ams NSD-2101 Piezo motor driver asic for sql-rv series reduced voltage squiggleâ® rv and utafâ ¢ motor Datasheet

Data Sheet
NSD-2101
P i e z o M o t o r D r i v e r A S I C f o r S QL- RV S er ie s
R e d u c e d Vol t a g e S Q U I G G L E ® RV a n d U TA F ™ M o t o r s
1 General Description
2 Key Features
Industry’s smallest piezo motor drive solution with direct battery
drive
- Wide input supply voltage: 2.3 to 5.5 VDC
- 1.8 x 1.8 mm 4 x 4 ball grid array or 4 x 4 mm 16-pin QFN
(minimum order quantities for QFN apply)
Low power consumption:
- Proprietary design optimizes power usage
- Hard power-down mode for lowest power consumption
- Idle mode via software for reduced power while preserving
frequency calibration
Proprietary frequency tracking controls maximizes motor
performance over a range of operating and environmental
conditions
In combination with the SQUIGGLE® RV or UTAF, the NSD-2101
provides the industry’s smallest piezo motor drive solution with direct
battery drive; no boost circuit required.
The NSD-2101 is a dedicated piezo motor driver ASIC capable of
driving a SQL-RV Series Reduced Voltage SQUIGGLE® RV motor
or UTAF motor from a single 2.3 to 5.5 VDC supply. The motor can
be controlled using a standard I²C interface.
The NSD-2101 uses proprietary control technology to dynamically
adjust motor drive frequency to maintain optimal motor performance
and minimal power consumption over wide temperature ranges and
operating conditions. A built in oscillator eliminates the need for an
external master clock.
Built-in oscillator; no external clock or oscillator required
I²C interface for direct serial interface to microprocessor
On-chip registers for storing driver instructions
3 Applications
The NSD-2101 is ideal for SQL-RV-1.8 SQUIGGLE® RV
piezoelectric motor driver and UTAF piezoelectric motor driver.
Figure 1. NSD-2101 Functional Block Diagram
C2
VDD
VDDP
+
VCC
BandGap
XPD
Power Save
Frequency
Tracking &
Control
V/IReferences
VCO
PPTRIM
SDA
SCL
-
Startup
NSD-2101
LDO
C1
Control
2.3V - 5.5V
1 x MLA
Squiggle
Motor Driver
I²C Interface &
Registers
Connection to
SQUIGGLE® RV
Motor
Connection to
UTAF motor
P1-1
P1-1
P1-2
P1-2
P2-1
P2-1
P2-2
P2-2
ADR
Test
VSS
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TM
VSSP
Revision 0.4
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NSD-2101
Data Sheet - C o n t e n t s
Contents
1 General Description ..................................................................................................................................................................
1
2 Key Features.............................................................................................................................................................................
1
3 Applications...............................................................................................................................................................................
1
4 Pin Assignments .......................................................................................................................................................................
3
4.1 Pin Descriptions....................................................................................................................................................................................
3
5 Absolute Maximum Ratings ......................................................................................................................................................
4
6 Electrical Characteristics...........................................................................................................................................................
5
6.1 DC/AC Characteristics for Digital Inputs and Outputs ..........................................................................................................................
5
7 Detailed Description..................................................................................................................................................................
6
7.1 Output Drivers ......................................................................................................................................................................................
6
7.2 Power Dissipation Control ....................................................................................................................................................................
8
7.3 Frequency Tracking..............................................................................................................................................................................
9
7.4 I²C.........................................................................................................................................................................................................
9
7.5 Register Map ......................................................................................................................................................................................
10
7.6 Control Register..................................................................................................................................................................................
11
7.7 Period Counter ...................................................................................................................................................................................
11
7.8 Pulse Counter.....................................................................................................................................................................................
12
7.9 Pulse Width Control............................................................................................................................................................................
12
7.10 Phase Shift .......................................................................................................................................................................................
12
7.11 Period Offset.....................................................................................................................................................................................
13
7.12 Hybrid Speed Register .....................................................................................................................................................................
8 Application Information ...........................................................................................................................................................
13
14
8.1 Integration with SQL-RV-1.8 SQUIGGLE Motor.................................................................................................................................
15
8.2 Integration with UTAF Motors .............................................................................................................................................................
17
8.3 Integration with Other Motors .............................................................................................................................................................
17
9 Package Drawings and Markings ...........................................................................................................................................
18
10 Ordering Information.............................................................................................................................................................
21
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Revision 0.4
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NSD-2101
Data Sheet - P i n A s s i g n m e n t s
4 Pin Assignments
P1-1
P1-2
P2-1
P2-2
Figure 2. Pin Assignments (Top View)
16
15
14
13
TM
1
12
VDDP
XPD
2
11
VDDP
SDA
3
10
VSSP
SCL
4
9
VSSP
1
2
3
4
A
VDD
VSSP
VDDP
P2-2
B
VSS
VSSP
VDDP
P2-1
C
VCC
ADR
TM
P1-2
D
SCL
SDA
XPD
P1-1
5
6
7
8
ADR
VCC
VSS
VDD
NSD-2101
1.8 x 1.8 mm 4-by-4 Ball Grid Array
4 x 4 mm 16-pin QFN
4.1 Pin Descriptions
Table 1. Pin Descriptions
Pin Name
Pin Number
Pin Type
TM
1
Digital input
XPD
2
Analog I/O
SDA
3
Input / Output
SCL
4
Digital input / Digital
output open drain
Input
I²C clock
ADR
5
Digital input
Input
Address input for I²C
VCC
6
Power
Internal LV Power Supply
VSS
7
GND
Signal Ground Analog
VDD
8
Power
Power Supply
VSSP
9
VSSP
10
GND
Power Ground Drivers
VDDP
11
VDDP
12
P2-2
13
P2-1
14
P1-2
15
P1-1
16
Supply pad
Character
Input
Power
Description
Test mode selection input; connected to VSS
Shut down input, low active
I²C data IO
Power Supply Driver
Power Supply Driver
Half Bridge Phase2 inverted
Analog I/O
Output
Half Bridge Phase2
Half Bridge Phase1 inverted
Half Bridge Phase1
Note: SDA (Data IO) and SCL (Data clock) constitute an I²C interface. Both have open drain outputs.
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NSD-2101
Data Sheet - A b s o l u t e M a x i m u m R a t i n g s
5 Absolute Maximum Ratings
Stresses beyond those listed in Table 2 may cause permanent damage to the device. These are stress ratings only, and functional operation of
the device at these or any other conditions beyond those indicated in Electrical Characteristics on page 5 is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Table 2. Absolute Maximum Ratings
Symbol
Parameter
Min
VVDD
Voltage at supply pin
VVDDP
Max
Units
-0.3
7
V
Voltage at supply pin for drivers
-0.3
7
V
VVCC
Voltage at low voltage supply pin
-0.3
5.0
V
Internal LV supply (VCC)
VVSSP
Voltage at VSSP
-0.3
0.3
V
GND reference for drivers
VVSS
Voltage at VSS
0
0
V
GND reference potential
VLV
Voltage at ADR, SDA, SCL, XPD, TM
-0.3
7
V
Iscr
Input current (latchup immunity)
-100
100
mA
Norm: JESD78
ESD
Electrostatic discharge
±1
kV
Norm: MIL 883 E method 3015.
Human body model: R=1.5kΩ, C=100pF,
measured and qualified only in QFN16
package.
Ptot
Total power dissipation
Rthja
Thermal resistance QFN16 4x4mm
29.7
Tstrg
Storage temperature
-40
Tbody
Typ
33
1
W
36.3
K/W
150
ºC
Package body temperature
Humidity non-condensing
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5
Revision 0.4
260
ºC
85
%
Comments
Multi-Layer JEDEC board
Norm: IPC/JEDEC J-STD-020C.
The reflow peak soldering temperature
(body temperature) specified is in
accordance with IPC/JEDEC J-STD-020C
“Moisture/Reflow Sensitivity Classification
for Non-Hermetic Solid State Surface
Mount Devices”.
The lead finish for Pb-free leaded
packages is “Matte Tin” (100% Sn).
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NSD-2101
Data Sheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6 Electrical Characteristics
Table 3. Operating Conditions
Symbol
Parameter
Conditions
Min
VVDD
Voltage at VDD
Supply voltage
(VDD/VDDP rise time is between 10µs and
10ms. Above 5.0V only half bridge mode
should be used)
VVDDP
Voltage at VDDP
VVCC
Typ
Max
Units
2.3
5.5
V
Driver supply
(VDD/VDDP rise time is between 10µs and
10ms. Above 5.0V only half bridge mode
should be used)
2.3
5.5
V
Voltage at VCC
Internal LV supply
1.9
3.0
V
VVSSP
Voltage at VSSP
GND reference for drivers
-0.1
0.1
V
VVSS
Voltage at VSS
GND reference
0
0
V
VLV
Voltage at SDA,SCL, XPD, TM
-0.3
5.5
V
Tjunc
Junction temperature
-30
125
ºC
Ptot
Total power dissipation
Total power dissipation needs to be less
than 1W to keep junction temperature in
specified range
1
W
IPd
Power-down current consumption
XPD=LOW, temp=27ºC;
No activity on I²C
5
µA
ISb
Stand-by current consumption
XPD=HIGH, pulse generation is stopped
3.5
mA
INom
Operating current consumption
Without output switching current
10
mA
IIdle
Idle mode current consumption
XPD=HIGH, temp=27ºC, VCO powered
down, no digital activity; mode set by I²C,
frequency trimming preserved
1.0
mA
Max
Units
6.1 DC/AC Characteristics for Digital Inputs and Outputs
Table 4. CMOS Input: XPD, ADR, CLK
Symbol
Parameter
Conditions
Min
Typ
VIH
High level input voltage
1.2
VDD
V
VIL
Low level input voltage
VSS
0.3
V
ILEAK
Input leakage current
-1
+1
µA
CIN
Capacitive Load
15
pF
Max
Units
Table 5. CMOS I²C Interface: SDA, SCL
Symbol
Parameter
VIH
High level input voltage
1.2
VDD
V
VIL
Low level input voltage
VSS
0.3
V
ILEAK
Input leakage current
-1
+1
µA
VOH
High level output voltage
Depending on external pull-up
resistor
VVDD -0.5
VVDD
V
VOL
Low level output voltage
At 3mA output current
VSS+0.4
V
CL
Capacitive load: SDA, SCL
50
pF
RPU
External pull-up resistor: SDA, SCL
As defined by I²C spec
7.1
kΩ
SCL
I²C write frequency
Maximum clock frequency to write
data
400
kHz
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Conditions
Revision 0.4
Min
1.2
Typ
6.0
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NSD-2101
Data Sheet - D e t a i l e d D e s c r i p t i o n
7 Detailed Description
Figure 1 shows the main building blocks of the system:
Supply input
LDO and bypass capacitors
I²C interface
Registers
Oscillator
Frequency tracking
Full bridge driver
The input voltage is supplied directly to the full bridge driver. With a full bridge drive, each piezo element sees twice the input voltage (2 x VDD).
However, the average input voltage to the piezo can be regulated by the ASIC between VDD and 2 x VDD. This average voltage, which can be
set via I²C along with the duty cycle (or pulse width) of the drive signal, determines the speed of the motor. The result being at lower speeds, the
motor consumes less power.
I²C registers also define the initial switching frequency of the motor, which can be adjusted from 50 kHz to 200 kHz based on the type of motor
being driven. Other registers control motor direction and the number of pulses the motor is active (correlating to distance traveled). The XPD
input enables a stand-by mode.
7.1 Output Drivers
The output drivers operate rail to rail and are capable of driving capacitive load up to 60nF. The concept is based on two full bridges per motor.
The reduced voltage Squiggle motor consists of 2 plates per phase and 2 phases. In power down mode the output drivers are pulled to ground.
The same applies when the motor is off.
Table 6. Characteristics for Output Drivers
Symbol
Parameter
Conditions
ftr
Rise/fall time from 0.23V to 2.07V and
vice versa
CLOAD 50nF,
ftf
CLOAD
Min
1
VDD=2.3V
Load capacitance
2
Ilim
Current limit for driver outputs
fDFR
Drive frequency range
fDC
Switching frequency duty cycle
tDT
Dead time (additional)
fPS
Phase shift
fPSE
Phase shift error
3
VCO clock cycles
4
Max
Units
0.08
0.8
µs
10
60
nF
1000
1600
mA
50
200
kHz
1
50
%
2
-160
Typ
4
9
+90
deg
±3
deg
1. Measured at 10% to 90% of minimum VDD=2.3V. Maximum with 4 clocks dead-time.
2. Current limit is valid for full bridge and half bridge configuration. Due to the dynamic behavior of the output driver the maximum current
limit can not be reached under all conditions. Device can only be used for direct motor drive.
3. For this frequency range, frequency tracking is implemented.
4. Error of dead time is maximum +1 VCO clock cycle.
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NSD-2101
Data Sheet - D e t a i l e d D e s c r i p t i o n
Figure 3. Motor Drive Concept (SQUIGGLE® RV Motor)
Motor Drive Concept
VIN
P1-1
VIN
P1-2
0V
VIN
VIN
P1-1
or
P2-1
0V
P1-2
or
P2-2
Phase Shift
+90 is Forward
-90 is Reverse
P2-1
VIN
P2-2
0V
VIN
Full Bridge Drive
SQUIGGLE® RV Motor
0V
Figure 4. Motor Drive Concept (UTAF Motor)
Motor Drive Concept
VIN
P1-1
VIN
P1-2
0V
VIN
VIN
P1-1
or
P2-1
P1-2
or
P2-2
Full Bridge Drive
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0V
Phase Shift
+72 is Forward
-108 is Reverse
P2-1
VIN
P2-2
0V
VIN
0V
Revision 0.4
UTAF Motor
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NSD-2101
Data Sheet - D e t a i l e d D e s c r i p t i o n
The rise and fall time definition is shown in Figure 5. Time between crossing 10% and 90% threshold of minimum VDD is measured, 10% to 90%
for rise time and 90% to 10% for fall time. A full bridge switching cycle will take longer.
Figure 5. Rise / Fall Time Definition
V(half-bridge)
VDD = 2.3V
90%
10%
0V
t
tr
tf
In Figure 6, the effect of current limit in the output drivers is shown. Each half-bridge output can deliver 1000mA.
Figure 6. Output Driver Current Limit
I(half-bridge)
Ilim = 1600mA
typ 1300mA
Ilim = 1000mA
0mA
t
7.2 Power Dissipation Control
Following techniques are implemented to keep the system and on-chip power dissipation low.
Selectable half bridge mode depending on input supply voltage
Selective charge control for full bridge mode
Hybrid Control for full bridge mode
Table 7. Power Dissipation Control
Symbol
Parameter
Conditions
Min
Typ
Max
Units
When half-bridge mode is enabled then the output driver
will switch to half-bridge drive depending on input supply
voltage. Typical system power dissipation can be reduced
down to 25% of standard full-bridge drive. When VDD is
higher than 5.0V only half bridge mode should be used to
avoid exceeding max total power dissipation of 1W. A
typical hysteresis of 100mV is implemented to increase
immunity against supply disturbances.
4.3
4.5
4.7
V
4.2
4.4
4.6
V
50
%
75
%
Selectable half-bridge
HBthr
Rising Threshold
HBthf
Falling Threshold
Selective charge control for full-bridge
SCCPDS
Power dissipation saving
By adding an additional state in the full bridge switching
scheme the power dissipation can be reduced due to the
fact that the effective voltage on the capacitor is reduced.
30
Hybrid Control for full-bridge
PSPDS
Power dissipation saving
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With this technique the power dissipation can be reduced
by switching periodically from full-bridge to half-bridge
mode. Power saving in comparison to standard full-bridge
drive is mainly depending on duty cycle between halfbridge and full-bridge. Hybrid Control is also used for
speed control.
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NSD-2101
Data Sheet - D e t a i l e d D e s c r i p t i o n
7.3 Frequency Tracking
Based on the motor type, an initial drive signal period must be written to the NSD-2101. The period is specified in units of 0.04 µsec (based on
the nominal internal VCO frequency of 25 MHz). In the case of an SQL-RV-1.8 motor, the period may be 148 (94h) to generate a drive frequency
of ~168.9 kHz.
The NSD-2101 is able to then optimize the drive frequency by, on command, sweeping over a range of frequencies, centered at the specified
period, and settling on the frequency at which the best motor performance was detected. Alternatively, the NSD-2101 may be commanded to
incrementally step the frequency in the direction of increasing motor performance (changing the step direction when the performance drops).
In either case, the NSD-2101 adjusts the frequency by adjusting the VCO trimming, rather than the period count. This affords much higher
resolution than is possible by changing the period count.
Whether sweep mode or incremental (see ‘Control Register’ in Table 8 on page 10), the calibration does not start until a pulse count has been
loaded into registers 02h and 03h.
A sweep calibration is typically performed following a power-up. The sweep calibration offers the greatest range of frequencies. Incremental
calibration offers the best frequency resolution and can be performed periodically as the motor is being used.
7.4 I²C
The I²C interface is used to control the NSD-2101 and set the value of several registers. These registers will define the direction and duration of
the output driver signals, the duty cycle, phase shift and average voltage to the motor.
Start/Stop Condition: A HIGH to LOW transition on the SDA line while SCL is HIGH is the start condition for the bus. A LOW to HIGH
transition on the SDA line while SCL is HIGH is the stop condition.
Every byte put on the SDA line must be 8-bits long. Each byte must be followed by an acknowledge bit. Data is transferred with the most
significant bit (MSB) first.
Data transfer with acknowledge is obligatory. The acknowledge-related clock pulse is generated by the master. The receiver must pull down the
SDA line during the acknowledge clock pulse.
The NSD-2101 is a slave device on the bus. There are two different access modes:
- Byte write
- Page write
The device can be addressed using 7-bit addressing. The first 6 bits are fixed. The last bit can be set via package pin.
Figure 7. 7-Bit Device Address
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NSD-2101
Data Sheet - D e t a i l e d D e s c r i p t i o n
7.5 Register Map
Table 8 lists out the registers which can be addressed over the I²C interface.
Table 8. I²C Registers
Description
Address
Control Register
00h
Period count
01h
Data Byte
MSB
LSB
PS[1] PS[0]
X
X
X
CN[1] CN[0]
X
Pulse count (high byte)
02h
P
D
Pulse count (low byte)
03h
X
X
X
X
Pulse width
04h
X
X
X
Phase shift
05h
X
X
X
Period offset
06h
IDL
HB
X
DS[1] DS[0]
HYB
X
P1
P2
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
DT
X
X
Note
P: Period count MSB;
D: Direction bit;
DS: Dead time selection bits: ‘00’=2,
‘01’=4, ‘10’=6 and ‘11’=8 VCO clocks.
X
CN needs to be 00 to enable Period
offset. Period offset is not used when
either Incremental or Sweep Frequency
Tracking is active.
IDL: Sets idle mode;
HB: Enable half bridge operation if VDD
> HBth;
HYB: Enable hybrid speed control;
DT: Enable signal for increased dead
time;
Selection bits(DS[1:0]) are only valid
when DT=1;
Selection bits should not be changed
when the output driver is active.
Hybrid speed
07h
X
X
X
X
X
X
X
X
Hybrid Speed register: 0… half bridge;
128…full bridge operation; linear
transition for values in between;
Default: 128. Values from 1 to 127 are
used for linear speed control.
Reserved register
10h
X
X
X
X
X
X
X
X
Reserved register used for device test
only, not accessible during normal
operation.
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NSD-2101
Data Sheet - D e t a i l e d D e s c r i p t i o n
7.6 Control Register
The control register is used to trigger frequency calibration as well as to select and enable the drive phases.
Table 9. Control Register
Control Flag Mask
Abbr
Default
1000 0000
0
Reserved (leave 0)
Phase Select for sensing: PS[1] PS[0]:
00=None
01=Phase1
10=Phase2
11= Both Phases
0100 0000
PS[1]
1
0010 0000
PS[0]
1
0001 0000
Description
0
Reserved (leave 0)
Calibrate Now: CN[1] CN[0]:
00=None
01=Incremental
10=Sweep
11=reserved
0000 1000
CN[1]
0
0000 0100
CN[0]
0
0000 0010
P1
1
Enable Phase1
0000 0001
P2
1
Enable Phase2
7.7 Period Counter
The period counter is used to define the switching frequency of the motor. The pulse period is generated by dividing the internal VCO clock
frequency by the given period counter value. The MSB in the high byte of the pulse counter (p) is used as the MSB for the period counter.
At 25MHz clock a decimal period counter value of 125 gives an output frequency of 200 kHz. A period counter value of 126 results in a switching
frequency of 198.41 kHz. This is equal to a maximum frequency step of 1.59 kHz. The frequency resolution gets better for lower switching
frequencies assuming a fixed VCO clock frequency.
Table 10 lists out few examples to define period counter and output switching frequency relationship. The values are given for 25MHz typical
VCO clock frequency. The switch frequency is given as:
fD = 25MHz / period counter value
(EQ 1)
Table 10. Period Counter Values
Period Counter Value
Typ
Unit
0 0111 1101
200.00
kHz
0 0111 1110
198.41
kHz
0 1001 0001
172.4
kHz
0 1010 0110
150.60
kHz
0 1010 0111
149.70
kHz
1 1111 0011
50.10
kHz
1 1111 0100
50.00
kHz
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NSD-2101
Data Sheet - D e t a i l e d D e s c r i p t i o n
7.8 Pulse Counter
The pulse counter sets the number of pulses the motor should be active. When a new value is written to the pulse count register an internal
counter is started to count generated output pulses. Writing all zeros to the pulse counter stops the motor even if the previous set counter value
is not completed, all outputs pulled to ground. The same is valid for power down mode. Bit 6 in the pulse counter (d) is used to set the direction
of motor motion.
Table 11. Pulse Counter Values
Pulse Counter Value
Typ
Unit
Conditions
XXXX X000 0000 0000
0
pulses
Motor is off, driver outputs are low
XXXX X100 0000 0000
1024
pulses
XXXX X111 1111 1111
2047
pulses
Maximum possible number of pulses
7.9 Pulse Width Control
A register is used to define the duty cycle of the driver output signal. The default value for this register set during power up or power down (XPD
= LOW) is equal to 00h. In this case the default duty cycle of 50% is generated. The resulting duty cycle and resolution of single steps is
depending on the master clock frequency and the switching frequency of the driver output. Table 12 provides an example for 25MHz master
clock and 200kHz driver frequency. The value of the duty cycle register should not exceed 50.4% of the period counter value. Pulse Width
Modulation is used for speed control when motor is operating in half bridge mode.
Table 12. Pulse Width Register Values
Pulse Width Register
Typ
Unit
Conditions
0000 0000
49.6/50.4
%
default
0000 0001
0.8
%
0000 1101
10.4
%
0001 1011
21.6
%
0011 0101
42.4
%
0011 1110
49.6
%
0011 1111
50.4
%
If operating in half bridge mode, the pulse width can be used to adjust speed. At 50% the motor will operate at its maximum speed. To reduce the
speed, the pulse width may be reduced. However, below ~15%, there may not be enough energy in the signal to move the motor.
7.10 Phase Shift
A register is used to define the phase shift between the two phases of the driver output signal. The default value for this register set during power
up or power down (XPD = LOW) is equal to 00h. In this case the default phase shift of 90° is generated. The resulting phase shift and resolution
of single steps is depending on the master clock frequency and the switching frequency of the driver output. Table 13 provides an example for
25MHz master clock and 200kHz driver frequency. The value of the phase shift register should not exceed 50.4% of the period counter value.
Negative phase shift values are achieved by changing the direction bit: -160deg = 20deg and inverted direction bit.
Table 13. Phase Shift Register Values
Phase Shift Register
Typ
Unit
Conditions
0000 0000
90.5
deg
Default (Normal for both SQL and UTAF)
0000 0001
2.88
deg
0000 1101
37.44
deg
0000 1110
40.32
deg
0001 1111
89.28
deg
0010 0000
92.16
deg
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Revision 0.4
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NSD-2101
Data Sheet - D e t a i l e d D e s c r i p t i o n
7.11 Period Offset
Period Offset register defines the offset which is added to the period counter to shift the switching frequency. It also provides some additional
control bits.
This offset is only activated when frequency tracking is stopped. An offset has been provided as some types of motors operate better at slightly
below mechanical resonance. Table 14 provides an example for 25MHz master clock and 200kHz nominal driver frequency. Period offset is only
supposed to lower drive frequency.
Table 14. Period Offset Register Values
Period Offset Register
Typ
Unit
Conditions
0000 0000
0
%
Default, no change of drive frequency
0000 0001
-0.8
%
0000 0010
-1.6
%
0000 0111
-5.6
%
Maximum period offset
1000 0000
0
%
Idle mode enabled
0100 0000
0
%
Half bridge mode enabled
0010 0000
0
%
Hybrid speed control enabled
0001 0000
0
%
Increased dead time enabled
Idle mode reduces power consumption while preserving the most recent frequency calibration. To further reduce power, the XPD pin must be
pulled to ground.
7.12 Hybrid Speed Register
The hybrid speed register allows the average voltage as seen by the motor to be set from VDD to 2 x VDD. This provides a power efficient
method of reducing the speed of the motor. The value of the register can vary from 0 (half bridge) to 128 (full bridge). The average voltage can
be calculated in the following manner.
VAVG = VDD + (RegisterValue * VDD / 128)
(EQ 2)
Where: VDD is the supply voltage
Table 15. Hybrid Speed Register Values
Hybrid Speed Register
Typ
Unit
Conditions
0000 0000
0
%
VDD (half bridge)
0010 0000
25
%
VDD + 0.25 * VDD
0110 0000
75
%
VDD + 0.75 * VDD
1000 0000
100
%
VDD + VDD (full bridge)
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NSD-2101
Data Sheet - A p p l i c a t i o n I n f o r m a t i o n
8 Application Information
The NSD-2101 is designed to drive one SQL-RV-1.8 SQUIGGLE® RV motor or one UTAF motor. Recommended external components are as
follows:
Table 16. External Components
Component
Manufacturer
Part Number
WxLxH [mm]
C1 470nF Cap 4.0V
TAIYO-YUDEN
AMK063BJ474MP-F
(0201)
C2 4.7µF Cap 6.3V
PANASONIC
ECJ-0EB0J475M
C2 10µF Cap 6.3V
PANASONIC
ECJ-1VB0J106M
For UTAF only
(max 35nF) (0402)
Full load (0603)
1
1
1. A maximum ESR of 100mΩ at motor switching frequency is assumed. The series resistance of the input supply (VDD, VDDP) should be
maximum 50mΩ and capable of delivering at least 1W of power. ESR information for C2 is still missing.
New Scale offers a convenient MC-33DB-RV evaluation board which includes the components, along with input and motor connectors, to take
full advantage of the NSD-2101 ASIC.
The XPD input can be used to place the ASIC in stand-by mode for minimal current consumption when the motor is not moving. Alternatively, the
designer can implement an external switch to power off the ASIC completely when the motor is not moving: the SQUIGGLE® RV motor holds its
position with the power off.
Figure 8. NSD-2101
SCL
P2-2
P2-1
14
13
12
2
11
NSD-2101
3
10
4
9
ADR
5
6
7
VDDP
2.3V – 5.5V
VDDP
C2
VSSP
VSSP
+
-
8
VDD
SDA
15
VSS
µC
XPD
16
1
VCC
TM
P1-2
P1-1
SQL-RV or UTAF
C1
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NSD-2101
Data Sheet - A p p l i c a t i o n I n f o r m a t i o n
8.1 Integration with SQL-RV-1.8 SQUIGGLE Motor
Communicating with the NSD-2101.
The address of the NSD-2101 is 54h (unless the ADR pin is held high in which case the address would be 55h).
I²C supports 8 data bits and 1 acknowledge bit for a total of 9 bits or clock cycles per byte. When attempting to select a device, the first byte
transmitted by the master contains the device address. This address occupies the upper 7 data bits with data bit 0 having a value of zero which
indicates a write operation (theNSD-2101 does not support a read operation).
Therefore when addressing the NSD-2101 the actual value sent by the host during the first 8 SCL (clock) cycles would be A8h (or AAh if ADR pin
high). If the NSD-2101 is powered and connected properly to the SDA/SCL lines then on the 9th clock pulse, the NSD-2101 will hold the data line
low (acknowledge).
The second byte transmitted must be the number of the register to be written. For example, if attempting to send a pulse count, then the register
value would be 2.
The third and any subsequent bytes are the values to be written to the specified register and, if more than three bytes are being sent, the
following registers in increasing order.
If the following data were sent over the I²C bus:
A80277FF
Then registers 02 and 03 of the NSD-2101 would receive values of 77h and FFh respectively.
Supporting More Than Two NSD-2101s on a Single I²C Bus.
To support more than two NSD-2101 drivers on the same I²C bus, the ADR pin may be used as a chip select. That is, one driver is held low by
the host and on all others it is held high. The host then sends commands to the driver with ADR held low. This of course requires that there be a
separate chip select line for each NSD-2101.
How Motion is Generated.
Motion is initiated by directing the NSD-2101 to issue pulses to the motor. In the case of the SQL-RV-1.8 motor, to get any motion, the interval
between the start of each pulse (i.e. the period) must be within some tolerance (e.g. ±2KHz) of the resonant frequency of the motor (e.g. ~172
kHz).
The closer this period is to the resonant frequency of the motor, the more speed/push force is available. Keep in mind that this is a friction drive
which means the amount of motion is dependent on supply voltage, applied frequency vs. actual resonant frequency and the load on the motor.
From an idle state, a minimum of 5 to 10 pulses are required to build up enough orbital motion (of the nut about the screw) to advance the screw.
The minimum pulse count varies with load (higher load, more pulses) and whether or not motion is against or with the load (more against, fewer
with).
As shown in Figure 3, the drive signal is composed of two waveforms (square waves) and each waveform may be full or half bridge. In the case
of the SQL motor, these waveforms are 90 degrees out of phase (in keeping with the geometry of the nut). The phase that leads determines the
direction of motion (direction is set by the host using a bit from the pulse count register).
By default the pulse width of each waveform is 50% of the period (i.e. if register 04 is zero; e.g. pulse with would be 2.9 µsec if the period is 5.8
µsec). But you can adjust the pulse width as one means to regulate speed. The shorter the pulse width (below 50% of the period), the less time
the piezo has to change shape and thus the amount of engagement between nut and screw is reduced.
The default phase shift between waveforms is 25% of the period (i.e. if register 05 is zero). This can also be adjusted and would be for other
motor geometries but in the case of the SQL-RV-1.8; 25% is recommended.
A second means to adjust speed is to set the ratio of full bridge pulses to half bridge pulses (Hybrid Speed Control). This effectively sets the
average voltage seen by the motor. If the supply is 3V then in full bridge the motor “sees” 6V. But if the hybrid speed is 33% then, on an average,
the motor sees 4V.
Note: Due to dissipation limitations of the driver chip, the maximum supply voltage for full bridge operation is 4.5V (9V to the piezo). Although
the driver supports a supply of up to 5.5V, at any level above 4.5V, the output needs to be half bridge. Within that limitation the hybrid
speed control is more power efficient than the pulse width control method of the regulating speed since the amount of switching into the
capacitive load of the motor is being reduced.
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Revision 0.4
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NSD-2101
Data Sheet - A p p l i c a t i o n I n f o r m a t i o n
Directing the NSD-2101.
The basic command that is sent to the NSD-2101 is the pulse count (with direction). When a non-zero value is written to registers 02 and 03 by
the host microprocessor, the NSD-2101 begins generating pulses on the output pins at the interval defined by the period register (01). For each
pulse, the specified pulse count is decremented. Pulse generation continues until the pulse count reaches zero or the host writes a zero to
registers 02 and 03. See Register Map (page 10) and Pulse Counter (page 12).
Since the pulse counter is limited to 2047 (11 bits), the maximum duration of motion is the 2047 x period. If the period were 5.8 µsec (172.4 kHz),
then the duration would be ~11.8 msec. Therefore to produce continuous motion, the pulse count must be reloaded by the host before the
previous pulse count expires (in this case - at least every 11.7 msec - but every 10 msec would provide more margin allowing for variations in
motor frequency and overhead in the host processer handling I²C traffic).
Given the nominal 25MHz power-up frequency of the VCO within the NSD-2101, the motor period is specified in units of 40 nsec. Therefore the
period value necessary to generate a frequency of 172.4 kHz is 145 (or 91 hexadecimal).
As indicated in the previous section, to generate motion, the pulse period must be very near the interval of the mechanical resonant frequency of
the motor. However, for a given motor type, manufacturing tolerances, ambient temperature and mounting have an affect on this resonant
frequency. To cancel out these affects, the NSD-2101 supports a frequency tuning (or calibration) feature.
Therefore on power-up, it is recommended that after an appropriate default period count for the given motor type is loaded, a frequency sweep
calibration is performed followed by an incremental calibration. See Frequency Tracking (page 9). The sweep needs to be performed only once
(for a given power cycle); After that, the incremental calibration will keep the motor in tune.
Note: While performing the frequency calibration, the NSD-2101 is adjusting the trimming of its internal VCO to maximize the performance of
the motor (not the period count itself).
Furthermore, it is recommended that frequency calibration be performed in a direction that is against the load (typically forward). The reason is
that, depending on the mass being moved (i.e. the inertia), there may be chatter (intermittent contact between the load and the screw) when
moving with the load. This chatter can affect the calibration.
Starting a frequency sweep calibration (assuming an SQL-RV-1.8 motor):
Reg
Value (hex)
Comment
00
6B
Enables sweep calibration using both motor phases
01
91
172.4 kHz
02
77
Fwd, DT=11*, Upper 3 bits of pulse count set
03
FF
Lower 8 bits of pulse count set
Actual data stream: A8006B9177FF (the host should wait at least 10 msec after start)
Starting a frequency incremental calibration:
Reg
Value (hex)
Comment
00
67
Enables inc. calibration using both motor phases
01
91
172.4 kHz
02
77
Fwd, DT=11*, Upper 3 bits of pulse count set
03
FF
Lower 8 bits of pulse count set
Actual data stream: A800679177FF (the host should wait at least 10 msec after start)
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Revision 0.4
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NSD-2101
Data Sheet - A p p l i c a t i o n I n f o r m a t i o n
Normal operation:
Reg
Value (hex)
Comment
00
63
Using both motor phases, no calibration enabled.
Actual data stream: A80063
Moving Fwd (full count):
Reg
Value (hex)
Comment
02
77
Fwd, DT=11*, Upper 3 bits of pulse count set
03
FF
Lower 8 bits of pulse count set
Actual data stream: A80277FF
Moving Rev (full count):
Reg
Value (hex)
Comment
02
37
Rev, DT=11*, Upper 3 bits of pulse count set
03
FF
Lower 8 bits of pulse count set
Actual data stream: A80237FF
Stopping the Motor:
Reg
Value (hex)
Comment
02
00
Direction & DT* don't matter. Zero upper count bits
03
00
Zero lower count bits
Actual data stream: A8020000
Note: *DT (dead time): The time interval between the switching of the low side and the high side of a full bridge waveform. The best power
efficiency is achieved when using the maximum dead time (i.e. DT=11). This minimizes the power consumed while having no affect on
speed/push force.
8.2 Integration with UTAF Motors
New Scale Technologies works closely with OEM customers to provide assistance in using the UTAF motor with the NSD-2101. Please contact
New Scale for assistance.
8.3 Integration with Other Motors
The NSD-2101 was designed for use with New Scale Technologies’ SQUIGGLE and UTAF motors. Support for other piezo motors may be
provided, for a fee, to qualified OEMs. Contact austriamicrosystems or New Scale Technologies to discuss your application.
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Revision 0.4
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NSD-2101
Data Sheet - P a c k a g e D r a w i n g s a n d M a r k i n g s
9 Package Drawings and Markings
The devices are available in a 16-pin QFN (4x4mm) package or 4-by-4 BGA (1.8x1.8mm) package.
Figure 9. 16-pin QFN (4x4mm) Package Drawings and Dimensions
13
14
15
16
12
1
11
2
10
3
9
4
8
7
6
5
m
m
Symbol
A
A1
A3
b
D
E
D2
E2
Min
0.80
0.18
2.50
2.50
Nom
0.85
0.203 REF
0.23
4.00 BSC
4.00 BSC
2.70
2.70
Max
0.90
0.05
0.28
2.70
2.70
Symbol
e
L
aaa
bbb
ccc
ddd
eee
Min
0.35
Nom
0.65 BSC
0.40
0.10
0.10
0.10
0.05
0.08
Max
0.45
Notes:
1. Dimensioning and tolerancing conform to ASME Y14.5M-1994.
2. All dimensions are in millimeters, angles are in degrees.
3. Dimension b applies to metalized terminal and is measured between 0.25mm and 0.30mm from terminal tip. Dimension L1 represents
terminal full back from package edge up to 0.1mm is acceptable.
4. Coplanarity applies to the exposed heat slug as well as the terminal.
5. Radius on terminal is optional.
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NSD-2101
Data Sheet - P a c k a g e D r a w i n g s a n d M a r k i n g s
Figure 10. 4-by-4 BGA (1.8x1.8mm) Package Drawings
VDDP
VSSP
Figure 11. Recommended PCB Layout (Top View)
C2
VDD
P2-2
VSS
P2-1
P1-2
C1
XPD
SDA
SCL
P1-1
Denotes via to ground plane
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NSD-2101
Data Sheet - R e v i s i o n H i s t o r y
Revision History
Revision
Date
Owner
Description
0.1
15 Jan, 2010
0.2
24 Feb, 2010
0.3
16 Jun, 2010
Corrected BGA diagram (see Figure 2), added “Top View” to figure title
for clarity (see Figure 11)
0.4
26 Aug, 2010
Updated Table 3 with current consumption info, Corrected info in
Figure 4 and Table 10, Added Section 8.1, 8.2 and 8.3.
Initial revision
Updated Key Features (page 1), Pin Assignments (page 3)
rweber (NST) /
pmo (AMS)
Note: Typos may not be explicitly mentioned under revision history.
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NSD-2101
Data Sheet - O r d e r i n g I n f o r m a t i o n
10 Ordering Information
The devices are available as the standard products shown in Table 17.
Table 17. Ordering Information
Ordering Code
Description
Delivery Form
Package
NSD-2101
Ultrasonic piezo motor driver IC, output for one SQL-RV
series reduced voltage SQUIGGLE® RV
Tape & Reel
QFN-16 (4x4mm) or Wafer Level
Chip Scale Package
Note: All products are RoHS compliant and Pb-free.
Buy our products or get free samples online at ICdirect: http://www.austriamicrosystems.com/ICdirect
For further information and requests, please contact us mailto:[email protected]
or find your local distributor at http://www.austriamicrosystems.com/distributor
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NSD-2101
Data Sheet - C o p y r i g h t s
Copyrights
Copyright © 1997-2010, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®.
All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of
the copyright owner.
All products and companies mentioned are trademarks or registered trademarks of their respective companies.
Disclaimer
Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale.
austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding
the freedom of the described devices from patent infringement. austriamicrosystems AG reserves the right to change specifications and prices at
any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for
current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range,
unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are
specifically not recommended without additional processing by austriamicrosystems AG for each application. For shipments of less than 100
parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location.
The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems AG shall not
be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use,
interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing,
performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of
austriamicrosystems AG rendering of technical or other services.
Contact Information
Headquarters
austriamicrosystems AG
Tobelbaderstrasse 30
A-8141 Unterpremstaetten, Austria
Tel: +43 (0) 3136 500 0
Fax: +43 (0) 3136 525 01
For Sales Offices, Distributors and Representatives, please visit:
http://www.austriamicrosystems.com/contact
Contact Information
New Scale Technologies, Inc.
121 Victor Heights Parkway
Victor, NY 14564
Tel: +1 585 924 4450
Fax: +1 585 924 4468
[email protected]
www.newscaletech.com
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