IntelliFET Know How Guide

June 2010
Know How Guide
IntelliFET - low side self-protected MOSFET
Features
Benefits
•
Load dump protection
•
Designed for harsh operating
environments without the need for
extra clamps.
•
Thermal shutdown (non-latching auto
restart)
•
Self-protecting when in high
current/high temperature
applications – increasing reliability
•
Short circuit protection
•
Device protects both itself and the
load from over current conditions
•
Over voltage protection
•
•
•
Input •protection (ESD)
Particularly important when driving
inductive loads, to protect against
over-voltage breakdown
•
No external ESD protection required
•
3.3V and µC compatible inputs
•
No gate drivers or level shifters
required
•
Status flag pin with three voltage
levels (ZXMS6002G, ZXMS6003G
only)
•
Provides feedback on the condition
of the MOSFET, thereby providing
feedback on the condition of the
load
Applications
•
Lamp driver
•
Motor driver
•
Solenoid driver
•
Compatible with a wide variety of resistive, capacitive and inductive loads
•
5V microcontroller compatible low side switch
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June
2010
IntelliFET - low side self-protected IntelliFET family
The need for self-protected MOSFETs
While it’s been said many times before, the automotive electrical environment is tough! It is a lot
tougher than consumer electronics' for example. Figure 1 provides the classic illustration: the nominal
12V DC battery voltage of a vehicle swinging from a negative 12V (due to a reversed battery) through
to a positive 125V DC (due to load dump transients and inductive field decay).
Figure1
Voltage
Load Dump
125V
Noise,
Transients
~85V
Jump Start
24V
12V, nominal
0
Time
Crank
Voltage
6V
Noise,
Transients
Reverse
Battery
Apart from routine events such as these there are considerations as to what happens if:
• The wrong load, an overload (e.g. wrong type of bulb), is connected.
• The load is stalled or develops a short circuit or partial short circuit.
• A foreign object (a screwdriver) short circuits the load.
• Module cooling proves insufficient in extreme (fault) circumstances and devices overheat.
Similarly, Self protected MOSFETs are ideally suited to use in harsh industrial environments where
there is a need for immunity from radiated and conducted emissions.Consequently, self-protected
MOSFETs have proliferated into a number of non automotive applications that include:
•
•
•
•
•
•
•
•
Remote I/O controller outputs (Programmable Logic Controllers)
Distributed I/O Modules
Relay driving
Lamp driving
Proximity switches
Alarm system
GPS system
Relay driving in HVAC applications
When solid state electronics were first deployed in automotive applications supporting electric
windows for example, system designers either relied on the inherent ruggedness of large MOSFETs to
absorb the energy from transient load dumps or used discrete voltage clamp circuits. Such
approaches only served to increase both complexity and cost. The self-protected MOSFET was
therefore developed to address such limitations and improve overall circuit reliability.
Introducing the Diodes Inc IntelliFET portfolio of self-protected MOSFETs
Self-protected MOSFETs integrate a power MOSFET with a complete array of protection circuits that
guard against ESD, over-current, over-voltage, and over-temperature conditions. A typical block
diagram of a low-side protected MOSFET is shown in Fig. 2
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IntelliFET - low side self-protected IntelliFET family
Figure 2 – Block Diagram Lowside self-protected MOSFET
D
IN
Human
body ESD
protection
Over-voltage Protection
Over-current
protection
dV/dt limit
Logic
Overtemperature
protection.
S
When an ‘intelligent’ MOSFET senses the presence of any one of these potentially catastrophic
conditions, it protects both itself and the load connected to it. The integration of these protection
functions therefore improves overall system reliability. The addition of features such as status flags
also helps improve overall system performance by providing a diagnostics capability that can aid the
isolation and rectification of faults within a vehicle.
Self-protected MOSFETs can be categorised as either low side devices, where the load is switched
with reference to ground, or high side devices, where the load is switched with reference to a floating
point. This know-how guide outlines the function, operation and competitive environment of the
Diodes Inc low-side portfolio.
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2010
IntelliFET - low side self-protected IntelliFET family
Overview of the InteliFET low side family
ZXMS6004/5DT8 – dual devices that provide
customers with a thermally efficient alternative
to SO8.
ZXMS6004/5DG – drain connected to the tab
(improved power handling capability).
Released for those customers that don’t need
the benefits of the features of the
ZXMS6004FF.
ZXMS6004/5SG – source connected to the
tab – matches the pin-out of BSP75N.
ZXMS6004FFTA – provides the performance
of a BSP75 fet but occupies 85% less board
space
BSP75N - matches the pin-out (SOURCE
connected to TAB) of the industry standard
BSP75N.
ZXMS6002G – has DRAIN connected to TAB
as in the BSP75G, plus a fourth ‘STATUS’ pin
providing a voltage-level indicative of the
internal gate status.
ZXMS6003G - has DRAIN connected to TAB
as in the BSP75G, plus a fourth
‘PROGRAM/STATUS’ pin requiring an
external resistor to be connected between
itself and Vin Adjustments to the value of this
resistor provide for adjustment of the
operational current-limit.
With the external resistor in place, the
‘PROGRAM/STATUS’ pin also provides a
voltage-level indicative of the internal gate
status, in similar fashion to the ZXMS600
BSP75G - has DRAIN connected to TAB,
offering improved thermal impedance (and
hence power handling capability) over the
Zetex BSP75N, but with different pin-out.
ZXMS6003G - has DRAIN connected to TAB
as in the BSP75G, plus a fourth
‘PROGRAM/STATUS’ pin requiring an
external resistor to be connected between
itself and Vin Adjustments to the value of this
resistor provide for adjustment of the
operational current-limit.
ZXMS6001G – has the drain connected to
TAB asin the BSP75G but has a 500uA input
current and is able to operate down to 4V
input.
With the external resistor in place, the
‘PROGRAM/STATUS’ pin also provides a
voltage-level indicative of the internal gate
status, in similar fashion to the ZXMS6002G
Part Number
TAB
BVDSS
(V)
BSP75G
BSP75N
ZXMS6001N3
ZXMS6002G
ZXMS6003G
ZXMS6004DG
ZXMS6004FF
ZXMS6004SG
ZXMS6004DT8
ZXMS6005DG
ZXMS6005SG
ZXMS6005DT8
Drain
Source
Source
Drain
Drain
Drain
N/A
Source
Drain
Source
60
60
60
60
60
60
60
60
60
60
60
60
ID(A) VIN
= 5V
1.4
1.2
1.1
1.4
1.4
1.3
1.3
1.3
1.2
2
2
1.8
PD
(W)
2.5
1.5
1.5
2.5
2.5
3
1.5
1.6
2.3
1.6
1.6
1.6
RDS (on) Max(Ω) @VIN =
3V
5V
10V
0.675
0.55
0.675
0.55
2
0.675
0.675
0.55
0.675
0.55
0.6
0.5
0.6
0.5
0.6
0.5
0.6
0.5
0.25
0.2
0.25
0.2
0.25
0.2
-
VDS(S/C)
VIN = 5V
36
36
36
36
36
36
36
36
36
36
36
36
EAS
(mJ)
550
550
550
550
550
490
90
480
210
490
490
210
Package
Outlines
SOT223
SOT223
SOT223
SOT223
SOT223
SOT223
SOT23F
SOT223
SM8
SOT223
SOT223
SM8
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IntelliFET - low side self-protected IntelliFET family
Relevant to ZXMS6002G, ZXMS6003G only:
Both of these devices feature a STATUS pin, the voltage on which is identical to that being applied
internally to the MOSFET gate. This pin can therefore be used to indicate the mode of device
operation (normal, over-current-shutdown or over-temperature shutdown) as shown below:
Current Limiting and Over Temp Shutdown
Status Indication at Vin=5V
Current Limiting and Over Temp Shutdown
Status Indication at Vin=10V
8
8
VIN =5V
7
6
5
Typical VStatus (V)
Typical VStatus (V)
7
Normal Operation
4
3 Current limit operating
2
Over Temp
Shutdown
1
0
25 50 75 100 125 150 175 200 225 250
Normal Operation
VIN = 10V
6
5
4
3
Current limit operating
2
Over Temp
Shutdown
1
0
25 50 75 100 125 150 175 200 225 250
Typical Temperature (°C)
Typical Temperature (°C)
The behaviour shown is typical of that observed on the ZXMS6002G, and also typical of that
observed on the ZXMS6003G device with Rprog = 24k…• 湮捥整⁤敢睴敥楖湡⁤呓呁单瀠湩⹳
Relevant to ZXMS6003G only:
Unlike all other devices within this family, the ZXMS6003G requires connection of an external
resistor (Rprog) in order to function. Rprog is connected between the Vin and STATUS pins, and its
value determines the operational current-limit as shown below.
The customer may use this trimming capability in order to provide a desirable level of start-up current
limitation, when driving loads which generate high initial current surges (e.g. lamps, motors).
Current Limit (A)
This feature may also be used to adjust the degree of IV protection which will apply under load-dump
conditions.
1
VIN = 10V
VIN = 5V
0.1
0
20
40
60
80
Rprog (kΩ)
Current Limit vs Rprog
100
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2010
IntelliFET - low side self-protected IntelliFET family
Function and operation of Diodes’ Low Side IntelliFET portfolio
The protection circuitry described in the following paragraphs is based on the Diodes Inc ZXMS6xxx
series of low side self-protected MOSFET (IntelliFET). These devices have a VDS of 60V and a
typical RDS(ON) 景戠瑥敷湥㔠洰 …湡⁤⸰☵ ; It operates in circuit in much the same way as a standard
unprotected MOSFET. The device is turned on by a logic high (5V) however unlike a standard
MOSFET a small current of the order 100uA is drawn by the input to power the on board protection
circuitry. Similarly, the device is turned off by a logic low of <0.7V. Figure 3 illustrates this point.
Figure 3 – Function of a low-side self protected MOSFET
D
Over-Voltage
Clamping
I
Over-Current
Protection
ESD
Over-Temperature
Protection
S
The IntelliFET portfolio features an ESD rating of 4kV based on the Electrostatic discharge model.
ESD protection is provided on the input by clamp diodes to protect both the internal gate and the
protection circuitry and across the Drain-Source is protected by its built-in Miller capacitance, active
clamping, and reverse (body-drain) diode.
Over-voltage protection is implemented via a Zener diode stack operating as an active clamp that
turns the gate on when the VDS exceeds 65V. Active clamping ensures that the whole of the
MOSFET is turned on and the voltage energy dissipated across the entire area of the MOSFET. For
example, when a relay deactivates, any generated transient would be clamped at 65V for the
duration of the transient and the energy dissipated. Once the transient’s energy has been dissipated
the device would revert to normal off state.
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IntelliFET - low side self-protected IntelliFET family
Figure 4 – Overvoltage protection – active clamping
D
Over-Voltage
Clamping
Internal active clamp circuit protects the
MOSFET and load for voltages >65V (typ.)
I
S
Over-temperature protection is provided by a temperature sensor and a hysteresis circuit. This over
temperature thermal shutdown circuit is active whenever the input is logic high (usually 5V) and
constantly monitors the junction temperature. It does this completely independently of over-current,
clamping etc. Once the temperature of the MOSFET device reaches the threshold temperature of
0
typically 175 C the thermal shutdown circuit turns the internal gate off and interrupts the dissipation.
The hysteresis of this circuit ensures that the output of the device will turn back on again once the
device has cooled by around 10°C. This behaviour is illustrated in Fig. 5. Note that during overtemperature hysteresis cycling, on the right of the chart, the over-current protection levels never
return to the initial (25°C) values.
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IntelliFET - low side self-protected IntelliFET family
Figure 5 – Over-temperature protection – thermal shutdown with hysteresis
Tj=Tamb
Tj=Ttrip
Over-current protection is effected through a current limit circuit. During normal operation the full
input voltage (5V) is delivered to the internal gate as long as the VDS is small and low dissipation is
assured. However, if the load current rises sufficiently to generate a substantial VDS, then the device
reacts by reducing the internal gate drive and restricting the drain current (ID). This functionality is
illustrated in Figure 6.
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2010
IntelliFET - low side self-protected IntelliFET family
Figure6 – current limiting – typical output characteristics.
Current limited
by the device
Rds(on)
mode
For example, at turn on an incandescent lamp has a low resistance that increases as the lamp heats
up. If the lamp is being driven by a self-protected MOSFET the inrush current associated with this
low resistance will be limited by the over-current protection circuit, protecting the MOSFET and
prolonging the life of the lamp.
The over-current and over-temperature protections are completely independent functions. In a cool
ambient environment the over-current regulation may operate for substantial periods before
temperatures approach the threshold of the over-temperature thermal shutdown circuit. In a hot
enough ambient environment the over-temperature will turn-off the output even if there is little or no
dissipation in the device.
Normally though, the two functions work together. The normal protection sequence is that an
excessive load condition causes the over-current circuit to reduce the gate drive and self-regulate
the current. Then, if the condition persists for long enough, the device temperature rises until overtemperature cycling begins. Over-temperature cycling will continue until the Input voltage or
overload conditions are removed.
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IntelliFET - low side self-protected IntelliFET family
Competitive Environment
•
The IntelliFET market is
Page 10
June
2010
IntelliFET - low side self-protected IntelliFET family
Cross Reference to Infineon
Competitor
Part
Basic specification of
competitor part
VDS
clamp
RDSON
(mOhm)
BSP75G
BSP75N
BSP76
(V)
60
60
42
BTS3410G
42
200
BTS3118N
BTS3118D
BSP77
BSP78
42
42
42
42
100
100
100
50
500
500
200
Diodes Near
Equivalent
Package
SOT223
SOT223
SOT223
SO8
(dual)
SOT223
Dpak
SOT223
SOT223
Comment
ZXMS6004DG
ZXMS6004SG
ZXMS6005DG
ZXMS6005DT8
ZXMS6006DG
ZXMS6006K
ZXMS6005DG
ZXMS6008DG
Provides, same performance in smaller
package
Scheduled for release Q3
Scheduled for release Q3
Scheduled for release Q3
Scheduled for release Q3
Cross Reference to ST
Competitor
Part
Basic specification of competitor
part
RDSON
VDS clamp (V)
Package
Diodes Near
Equivalent
Comment
(mOhm)
VNS1NV04D
42
250
SO8 (dual)
ZXMS6005DT8
VNS3NV04D
42
120
SO8 (dual)
ZXMS6006DT8
VNN7NV04P
VNS7NV04P
VNLS160N3
VNLS160N5
VNN7NV04P
VNS7NV04P
VND7NV04P
VNN3NV04
VNS3NV04D
VND3NV04
VNN1NV04
VNS1NV04D
VND1NV04
42
42
42
42
42
42
42
42
42
42
42
42
42
60
60
160
160
60
60
60
120
120
120
250
250
250
SOT223
SO8
SOT223
DPak
SOT223
SO8
DPak
SOT223
SO8
DPak
SOT223
SO8
DPak
ZXXMS6008DG
ZXMS6008N8
ZXMS6007DG
ZXMS6007K
ZXMS6008DG
ZXMS6008N8
ZXMS6008K
ZXMS6007DG
ZXMS6007N8
ZXMS6007K
ZXMS6005DG
ZXMS6005N8
ZXMS6006K
Provides, same performance in smaller
package
Provides, same performance in smaller
package
Scheduled for Q3 release
Scheduled for Q3 release
Scheduled for Q3 release
Scheduled for Q3 release
Scheduled for Q3 release
Scheduled for Q3 release
Scheduled for Q3 release
Scheduled for Q3 release
Scheduled for Q3 release
Scheduled for Q3 release
Scheduled for Q3 release
Scheduled for Q3 release
Scheduled for Q3 release
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IntelliFET - low side self-protected IntelliFET family
Cross reference to NXP
Competitor
Part
BUK127-50DL
BUK127-50GT
BUK117-50DL
Basic specification of competitor part
VDS clamp
(V)
RDSON
50
50
50
200
200
100
Package
Diodes Near
Equivalent
SOT223
SOT223
SOT223
ZXMS6005DG
ZXMS6005DG
ZXMS6006DG
Comment
(mOhm)
scheduled for Q3 release
Target Customers
•
Automotive electronics manufacturers – see list below
•
Industrial/security peripheral driving applications
•
Motor control design and manufacturers
Target Markets
•
Automotive electronics manufacturers – see list below
•
Industrial/security peripheral driving applications
•
Motor control design and manufacturers
•
Automotive electronics manufacturers include:
•
Delphi – Hella – Valeo – Johnson Controls – Motorola AIEG – Bosch – Siemens VDO – Lear – TRW
– AB Automotive
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IntelliFET - low side self-protected IntelliFET family
Supporting information
•
•
Samples – available now
Datasheets available online
www.diodes.com
•
To download selected data sheet, enter p/n in our website Product Data Sheet search.
Solderability, Reliability and Environmental Highlights
Qualified to rigorous AEC-Q101 (automotive) standards for high reliability
Compliant with RoHS environmental standards and lead free design
Pb-Free, 100% Matte-Tin Plating
Withstands 260°C Solder Reflow
Meets Moisture Sensitivity Level (MSL
Sales offices
The Americas
Europe
Taiwan
Shanghai
Shenzhen
Korea
3050 E. Hillcrest Drive
Westlake Village,
CA 91362-3154
Tel: (+1) 805 446 4800
Fax: (+1) 805 446 4850
Kustermannpark
Balanstraße 59,
D-81541 München
Germany
Tel: (+49) 894 549 490
Fax: (+49) 894 549 4949
7F, No. 50,
Min Chuan Road
Hsin-Tien
Taipei, Taiwan
Tel: (+886) 289 146 000
Fax: (+886) 289 146 639
Rm. 606, No.1158
Changning Road
Shanghai, China
Tel: (+86) 215 241 4882
Fax (+86) 215 241 4891
Room A1103-04,
ANLIAN Plaza, #4018
Jintian Road
Futian CBD,
Shenzhen, China
Tel: (+86) 755 882 849 88
Fax: (+86) 755 882 849 99
6 Floor, Changhwa B/D,
1005-5 Yeongtong-dong,
Yeongtong-gu, Suwon-si,
Gyeonggi-do, Korea 443-813
Tel: (+82) 312 731 884
Fax: (+82) 312 731 885
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IntelliFET - low side self-protected IntelliFET family
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