HITFET
®
Table of Contents
Page
Abstract
............................................................................................................................................
2
Introduction
......................................................................................................................................
3
HITFET
®
Construction
.....................................................................................................................
4
Protection-Functions
.......................................................................................................................
5
Drive Requirements
.........................................................................................................................
7
Current-Sense
..................................................................................................................................
8
Status Feedback Signal
.................................................................................................................
10
Reverse Polarity
.............................................................................................................................
11
Typical Applications
......................................................................................................................
11
Summary
........................................................................................................................................
13
References
.....................................................................................................................................
13
SIPMOS
®
HITFET
®
TEMPFET
®
PROFET
®
milliFET
®
are registered trademarks of Siemens AG.
Semiconductor Group
1
1998-07-01
HITFET
®
Abstract
Today’s wide palette of intelligent power
semiconductors provides system engineers with
many opportunities to develop more reliable
systems at lower overall cost in a smaller
package. Many of these intelligent power
semiconductors require very few external
components, if any, since they have a built-in
protection against overtemperature or short
circuit, and can be driven directly by a
microcontroller. Siemens offers a wide variety of
smart power switches for high-side and low-side
applications. The name PROFET
®
(fully PROte-
cted FET) designates high-side switch families
that require a minimum number of external
Table 1
Type
BTS 117
BTS 133
BTS 141
BTS 149
components while providing high-side switching
function with numerous protection functions
needed
in
automotive
and
industrial
(1)
®
applications . The name TEMPFET (TEMpe-
rature Protected FET) designates a family of
short circuit and overtemperature protected low
side switches
(2,3)
. Finally, there is also a family of
new low-side switches called HITFET
®
(High
InTegration FET) which includes a very high level
of integration of control and protection functions
in a single package
(4)
. This paper describes
HITFET
®
devices in detail. In the following tables
all available types are listed:
3-Pin HITFET
®
with Fixed Current Limit
V
DS(AZ)
[V]
60
60
60
60
R
DS(ON)
[mΩ]
100
50
28
18
I
D-ISO min
[A]
3.5
7
12
19
I
D(lim) min
[A]
10.5
21
25
30
Status at
Input Pin
single
single
single
single
Package
TO 220
TO 220
TO 220
TO 220
Table 2
Type
5-Pin HITFET
®
with Adjustable Current Limitation and Current Sense
V
DS(AZ)
[V]
60
60
60
60
R
DS(ON)
[mΩ]
100
50
28
18
I
D-ISO min
[A]
3.5
7
12
19
I
D(lim) min
[A]
2.5
…
45
7
…
80
12
…
130
19
…
220
Status at
Current
Sence Pin
analog
analog
analog
analog
Package
BTS 917
BTS 933
BTS 941
BTS 949
TO 220/5
TO 220/5
TO 220/5
TO 220/5
Semiconductor Group
2
1998-07-01
HITFET
®
Introduction
V bb
+
LOAD
M
Drain
2
Overvoltage
protection
1
IN
dv/dt
limitation
Current
limitation
ESD
Overload
protection
Over-
temperature
protection
Short circuit
Short circuit
protection
protection
Source
3
HITFET
®
Figure 1
HITFET
®
Block Diagram, Fixed Current Limit
V bb
+
2
NC
Drain
dv/dt
IN
limitation
Current
limitation
Overvoltage
protection
LOAD
M
3
1
4
CC
Over-
temperature
protection
ESD
R
CC
Overload
protection
Short circuit
Short circuit
protection
protection
Source
5
HITFET
®
Figure 2
HITFET
®
Block Diagram, Adjustable Current Limit
Semiconductor Group
3
1998-07-01
HITFET
®
The HITFET
®
device designs are based on the
standard SIPMOS
®
(Siemens Power MOS)
technology with additional elements that provide
new and unique characteristics.
Figure 1
and
Figure 2
show that each HITFET
®
type has a
built-in protection against overvoltage, overtem-
perature, short circuit, ESD, and switching speed
limiting (dv/dt limiting) circuit. The most important
are the short circuit and overtemperature
protection. They are achieved by the use of two
separate temperature sensors. The combination
of the sensors guarantees that the power chip
temperature is limited to a relatively low transient
temperature during severe overload conditions
and to a very safe maximum operating
temperature on a continuous base just slightly
above the maximum specified operating
temperature of 150 °C. Almost equally important
are the protection against overvoltage transients
that allows for trouble-free operation with
inductive loads, and a current limiting circuit that
provides safe operating current values at all
times. The voltage slew rate limiting circuit that is
connected in series between the input and the
power transistor gate connection virtually
eliminates EMI noise by keeping the switching
speed within a desirable range.
Figure 2
also
shows a current sense terminal for devices
packaged in a 5-pin TO-220 package. The
current limit value can be programmed by
connecting an appropriate resistor value
between the pins 4 and 5.
The uniqueness of the HITFET
®
design is that
most if not all of the external components that a
SIPMOS
®
or TEMPFET
®
transistor may need for
protection or for on-resistance optimization are
eliminated. The HITFET
®
dynamic behavior is
nearly the same as that of a TEMPFET
®
with the
same basic ratings except that the switching
speed of the HITFET
®
is limited internally.
HITFET
®
Construction
' Y VVI R X 7 IR WI 4 EH
8 I Q T I VEXY VI 4 EH
7 S Y VGI & S R H MR K
4EH
-R T Y X 4 EH
4 S [ IV 8 VER WMWXS V
' IPPW
8 I Q T I VEXY VI
7 I R WS V
Figure 3
HITFET
®
Power Chip Layout
Semiconductor Group
4
1998-07-01
HITFET
®
C h ip -o n-ch ip
e xte rn al
se n sor
In pu t
D ra in
S ou rce
C u rre n t
L im it/S e n se
Figure 4
HITFET
®
Internal Assembly
Figure 3
and
Figure 4
show the HITFET
®
internal construction that includes a SIPMOS
®
power chip with integrated control and protection
circuits, and a separate chip-on-chip thermal
sensor. The three pin version has a fixed current
limit, while the 5-pin version has an adjustable
(programmable) current limit capability. The chip-
on-chip construction of a HITFET
®
is identical to
the construction of a TEMPFET
®
. The same type
of temperature sensor chip is glued on the top
surface of the power chip. The HITFET
®
power
chip is a new design based on the milli-Smart
technology. It combines a very low
R
on
vertical
power SIPMOS
®
(specific resistance of
0.25
Ω/mm
2
) with integrated control and
protection circuits, fabricated using self-isolated
lateral CMOS devices. The integrated drive
stage and all protection functions require about
1 mm
2
of the chip area regardless of the overall
device size. This allows production of a family of
devices with a maximum resistance as low as
18 mΩ in a TO-220 package. All HITFET
®
devices have a minimum breakdown voltage
above 60 V over the entire temperature
Semiconductor Group
5
operating range of
−
40 °C to + 150 °C and are
fully compatible with logic level and standard
level input drive voltages. The result is that one
can replace several TEMPFET
®
types with a
single HITFET
®
type.
Protection-Functions
As already mentioned, a HITFET
®
is fully
protected
against
ESD,
short
circuit,
overtemperature, overvoltage, and overcurrent.
The ESD protection is designed for 3 kV human
body model capability for any pin combination. It
is provided by a 11 V (typical voltage) zener
diode connected between the input and source
pins, and several zener diodes and one blocking
diode connected in series between the drain and
gate terminals of the power chip. The
combination of the above elements provides the
ESD protection for any pin combination for either
polarity. Furthermore, the same string of zener
diodes provides protection against inductive turn-
off overvoltage transients once the drain to
source voltage exceeds 60 V. As soon as the
1998-07-01
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
