MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 1 of 25 Device specification
Rev 2 Jun/12
Features and Benefits
Supply voltage up to 12 V.
Interface directly with 3.3/5 V CMOS logic µP
Serial peripheral interface
Can drive two air core actuators over the full 360° and one over 90°.
Open circuit or short circuit detection of the drivers’ outputs.
Small size (SSOP20 package)
Real time angle tracking
Applications
Air-core meter Driver Dashboard
Industrial Metering
Ordering Code
Product Code Temperature Code Package Code Option Code Packing Form Code
MLX10420 R FR AAA-000 RE
Legend:
Temperature Code: R for Temperature Range -40°c to 105°c
Package Code: FR for SSOP 209 mil
Packing Form: RE for Reel
Ordering example: MLX10420RFR-AAA-000-RE
1 Functional diagram
2 General Description
The MLX10420 is a µP peripheral for air-core
meters control using SIN/COS PWM commands.
The circuit controls two independent sets of
CMOS power bridges. A ten bit angle is
displayed with 9 bits per quadrant. The PWM
frequency is set by an on chip oscillator. A
power-on self test detects open or short-circuits
outputs for each air-core meter and a real time
angle tracking avoids display errors.
The chip can also drive one small angle air-core
meters (90°).
The communication with the µP is done via a
three wires serial link.
The chip outputs an error status on a special pin.
logic
SIN1P
SIN1M
COS1P
VSS
VCC
VSS
VCC
COS1M
BUF 1
360deg
SIN2P
SIN2M
COS2P
COS2M
BUF 2
360deg
ROM SEQ
BUF 3
90deg OUT3
RC
OSC
SPI
POR
CSB
SCLK
SI
SO
ERRB
TEST
VIO
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 2 of 25 Device specification
Rev 2 Jun/12
3 History
Table 1 shows the revisions of this document.
Version
Date
Name
Description
1.0
20/4/07
hva
Initial version
1.1
2/8/07
h
va
Major rework
1.2
3/10/07
hva
Rework at DI phase
1.3
02/06/08
fbe
Updated
SPI message format
1.4
09/10/08
fbe
Updated block diagram (missing VIO pin) §6
Updated Calibration procedure timings from 16us to 17.5us §12.4.5.4
1.5
13/05/2009
fbe
Layout rework
1.6
13/6/2012
adl
Logo, ordering code, disclaimer
Table 1: revision history
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 3 of 25 Device specification
Rev 2 Jun/12
4 Table of contents
1 FUNCTIONAL DIAGRAM .......................................................................................................................... 1
2 GENERAL DESCRIPTION ........................................................................................................................ 1
3 HISTORY .................................................................................................................................................... 2
4 TABLE OF CONTENTS ............................................................................................................................. 3
5 TABLE OF FIGURES ................................................................................................................................ 4
6 TABLE OF TABLES .................................................................................................................................. 4
7 GLOSSARY OF TERMS ............................................................................................................................ 5
8 MAXIMUM RATINGS ................................................................................................................................. 6
9 PAD DEFINITIONS AND DESCRIPTIONS ............................................................................................... 7
10 GENERAL ELECTRICAL SPECIFICATIONS ......................................................................................... 9
10.1
S
TATIC
C
HARACTERISTICS
.................................................................................................................... 9
10.2
D
YNAMIC CHARACTERISTICS
............................................................................................................... 11
11 DETAILED BLOCK DIAGRAM DESCRIPTION .................................................................................... 13
11.1
B
LOCK DIAGRAM DIGITAL PART
............................................................................................................ 13
11.2
G
AUGE DRIVER OPERATION
................................................................................................................. 13
11.2.1 Air-core meters 360° ................................................................................................................. 13
11.2.2 air-core meter 90° ..................................................................................................................... 14
11.3
A
NGLE TRACKING
............................................................................................................................... 15
11.4
S
ERIAL LINK
....................................................................................................................................... 15
11.4.1 Introduction ............................................................................................................................... 15
11.4.2 Signal description ...................................................................................................................... 15
11.4.3 Functional description ............................................................................................................... 16
11.4.4 Communication memory maps ................................................................................................. 17
11.4.5 Register description .................................................................................................................. 17
11.4.5.1 AIRCORE1 ......................................................................................................................................... 17
11.4.5.2 AIRCORE2 ......................................................................................................................................... 17
11.4.5.3 AIRCORE3 ......................................................................................................................................... 18
11.4.5.4 CAL ..................................................................................................................................................... 18
11.4.5.5 RST ..................................................................................................................................................... 19
11.4.5.6 TEST ................................................................................................................................................... 19
11.4.6 Status register ........................................................................................................................... 19
11.5
E
RROR OUTPUT
.................................................................................................................................. 20
11.6
PWM
GENERATION
............................................................................................................................ 20
11.6.1 Air-core meter 360° ................................................................................................................... 20
11.6.2 Air-core meter 90° ..................................................................................................................... 21
11.7
T
EST
................................................................................................................................................. 21
12 APPLICATIONS INFORMATION .......................................................................................................... 22
13 STANDARD INFORMATION REGARDING MANUFACTURABILITY OF MELEXIS PRODUCTS
WITH DIFFERENT SOLDERING PROCESSES ........................................................................................ 23
14 ESD PRECAUTIONS ............................................................................................................................. 23
15 PACKAGE INFORMATION ................................................................................................................... 24
16 DISCLAIMER ......................................................................................................................................... 25
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 4 of 25 Device specification
Rev 2 Jun/12
5 Table of figures
Figure 1: Pinning diagram ................................................................................................................................................................... 8
Figure 2: SPI timing characteristics ................................................................................................................................................... 12
Figure 3: Digital part block diagram .................................................................................................................................................. 13
Figure 4: Test for short-circuits and open circuits .............................................................................................................................. 14
Figure 5: Full bridge configuration ..................................................................................................................................................... 14
Figure 6: Single 16-bit word SPI communication timing diagram ....................................................................................................... 16
Figure 7: multiple 16-bit word SPI communication timing diagram .................................................................................................... 16
Figure 8: Calibration sequence timing diagram ................................................................................................................................. 19
Figure 9: Quadrants and PWM sign .................................................................................................................................................. 20
Figure 10: Typical application diagram .............................................................................................................................................. 22
Figure 11: Package information drawing ........................................................................................................................................... 24
6 Table of tables
Table 1: revision history ...................................................................................................................................................................... 2
Table 2: abbreviations used in this document ..................................................................................................................................... 5
Table 3: absolute maximum ratings .................................................................................................................................................... 6
Table 4: Pinout of MLX10420 ............................................................................................................................................................. 7
Table 5: SSOP20 package information ............................................................................................................................................... 8
Table 6: Static electrical specifications .............................................................................................................................................. 10
Table 7: Dynamic characteristics MLX10420 .................................................................................................................................... 12
Table 8: Self test description ............................................................................................................................................................. 14
Table 9: Data transfer timing ............................................................................................................................................................. 16
Table 10: Memory map ..................................................................................................................................................................... 17
Table 11: Quadrant definition ............................................................................................................................................................ 20
Table 12: PWM definition .................................................................................................................................................................. 21
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 5 of 25 Device specification
Rev 2 Jun/12
7 Glossary of Terms
Table 2 explains the abbreviations used in this document.
CMOS Complementary Metal Oxide Semiconductor (standard logic family)
DC direct current
ESD Electro-Static Discharge
HBM human body model (for ESD)
i.e. 'id est' … which is …
POR Power On Reset
PWM Pulse Width Modulation
RCOSC RC oscillator
rev revision
RT room temperature
TA ambient temperature
TC temperature coefficient
tri-state high impedant state of a driver output
Table 2: abbreviations used in this document
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 6 of 25 Device specification
Rev 2 Jun/12
8 Maximum ratings
Table 3 shows the maximum ratings of the chip.
Parameter. Min Max Unit
Supply
Supply voltage range
VCC
-
0.3
14
V
maximum supply current
at VCC
1
00
mA
Supply voltage range VIO
-
0.3
5.5
V
maximum supply current
at VIO
3
mA
Others
Operating ambient Temperature Range, T
A
-
40
105
°C
Storage Temperature Range, T
S
-
50
150
°
C
ESD Sensitivity (AEC Q100 002), equivalent to discharge 100pF
with 1.5kOhms
-
2
2
kV
Maximum continuous current in motor driver
--
50
50
mA
Table 3: absolute maximum ratings
Exceeding the absolute maximum ratings in Table 3 may cause permanent damage. Exposure to absolute-
maximum-rated conditions for extended periods may affect device reliability.
Note:
• Latch-up immunity will be verified according to AEC Q100 004.
• the maximum ratings are valid over the full operating temperature range, T
A
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 7 of 25 Device specification
Rev 2 Jun/12
9 Pad definitions and descriptions
Pin Pad Name Function
1
VCC
Supply
2 SIN1P Output buffer (coil 1 air-core 1 )
3 SIN1M Output buffer (coil 1 air-core 1)
4 VSS Ground
5 COS1P Output buffer (coil 2 air-core 1 )
6 COS1M Output buffer (coil 2 air-core 1 )
7 OUT3 Output buffer (air-core 3 )
8 VCC Supply
9 ERRB Error output
10 TEST Input
11 SI Serial Data IN
12 SCLK Serial clock
13 VIO Supply for the digital interface pins
14 CSB Chip select
15 SO Serial Data OUT
16 COS2M Output buffer (coil 2 air-core 2 )
17 COS2P Output buffer (coil 2 air-core 2 )
18 VSS Ground
19 SIN2M Output buffer (coil 1 air-core 2 )
20 SIN2P Output buffer (coil 1 air-core 2 )
Table 4: Pinout of MLX10420
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 8 of 25 Device specification
Rev 2 Jun/12
Pin-out diagram:
Figure 1: Pinning diagram
SSOP20 Package information Table 5 gives the information that will be available on the top side of the
package.
X
CHIP VER
S
ION
NNNNNNN
LOT NUMBER
YY
YEAR CODE
WW
WEEK CODE
Table 5: SSOP20 package information
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 9 of 25 Device specification
Rev 2 Jun/12
10 General Electrical Specifications
10.1 Static Characteristics
The static characteristics are shown in Table 6. The device works up to specification from -40
o
C till 105
o
C,
VCC = 4.5V to 12V, unless otherwise specified. Positive currents flow into the IC.
Parameter. Symbol Test Conditions Min Typ Max Units
VCC supply
Supply
current
I
CC
Inputs at V
CC
or VSS, no loads
on outputs
5.5
mA
Maximum power dissipation
PDmax
200
mW
VIO supply
Supply voltage (note
2
)
VIO
3
5.5
V
Supply current
IIO
Inputs at V
CC
or VSS, no loads
on outputs
0
.5
mA
Input CSB
Input voltage low
0.3
VIO
Input voltage high
0.7
VIO
Hysteresis (note
1
)
VCC = 8.5V
0.1
V
Leakage current
Pin at V
IO
-
1
1
µA
Pull
-
up resistance
125
750
kOhm
Input SCLK
Input voltage low
0.3
VIO
Input voltage high
0.7
VIO
Hysteresis (note
1
)
VCC = 8.5V
0.1
V
Leakage current
Pin at
VSS
-
1
1
µA
Pull
-
down resistance
125
750
kOhm
Input SI
Input voltage low
0.3
VIO
Input voltage high
0.7
VIO
Hysteresis
(note
1
)
VCC = 8.5V
0.1
V
Leakage current
Pin at V
IO
or
VSS
-
1
1
µA
Output SO
Output voltage low
Iout < 500 µA
0.2
VIO
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 10 of 25 Device specification
Rev 2 Jun/12
Output
voltage high
Iout >
-
500 µA
0.8
VIO
Leakage current when in tri
-
state
Pin at V
IO
or
VSS
-
10
10
µA
Output ERRB
Output voltage low
Iout < 500 µA
0.3
V
High level output leakage
current
pin at V
IO
10
µA
Output SIN1P, SIN1M,
COS1P, COS1M, SIN2P,
SIN2M, COS2P, COS2M
Drop
-
out voltage for each pair
of buffers
VCC=8.5V, Tamb=25degC,
I=30mA
1.6
V
Mismatch of drop
-
out voltage
VCC=8.5V, Tamb=25degC,
I=30mA
-
50
50
mV
Output OUT3
Output voltage
low
VCC=8.5V, Tamb=25degC,
I=40mA
0.6
V
Output voltage high
VCC=8.5V, Tamb=25degC, I=
-
40mA
6.8
V
Table 6: Static electrical specifications
Note:
1. Not tested in production, guaranteed by design.
2. The voltage at VIO should never exceed the voltage at VCC.
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 11 of 25 Device specification
Rev 2 Jun/12
10.2 Dynamic characteristics
Table 7 shows the dynamic characteristics of the chip. DC Operating Parameters are default T
A
= -40
o
C to
105
o
C, V
sup
= 4.5V to 12V, unless otherwise specified.
Parameter. Symbol Test Conditions Min Typ Max Units
On chip oscillator
Clock frequency
Fclku
At
V
sup
= 12V, uncalibrated
0.7
1
1.
7
MHz
Absolute tolerance of the
clock frequency after
calibration
Tolclka
At
V
sup
= 12V
,
25
o
C
, after full
calibration to 1MHz
-
10
10
%
Temperature
variation of the
clock frequency after
calibration
Tolclkt
At
V
sup
= 12V, after full
calibration to 1MHz
-
6
6
%
Serial communication
Recommended Frequency of
SPI Operation
FSPI
0.5
1.0
MHz
Falling edge of CS
B
to Rising
Edge of SCLK (Required
Setup Time) (note 7)
TLEAD
20
ns
Falling edge of SCLK to
Rising Edge of CSB
(Required Setup Time) (note
7)
TLAG
20
ns
SI to Falling Edge of SCLK
(Required Setup Time) (note
7)
TSISU
75
ns
Falling Edge of SCLK to SI
(Required Hold Time) (note
7)
TSI
75
ns
SO Rise Time (CL=200pF)
(note 7)
TRSO
75
ns
SO Fall Time (CL=200pF)
(note 7)
TFSO
75
ns
SI, CS
B
, SCLK, Incoming
Signal Rise Time (Note 1, 7)
TRSI
75
ns
CS
B
, SCLK, Incoming Signal
Fall Time (Note 1, 7)
TFSI
75
ns
Rising Edge of CS
B
to
Falling Edge of CSB
(Required Setup Time) (Note
5, 7)
TCSB
32
µs
Rising Edge of
VCC
to
Falling Edge of CSB
(Required Setup Time) (Note
6, 7)
TEN
10
m
s
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 12 of 25 Device specification
Rev 2 Jun/12
Time from Falling Edge
of
CSB to SO Low Impedance
(Note 2, 7)
TSO_EN
150
ns
Time from Rising Edge of
CSB to SO High Impedance
(Note 3, 7)
TSO_DIS
150
n
s
Time from Rising Edge of
SCLK to SO Data Valid (Note
4, 7) 0.2 VCC < = SO> = 0.8
VCC, CL = 200 pF
TVALID
150
ns
Table 7: Dynamic characteristics MLX10420
Note:
1. Rise and Fall time of incoming SI, CSB, and SCLK signals suggested for design consideration to
prevent the occurrence of double pulsing.
2. Time required for output status data to be available for use at SO. 1 K Ohm load on SO.
3. Time required for output status data to be terminated at SO. 1 K Ohm load on SO.
4. Time required to obtain valid data out from SO following the rise of SCLK.
5. This value is for a 1 MHz calibrated internal clock; it will change proportionally as the internal clock
frequency changes.
Writing to register AIRCORE1 and AIRCORE2 need special attention. Consecutive writing to one of
these registers must have a delay of at least 256usec (with 1MHz on-chip oscillator). For more
information see 11.6.1.
6. The SPI interface can be used only after chip self-test (about 10mS at 1 MHz calibrated internal
clock).
7. This parameter is ‘guaranteed by design’, and not measured during production.
Figure 2: SPI timing characteristics
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 13 of 25 Device specification
Rev 2 Jun/12
11 Detailed block diagram description
11.1 Block diagram digital part
SPI
F-calibr.
Test
controller
Angle
latch
Error
Generator
POR
Self-test
logic
Counter/PWM
generator
MUX
PWM1
360
VIO
CS
DIN
DOUT
SCLK
POR
POR
Short/open circuit detector
Osc_calibr[2:0]
ROM
SIN/COS
converter
DATA[8:0]
Control
Control
F[8:0] PWM2
360
PWM3
90
Control
Control
TEST
PORB
RSTB
OSC OSC
POR
OSC
PWM1 Driver
PWM3 Driver
PWM2 Driver
Vdd(+5V)
F[8:0]
F[8:0]
F[8:0]
DATA[8:0]
DATA[8:0]
DATA[8:0]
Figure 3: Digital part block diagram
11.2 Gauge driver operation
11.2.1 Air-core meters 360°
Immediately after a reset, the chip checks if there is any short-circuit or open circuit on each buffer driver
output (This test is not made for output OUT3). For this test, each buffer is held in a high impedance state
and large internal resistances (100kΩ) are sequentially connected on each pair of buffers (note : the actuator
coil must be connected on each bridge).
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 14 of 25 Device specification
Rev 2 Jun/12
Figure 4: Test for short-circuits and open circuits
Three tests are done (see Figure 4):
condition test for :
Test 1 S1 closed, S2 open V1 = VSS
Test 2 S1 closed, S2 closed V1 = VCC/2
Test 3 S1 open, S2 closed V1 = VCC
Table 8: Self test description
During the tests the pin ERRB is at logic level 0. When the tests are finished ERRB stays at 0 if one (or more)
test fails or changes to high impedance state if everything is OK.
These tests last approximately 6 ms.
After the test all buffers are at VSS. The chip waits for the µP to send an angle/quadrant value and then
outputs a PWM signal on every buffer. Every air-core meter coil is connected in a bridge, so the current Icoil
can be either positive or negative. The total drop-out of a bridge is:
Vd = | VCC - Vcoil |
The four bridges have the same drop-out for the same current Icoil.
Figure 5: Full bridge configuration
11.2.2 air-core meter 90°
There is one PWM output for air-core meter 3.
During reset the driver is put at VCC.
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 15 of 25 Device specification
Rev 2 Jun/12
11.3 Angle tracking
The generation of the angle for the air-core meters 1 and 2 (the 360° air-core meters) consists of an angle
value and a quadrant definition. The chip continuously monitors that the angle values received are consistent.
If there is no continuity between two consecutive quadrant values sent (for AIRCORE1 or AIRCORE2) an
error is generated and the last received angle value is discarded. The previous values are kept and the µP
must initialize a new transmission to the chip. The error can be read via the ERRB output (see par. 11.5) or
via the status register (see par. 11.4.6).
If an angle value is sent to the chip with the control bit AT set to ‘0’, then the angle tracking is disabled and
the new angle value will always be accepted.
11.4 Serial link
11.4.1 Introduction
The SPI interface has a full duplex, three-wire synchronous, 16-bit serial synchronous interface data transfer
and four I/O lines associated with it: SI, SO, SCLK, and CSB. The SI/SO pins follow a first in / first out (D0 /
D15) protocol with both input and output words transferring the least significant bit first.
The I/O pins are supplied via the pin VIO. By connecting this pin VIO to the supply of the µP interface pins a
perfect interface is guaranteed for all types of µP.
11.4.2 Signal description
The Chip Select (CSB) pin enables communication with the master device. When this pin is in a logic [0]
state, the chip is capable of transferring information to, and receiving information from, the master. The chip
latches data in from the Input Shift registers to the addressed registers on the rising edge of CSB. The output
driver on the SO pin is enabled when CSB is logic [0]. When CSB is logic high, signals at the SCLK and SI
pins are ignored; the SO pin is tri-stated (high impedance). CSB will only be transitioned from a logic [1] state
to a logic [0] state when SCLK is a logic [0]. CSB has an internal pull-up connected to the pin.
SCLK clocks the Internal Shift registers of the chip. The Serial Input (SI) pin accepts data into the Input Shift
register on the falling edge of the SCLK signal while the Serial Output pin (SO) shifts data information out of
the SO Line Driver on the rising edge of the SCLK signal. It is important the SCLK pin be in a logic [0] state
whenever the CSB makes any transition. SCLK has an internal pull down. When CSB is logic [1], signals at
the SCLK and SI pins are ignored; SO is tri-stated (high impedance). See the Data Transfer Timing diagrams
in Figure 6 and Figure 7.
The SI pin is the input of the Serial Peripheral Interface (SPI). Serial Input (SI) information is read on the
falling edge of SCLK. A 16-bit stream of serial data is required on the SI pin, beginning with the least
significant bit (LSB). After transmitting a 16-bit word, the CSB pin has to make a transition to a logic [1] before
transmitting a new word. SI information is ignored when CSB is in a logic high state.
The Serial Output (SO) data pin is a tri-stateable output from the Shift register. The Status register bits will be
the first 16-bits shifted out. Those bits are followed by the message bits clocked in FIFO, when the device is
in a daisy chain connection, or being sent words of 16-bit multiples. Data is shifted on the rising edge of the
SCLK signal. The SO pin will remain in a high impedance state when the CSB pin is put into a logic high
state.
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 16 of 25 Device specification
Rev 2 Jun/12
11.4.3 Functional description
This section provides a description of the chip SPI behaviour. To follow the explanations below, please refer
to the timing diagrams shown in Figure 6 and Figure 7.
Pin Description
CSB (1 to 0) SO pin is enabled
CSB (0 to 1) The chip configuration and desired output states are transferred
and executed according to the data in the shift registers.
SO Will change state on the rising edge of the SCLK pin signal
SI Will accept data on the falling edge of the SCLK pin signal
Table 9: Data transfer timing
CSB
D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 D13 D14 D15
SCLK
OD0 OD1 OD2 OD3 OD4 OD5 OD6 OD7 OD8 OD9 OD10 OD11 OD12 OD13 OD14 OD15
SI
SO
Figure 6: Single 16-bit word SPI communication timing diagram
Figure 7: multiple 16-bit word SPI communication timing diagram
DATA INPUT
The input Shift register captures data at the falling edge of the SCLK clock. The SCLK clock pulses exactly
16 times only inside the transmission windows (CSB in a logic [0] state). By the time the CSB signal goes to
logic [1] again, the contents of the Input Shift register are transferred to the appropriate internal register,
according to the address contained in bits 1-3. The signal CSB should be kept high for a minimum time as
defined in Table 7. That data is specified in Figure 2. It must be long enough so that the internal clock is able
to capture the data from the input Shift register and transfer it to the internal registers.
DATA OUTPUT
At the first rising edge of the SCLK clock, with the CSB at logic [0], the contents of the Status Word register
are transferred to the Output Shift register. The first 16 bits clocked out are the status bits. If data continues to
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 17 of 25 Device specification
Rev 2 Jun/12
clock in before the CSB transitions to a logic [1], the device to shift out the data previously clocked in FIFO
after the CSB first transitioned to logic [0].
11.4.4 Communication memory maps
The chip is capable of interfacing directly with a micro controller, via the 16-bit SPI protocol described and
specified below. The device is controlled by the microprocessor and reports back status information via the
SPI. This section provides a detailed description of all registers accessible via serial interface. The various
registers control the behaviour of this device.
A message is transmitted by the master beginning with the LSB (D0) and ending with the MSB (D15).
Multiple messages can be transmitted in succession to accommodate those applications where daisy
chaining is desirable, or to confirm transmitted data, as long as the messages are all multiples of 16 bits.
Data is transferred through daisy chained devices, illustrated in Figure 7.
The chip uses seven registers to configure the device and control the state of the outputs. The registers are
addressed via D1-D3 of the incoming SPI word, as described in Table 10.
Address [D3:D1] Use Name
001 Writing request air-core 1 AIRCORE1
011 Writing request air-core 2 AIRCORE2
100 Writing request air-core 3 AIRCORE3
101 Chip reset RST
110 Oscillator calibration CAL
111, 010, 000 test TST
Table 10: Memory map
Writing to the test addresses will have no effect in normal operation mode, i.e. when input TEST is at VSS.
On the low to high transition of CSB the values in the receiver buffer are stored into the internal registers of
the chip if no angle tracking error was detected by the chip.
The chip outputs an error status on pin ERRB within 2usec after the rising edge of CSB. The output ERRB
goes back to tri-state at the next rising edge of CSB if no new angle tracking error is detected, or after chip
reset.. The error status can also read via the status register.
11.4.5 Register description
11.4.5.1 AIRCORE1
Address: 001
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D
3
D
2
D
1
D0
write
x P11 P12
P13
P14
P15
P16
P17
P18
P19
Q10
Q11
0 0 1 AT
These bits are write-only.
• P10 – P19: value of the requested angle, P11 is LSB.
• Q10 – Q11: value of the requested quadrant.
• AT: angle tracking is switched on if set to ‘1’, switched off if set to ‘0’.
11.4.5.2 AIRCORE2
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 18 of 25 Device specification
Rev 2 Jun/12
Address: 0
11
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D
3
D
2
D
1
D0
write
x P21 P22
P23
P24
P25
P26
P27
P28
P29
Q20
Q21
0 1 1 AT
These bits are write-only.
• P21 – P29: value of the requested angle.
• Q20 – Q21: value of the requested quadrant.
• AT: angle tracking is switched on if set to ‘1’, switched off if set to ‘0’.
11.4.5.3 AIRCORE3
Address:
1
00
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D
3
D
2
D
1
D0
write
x P31
P32 P33
P34
P35
P36
P37
P38
P39
x x 1 0 0 x
These bits are write-only.
• P31 – P39: value of the requested angle, P31 is LSB
11.4.5.4 CAL
Address: 1
1
0
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D
3
D
2
D
1
D0
write
x x x x x x x x x x x x 1 1 0 x
These bits are write-only.
Bits D0 and [D4:D15] are ‘don’t care’.
Principle of operation:
• The osc has 4 bits of trimming TRIM[3:0].
• After reset the oscillator starts at typical frequency (TRIM[3:0] = 1000).
• When the chip receives a CAL command it enters a special calibration mode.
o The oscillator is put to minimum frequency, i.e. TRIM[3:0] is reset to 0000.
o The uP will send pulses on the CSB line of 17.5 usec. During these pulses the SCLK line
must remain low. (Time between two consecutive pulses must be 10 usec minimum).
o During each of these pulses the chip counts a 4 bit counter to check its frequency.
o If the on chip frequency is too low it will increase its trimming state with 1.
o The uP can send as many pulses as he wants. After max 16 pulses the chip has its optimal
frequency.
o The chip leaves this mode as soon as a transition on SCLK is detected. This can be the first
rising edge of SCLK in a normal SPI communication.
o During the calibration mode the output SO remains in tri-state.
• During CAL, the drivers can be active, but can not change state.
• If the uP applies pulses longer or shorter than 17.5usec, the oscillator can be calibrated to an other
frequency (within its trimming range).
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 19 of 25 Device specification
Rev 2 Jun/12
Figure 8: Calibration sequence timing diagram
11.4.5.5 RST
Address:
101
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D
3
D
2
D
1
D0
write
x x x x x x x x x x x x 1 0 1 x
These bits are write-only.
All bits are ‘don’t care’.
When writing to this address, the chip will initiate an on-chip reset pulse when CSB goes high. The reset
signal will be active for one period of the on-chip oscillator. After that the normal startup sequence is started.
11.4.5.6 TEST
Any other codes are reserved for test. Users are not allowed to use these modes.
11.4.6 Status register
Status
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
read
0 0 0 0 0 0 0 0 0 0 0 0 EAT
EL2 EL1 x
These bits are read-only.
• EAT: angle tracking error. This bit is read as ‘1’ if an angle tracking error was detected during the
previous message.
• EL1: load error for driver AIRCORE1. This bit is set to ‘1’ if an error is detected during the self test
procedure after reset.
• EL2: load error for driver AIRCORE2. This bit is set to ‘1’ if an error is detected during the self test
procedure after reset.
• EAT: angle tracking. This bit is read as ‘1’ if an angle tracking error was detected for AIRCORE1 or
AIRCORE2 during the previous message.
Transmission of the status register is done beginning with the LSB (D0) and ending with the MSB (D15).
CSB
SCLK
SI
SO
D0:D15
OD0:OD15
cal.
mode
TRIM[3:0]
‘1000'
17.5usec
don't care
‘0000' ‘0001' ‘0010' ‘0011' ‘target'‘target' ‘target'
Calibration
command
> 10usec
17.5usec 17.5usec 17.5usec 17.5usec 17.5usec
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 20 of 25 Device specification
Rev 2 Jun/12
11.5 Error output
The chip has an error output ERRB. This is a pull down output driver. It is active low when indicating an error,
and tri-state when no error is indicated.
There are 3 possible indications:
• The chip is in reset – self test mode.
• Detection of error during the self test procedure following the reset (see par. 1311.2.1). In this case
the ERRB output remains low. It can only go to tri-state by restarting the self test procedure.
• Detection of an angle tracking error (if enabled). The chip outputs this error status within 2usec after
the rising edge of CSB. The output ERRB goes back to tri-state at the next rising edge of CSB if no
new angle tracking error is detected, or after chip reset.
11.6 PWM generation
11.6.1 Air-core meter 360
°
From the angle value received from the µP (range [0° - 89.8°]) the chip generates two PWM signals with 9
bits resolution:
• the first one represents the sine PWMSIN
• the second one is the cosine PWMCOS
The chip uses a ROM 512x9 which contains the sine of any angle in the range [0° - 89.8°] (note that the LSB
value of the angle is not used).
A value of angle greater than 90° is obtained using different quadrant values:
quadrant
D4:D5
angle
Q1 00 0°
≤
α
< 90°
Q2 01 90°
≤
α
< 180°
Q3 10 180°
≤
α
< 270°
Q4 11 270°
≤
α
< 360°
Table 11: Quadrant definition
The PWM signals are switched to the outputs depending on the value of the quadrant:
Figure 9: Quadrants and PWM sign
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 21 of 25 Device specification
Rev 2 Jun/12
quadrant
angle
D4:D5
SIN1M
SIN1P
COS1M
COS1P
Q1
0°
≤
α
< 90°
00 0 PWMSIN 0 PWMCOS
Q2
90°
≤
α
< 180°
01 0 PWMCOS PWMSIN 0
Q3
180°
≤
α
< 270°
10 PWMSIN 0 PWMCOS 0
Q4
270°
≤
α
< 360°
11 PWMCOS 0 0 PWMSIN
Reset = Q1 0 00 0 0 0 0
Table 12: PWM definition
air-core meter 1 is driven by outputs SIN1M/P and COS1M/P.
air-core meter 2 is driven by outputs SIN2M/P and COS2M/P.
The PWM frequency is given by FPWM = FOSC / 512 where FOSC is the frequency of the on chip
oscillator.
When the chip receives an SPI command that writes to AIRCORE1 or AIRCORE2, the received angle is
transferred to an intermediate latch at the rising edge of CSB. After that moment the received angle is verified
(if the angle tracking feature is enabled) within 32 usec. If accepted, the angle is transferred to the
corresponding PWM generator circuit at the start of the next PWM period. The delay between reception of the
SPI command and the transfer to the output will be not more than 256usecs typically. If the uP sends a next
SPI command to the same register before the previous data were sent to the PWM generator, the previous
data will be lost and overwritten by the new received angle. The risk exists that the air-core gauge meter
receives data from different, non-adjacent quadrants.
After reset the 4 outputs go to 0, meaning the angle is 0.
11.6.2 Air-core meter 90
°
The value in bits D6:D14, transmitted by the µP, is directly the PWM value. D0, D15 and the quadrant bits
D4:D5 are not used. A PWM of 0% corresponds to an output constantly at VCC, a PWM of 100%
corresponds to an output constantly at VSS.
When the chip receives an SPI command that writes to AIRCORE3, the received angle is transferred to an
intermediate latch at the rising edge of CSB. The angle is transferred to the corresponding PWM generator
circuit at the start of the next PWM period. The delay between reception of the SPI command and the transfer
to the output will be not more than 256usecs typically. If the uP sends a next SPI command to the same
register before the previous data were sent to the PWM generator, the previous data will be lost and
overwritten by the new received angle.
After reset the PWM is set to 0%, meaning the output goes to VCC.
11.7 Test
For efficient testing of the chip a test input pin TEST is foreseen.
This pin must be connected to VSS during normal operation.
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 22 of 25 Device specification
Rev 2 Jun/12
12 Applications Information
Following is an example of an application diagram with 2 360° air-core meters and 1 90° air-core meter.
Figure 10: Typical application diagram
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 23 of 25 Device specification
Rev 2 Jun/12
13 Standard information regarding manufacturability of Melexis
products with different soldering processes
Our products are classified and qualified regarding soldering technology, solderability and moisture sensitivity
level according to following test methods:
Reflow Soldering SMD’s (Surface Mount Devices)
• IPC/JEDEC J-STD-020
Moisture/Reflow Sensitivity Classification for Nonhermetic Solid State Surface Mount Devices
(classification reflow profiles according to table 5-2)
• EIA/JEDEC JESD22-A113
Preconditioning of Nonhermetic Surface Mount Devices Prior to Reliability Testing
(reflow profiles according to table 2)
Wave Soldering SMD’s (Surface Mount Devices) and THD’s (Through Hole Devices)
• EN60749-20
Resistance of plastic- encapsulated SMD’s to combined effect of moisture and soldering heat
• EIA/JEDEC JESD22-B106 and EN60749-15
Resistance to soldering temperature for through-hole mounted devices
Iron Soldering THD’s (Through Hole Devices)
• EN60749-15
Resistance to soldering temperature for through-hole mounted devices
Solderability SMD’s (Surface Mount Devices) and THD’s (Through Hole Devices)
• EIA/JEDEC JESD22-B102 and EN60749-21
Solderability
For all soldering technologies deviating from above mentioned standard conditions (regarding peak
temperature, temperature gradient, temperature profile etc) additional classification and qualification tests
have to be agreed upon with Melexis.
The application of Wave Soldering for SMD’s is allowed only after consulting Melexis regarding assurance of
adhesive strength between device and board.
Melexis is contributing to global environmental conservation by promoting lead free solutions. For more
information on qualifications of RoHS compliant products (RoHS = European directive on the Restriction Of
the use of certain Hazardous Substances) please visit the quality page on our website:
http://www.melexis.com/quality.aspx
14 ESD Precautions
Electronic semiconductor products are sensitive to Electro Static Discharge (ESD).
Always observe Electro Static Discharge control procedures whenever handling semiconductor products.
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 24 of 25 Device specification
Rev 2 Jun/12
15 Package Information
Figure 11: Package information drawing
SYMBOLS DIMENSIONS IN MILLIMETERS
MIN NOM MAX
A 1.73 1.86 1.99
A1 0.05 0.13 0.21
A2 1.68 1.73 1.78
B 0.25 0.38
C 0.09 0.20
D 7.07 7.20 7.33
E 5.20 5.30 5.38
e 0.65
H 7.65 7.80 7.90
L 0.63 0.75 0.95
N 20
α 0º 4º 8º
MLX10420AA
3-channel air-core gauge driver
with serial interface
3901010420 Page 25 of 25 Device specification
Rev 2 Jun/12
16 Disclaimer
Devices sold by Melexis are covered by the warranty and patent indemnification provisions appearing in its
Term of Sale. Melexis 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.
Melexis 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 Melexis 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
Melexis for each application.
The information furnished by Melexis is believed to be correct and accurate. However, Melexis 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, interrupt 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 Melexis’ rendering
of technical or other services.
© 2012 Melexis NV. All rights reserved.
For the latest version of this document, go to our website at
www.melexis.com
Or for additional information contact Melexis Direct:
Europe, Africa, Asia: America:
Phone: +32 1367 0495 Phone: +1 248 306 5400
E-mail: sales_europe@melexis.com E-mail: sales_usa@melexis.com
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