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FEATURES
• LOW COST COMPLETE H-BRIDGE
• SELF-CONTAINED SMART LOWSIDE/HIGHSIDE DRIVE
CIRCUITRY
• SINGLE SUPPLY OPERATION
• WIDE SUPPLY RANGE: UP TO 80V
• 5A CONTINUOUS OUTPUT
• HERMETIC SEALED PACKAGE
• HIGH EFFICIENCY: 95%
• FOUR QUADRANT OPERATION, TORQUE
CONTROL CAPABILITY
APPLICATIONS
• BRUSH TYPE MOTOR CONTROL
• CLASS D SWITCHMODE AMPLIFIER
• REACTIVE LOADS
• MAGNETIC COILS (MRI)
• ACTIVE MAGNETIC BEARING
• VIBRATION CANCELLING
DESCRIPTION
The SA51 is a pulse width modulation amplifier that can sup-
ply 5A continuous current to the load. The full bridge amplifier
can be operated over a wide range of supply voltages. All of
the drive/control circuitry for the lowside and highside switches
are internal to the hybrid. The user provides a TTL compatible
PWM signal for simultaneous amplitude and direction control
in four quadrant mode. The internal circuitry will provide proper
deadtime protection for each half bridge. All N-channel FETs
mean the best efficiency for the size, both in terms of on-re-
sistance and switching capability. For an idle/sleep mode or
for fault protection, a TTL compatible disable pin is provided
so as to shut down all four transistors. The SA51 is packaged
in a space efficient isolated 8-pin TO-3 that can be directly
connected to a heatsink.
BLOCK DIAGRAM
TYPICAL APPLICATION
EXTERNAL CONNECTIONS
8-PIN TO-3
PACKAGE STYLE CE
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ABSOLUTE MAXIMUM RATINGS
SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS SUPPLY VOLTAGE, +VS 80V5
OUTPUT CURRENT, peak 7A
LOGIC SUPPLY VOLTAGE, Vcc 16V
POWER DISSIPATION, internal 120W1
TEMPERATURE, pin solder - 10s 300°C
TEMPERATURE, junction3 150°C
TEMPERATURE, storage –65 to +150°C
OPERATING TEMPERATURE RANGE, case –65 to +125°C
INPUT VOLTAGE, INPUT 0 to Vcc
INPUT VOLTAGE, DIS 0 to Vcc
SA51
SPECIFICATIONS
PARAMETER TEST CONDITIONS2 MIN TYP MAX UNITS
INPUT
PWM PULSE LOW VOLTAGE 0 0.6 Vdc
PWM PULSE HIGH VOLTAGE 3.6 5.0 Vdc
PWM FREQUENCY 45 500 KHz
DISABLE ON 3.6 VCC Vdc
DISABLE OFF 0 0.6 Vdc
OUTPUT
Vds (ON) VOLTAGE, each MOSFET Ids = 5A 1.25 1.8 Vdc
TOTAL Ron, both MOSFETs 0.5 Ω
EFFICIENCY, 5A OUTPUT +VS = 80V 95 %
CURRENT, continuous 5 A
CURRENT, peak T = 100ms 7 A
SWITCHING CHARACTERISTICS4 +VS = 28V, Vcc = 12V, Ic =2A
RISE TIME 36 54 nS
FALL TIME 170 250 nS
DEAD TIME 100 nS
POWER SUPPLY
+VS VOLTAGE5 +VS Current = Load Current 80 Vdc
Vcc VOLTAGE 9.5 12 15 Vdc
Vcc CURRENT Vcc = 12Vdc 11 18 mA
THERMAL3
RESISTANCE, junction to case Full temp range, for each transistor 2.0 °C/W
RESISTANCE, junction to air Full temperature range 30 °C/W
TEMPERATURE RANGE, case –25 +85 °C
The SA51 is constructed from MOSFET transistors. 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 850°C to avoid generating toxic fumes.
CAUTION
NOTES: 1. Each of the two active output transistors can dissipate 60W.
2. Unless otherwise noted: TC = 25°C, Vcc = 12Vdc.
3. Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dissipation to
achieve high MTTF. For guidance, refer to the heatsink data sheet.
4. Guaranteed but not tested.
5. Derate to 70V below TC = +25°C.
WARNING—AMPLIFIER PROTECTION
The SA51 contains an internal logic chip that turns on and
turns off output MOSFET drivers at a certain sequence. Noise
or oscillation caused by external wiring inductance, lack of
proper power supply bypass capacitors, ground, supply, and
local internal loops may be fed back to this logic chip and cause
it to turn on one or more MOSFET drivers at the wrong time,
thus destroying the SA51. A well laid out PC board with low
impedance copper ground plane is necessary for the SA51
to function properly. The Apex EK-SA51 evaluation board
is recommended for fast and easy breadboarding of circuits
using the SA51.
APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL prodlit@apexmicrotech.com
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TYPICAL PERFORMANCE
GRAPHS
SA51
Typical performance curves with Vcc = 12V, PWM at 45kHZ and case temperature at 25°C, unless otherwise specified.
APEX MICROTECHNOLOGY CORPORATION • 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: 1 (800) 546-2739
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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.
SA51U REV. F JUNE 2002 © 2002 Apex Microtechnology Corp.
OPERATING
CONSIDERATIONS SA51
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 and heat sink selection.
The "Application Notes" and "Technical Seminar" sections
contain a wealth of information on specific types of applica-
tions. Information on package outlines, heat sinks, mounting
hardware and other accessories are located in the "Packages
and Accessories" section. Evaluation Kits are available for most
Apex product models, consult the "Evaluation Kit" section for
details. For the most current version of all Apex product data
sheets, visit www.apexmicrotech.com.
PIN DESCRIPTION
VCC - is the low voltage supply for powering internal logic and
drivers for the lowside and highside MOSFETS. The supplies
for the highside drivers are derived from this voltage.
VS - is the higher voltage H-bridge supply. The MOSFETS
obtain the output current from this supply pin. The voltage on
this pin is limited to +80V by the drive IC. The MOSFETS are
rated at 100 volts. Proper by-passing to GND with sufficient
capacitance to suppress any voltage transients, and to ensure
removing any drooping during switching, should be done as
close to the pins on the hybrid as possible.
A OUT - is the output pin for one half of the bridge. When
the PWM input is high, this output will be pulled up to Vs.
B OUT - is the output pin for the other half of the bridge. When
the PWM input is low, this output will be pulled up to Vs.
RSENSE - This is the common connection for the bottom of
the bridge. This can have a sense resistor connected to the Vs
return ground for current limit sensing, or can be connected
directly to ground. The maximum voltage on this pin is ±2 volts
with respect to GND.
GND - is the return connection for the input logic and Vcc.
PWM INPUT - is a TTL compatible input pin for providing the
PWM signal to modulate the output switches. The duty cycle
can be between 0% (DC low) and 100% (DC high).
DISABLE INPUT - is a TTL compatible input for providing
a shutdown signal to the hybrid for disabling all four switches
in the bridge regardless of the PWM input level. A digital 1
disables, a digital 0 enables.
TYPICAL SYSTEM OPERATION
Below is a diagram of a typical application of the SA51. The
design Vcc voltage is +12 volts and should have a low ESR
bypass capacitor such as a tantalum electrolytic. The PWM
and DISABLE signals are typically provided by some type of
microprocessor control. The PWM signal will be a TTL signal
with a pulse frequency required by the system, and pulse duty
cycles according to the required direction/speed. A 0% duty
cycle (continuous TTL low) will mean full voltage to the motor
in one direction. A 100% duty cycle (continuous TTL high) will
mean full voltage to the motor in the other direction. A 50%
duty cycle will hold the motor at 0 RPM.
Current sensing is done in this case by a 0.1 ohm sense
resistor to sense current from either leg of the bridge. It is
important to make the high current traces as wide as possible
to keep inductance down. The storage capacitor connected
to the +Vs and the hybrid GND should be large enough to
provide the high energy pulse without the voltage sagging
too far. The storage capacitor should be a low ESR ceramic
capacitor or large polypropylene capacitor. Mount capacitor
as close to the hybrid as possible. The connection between
GND and the +Vs return should not be carrying any motor
current. The sense resistor signal is common mode filtered as
necessary to feed the limiting circuitry for the microprocessor.
This application will allow full four quadrant torque control for
a closed loop servo system.
A snubber network is usually required, due to the inductance
in the power loop. It is important to design the snubber network
to suppress any positive spikes above +VS and negative spikes
below -2V with respect to Pin 5 (GND) of the hybrid.
