APEX MICROTECHNOLOGY CORPORATION TELEPHONE (520) 690-8600 FAX (520) 888-3329 ORDERS (520) 690-8601 EMAIL prodlit@apexmicrotech.com
1
FEATURES
IGBT OUTPUTS
WIDE SUPPLY RANGE--16-450V
20A TO 100C CASE
3 PROTECTION CIRCUITS
SYNCHRONIZED OR EXTERNAL OSCILLATOR
FLEXIBLE FREQUENCY CONTROL
APPLICATIONS
MOTORS
REACTIVE LOADS
MAGNETIC BEARINGS
LARGE PIEZO ELEMENTS
OFF-LINE DRIVERS
C-D WELD CONTROLLER
DESCRIPTION
The SA08 is a pulse width modulation amplifier that can
supply 9KW to the load. An internal oscillator requires no
external components. The clock input stage divides the oscil-
lator frequency by two, which provides the switching frequency
of 22.5 kHz. The oscillator may also be used to synchronize
multiple amplifiers. Current sensing is provided for each half
of the bridge giving amplitude and direction data. A shutdown
input turns off all four drivers of the H-bridge output. A high
side current limit and the programmable low side current limit
protect the amplifier from shorts to supply or ground in addition
to load shorts. The H-bridge output IGBTs are protected from
thermal overloads by directly sensing the temperature of the
die. The 12-pin hermetic MO-127 power package occupies
only 3 square inches of board space.
BLOCK DIAGRAM AND TYPICAL APPLICATION
MOTOR TORQUE CONTROL
EXTERNAL CONNECTIONS
12-PIN POWER DIP
PACKAGE STYLE CR
APEX MICROTECHNOLOGY CORPORATION 5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
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PARAMETER
TEST CONDITIONS
2
MIN
TYP
MAX
UNITS
CLOCK (CLK)
CLK OUT, high level
4
I
OUT
1mA
4.8
5.3
V
CLK OUT, low level
4
I
OUT
1mA
0
.4
V
CLK IN, low level
4
0
.9
V
CLK IN, high level
4
3.7
5.4
V
FREQUENCY
44.10
45.00
46.90
kHz
ANALOG INPUT (+PWM)
center voltage
5
V
P-P voltage
0/100% modulation
4
V
FLAG
FLAG, high level
10
V
FLAG, low level
0
V
OUTPUT
TOTAL DROP
I = 20A
5.4
V
EFFICIENCY, 20A output
V
S
= 380V
98
%
SWITCHING FREQUENCY
OSC in 2
22.05
22.50
22.95
kHz
CURRENT, continuous
4
100C case
20
A
CURRENT, peak
4
28
A
POWER SUPPLY
VOLTAGE, V
S
Full temperature range
16
5
240
450
V
VOLTAGE, V
CC
Full temperature range
14
15
16
V
CURRENT, V
CC
I
OUT
= 0
80
mA
CURRENT, V
CC,
shutdown
50
mA
CURRENT, V
S
No Load
90
mA
I
LIM
/SHUTDOWN
TRIP POINT
90
110
mV
INPUT CURRENT
100
nA
THERMAL
3
RESISTANCE, junction to case
Full temperature range, for each die
1
C/W
RESISTANCE, junction to air
Full temperature range
12
C/W
TEMPERATURE RANGE, case
Meets full range specifications
25
+85
C
ABSOLUTE MAXIMUM RATINGS
SPECIFICATIONS
SA08
ABSOLUTE MAXIMUM RATINGS
SUPPLY VOLTAGE, +V
S
450V
SUPPLY VOLTAGE, V
CC
16V
POWER DISSIPATION, internal
1
250W
TEMPERATURE, pin solder - 10s
300C
TEMPERATURE, junction
2
150C
TEMPERATURE, storage
65 to +150C
OPERATING TEMPERATURE RANGE, case
55 to +125C
INPUT VOLTAGE, +PWM
0 TO +11V
INPUT VOLTAGE, I
LIM
0 TO +10V
The SA08 is constructed from static sensitive components. ESD handling procedures must be observed.
The internal substrate contains beryllia (BeO). Do not break the seal. If accidentally broken, do not crush,
machine, or subject to temperatures in excess of 850C to avoid generating toxic fumes.
CAUTION
NOTES: 1. Each of the two active output transistors can dissipate 125W.
2. Unless otherwise noted: T
C
= 25C, V
S
, V
CC
at typical specification.
3. Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dis-
sipation to achieve high MTTF. For guidance, refer to the heatsink data sheet.
4. Guaranteed but not tested.
5. If 100% duty cycle is not required V
S(MIN)
= 0V.
SPECIFICATIONS
APEX MICROTECHNOLOGY CORPORATION 5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
4
adjusted so as to
reduce the switch-
ing noise well below
100 mV to prevent
false current limit-
ing. The sum of the
DC level plus the
noise peak will de-
termine the current
limiting value. As
in most switching
circuits it may be
difficult to deter-
mine the true noise
amplitude without
careful attention to
grounding of the oscilloscope probe. Use the shortest possible
ground lead for the probe and connect exactly at the GND
terminal of the amplifier. Suggested starting values are C
FILTER
= .1uF, R
FILTER
= 5k .
The required value of R
LIMIT
in voltage mode may be cal-
culated by:
R
LIMIT
= .1 V / I
LIMIT
where R
LIMIT
is the required resistor value, and I
LIMIT
is the
maximum desired current. In current mode the required value
of each R
LIMIT
is 2 times this value since the sense voltage is
divided down by 2 (see Figure B). If R
SHDN
is used it will further
divide down the sense voltage. The shutdown divider network
will also have an effect on the filtering circuit.
BYPASSING
Adequate bypassing of the power supplies is required for
proper operation. Failure to do so can cause erratic and low
efficiency operation as well as excessive ringing at the out-
puts. The Vs supply should be bypassed with at least a 1F
ceramic capacitor in parallel with another low ESR capacitor
of at least 10F per amp of output current. Capacitor types
rated for switching applications are the only types that should
be considered. The bypass capacitors must be physically
connected directly to the power supply pins. Even one inch of
lead length will cause excessive ringing at the outputs. This is
due to the very fast switching times and the inductance of the
lead connection. The bypassing requirements of the Vcc supply
are less stringent, but still necessary. A .1F to .47F ceramic
capacitor connected directly to the Vcc pin will suffice.
STARTUP CONDITIONS
The high side of the IGBT output bridge circuit is driven by
bootstrap circuit and charge pump arrangement. In order for
the circuit to produce a 100% duty cycle indefinitely the low
side of each half bridge circuit must have previously been in
the ON condition. This means, in turn, that if the input signal
to the SA08 at startup is demanding a 100% duty cycle, the
output may not follow the command and may be in a tri-state
condition. The ramp signal must cross the input signal at
some point to correctly determine the output state. After the
ramp crosses the input signal level one time, the output state
will be correct thereafter.
OPERATING
CONSIDERATIONS
SA08
GENERAL
Please read Application Note 30 on "PWM Basics". Refer
to Application Note 1 "General Operating Considerations" for
helpful information regarding power supplies, heat sinking and
mounting. Visit www.apexmicrotech.com for design tools that
help automate pwm filter design; heat sink selection; Apex's
complete Application Notes library; Technical Seminar Work-
book; and Evaluation Kits.
CLOCK CIRCUIT AND RAMP GENERATOR
The clock frequency is internally set to a frequency of ap-
proximately 45kHz. The CLK OUT pin will normally be tied to
the CLK IN pin. The clock is divided by two and applied to an
RC network which produces a ramp signal. An external clock
signal can be applied to the CLK IN pin for synchronization
purposes, but must be 45 kHz +/- 2%.
FLAG OUTPUT
Whenever the SA08 has detected a fault condition, the flag
output is set high (10V). When the programmable low side cur-
rent limit is exceeded, the FLAG output will be set high. The
FLAG output will be reset low on the next clock cycle. This
reflects the pulse-by-pulse current limiting feature. When the
internally-set high side current limit is tripped or the thermal
limit is reached, the FLAG output is latched high. See PRO-
TECTION CIRCUITS below.
PROTECTION CIRCUITS
A fixed internal current limit senses the high side current.
Should either of the outputs be shorted to ground the high side
current limit will latch off the output transistors. The temperature
of the output transistors is also monitored. Should a fault con-
dition raise the temperature of the output transistors to 165C
the thermal protection circuit latch off the output transistors.
The latched condition can be cleared by either recycling the
V
cc
power or by toggling the I LIMIT/SHDN input with a 10V
pulse. See Figures A and B. The outputs will remain off as
long as the shutdown pulse is high (10V).
CURRENT LIMIT
There are two load current sensing pins, I SENSE A and I
SENSE B. The two pins can be shorted in the voltage mode
connection but both must be used in the current mode connec-
tion (see figures A and B). It is recommended that R
LIMIT
resistors
be non-inductive. Load current flows in the I SENSE pins. To
avoid errors due to lead lengths connect the I LIMIT/SHDN pin
directly to the R
LIMIT
resistors (through the filter network and
shutdown divider resis-
tor) and connect the
R
LIMIT
resistors directly
to the GND pin.
Switching noise
spikes will invariably be
found at the I SENSE
pins. The noise spikes
could trip the current
limit threshold which
is only 100 mV. R
FILTER
and C
FILTER
should be
This data sheet has been carefully checked and is believed to be reliable, however, no responsibility is assumed for possible inaccuracies or omissions. All specifications are subject to change without notice.
SA08U REV D OCTOBER 2004 2004 Apex Microtechnology Corp.
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