Datasheet SA14 Datasheet (Apex)

SA14

USA BeO

∆

TE949311

PULSE WIDTH MODULATION AMPLIFIER

MICROTECHNOLOGY

HTTP://WWW.APEXMICROTECH.COM (800) 546-APEX [phone]

FEATURES

• HALF BRIDGE OUTPUT

• WIDE SUPPLY RANGE—16-200V

• 20A CONTINUOUS TO 85°C CASE

• 3 PROTECTION CIRCUITS

• ANALOG OR DIGITAL INPUTS

• SYNCHRONIZED OR EXTERNAL OSCILLATOR

• FLEXIBLE FREQUENCY CONTROL

APPLICATIONS

• MOTORS

• REACTIVE LOADS

• LOW FREQUENCY SONAR

• LARGE PIEZO ELEMENTS

• OFF-LINE DRIVERS

• C-D WELD CONTROLLER

DESCRIPTION

The SA14 is a half bridge pulse width modulation amplifier
that can supply 4000W to the load. Flexible frequency control
is provided. An internal 45kHz oscillator requires no external
components and can be used to synchronize multiple ampli­fiers. The oscillator output may be divided down and con­nected to the clock input to lower the switching frequency . The
clock input stage divides by two and determines the output
switching rate (normally 22.5 kHz). A shutdown input turns off
both output drivers. High side current sensing protects the
amplifier from shorts to ground. In addition, the half bridge
output MOSFETs 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
PROGRAMMABLE POWER SUPPLY

SA14

EXTERNAL CONNECTIONS

NC

CLK IN

CLK OUT

+PWM

–PWM/RAMP

SIG GND

1
2
3

TOP

TOP

VIEW

VIEW

4
5
6

SHDN

Case tied to pin 5. Allow no current in case. Bypassing of supplies
is required. Package is Apex MO-127 (STD). See Outline
Dimensions/Packages in Apex data book.

If +PWM < RAMP/–PWM then OUT = HIGH.
*See text.

12
11
10

9
8
7

NC

*

VCC

*

+VS

OUT
PWR GND

Vcc

10

+PWM

3

CLK OUT

CLK IN

SIG GND

4

470pF

56K

2

1

5

–PWM/RAMP

CONTROL

SIGNAL

3/7V

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5V

÷2OSC

10V
P-P

CURRENT

LIMIT

PWM

OUTPUT
DRIVERS

SHUTDOWN

CONTROL

5V

9

+V

OUT

8

12

NC

NC

11

6

SHDN

7

PWR GND

S

LOAD

5K

.01µF

RSENSE

SA14

ABSOLUTE MAXIMUM RATINGS

SPECIFICATIONS

ABSOLUTE MAXIMUM RATINGS

SUPPLY VOLTAGE, +V
SUPPLY VOLTAGE, V
POWER DISSIPATION, internal 150W
TEMPERATURE, pin solder - 10s 300°C
TEMPERATURE, junction

S

CC

2

200V
16V

150°C
TEMPERATURE, storage –65 to +150°C
OPERATING TEMPERATURE RANGE, case –55 to +125°C
INPUT VOLTAGE, +PWM 0 to +11V
INPUT VOLTAGE, –PWM 0 to +11V

SPECIFICATIONS

INPUT VOLTAGE, I

PARAMETER TEST CONDITIONS

LIM

2

MIN TYP MAX UNITS

0 to +10V

CLOCK (CLK)

CLK OUT, high level
CLK OUT, low level
FREQUENCY 44 45 46 kHz

4

4

I

≤ 1mA 4.8 5.3 V

OUT

I

≤ 1mA 0 .4 V

OUT

RAMP, center voltage 5V
RAMP, P-P voltage 4V
CLK IN, low level
CLK IN, high level

4

4

0.9V

3.7 5.4 V

OUTPUT

R

ON

EFFICIENCY, 10A output VS = 200V 97 %
SWITCHING FREQUENCY OSC in ÷ 2 22.05 22.5 22.95 kHz
CURRENT, continuous
CURRENT, peak

4

4

Each output driver .11 Ω

85°C case 20 A

30 A

POWER SUPPLY

VOLTAGE, V
VOLTAGE, V
CURRENT, V
CURRENT, V
CURRENT, V

I

/SHUTDOWN

LIM

S
CC

CC

shutdown 50 mA

CC,
S

Full temperature range 16
Full temperature range 14 15 16 V
I

= 0 80 mA

OUT

No Load 50 mA

5

120 200 V

TRIP POINT 90 110 mV
INPUT CURRENT 100 nA

THERMAL

3

RESISTANCE, junction to case Full temperature range, for each die .83 °C/W
RESISTANCE, junction to air Full temperature range 12 °C/W
TEMPERATURE RANGE, case Meets full range specifications –25 +85 °C

NOTES: 1. Each of the two output transistors can dissipate 150W.

2. Unless otherwise noted: TC = 25°C, VS, VCC at typical specification.

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. If 100% duty cycle is not required V

CAUTION

The SA14 is constructed from MOSFET transistors. ESD handling procedures must be observed.

S(MIN)

= 0V.

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.

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TYPICAL PERFORMANCE

–50 –25 0 25 50 75 100 125

80

85

90

95

100

105

110

115

Vcc QUIESCENT CURRENT

NORMALIZED Vcc QUIESCENT CURRENT, (%)

1M100K

95

98

99

100

CLOCK LOADING

96

97

10K

NORMALIZED FREQUENCY, (%)

CASE TEMPERATURE, (°C)

CLOCK LOAD RESISTANCE, (Ω)

0.6
SOURCE TO DRAIN DIODE VOLTAGE

10

REVERSE DIODE

FLYBACK CURRENT, Isd (A)

5

6

7

8

3
2

2

4

5

6

7

8

3
2

4

1

25 50 75 100 125 150

18

20

CONTINUOUS OUTPUT

16

0.8 1.0 1.2 1.4 1.6

5

0 25 50 75 100 125 150 175 200

2510 15 20

CASE TEMPERATURE, (°C)

CONTINUOUS AMPS

12

14

0 75 100

CASE TEMPERATURE, (°C)

0

POWER DERATING

150

25

DUTY CYCLE VS ANALOG INPUT

DUTY CYCLE, (%)

50 125

25

50

75

100

125

0

20

40

60

80

100

INTERNAL POWER DISSIPATION, (W)

ANALOG INPUT, (V)

35476

SWITCHING FREQUENCY, F (kHz)

Vs, (V)

75

80

85

90

100

95

Vcc QUIESCENT CURRENT

NORMALIZED Vcc QUIESCENT CURRENT, (%)

20

40

60

120

100

80

140

Vs QUIESCENT VS VOLTAGE

525

SWITCHING FREQUENCY, F (kHz)

20

40

60

80

Vs QUIESCENT VS FREQUENCY

NORMALIZED Vs QUIESCENT CURRENT, (%)

NORMALIZED Vs QUIESCENT CURRENT, (%)

100

10 15 20

EACH ACTIVE

OUTPUT TRANSISTOR

F NOMINAL = 45kHz

Vcc = 15V
F = 22.5 kHz

NORMAL
OPERATION

SHUTDOWN
OPERATION

Vs = 120V, NO LOAD

0 5 10 15 20

OUTPUT CURRENT, (A)

0

1

2

3

4

5

TOTAL VOLTAGE DROP

TOTAL VOLTAGE DROP, (V)

125°C

100°C

85°C

60°C

25°C

–55°C –25°C

CASE TEMPERATURE

–50

CASE TEMPERATURE, (°C)

CLOCK FREQUENCY OVER TEMP

NORMALIZED FREQUENCY, (%)

–25 0 25 50 75 100 125

98.0

98.5

99.0

99.5

100

100.5

101.0

101.5

102.0

GRAPHS

SA14

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OPERATING
CONSIDERATIONS

SA14

GENERAL

Helpful information about power supplies, heatsinking and
mounting can be found in the “General Operating Consider­ations” section of the Apex data book. For information on the
package outline, heatsinks, and mounting hardware see the
“Package Outlines” and “Accessories” section of the data
book. Also see Application Note 30 on “PWM Basics.”

CLOCK CIRCUIT AND RAMP GENERATOR

The clock frequency is internally set to a frequency of
approximately 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 at the –PWM/
RAMP pin. An external clock signal can be applied to the CLK
IN pin for synchronization purposes. If a clock frequency lower
than 45kHz is chosen an external capacitor must be tied to the
–PWM/RAMP pin. This capacitor, which parallels an internal
capacitor, must be selected so that the ramp oscillates 4 volts
p-p with the lower peak 3 volts above ground.

PWM INPUTS

The half bridge driver may be accessed via the pwm input
comparator. When +PWM < -PWM then OUT is HIGH. A
motion control processor which generates the pwm signal can
drive these pins with signals referenced to SIG GND.

PROTECTION CIRCUITS

A high side current monitor will latch off the output transistors
when the high side current rises to approximately 150% of
rated output. The temperature of the output transistors is also
monitored. When either of the output transistors reaches
approximately 165°C both are latched off. In either case, it will
be necessary to remove the fault condition and recycle power
to Vcc to restart the circuit. A short to +Vs can be protected
against by inserting a sensing resistor into the PWR GND
circuit as shown in Figure A.

PWR GND

SHDN

R

1

C

1

R

SENSE

FIGURE A. PROTECTING AGAINST SHORTS TO +Vs.

An external shutdown command can be mixed with the
protection circuit of Figure A. In figure B a 5V shutdown
command signal is divided down by R

, R1 to the 100 mV

2

threshold level of the SHDN pin of the SA14. As long as the
shutdown command remains high both output transistors will
remain off.

PWR GND

R

2

SHUTDOWN

SHDN

FIGURE B. ADDING SHUTDOWN CONTROL.

R

1

C

1

R

SENSE

SIGNAL

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 outputs.
The Vs supply should be bypassed with at least a 1µF ceramic
capacitor in parallel with another low ESR capacitor of at least
10µF 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 .1µF to .47µF ceramic
capacitor connected directly to the Vcc pin will suffice.

STARTUP CONDITIONS

The high side of the all N channel output half bridge circuit
is driven by a bootstrap circuit and charge pump arrangement.
In order for the circuit to produce a 100% duty cycle indefinitely
the low side transistor must have previously been in the ON
condition. This means, in turn, that if the input signal to the
SA14 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.

In Figure A, the sense resistor inserted into the PWR GND
connection is tied to the SHDN pin. When the current from a
short to +Vs develops 100 mV across the sense resistor the
shutdown circuit will shut off the output transistors for the
remainder of the switching cycle. The SA14 will restart at the
beginning of a new cycle and retest for this condition. This
circuit does not test for shorts to ground. The RC circuit R

1, C1

filters out any switching spikes and may need to be adjusted to
ignore normal current spikes in the application circuit.

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.

SA14U REV. D MARCH 1999 © 1999 Apex Microtechnology Corp.