APEX MICROTECHNOLOGY CORPORATION TELEPHONE (520) 690-8600 FAX (520) 888-3329 ORDERS (520) 690-8601 EMAIL prodlit@apexmicrotech.com
INTRODUCTION
This easy-to-use kit provides a platform for the evaluation of
PWM amplifiers using the SA18 pin-out configuration. It can be used
to analyze a multitude of standard or proprietary circuit configura-
tions, and is flexible enough to do most standard amplifier test
configurations.
The schematic is shown in Figure 2. Note that all of the compo-
nents shown on the schematic will probably not be used for any
single circuit. Some components will simply be omitted, while others
require installation of a jumper to complete the signal path.
Only components unique to the EK18 are provided in this kit.
Hardware similar to that shown in figure 1 must be obtained locally.
BEFORE YOU GET STARTED
*
All Apex amplifiers should be handled using proper ESD precau-
tions.
*
Always use the heatsink included in this kit with TW05 washer.
*
Always use adequate power supply bypassing.
*
Do not change connections while the circuit is powered.
*
Initially set all power supplies to the minimum operating levels
allowed in the device data sheet.
*
Check for oscillations.
H T T P : / / W W W . A P E X M I C R O T E C H . C O M ( 8 0 0 ) 5 4 6 - A P E X ( 8 0 0 ) 5 4 6 - 2 7 3 9
M I C R O T E C H N O L O G Y
EVALUATION KIT FOR SA18 PINOUT
EK18
PARTS LIST
Apex Part #
Description
Quantity
HS18
Heatsink
1
MS04
PC mount Cage Jacks
1 Bag/12
each
EVAL19
PC Board
1
60SPG00001
Spacer Grommets
4
TW05
Thermal Washer
1 Box/10
each
ZX7R105KTL
1
F Cap ST2225B105K501LLXW 2
Novacap
OX7R105KWN 1
F Cap 1825B105K201N,
1
Novacap
TS01
Terminal Strip 66505
1
Beau Interconnect
EC01
470
f Cap
1
United Chemi-Con
82DA471M500MG2D
HS22
Heatsink
1
Thermolly 6025B
CSR03
0.010 ohm resistor
1
Caddock MP916-0.010 - 5%
CSR04
0.020 ohm resistor
1
Caddock MP930-0.020 - 5%
FIGURE 1.
APEX MICROTECHNOLOGY CORPORATION 5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
EVALUATION KIT
FOR SA18 PIN-OUT
EK18
ASSEMBLY
During assembly refer to Figure 1 and Figure 4.
1. From the DUT of the PCB insert and solder the 12 cage jacks.
Also solder the cage jacks from the circuit side as well, making
sure the cage jack remains flush with the component side of the
PCB.
2. Solder the 3 surface mount ceramic capacitors to the compo-
nent side of the PCB.
3. From the component side of the PCB insert the terminal strip.
Solder from the circuit side of the PCB. Be sure that the GND
terminal hole in the PCB is fully filled with solder.
4. Two values of current limiting power resistors are supplied.
Select one value (see the amplifier data sheet to learn how to
calculate which resistor will suit your need). Coat the backside
of the power resistor with heat sink compound (not supplied).
Using 4-40 screws and nuts (not supplied) mount the resistors
to the two small heat sinks supplied. Solder the resistor/heat sink
assembly to the component side of the PCB.
5. Insert the electrolytic capacitor into the PCB from the compo-
nent side and solder from the circuit side making sure to fill the
mounting holes with solder.
6. From the circuit side, push spacer grommets into PCB until fully
seated. Grommets will snug when screws are inserted for
heatsink mounting.
7. Apply TW05 thermal washer to the bottom of the amplifier.
8. Use #14 sleeving to insulate and align at least 2 opposite pins
of the amplifier.
9. Mount amplifier to heatsink using #6 screws and nuts. Torque
the part to the specified 8 to 10 in-lbs (.9 to 1.13 N*M). Do not
over torque.
10. Install components as needed. External connections may be
soldered directly or standard banana jacks may be soldered to
the large pads at the edge of the PCB.
11. Insert amplifier pins into cage jacks and fasten PCB to heatsink.
APEX MICROTECHNOLOGY CORPORATION TELEPHONE (520) 690-8600 FAX (520) 888-3329 ORDERS (520) 690-8601 EMAIL prodlit@apexmicrotech.com
FIGURE 2. PCB SCHEMATIC.
A block diagram of the SA18 is shown in Figure
2 along with pcb connections of all the commonly
used external components. Your application circuit
will not use all of the components. Add those
components required by your circuit. You may
have to jumper some components to make the
desired electrical connections. J1 is an optional
way to connect the clock circuit. Power supply
bypassing is particularly important and that is why
high quality ceramic chip capacitors are supplied
with the kit. In addition, a large electrolytic capacitor
is included. This capacitor was selected expressly
for this evaluation kit and may not be (and likely
won't be) suitable for your end application. You will
need to select an electrolytic capacitor based on
your analysis of the capacitor's ripple current, ripple
current tolerance, operating temperature, operat-
ing voltage, acceptable service life and acceptable
supply ripple. Note that the signal ground and
power ground are separated and tie together only
at the ground pin (5). A breadboarding area is
supplied which can accomodate 1 or 2 IC amplifiers
and associated components. The large terminal
pads can be used to solder wire connections or
bannana jacks.
Note that the EK18 Evaluation Kit uses the same
circuit board as the EK15 Evaluation Kit intended
for the apex model SA08. As such the designations
on the PCB are those for the SA08. The SA18 is a
half bridge version of the SA08 and the SA18 is
identical in design except for that fact. Some of the
SA18 pin designations are, however, different. The
SA18 OUT pin is equivalent to the SA08 B OUT pin.
Pin 7 (PWR GND) of the SA18 is equivelent to the
Isense B pin on the SA08. A OUT on the terminal
block is not used for the SA18. See the data sheet
for the SA18 for specific operating considerations.
EVALUATION KIT
FOR SA18 PIN-OUT
EK18
SA18
+PWM
1
2
3
4
5
6
12
11
10
9
8
7
SIG
GND
PWR
GND
RAMP/-PWM
OR
FLAG
ILIM/SHDN
C3
R3
C2
C1
R4
J1
CLK IN
CLK OUT
+ PWM
FLAG
5V
10V
CLOCK
A OUT
Vcc
+ Vs
B OUT
OUT
Vcc
+ Vs
PWR
GND
H
BRIDGE
DRIVER
Ra
R2
R1
CVcc
CVs1-3
5V
10V
.1V
10V
1k
1000pf
50k
Vcc
50
910
.01
F
56k
5V
GND ILim/SHDN
f/2
TL
470pF
D1
Rb
APEX MICROTECHNOLOGY CORPORATION 5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
FIGURE 3. FUNCTIONAL TEST CIRCUIT
The schematic of Figure 3 can be used to
verify the functionality of your amplifier and help
you gain a familiarity with proper operation. At
Out with respect to ground, you should observe
a square wave approximately 30 V in amplitude
with a fixed frequency and duty cycle that varies
from approximately 0 to 100% at a rate of 1 Hz.
The current limit is set to 2 amps.
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.
EK18U REV. A JUNE 1999 1999 Apex Microtechnology Corp.
EVALUATION KIT
FOR SA18 PIN-OUT
EK18
SA18
CLK IN
CLK OUT
+ PWM
FLAG
GND
5V
+PWM
SIG
GND
PWR
GND
RAMP/-PWM
OR
FLAG
ILIM/SHDN
J1
CLOCK
C1
.01F
C3
.1
F
1 Hz SINE WAVE
+3/+7 V AMPLITUDE
VALLEY TO PEAK
10V
56k
5V
f/2
TL
470pF
ILim/SHDN
H BRIDGE DRIVER
1k
1000pf
50k
Vcc
50 910
.01
F
5V
10V
.1V
10V
OUT
Vcc
+ Vs
PWR
GND
12
11
10
9
8
7
A OUT
Vcc
+ Vs
OUT
CVcc
1
F
CVs1-3
Rb
.1 OHM
30V HIGH
AMP
SUPPLY
15V
200 mA
SUPPLY
50
50 OHM 25 WATT
DUMMY LOAD
JUMPERED
1
2
3
4
5
6
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