PDu100
Miniature 200 Vp-p Piezo Driver with
Built-in High-Voltage Power Supply
Size: 12x10 mm, Weight: 0.5 gramSpecifications
Power Supply
Max Unipolar Output+100 VMax Bipolar Output

100 V

Av. Output Current

15 mA

Power Bandwidth

3.2 kHz

Peak Output Current

100 mA

Signal Bandwidth
Dimensions
WeightGain
Input Voltage

The PDu100 is the industry’s smallest and lightest
driver for piezoelectric actuators. The PDu100 candrive two-wire piezoelectric actuators andbenders up to ±100 V. The PDu100 can also drive
three-wire piezoelectric benders and stackactuators up to +100 V. Applications include
battery powered robotics, piezoelectric motors,
and ultra low-power positioning and manipulation
systems.
The PDu100 is protected against short circuit,current overload, and excessive temperature. A
shutdown pin is also provided that reduces thesupply current to 1 mA when pulled low.
The output voltage range and gain of the PDu100
is customizable to meet the requirements of OEM
applications.

3 V to 5.5 V

Input Offset
Load
OverloadNoise

60 kHz (unloaded)
11.8 x 12.9 mm (0.46 x 0.51 in)
560 mg (0.018 oz)
27.5 V
Vs/2 1.8 V (Zin = 100k)
100 mV
Unlimited capacitive loads
Thermal and current
overload protection
70mV RMS (270 + 10uF Load)

Environment-40 to 70C (-40 to 158F)
Non-condensing humidity

Quiescent Current

25 mA (1 mA in Shutdown)

11.8 mm-en
Vin+gVsen
VinGVs12.9 mmg
Vb

InputsEnableInput
GroundSupply Voltage+g
Vb

Outputs
Negative Out
Positive Out
GroundBias Voltage

Figure 1. Connection diagram

Operation

Example Applications

The system block diagram is illustrated in Figure 2. A
boost converter generates a high-voltage rail to supply
a pair of complementary amplifiers. A single output
can be used to drive a unipolar load up toV orboth amplifiers can be used to produce
V.

Some typical application circuits are shown below. The
optional output resistance Ro is used to reduce noise
as described in “Noise” on page 3.

The input is selectable between a unipolar signal
biased at half the supply voltage or a bipolar signal.
The amplifier gain is 27.5 so a 3.6 Vp-p input willproduce a 100 Vp-p output. Both amplifier channels
are biased at half the output range (50 V).

Input
V 1.8Vg
Vs

5V-enVinRo+0V to100V+gVb

100 V Piezo stack driver with 50 V bias
EnableSupply3V - 5.5VVs 1.8V

BoostConverter

Input
OffsetHV Bus27.5

BiasVoltage

Bias
Voltage

Bipolar Unipolar
Load+ Load+

Input
V 1.65Vg
Vs

5V-enVin+gVb+
Ro90 V90 V Piezo bender driver+0V toRo

-27.5

Input
V 1.8V-5V

Figure 2. PDu100B Block Diagram

The overall system gain is determined by the output
configuration. The possible combinations are listedbelow.
Output
TypeUnipolar
BipolarGain
27.555

Input
Range
½ Vs
V
½ VsV

OutputRange
100 VV-en
Ving
Vs+ 100V+g
Vb

100VRo+ to 0V
100V

100 V Three-wire bender driver with bias

Input
V 1.1V5V-en
Ving
Vs

+g
Vb

RoRo+Table 1. System gain and voltage range

60 V Push-pull stack driver or bender driver

Both output amplifiers are biased at approximatelyhalf the HV Bus voltage, i.e. 50 V.

Figure 3. Application circuits

The gain and output voltage ranges can be customizedby contacting info@piezodrive.com.

Output Current
The maximum average output current is 15 mA.
However, for periods less than 100 us an output
current of approximately 100 mA is possible. This isuseful for achieving small, high-speed step changes inthe output voltage.

+ 0V to60V

Power Bandwidth
The output slew-rate of the PDu100 is 1 V/us.
Therefore, the maximum frequency sine-wave isThe power bandwidth for a range of output voltages islisted below
Voltage Range
60 V
70 V
90 V
100 V

Power Bandwidth
5.3 kHz4.5 kHz
3.5 kHz
3.2 kHz

Table 2. Unloaded power bandwidthWith a capacitive load, the power bandwidth is limitedby the maximum output current. For a sine wave

Noise
The output voltage of the PDu100 contains switching
noise from the boost converter and random noisefrom the high-voltage amplifier. The amount of noise
seen by the load capacitance is determined by the sizeof the output resistance and signal bandwidth.
To determine the output resistance required for aparticular noise level, the required bandwidth should
be selected from Figure 5 below. The correct
resistance can then be calculated from1000mVThe power bandwidth is listed below for a range ofload capacitances and output voltages.
Load (uF)
0.01
0.03
0.1
0.3
13
103060 V
5300
2600
790
260
79
26
8.0
2.7

100 V
3200
1500
470
150
47
15
4.8
1.6

100 V
2300
790
23079
23
8.0
2.4
0.8

100mV10mV
1Hz

10Hz

100Hz

1kHz

10kHz

100kHzTable 3. Power bandwidth versus voltage range

Figure 5. RMS output noise versus bandwidth

In the following figure, the maximum peak-to-peakvoltage is plotted against frequency for a range ofcapacitive loads.

The correct circuit configurations for different
applications are illustrated in Figure 3.

Peak to Peak Voltage (V)

200

10uF

3uF

1uF 300nF 100nF 30nF

The noise was measured with a 5 V supply and static
input voltage. When current is drawn from the output,
the ripple will increase due to action from the boost
converter.

150

Signal Bandwidth100The unloaded small signal bandwidth of the PDu100 isapproximately 60 kHz. With a capacitive load, thesignal bandwidth is determined by the output
resistance, that is

50

0010

110

210
Frequency (Hz)Figure 4. Power bandwidth310

Supply Current

Dimensions

The supply current
is related to the load current
through the following power balance equation:

where
is the supply voltage. With a capacitive loadand sinusoidal voltage, the peak and average output
current is1111

11

11where,is the peak to peak voltage across the load
capacitance. The average supply current can bewritten

Power Dissipation
With a capacitive load, power dissipation is theproduct of supply voltage and the average current,
that isWhen operating at full power bandwidth, the worstcase power dissipation is approximately 2.5 W. The
thermal impedance of the PDu100 from junction toambient is 45. Therefore, the maximum
temperature rise is approximately 90
above
ambient.
When continuous power dissipation above 1 W isrequired, the PDu100 is designed to be mounted onto
a thermal sink using a thermally conductive doublesided adhesive such as 3M 8940 or Bergquist BONDPLY 100.

Figure 6. Dimensions (Inches)

1111111
1Enable / Shutdown
The Enable pad can be pulled low to disable theamplifier and reduce the quiescent current to 1 mA. It
can be driven by a logic output or an open collector
output. The recovery time after a shut-down is 2 ms.

Overload Protection
The PDu100 is protected against over-current andthermal overload. If the temperature exceeds 150
the amplifier will be disabled until the temperature
reduces.

Figure 7. Dimensions (mm)Contact and Support
info@piezodrive.com