|
|
PDF PI2061 Data sheet ( Hoja de datos )
| Número de pieza | PI2061 | |
| Descripción | High Side High Voltage Load Disconnect Switch Controller IC | |
| Fabricantes | Picor | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de PI2061 (archivo pdf) en la parte inferior de esta página. Total 16 Páginas | ||
|
No Preview Available !
Not Recommended for New Designs
PI2061
Cool-Switch® Series
High Side High Voltage Load Disconnect Switch Controller IC
Description
The PI2061 is a high-speed electronic circuit breaker
controller IC designed for use with N-channel MOSFETs in
high side load disconnect switch solutions for medium
voltage applications. The PI2061 Cool-Switch® controller
enables an extremely low power loss solution with fast
dynamic response to an over current fault or EN Low
conditions.
Once enabled, the PI2061 monitors the MOSFET current
through a sense resistor. If an over current level is
sensed, the switch is quickly latched off to prevent the
power source from being overloaded. Bringing the EN
pin low will reset the over current latch allowing retry. To
avoid false tripping by the in-rush current, the over
current level is approximately doubled during start up,
until SN approaches about 0.8V below VC. The PI2061
has an internal charge pump to drive the gate of a high
side N-Channel MOSFET above the VC input. There is an
internal shunt regulator that regulates the VC input with
respect to the SGND pin for applications higher than 11
volts.
Table of Contents:
Pin Description
Electrical Specifications
Functional Description
Block Diagram
State Diagram
Typical Characteristics Plots
2
3
5
6
7
8
Features
Programmable latching over-current detection
Fast 120ns disconnect response to a load short
Fast disable via EN pin, typically 200ns.
4A gate discharge current
Internal charge pump
Fault status indication
Applications
Telecom System, ≤80V operation & 100V/100ms
Transient
N+1 Redundant Power Systems
Servers & High End Computing
High Side Circuit Breaker and Load Disconnect
Package Information
The PI2061 is offered in the following package:
10 Lead 3mm x 3mm DFN package
Application Information
12V Typical Application Example
48V Typical application Example
Layout Recommendation
Package Drawings
Ordering Information
9
12
13
14
15
15
Typical Application:
Event: Output Short
Vin
RS Iout
Vout
RVC
VC
0.1µF
26
GATE SP
3 VC
7
SN
D2
5 EN PI2061
4 SGND
PGND
1
FT 9 FT
D1
RTN
RPG
Figure 1: PI2061 in High Side Disconnect switch application
Current Trip Level
0A
Output Current
Over Current detection
Vout
Vin
MOSFET Turn Off Time
120ns
0V
Figure 2: PI2061 response time to output short fault condition
Picor Corporation • picorpower.com
PI2061
Rev 1.4
Page 1 of 16
1 page  
Not Recommended for New Designs
Functional Description:
The PI2061 Cool-Switch is designed to drive an N-channel
MOSFET in a high side Circuit Breaker application. As
shown in Figure 1, the load current is sensed through the
sense resistor (Rs). At power up the controller has a
higher threshold voltage compared to steady state
operation to allow capacitive load charging without
nuisance tripping of the breaker.
Differential Amplifier:
The PI2061 integrates a high-speed fixed offset voltage
differential amplifier to sense the difference between the
Sense Positive (SP) pin and Sense Negative (SN) pin
voltage with high accuracy. The amplifier output is
connected to the control logic that determines the state
of the fault latch. To avoid tripping the breaker due to
load capacitance during initial power up a higher
threshold is used. The amplifier will detect if the drop
across the sense resistor reaches 166mV and discharge
the gate of the MOSFET if detected. Once the load
voltage approaches the input potential the threshold is
lowered to 70mV. This allows for capacitive load
charging and continuous current sensing without the use
of a fixed sense blanking timer where excessive currents
may develop glitching the input bus prior to breaking.
VC Voltage Regulator and MOSFET Drive:
The biasing scheme in the PI2061 uniquely enables the
gate control relative to SGND and PGND pins via the
resistor RPG shown in Figure 1. The VC input provides
power to the control circuitry, the charge pump and the
gate driver. An internal regulator clamps the VC voltage
to 11.7V with respect to SGND.
The VC pin is connected through an external resistor to
the input power source and drain of the MOSFET. VC
switches over to the load potential once the gate drive is
enabled and over current condition is not present.
The internal regulator circuit has a comparator to
monitor VC voltage and pulls the gate low when VC to
SGND is lower than the VC Under-Voltage Threshold. As
shown in Figure 1 the lower bias resistor, RPG is placed
between the SGND connection and the system ground.
Gate Driver:
The PI2061 has an integrated charge pump that
approximately doubles the regulated VC with respect to
SGND enhancing the N-Channel MOSFET gate to source
voltage.
The internal gate driver controls the N-channel MOSFET
such that in the on state, the gate driver applies current
to the MOSFET gate driving it to bring the load up to the
input voltage and into the RDS(on) condition.
When an over current condition is sensed the gate driver
pulls the gate low to PGND and discharges the MOSFET
gate with 4A peak capability. A Schottky diode (D1 in
Figure 1) from PGND to the MOSFET source is required to
direct the Gate high discharge current into the Source.
The PI2061 applies high gate discharge current for fast
MOSFET turn off when a fault condition occurs to
prevent system disruption. Fast MOSFET turn off may
produce high voltage ringing due to parasitic inductance.
To prevent negative peaks at SN from injecting substrate
current, Schottky diode D2 (from SGND/PGND to SN pin
as shown in Figure 1) is required.
Enable Input: (EN)
This input provides control of the switch state enabling
and disabling with low current level signals. The active
high feature allows pulling/sinking a low current from
this input to disable the breaker. System control can
disable the switch and reset the over current latch by
pulling this pin to a logic low state.
Once enabled, the Gate pin will charge the MOSFET gate
to turn the load on. The load voltage will rise, reach the
input voltage and the device will sense the current
continuously once the POR interval has cleared relative
to the VC to SGND potential. The disable control with this
input is very fast, turning the switch off in typically
200ns. The response to open during an over current
event is typically 120ns and the switch will latch off until
reset by bringing this input low or recycling of the input
power.
Fault Status: (FT)
This open collector pin transitions to high resistance after
the Fault Status is delayed for 5μs when an over-current
fault or disable signal occurs. When the controller input
voltage is in under voltage, (VC - SGND < 7V) this pin is
high resistance as well. When the part is in a normal
operating condition and gate driver is enabled this pin is
low resistance. In high voltage applications this output
must be translated to the system return with external
circuitry. Leave this pin open if unused.
Picor Corporation • picorpower.com
PI2061
Rev 1.4
Page 5 of 16
5 Page 
Not Recommended for New Designs
N-Channel MOSFET Selection:
Several factors affect MOSFET selection including cost and
following ratings; on-state resistance (RDS(on)), DC current,
short pulse current, avalanche, power dissipation, thermal
conductivity, drain-to-source breakdown voltage (BVDSS),
gate-to-source voltage (VGS), and gate threshold voltage
(VGS (TH)).
The first step is to select a suitable MOSFET based on the
BVDSS requirement for the application. The BVDSS voltage
rating should be higher than the applied Vin voltage plus
expected transient voltages. Stray parasitic inductance in
the circuit can also contribute to significant transient
voltage condition, particularly during MOSFET turn-off
after an over current fault has been detected.
In a disconnect switch application when the output is
shorted, a large current is sourced from the power source
through the MOSFET. Depending on the input impedance
of the system, the current may get very high before the
MOSFET is turned off. Make sure that the MOSFET pulse
current capability can withstand the peak current. Also,
such high current conditions will store energy even in a
small parasitic inductance. The PI2061 has a very fast
response time to terminate a fault condition achieving
120ns typical and 200ns maximum. This fast response time
will minimize the peak current to keep stored energy and
MOSFET avalanche energy very low to avoid damage
(electrical stress) to the MOSFET.
Peak current during output short is calculated as follows,
assuming that the input power source has very low
impedance and it is not a limiting factor:
Where:
: Peak current in the MOSFET right before
it is turned off.
: Input voltage at MOSFET drain before
output short condition occurred.
: Over current turn-off time. This will
include PI2061 delay and the MOSFET
turn off time.
: Circuit parasitic inductance
The MOSFET avalanche energy during an input short is
calculated as follows:
Where:
:
:
Avalanche energy
MOSFET breakdown voltage
MOSFET RDS(on) and maximum steady state power
dissipation are closely related. Generally the lower the
MOSFET RDS(on), the higher the current capability and the
lower the resultant power dissipation for a given current.
This leads to reduced thermal management overhead, but
will ultimately be higher cost compared to higher RDS(on)
parts. It is important to understand the primary design goal
objectives for the application in order to effectively trade
off the performance of one MOSFET versus another.
Power dissipation in load switch circuits is derived from the
total drain current and the on-state resistance of the
selected MOSFET.
MOSFET power dissipation:
Where :
:
:
MOSFET Drain Current
MOSFET on-state resistance
Note:
In the calculation use RDS(on) at maximum MOSFET
temperature because RDS(on) is temperature dependent.
Refer to the normalized RDS(on) curves in the MOSFET
manufacturer’s datasheet. Some MOSFET RDS(on) values
may increase by 50% at 125°C compared to values at 25°C.
The Junction Temperature rise is a function of power
dissipation and thermal resistance.
Where:
:
MOSFET Junction-to-Ambient thermal
resistance
Picor Corporation • picorpower.com
PI2061
Rev 1.4
Page 11 of 16
11 Page | ||
| Páginas | Total 16 Páginas | |
| PDF Descargar | [ Datasheet PI2061.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| PI2061 | High Side High Voltage Load Disconnect Switch Controller IC | Picor |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |