Accel Instruments
TS200
Modulated Power Supply
The TS200 Modulated Power Supply is a
unique instrument for many test and
measurement applications such as LDO PSRR
measurement, battery simulator, op amp
CMRR measurement, function generator
amplifier, transient response test, four-quadrant
power supply, lab power amplifier and more.
The modulated power supply is designed for
bench test and measurement. It can output DC
or AC voltage or both. For example, it can
output a 3.3V DC voltage with a 300mVpp AC
sinewave riding on top of it. The TS200
features a modulation input to modulate the
output to produce any desired waveform.
PSRR Measurement
TS200 is ideal for power supply rejection ratio
or PSRR measurement. PSRR is commonly
tested for LDO regulators, op amps, audio
amps, etc. TS200 is especially powerful for
LDO PSRR testing at high load current (See
Application Section). TS200 can also test op
amp PSRR and CMRR. Conventional regulator
PSRR test techniques such as capacitor or
inductor coupled unable to support high LDO
load current (i.e. >1A). Various PSRR
measurement techniques are outlined below in
this datasheet. The application section shows
how to measure power supply rejection using
network analyzer. The TS200 is designed to
work with network analyzers such as Omicron
Lab Bode 100, AP Instruments (Ridley) model
300, Agilent 4395A, and Audio Precision
SYS2722
Waveform Amplifier
TS200 is also ideal as a function generator
amplifier for amplifying waveforms. It can
drive high current or high power or high
voltage load. The TS20 high voltage amplifier
can output up to 70V. As a waveform
amplifier, it accepts AC or DC input from a
Accel Instruments
function generator and amplify the waveform
by a factor of 10. TS200 is also great for pulse
amplifier and laboratory power amplifier.
Battery Simulator
TS200 modulated power supply can source or
sink current. It can be used as a battery
simulator. The TS200 has a variable DC output
that can easily simulate battery voltage
changes. Thus it is great for battery charger
testing such as those in battery operated
portable electronic systems.
Four Quadrant Power Supply
TS200 is a four quadrant power supply,
sometime referred to as bipolar power supply.
It can output both positive and negative voltage
and it can source and sink current up 3.0A. It is
sometimes refer to bipolar operational
amplifier
Applications
 LDO PSRR Measurements
 Battery simulator
 Amplifiers PSRR/CMRR Measurements
 Function generator amplifier
 Pulse/Waveform amplifier
 Four quadrant power supply
 Line transient response test
 Piezo amplifier and driver
Features
 Easy to use
 Can sink and source current
 AC or DC modulation input
 Offset (DC) voltage control
 Large DC voltage LCD
 Up to 3.0A
 Up to 70V output
 Thermal protection
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TS200
Order Information
Options
Output
Voltage
Range
TS200-0A -10V to +10V
TS200-0B
-10V to +10V
TS200-1A -20V to +20V
TS200-1B
-20V to +20V
TS200-2A -20V to +45V
TS200-2B
-20V to +45V
TS200-3A -10V to +70V
TS200-3B
-10V to +70V
TS200-4A 0V to +15V
TS200-5A -40V to +40V
TS200-5B
-40V to +40V
Accel Instruments
Modulation
Gain (V/V)
Output
Current
+1
+10
+1
+10
+1
+10
+1
+10
+1
+1
+10
See Typical
Performance
Curves
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TS200
Electrical Specifications
Parameter
Output Voltage Range
Continues Output Current
Modulation Input Voltage
Range
Modulation Gain
Min Modulation Frequency
Max Modulation Frequency
Slew Rate
LCD Voltmeter Accuracy
Condition/Note
TS200-0
TS200-1
TS200-2
TS200-3
TS200-4
TS200-5
See Typical Performance Curves
DC
Non-inverted
-3dB, no load
-3dB, no load,
small signal
A-version
B-version
AC-Coupled
DC-Coupled
AC-Coupled
DC-Coupled
Midrange
MIN TYP MAX
-10
+10
-20
+20
-20
+45
-10
+70
0
+15
-40
+40
-20
+20
0
20
UNIT
V
V
dB
1
Hz
DC
1.0
1.0
16
±1.0
MHz
V/s
%
General Specifications
Power supply adapter Input Voltage
Power supply adapter Input Frequency
Operating Temperature Range
Storage Temperature Range
Operating Humidity Range
Weight
Dimension (Inches)
Accel Instruments
100VAC to 240VAC
50Hz/60Hz
0°C to 40°C
-20°C to +60°C
20% to 80% (no condensation)
3.6 kg
10.0” x 8.5” x 5.25”
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TS200
Typical Performance
TS200-0A, 1-Ohm Load
TS200-0A, 3-Ohm Load
TS200-1A, 10-Ohm Load
TS200-1A, small signal 220pF Load
TS200-3B, 220pF Load
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TS200-3B, 220pF Load
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TS200
Typical Performance
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TS200
Typical Performance
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TS200
cannot drive a heavy load, the TS200
modulated power supply is very useful for
PSRR measurement for such devices as LDOs
(low dropout regulators) and power amplifiers.
PSRR measurement is easy with the aid of the
TS200. Figure 2 shows how to measure PSRR.
PSRR measurement technique involves a
network analyzer, TS200 power amplifier, and
device under test (DUT).
Basic theory of operation
AC
Mod
Input
20dB
DC
Output
DC Offset
Figure 1. TS200 Functional Equivalent
Source
Figure 1 shows the TS200 modulated power
supply functional equivalent diagram.
It
consisted of an AC-coupled or DC-coupled
input, a high current amplifier, and a DC
output offset. The adjustable DC offset sets the
modulated power supply DC voltage. This DC
offset feature is ideal for LDO or amplifier
PSRR measurement, because they require a
DC voltage.
Network
Ananyzer
Mod
Input
LDO
Output
TS200
DUT
A
(a)
Source
Network
Ananyzer
Mod
Input
LDO
Output
TS200
DUT
A
Load
B
The TS200 input signal is selectable either ACcoupled or DC-coupled. This allows added
flexibility for TS200 to work with variety of
instruments such network analyzers and
function generators.
(b)
Figure 2. LDO PSRR measurement setup. (a)
Calibration setup, (b) PSRR setup.
Figure 2 shows the LDO PSRR measurement
setup. Using a network analyzer, the source is
connected to the TS200 modulation input. The
TS200 output is connected to the LDO supply
input. It is recommended to reduce the LDO
input capacitance to minimum. Since the
TS200 can drive a heavy load, thus the LDO
output can be loaded with the desired loading
resistor (i.e. maximum specified load).
The A-version of the TS200 modulation input
gain by unity (non-inverted). The B-version of
the TS200 modulation input is amplified by a
factor of 10 or 20dB. The amplifier
configuration is non-inverted. The TS200
output can drive heavy resistive load or
capacitive load or both. Up to 3.5A is possible.
Applications
Set the TS200 modulation input to AC-coupled.
Adjust the DC Offset knob until the output DC
voltage reaches the desired voltage (i.e. 3.3V).
Typically for PSRR measurement, the supply
ripple amplitude is 200mVpp. If you are using
the A-version, set the network analyzer output
to 200mA. If you are using the B-version and
consider the modulation gain is 20dB, set the
network analyzer output amplitude to 20mVpp.
- LDO PSRR Measurement
Power supply rejection ratio (PSRR) or some
time called power supply ripple rejection
measurement are often difficult to measure,
especially when the device under test (DUT) is
heavily loaded. Because most network analyzer
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Load
B
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TS200
First the network analyzer and the TS200 need
to be calibrated. Figure 2a shows the
calibration setup. The network analyzer inputA and input-B are connected together at one
point on the DUT board near the LDO supply
input. Set the network analyzer to calibration
mode and sweep over the frequency range (i.e.
100Hz to 100kHz) to be measured. Save the
calibration data for later use. Refer the network
analyzer manual for detailed calibration setup.
- LDO PSRR Measurement with
Oscilloscope
Alternatively, PSRR measurement can be done
using an oscilloscope. Place the oscilloscope
probes as shown in Figure 4. CH1 probe is
connected to LDO supply input near the
capacitor and CH2 probe is connected to LDO
output near the capacitor. 1x probe is
recommended due high oscilloscope noise
floor.
After calibration, LDO PSRR measurement
setup is shown Figure 2b. The network
analyzer input-B is moved to the LDO output
near the capacitor while keeping input-A at the
LDO input. Again sweep the network analyzer
over the desired frequency range. You may
refer to the network analyzer manual for details.
After subtracting the calibration data, PSRR
data is plotted. Figure 3 shows an example of
PSRR plot. Table 1 shows a list of network
analyzers can be used with the TS200.
Connect a function generator to the TS200
Modulation input. Set the function generator
output to 200mVpp sinewave or 20mV if Bversion is used. Set the frequency to the
frequency of interest (i.e. 1kHz). Then set the
TS200 modulation to AC-couple. Adjust the
DC Offset knob until the TS200 output voltage
reaches the desired voltage (i.e. 3.3V).
Table 1. List of network analyzers
Manufacturer
Model
AP Instruments
Model 300
Omicron
Bode 100
Agilent
4395A
Audio Precision
SYS2722
Function
Generator
Or AWG
Mod
Input
Output
LDO
Load
TS200
DUT
CH1
Oscilloscope
CH2
Figure 4. PSRR measurement using an
oscilloscope.
PSRR (dB)
Using the oscilloscope, one can measure the
amplitude voltage at CH1 and CH2. Divide
CH2 by CH1 is the PSRR. One can use the
below equation for PSRR calculation in dB.
PSRR = 20log(CH2/CH1)
If PSRR is better than 40dB, it is
recommended to increase the TS200 output
ripple voltage 500mVpp due to oscilloscope
has lower sensitivity than network analyzer.
Frequency (Hz)
Figure 3. Example of PSRR plot.
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TS200
in Figure 5b. Then measure PSRR in the same
way as LDO in the previous section.
- Amplifier PSRR Measurement
The TS200 is also ideal for amplifier power
supply rejection ratio measurements, especially
power amps operating at maximum load
conditions. Such amplifiers as audio amplifiers
(class-A, B, AB, D and G) with heavy loading
are ideal for TS200. TS200 can also measure
PSRR for op-amps, differential amplifiers,
unity gain buffers, digital-to-analog converters,
and analog-to-digital converters, etc.
- Amplifier CMRR Measurement
Amplifier common-mode rejection ratio or
CMRR can be measure with TS200. Figure 6
shows how to measure CMRR. CMRR
measurement for amplifiers is same as PSRR
except for a few minor differences.
DUT
Source
Op amp PSRR measurement is same as LDO
except for a few minor differences. Please see
Figure 5 and refer to the previous section,
“LDO PSRR Measurement”, for amplifier
PSRR measurement.
Source
Network
Ananyzer
Mod
Input
Output
Network
Ananyzer
Output
Load
TS200
A
B
(a)
DUT
DUT
Source
TS200
A
Mod
Input
Network
Ananyzer
Load
B
Mod
Input
Output
Load
TS200
A
(a)
B
(b)
Source
Network
Ananyzer
Mod
Input
Output
Figure 6. CMRR measurement setup for
amplifier. (a) Calibration setup, (b) CMRR
setup.
DUT
TS200
Load
As shown in Figure 6, the amplifier’s positive
and negative inputs are connected together and
connected to the TS200’s output. Using a
network analyzer, the source is connected to
the TS200 modulation input.
A
B
(b)
Figure 5. PSRR measurement setup for
amplifier. (a) Calibration setup, (b) PSRR
setup.
Set the TS200 modulation input to AC-coupled.
Adjust the DC Offset knob until the output DC
voltage reaches the desired common-mode
voltage (i.e. ½ VCC). Typically for CMRR
measurement, the supply ripple amplitude is
200mVpp.
As shown in Figure 5, the amplifier input is
grounded, either AC or DC ground, for PSRR
measurement. Calibrate the setup as shown in
Figure 5a with the network analyzer input-A
and input-B connected to the same point at the
amplifier’s supply input. After calibration,
move input-B to the amplifier output as shown
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First the network analyzer and the TS200 need
to be calibrated. Figure 6a shows the
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TS200
calibration setup. The network analyzer inputA and input-B are connected together at one
point on the DUT board near the amplifier
input. Set the network analyzer to calibration
mode and sweep over the frequency range (i.e.
100Hz to 100kHz) to be measured. Save the
calibration data for later use. Refer the network
analyzer manual for detailed calibration setup.
If the B-version of the TS200 is used, the gain
is 20dB. Since the function generator’s output
voltage is amplified by a factor of 10. If the
TS200 is set to DC-couple, both the DC
voltage and AC signal are amplified by a factor
of 10. If TS200 is set to AC-couple, only AC
signal is amplified. The TS200 DC output is
set by its DC Offset knob.
After
calibration,
amplifier
CMRR
measurement setup is shown Figure 6b. The
network analyzer input-B is moved to the
amplifier output while keeping input-A at the
input. Again sweep the network analyzer over
the desired frequency range. You may refer to
the network analyzer manual for details.
- Line Transient Measurement
Function
Generator
Or AWG
Mod
Input
Output
LDO/SMPS
Load
TS200
DUT
CH1
Oscilloscope
CH2
- Waveform Amplifier
Figure 8. Line transient measurement setup.
Function
Generator
Or AWG
Mod
Input
Most LDOs and switch-mode power supply
(MSPS) specified their line transient
specifications. Line transient response specifies
its output voltage change after an input voltage
step change. For example, an LDO specified
its output voltage deviates less than 5mV for a
200mV input voltage step from 3.6V to 3.8V
in 10s. This is also called line step response.
Output
TS200
Figure 7. Waveform amplifier setup
The TS200 is also ideal for amplifying
waveforms for driving high-voltage or high
current or both. It is ideal for amplifying
function generator output to drive heavy load.
TS200 is acting as laboratory power amplifier.
Figure 8 shows how to measure line transient
response. A function generator generates a
square pulse with a specific rise and fall time
(i.e. 10s). The function generator is connected
to the input of TS200 and the TS200 output is
connected to the device under test. Typically
the TS200 is set to DC-couple. Set the function
generator’s pulse high and low voltages
generate the transient step. For example, to
generate a 3.6V to 3.8V voltage step, set the
function generator output voltage low to 3.6V
and output high voltage to 3.8V. If B-version
is used, set output voltage low to 0.36V and
Figure 7 shows the TS200 connection as a
high voltage or power amplifier. The function
generator or arbitrary waveform generator
(AWG) output is connected the TS200
modulation input. Typically, the TS200 DC
Offset or DC output voltage is set to zero and
input modulation is set to DC-couple.
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TS200
output high voltage to 0.38V, since the TS200
gain is 20dB.
In some applications, the device under test may
be sensitive to power supply noise. For
example, VCO (voltage controlled oscillator)
phase noise may be degraded with excessive
supply noise. TS200 can be use to aid supply
noise sensitive circuit testing.
It is recommended to keep the DUT input
capacitor to minimum (0.1F or less) to allow
faster rise and fall time. Use as short cables as
possible (Less than 12 inches) connecting
TS200 output and the DUT. Twist the cables to
together to minimize inductance.
Figure 10 shows a supply noise simulation
setup. The function generator is set to noise
output. The function generator output is
connected to TS200 Mod input. The input is
set to AC-couple. Adjust the DC Offset knob
until the TS200 output voltage reaches the
desired DUT supply voltage level. Adjust the
noise level on the function generator to see
how the DUT is responded to supply noise.
To measure the line transient step, connect an
oscilloscope probe (CH1) to the DUT input
and another probe (CH2) to the DUT output as
shown in Figure 8. The transient response is
measured at CH2. Figure 9 shows an example
of line transient measurement.
- Four Quadrant Supply and Battery
Simulator
The TS200 can be use as a four-quadrant
power supply or a batter simulator. Fourquadrant power supply can output positive or
negative (see voltage range option) voltage and
can sink or source current. The TS200 can act
as a battery simulator. It can output a positive
voltage and can sink or source current – just
like a real battery. The TS200 is useful for
testing battery chargers.
Figure 9. Line transient measurement example.
- Power Supply Noise Injector
Function
Generator
Or AWG
Mod
Input
To use the TS200 as a four-quadrant power
supply or battery simulator, leave the Mod
Input unconnected. Adjust the DC Offset knob
until the TS200 output voltage reaches the
desired supply voltage. The TS200 can source
as well as sink current.
Output
TS200
Figure 10. Power supply noise simulator
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TS200
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