Stencil Definition:
Figure 21 - Recommended stencil patterns. (All dimensions are in mm.)
Stencil definition is based on a 6mil stencil thickness, 80% of LGA pad area coverage.
Picor Corporation · picorpower.com
PI2211
Rev 1.0, Page 24 of 26

PI2211


PCB Layout Recommendations:
Figure 22 - Recommended PCB layout for measuring across the sense resistor (R1).
PCB Layout
The pc board layout shown in Figure 22 is representative of
the proper board layout for the most accurate current sensing
by the PI2211. The sense line are connected to the internal
centers of the sense resistor's pads, minimizing the added
resistance of the receiving copper.
Picor Corporation · picorpower.com
PI2211
Grounding for the PI2211 should be done using either a low
current ground plane or a local ground plane, contacting with
just the PI2211's ground pins and external components; then
connecting this plane to the system ground at a single point. It
is not recommended connecting the PI2211's ground pins and
external components to different ground planes or to high
current ground planes.
Rev 1.0, Page 25 of 26
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PI2211
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Warranty
Vicor products are guaranteed for two years from date of shipment against defects in material or workmanship when in normal use
and service. This warranty does not extend to products subjected to misuse, accident, or improper application or maintenance. Vicor
shall not be liable for collateral or consequential damage. This warranty is extended to the original purchaser only.
EXCEPT FOR THE FOREGOING EXPRESS WARRANTY, VICOR MAKES NO WARRANTY, EXPRESS OR LIMITED, INCLUDING, BUT NOT
LIMITED TO, THE WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Vicor will repair or replace defective products in accordance with its own best judgment. For service under this warranty, the buyer
must contact Vicor to obtain a Return Material Authorization (RMA) number and shipping instructions. Products returned without
prior authorization will be returned to the buyer. The buyer will pay all charges incurred in returning the product to the factory.
Vicor will pay all reshipment charges if the product was defective within the terms of this warranty.
Information published by Vicor has been carefully checked and is believed to be accurate; however, no responsibility is assumed for
inaccuracies. Vicor reserves the right to make changes to any products without further notice to improve reliability, function, or
design. Vicor does not assume any liability arising out of the application or use of any product or circuit; neither does it convey any
license under its patent rights nor the rights of others. Vicor general policy does not recommend the use of its components in life
support applications wherein a failure or malfunction may directly threaten life or injury. Per Vicor Terms and Conditions of Sale, the
user of Vicor components in life support applications assumes all risks of such use and indemnifies Vicor against all damages.
Vicor’s comprehensive line of power solutions includes high density AC-DC and DC-DC modules and accessory components, fully
configurable AC-DC and DC-DC power supplies, and complete custom power systems.
Information furnished by Vicor is believed to be accurate and reliable. However, no responsibility is assumed by Vicor for its use.
Vicor components are not designed to be used in applications, such as life support systems, wherein a failure or malfunction could
result in injury or death. All sales are subject to Vicor’s Terms and Conditions of Sale, which are available upon request.
Specifications are subject to change without notice.
Vicor Corporation
25 Frontage Road
Andover, MA 01810
USA
Picor Corporation
51 Industrial Drive
North Smithfield, RI 02896
USA
Customer Service: [email protected]
Technical Support: [email protected]
Tel: 800-735-6200
Fax: 978-475-6715
Picor Corporation · picorpower.com
PI2211
Rev 1.0, Page 26 of 26
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