OPEN DOTS TECHNOLOGY SPECIFICATION
Maintained by
OPEN DOTS ALLIANCE
REVISION 1.1
ECO No.
Rev.
Date
1.0
1.1
11/18/2015 PRELIMINARY RELEASE
1/27/2016
INITIAL RELEASE
Open Dots Specifications
Description of Change
1
Rev 1.1
Figure 1. Contact Point Mechanical Configuration
Contact Point Pattern Mechanical Specifications
Symbol
Parameter
d
Contact Radius
e
Angular contact separation
Bottom surface flatness
r
Radial contact separation
Conditions
Flat contact does not short
adjacent pad electrodes
Center contact as vertex
Device engaged with pad
Measured center-to-center
from center contact
Min
Typ
Max
Units
1.8
mm
118
120
122
0.1
deg
mm
9.63
9.78
9.93
mm
Materials and Specifications
Item
Material
Ball bearings
302/304 stainless
Or Copper
Ball tolerance
Ball plating
Springs
Spring plating
Magnets
Printed circuit board pad plating (if nonsolder contact is used to mate with spring)
Open Dots Specifications
Bright electrolytic nickel
Phosphor-Bronze
BeCu
Nickel or Silver
Neodymium-iron-boron
Specification
ABMA Grade 100 or better
(+/-0.0025mm)
QQ-N290A
(0.0025 to 0.0076mm thick)
ASTM B 159
ASTM B 197
Commercial
N42
Direct solder or ENIG
2
Rev 1.1
Mechanical Forces and Magnetic Flux
Symbol
Parameter
Conditions
Min
Typ
Fs
Fm
Fe
Individual spring force
Total magnetic force
External magnetic flux
Ball protrusion = 0mm
Device resting on pad
Anywhere external to housing
40
90
500
TBD
Conditions
Min
Typ
Max
Units
gf
gf
mG
Power Receiver Specifications
Symbol
Parameter
Max
Units
20
V
Electrical Specifications
Vin
Input Voltage
Device operates normally
10.4
Ton
Startup Delay
Input current <100mA during
this period
100
Vsd
Imin
Rsu
Shutdown voltage
Minimum input current
Startup resistance
Tr
Restart time constant
Cr
Rectifier capacitance
Max Rectifier Capacitor Voltage
Droop over 10 s
Vd
Cin
Input capacitance
Id
Plp
Rc
Rectifier Diode Reverse Leakage
Max Power Draw, low-v pad
Contact Resistance
r
ms
9
9.5
10
10.4
8
10.5
0.3
1
3
sec
20
50
200
F/A
0.5
V
30
pF
20
20
100
A
W
Vin = 20V
Move device from one pad to
another
At working voltage
Full Rated Load, Lowest Input
Voltage, 10 s Input Dropout
Measured between any two
contact points
Vr = 20V, All operating temps
Device detects Vp < 15.5V
Device rests on Nickel Electrode
Receiver Efficiency
90
V
mA
kohm
2
m A
%
Environmental
To
Operating temperature
Ts
Ho
Hs
Storage temperature
Operating humidity
Storage humidity
Recommended Minimum Range
5
45
C
-40
20
5
60
80
95
C
%RH
%RH
Quality and Reliability
Vesd
ESD immunity
Pos or Neg, 100pF, 150ohms,
>50 hits with no damage
15
kV
Embedded Pull-Down Magnet Configuration
Open Dots Specifications
3
Rev 1.1
Optional Embedded Pull-Down Magnet Operation and Compatibility
Item
Consideration
Pull-Down Magnetic flux
Pull-Down Magnet Diameter
Pull-Down Magnet Thickness
Pull-Down Magnet Gap to Surface
Balance with Pull-Down Magnets
Pull-Down Magnetic Polarity
Must not erase credit cards or interfere with host device operation
6.35mm nom
1.6mm nom
u = 0.5mm
Device shall rest firmly on contact constellation and not easily tip
The South pole of the magnets shall interface with the Open Dots pad
Figure 2. Pad Electrode Mechanical Definition
Figure 3. Minimum Radius Defintion
Recommended Pad Base Specifications
Symbol
Parameter
N
Rmin
Number of strips
Minimum Bend Radius
Open Dots Specifications
Conditions
Min
2
120
4
Typ
Max
Units
mm
Rev 1.1
Materials
Item
Consideration
Pad Electrode Strips
Option A: 0.381mm thick cold rolled carbon steel post-plated bright nickel 0.005mm
Option B: 0.381mm thick 430 stainless steel pre-plated with bright nickel 0.005mm
Figure 4. Pad Base Cross Section
Pad Contiguous Active Area Electrode Mechanical Specifications
Symbol
Parameter
Conditions
A
B
C
d
h
Burr Relief Width
Ridge Width
Strip Gap
Burr Relief Depth
Ridge Height
W
Width of strip
G
S
T
Gap Width
Array Spacing
Contact Strip Thickness
Note: S = W + G
P
Surface Flatness
After assembly, including
insulating spacer r height
Min
Typ
0.51
0.75
1.86
10.34
0.25
0.53
0.45
Max
Units
0.55
mm
mm
mm
mm
mm
10.3
mm
1.9
12.2
0.4
0.55
mm
mm
mm
0.20
mm
Pad Electrical Specifications
Symbol
Parameter
Conditions
Min
Typ
Max
Units
Vp
Nominal Low Power Pad Voltage
Up to 49 Watts
14.5
15
15.5
V
P15
Vph
P20
Available Pad Power
Nominal High Power Pad Voltage
Available Pad Power
Pad Efficiency
15V pad
50 Watts and over
20V pad
Including Wall Adapter
20
19.5
45
80
20
45
20.5
200
W
V
W
%
r
Open Dots Specifications
5
Rev 1.1
Pad Foreign Object and Safety Response
Symbol
Parameter
Conditions
Min
Typ
Max
Units
Wtp
Test Pulse Width
Foreign object detection test
3
5
10
s
Ptp
Test Pulse Period
3
ms
Cpth
Imax
nF
%
rated
Capacitance Threshold (pad)
All foreign object detection tests
occur at least once per pulse
Foreign object detection test
2.0
2.5
Current Threshold
Pad Rated Power Limit
100
120
Rp
Maximum Detect Resistance
Resistance directly across pad
10
ts
Short Circuit Detection Delay
Short applied to pad
4
Ipk
Peak current
Short applied to pad
200
k
s
%
Rated
Pad Turn-On Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Units
Vdh
Turn-on Detector High Voltage
Pad Turn-On Test
2.7
2.8
2.9
V
Vdl
Turn-On Detector Low Voltage
Non-Linearity Threshold
= Vdh / (4 * Vdl)
Pad Turn-On Test
Turn-On begin due to nonlinear load detected
Turn-On fail due to too much
capacitance
0.6
0.7
0.8
V
2.5
nF
NLth
Cth
Over-Capacitance Threshold
0.75
2.0
Note: Specifications subject to change without notice. Open Dots assumes no responsibility or liability for errors, omissions, or otherwise changes in the
specifications.
Open Dots Specifications
6
Rev 1.1