MAX14851
General Description
The MAX14851 is a six-channel digital isolator utilizing
Maxim’s proprietary process technology, whose monolithic design provides a compact and low-cost transfer
of digital signals between circuits with different power
domains. The technology enables low power consumption and high channel density.
The four unidirectional channels are each capable of DC
to 50Mbps, with two of the four channels passing data
across the isolation barrier in each direction. The two
bidirectional channels are open-drain, each capable of
data rates from DC to 2Mbps.
Independent 3.0V to 5.5V supplies on each side of the
isolator also make it suitable for use as a level translator.
The MAX14851 can be used for isolating SPI buses, I2C
buses, RS-232, RS-485/RS-422 buses, and general-purpose isolation. When used as a bus isolator, extra channels are available for power monitoring and reset signals.
The MAX14851 is available in a 16-pin QSOP (3.9mm x
4.94mm) package. The device is specified over the -40°C
to +125°C temperature range.
Six-Channel Digital Isolator
Benefits and Features
●● Complete Digital Isolation Solution
• 600VRMS Isolation for 60 Seconds
• Short-Circuit Protection on Unidirectional Outputs
• 200VRMS Working Isolation Voltage
• Four Unidirectional Signal Paths: 2-In/2-Out
• Two Bidirectional Open-Drain Signal Paths
• 50Mbps (max) Unidirectional Data Rate
• 2Mbps (max) Bidirectional Data Rate
●● Compatible with Many Interface Standards
•
•
•
•
I2C
SPI
RS-232, RS-485/RS-422
SMBus, PMBus Interfaces
Ordering Information appears at end of data sheet.
Functional Diagram
VCCA
Applications
●●
●●
●●
●●
●●
●●
Industrial Control Systems
I2C, SPI, SMBus, PMBus™ Interfaces
Isolated RS-232, RS-485/RS-422
Telecommunication Systems
Battery Management
Medical Systems
VCCB
MAX14851
INA1
OUTB1
INA2
OUTB2
INB1
OUTA1
600VRMS
DIGITAL
ISOLATOR
OUTA2
PMBus is a trademark of SMIF, Inc.
19-100058; Rev 0; 6/17
INB2
I/OA1
I/OB1
I/OA2
I/OB2
GNDA
GNDB
MAX14851
Six-Channel Digital Isolator
Absolute Maximum Ratings
VCCA to GNDA.........................................................-0.3V to +6V
VCCB to GNDB.........................................................-0.3V to +6V
OUTA1, OUTA2 to GNDA........................ -0.3V to (VCCA + 0.3V)
OUTB1, OUTB2 to GNDB....................... -0.3V to (VCCB + 0.3V)
INA1, INA2 to GNDA................................................-0.3V to +6V
I/OA1, I/OA2 to GNDA............................. -0.3V to (VCCA + 0.3V)
INB1, INB2, I/OB1, I/OB2 to GNDB.........................-0.3V to +6V
OUTA1, OUTA2, OUTB1, OUTB2 Continuous Current....±30mA
I/OA1, I/OA2 Continuous Current......................................±30mA
I/OB1, I/OB2 Continuous Current....................................±100mA
Continuous Power Dissipation (TA = +70°C)
QSOP (derate 9.6mW/°C above +70°C)...................771.5mW
Junction Temperature.......................................................+150°C
Storage Temperature Range............................. -65°C to +150°C
Lead Temperature (soldering, 10s).................................. +300°C
Package Thermal Characteristics (Note 1)
QSOP
Junction-to-Ambient Thermal Resistance (θJA)......103.7°C/W
Junction-to-Case Thermal Resistance (θJC)................37°C/W
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
Stresses beyond those listed under “Absolute Maximum Ratings” 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 the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
DC Electrical Characteristics
(VCCA - VGNDA = 3.0V to 5.5V, VCCB - VGNDB = 3.0V to 5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at
VCCA - VGNDA = 3.3V, VCCB - VGNDB = 3.3V, and TA = +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNIT
VOLTAGE SUPPLY
Supply Voltage
VCCA
Relative to GNDA
3.0
5.5
VCCB
Relative to GNDB
3.0
5.5
All inputs static at GND_
or VCC_. No load.
Supply Current
ICCA,
ICCB
Undervoltage Lockout
Threshold
VUVLO_
Undervoltage Lockout
Hysteresis
VUVLOHYS
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All inputs switching
(INA_, INB_ at 50Mbps
and I/OA_ at 2Mbps).
No load. (Note 3)
VCC_ rising (Note 4)
(Note 4)
VCCA = +5V
4
6.9
VCCB = +5V
3.6
6.1
VCCA = +3.3V
3.6
6.2
VCCB = +3.3V
3.2
5.5
VCCA = +5V
6.4
10.2
VCCB = +5V
5.8
9.2
VCCA = +3.3V
4.6
7.6
VCCB = +3.3V
4.1
6.7
2.6
2.85
2.45
55
V
mA
V
mV
Maxim Integrated │ 2
MAX14851
Six-Channel Digital Isolator
DC Electrical Characteristics (continued)
(VCCA - VGNDA = 3.0V to 5.5V, VCCB - VGNDB = 3.0V to 5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at
VCCA - VGNDA = 3.3V, VCCB - VGNDB = 3.3V, and TA = +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNIT
UNIDIRECTIONAL LOGIC INPUTS AND OUTPUTS (INA_, INB_, OUTA_, OUTB_)
Input Logic-High Voltage
Input Logic-Low Voltage
Input Hysteresis
Input Leakage Current
Input Capacitance
INA_ relative to GNDA
0.7 x
VCCA
INB_ relative to GNDB
0.7 x
VCCB
VIH
VIL
VHYST
IL
CIN
Output Logic-High
Voltage
VOH
Output Logic-Low
Voltage
VOL
V
INA_ relative to GNDA
0.8
INB_ relative to GNDB
0.8
INA_ relative to GNDA
0.45
INB_ relative to GNDB
0.45
INA_/INB_ = 0 or VCC_
-1
INA_, INB_, f = 1MHz
V
+1
2
OUTA_ relative to GNDA,
source current = 4mA
VCCA
- 0.4
OUTB_ relative to GNDB,
source current = 4mA
VCCB
- 0.4
V
µA
pF
V
OUTA_ relative to GNDA, sink current = 4mA
0.4
OUTB_ relative to GNDB, sink current = 4mA
0.4
V
BIDIRECTIONAL LOGIC INPUTS AND OUTPUTS (I/OA_, I/OB_)
Input Threshold Voltage
VIT
Input Logic-High Voltage
VIH
Input Logic-Low Voltage
VIL
Input/Output Logic-Low
Threshold Difference
∆VTOL
Input Hysteresis
VHYST
Input Leakage Current
Output Logic-Low
Voltage
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IL
VOL
I/OA_ relative to GNDA
0.5
I/OA_ relative to GNDA
0.7
I/OB_ relative to GNDB
0.5 x
VCCB
0.7
V
I/OA_ relative to GNDA
0.5
I/OB_ relative to GNDB
0.3 x
VCCB
I/OA_ relative to GNDA, 0.5mA ≤ IOUT ≤ 3.5mA
sink current (Note 6)
50
75
I/OB_ relative to GNDB
200
mV
I/OA_ = VCCA
-2
+10
I/OB_ = VCCB
-1
+1
0.65
0.8
I/OB_ relative to GNDB, IOUT = 35mA sink current
V
mV
I/OA_ relative to GNDA
I/OA_ relative to GNDA, 0.5mA ≤ IOUT ≤ 3.5mA
sink current
V
µA
V
0.4
Maxim Integrated │ 3
MAX14851
Six-Channel Digital Isolator
Switching Electrical Characteristics
(VCCA - VGNDA = 3.0V to 5.5V, VCCB - VGNDB = 3.0V to 5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at
VCCA - VGNDA = 3.3V, VCCB - VGNDB = 3.3V, and TA = +25°C.) (Note 3)
PARAMETER
SYMBOL
Common-Mode Transient
Immunity
CMTI
CONDITIONS
MIN
VIN_, I/O_ = VCC_ or VGND_ (Note 7)
TYP
MAX
3.2
UNIT
kV/µs
UNIDIRECTIONAL DYNAMIC SWITCHING CHARACTERISTICS (INA_, INB_, OUTA_, OUTB_)
Maximum Data Rate
DRMAX
INA_ to OUTB_, INB_ to OUTA_
Minimum Pulse Width
PWMIN
INA_ to OUTB_, INB_ to OUTA_
tDPLH
Propagation Delay
tDPHL
Pulse-Width Distortion
|tDPLH – tDPHL|
PWD
4.5V ≤ VCC_ ≤ 5.5V
4.0
11.8
3.0V ≤ VCC_≤ 3.6V
4.0
13.3
4.5V ≤ VCC_≤ 5.5V
4.3
11.6
3.0V ≤ VCC_≤ 3.6V
4.4
13.4
4.5V ≤ VCC_ ≤ 5.5V
2.9
3.0V ≤ VCC_ ≤ 3.6V
2.6
2
∆tDPLH, ∆tDPHL (Note 8)
8
tR
OUTA_, OUTB_, 10% to 90%, CL = 15pF,
Figure 1
5
tF
OUTA_, OUTB_, 90% to 10%, CL = 15pF,
Figure 1
5
tDSKEWPP
ns
ns
ns
OUTA1 to OUTA2 output skew, Figure 1
(Notes 8)
Part-to-Part Skew
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20
2
tDSKEWCC
Fall Time
INA_ to OUTB_, INB_
TO OUTA_, RL = 1MΩ,
CL = 15pF, Figure 1
(Note 8)
Mbps
OUTB1 to OUTB2 output skew, Figure 1
(Note 8)
Channel-to-Channel
Skew
Rise Time
INA_ to OUTB_, INB_ to
OUTA_, RL = 1MΩ, CL
= 15pF, Figure 1
50
ns
ns
ns
Maxim Integrated │ 4
MAX14851
Six-Channel Digital Isolator
Switching Electrical Characteristics (continued)
(VCCA - VGNDA = 3.0V to 5.5V, VCCB - VGNDB = 3.0V to 5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at
VCCA - VGNDA = 3.3V, VCCB - VGNDB = 3.3V, and TA = +25°C.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNIT
BIDIRECTIONAL DYNAMIC SWITCHING CHARACTERISTICS (I/OA_, I/OB_)
Maximum Data Rate
DRMAX
tPLHAB
tPHLAB
I/OA_ to I/OB_, I/OB_ to I/OA_
I/OA_ = 0.5V to I/OB_ =
0.7 x VCCB, CA = CB =
10pF, Figure 2
I/OA_ = 0.5V to I/OB_ =
0.4V, CA = CB = 10pF,
Figure 2
Propagation Delay
tPLHBA
tPHLBA
I/OB_ = 0.3V x VCCB to
I/OA_ = 0.9V, CA = CB
= 10pF, Figure 2
PWDAB
|tPLHAB – tPHLAB|
(Note 8)
PWDBA
|tPLHBA – tPHLBA|
(Note 8)
Pulse-Width Distortion
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I/OB_ = 0.5V x VCCB to
I/OA_ = 0.7 x VCCA, CA
= CB = 10pF, Figure 2
2
Mbps
4.5V ≤ VCC_ ≤ 5.5V,
RA = 1430W,
RB = 143W
25.4
85.8
3.0V ≤ VCC_ ≤ 3.6V,
RA = 953W,
RB = 95.3W
26.3
93.0
4.5V ≤ VCC_ ≤ 5.5V,
RA = 1430W,
RB = 143W
42.2
144.3
3.0V ≤ VCC_ ≤ 3.6V,
RA = 953W,
RB = 95.3W
49.5
189.0
4.5V ≤ VCC_ ≤ 5.5V,
RA = 1430W,
RB = 143W
43.7
122.9
3.0V ≤ VCC_ ≤ 3.6V,
RA = 953W,
RB = 95.3W
32.1
94.2
4.5V ≤ VCC_ ≤ 5.5V,
RA = 1430W,
RB = 143W
28.9
133.8
3.0V ≤ VCC_ ≤ 3.6V,
RA = 953W,
RB = 95.3W
29.6
117.2
ns
4.5V ≤ VCC_ ≤ 5.5V
62.2
3.0V ≤ VCC_ ≤ 3.6V
100.4
4.5V ≤ VCC_ ≤ 5.5V
32.0
3.0V ≤ VCC_ ≤ 3.6V
37.0
ns
Maxim Integrated │ 5
MAX14851
Six-Channel Digital Isolator
Switching Electrical Characteristics (continued)
(VCCA - VGNDA = 3.0V to 5.5V, VCCB - VGNDB = 3.0V to 5.5V, TA = -40°C to +125°C, unless otherwise noted. Typical values are at
VCCA - VGNDA = 3.3V, VCCB - VGNDB = 3.3V, and TA = +25°C.) (Note 3)
PARAMETER
SYMBOL
tFA
tFB
CONDITIONS
I/OA_ = 0.7 x VCCA to
0.3 x VCCA, CA = 40pF,
Figure 2
I/OB_ = 0.7 x VCCB
to 0.3 x VCCB, CB =
400pF, Figure 2
Fall Time
tFA
tFB
I/OA_ = 0.9 x VCCA
to 900mV, CA = 40pF
Figure 2
I/OB_ = 0.9 x VCCB to
400mV, CB = 400pF,
Figure 2
MIN
TYP
MAX
4.5V ≤ VCC_ ≤ 5.5V,
RA = 1430W
8.3
33.4
3.0V ≤ VCC_ ≤ 3.6V,
RA = 953W
8.8
43.8
4.5V ≤ VCC_ ≤ 5.5V,
RB = 143W
10.5
33.2
3.0V ≤ VCC_ ≤ 3.6V,
RB = 95.3W
12.9
48.3
4.5V ≤ VCC_ ≤ 5.5V,
RA = 1430W
16.1
86.7
3.0V ≤ VCC_ ≤ 3.6V,
RA = 953W
14.5
67.4
4.5V ≤ VCC_ ≤ 5.5V,
RB = 143W
23.0
75.1
3.0V ≤ VCC_ ≤ 3.6V,
RB = 95.3W
26.9
104.7
UNIT
ns
Note 2: All units are production tested at TA = +25°C. Specifications over temperature are guaranteed by design. All voltages of side
A are referenced to GNDA. All voltages of side B are referenced to GNDB, unless otherwise noted.
Note 3: Guaranteed by design. Not production tested.
Note 4: The undervoltage lockout threshold and hysteresis guarantee that the outputs are in a known state during a slump in the
supplies. See the Detailed Description section for more information.
Note 5: ΔVTOL = VOL – VIL. This is the minimum difference between the output logic-low voltage and the input logic threshold for
the same I/O pin. This ensures that the I/O channels are not latched low when any of the I/O inputs are driven low (see the
Bidirectional Channels section).
Note 6: CMTI is the maximum sustainable common-mode voltage slew rate while maintaining the correct output. CMTI applies to
both rising and falling common-mode voltage edges. Tested with the transient generator connected between GNDA and
GNDB.
Note 7: Pulse-width distortion is defined as the difference in propagation delay between low-to-high and high-to-low transitions on
the same channel. Channel-to-channel skew is defined as the difference in propagation delay between different channels on
the same device. Part-to-part skew is defined as the difference in propagation delays (for unidirectional channels) between
different devices, when both devices operate with the same supply voltage, at the same temperature and have identical
package and test circuits.
ESD Protection
PARAMETER
ESD
www.maximintegrated.com
SYMBOL
CONDITIONS
Human Body Model, all pins
MIN
TYP
±4
MAX
UNITS
kV
Maxim Integrated │ 6
MAX14851
Six-Channel Digital Isolator
Insulation and Safety Characteristics
PARAMETER
SYMBOL
CONDITIONS
VALUE
UNIT
Maximum Repetitive Peak
Isolation Voltage
VIORM
(Note 8)
282
VP
Maximum Working Isolation
Voltage
VIOWM
Continuous RMS voltage (Note 8)
200
VRMS
Maximum Transient Isolation
Voltage
VIOTM
t = 1s
850
VP
fSW = 60Hz, duration = 60s (Notes 8, 9)
600
VRMS
Maximum Withstand Isolation
Voltage
Maximum Surge Isolation Voltage
VISO
VIOSM
Basic insulation, 1.2/50µs pulse per IEC 61000-4-5
1
kV
>109
Ω
fSW = 1MHz (Note10)
12
pF
CPG
QSOP
3.2
mm
CLR
QSOP
3.2
mm
0.0026
mm
>400
V
Insulation Resistance
RS
TA = 150ºC, VIO = 500V
Barrier Capacitance Side A to
Side B
CIO
External Tracking (Creepage)
External Air Gap (Clearance)
Internal Clearance
Comparative Tracking Index
Distance through insulation
CTI
Material Group II (IEC 60112)
Climatic Category
Pollution Degree (DIN VDE 0110,
Table 1)
40/125/21
2
Note 8: VISO, VIOWM, and VIORM are defined by the IEC 60747-5-5 standard.
Note 9 Product is qualified at VISO for 60s and 100% production tested at 120% of VISO for 1s.
Note 10: Capacitance is measured with all pins on the field-side and logic-side tied together.
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Maxim Integrated │ 7
MAX14851
Six-Channel Digital Isolator
Test Circuits/Timing Diagrams
VCCA
INA1, INA2
VCCA
0.1µF
0.1µF
VCCA
GNDA
VCCB
VCCB
50%
50%
tDPLH
tDPHL
VCCB
MAX14851
OUTB1
50Ω
INA_
GNDA
50%
GNDB
OUTB_
CL
TEST
SOURCE
50%
tDSKEWCC
VCCB
90%
50%
OUTB2
RL
GNDB
GNDB
(A)
tDSKEWCC
50%
10%
tF
tR
(B)
Figure 1. Test Circuit (A) and Timing Diagram (B) for Unidirectional Channels
VCCA
R1
0.1µF
0.1µF
VCCB
VCCA
R2
VCCB
MAX14851
I/OA_
CL1
I/OB_
GNDA
CL2
GNDB
TEST
SOURCE
(A)
VCCA
I/OA1, I/OA2
VCCB
50%
GNDA
I/OB1, I/OB2
50%
GNDB
tDPLH
tDPHL
VCCB
50%
I/OB1
50%
50%
50%
tDPLH
tDPHL
VCCA
50%
I/OA1
VOL(min)
50%
VOL(min)
VCCB
VCCA
90%
I/OB2
90%
I/OA2
VOL(min)
tF
10%
VOL(min)
(B)
tF
10%
(C)
Figure 2. Test Circuit (A) and Timing Diagrams (B) and (C) for Bidirectional Channels
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Maxim Integrated │ 8
MAX14851
Six-Channel Digital Isolator
Typical Operating Characteristics
(VCCA – VGNDA = 3.3V, VCCB – VGNDB = 3.3V, all inputs idle, TA = +25°C, unless otherwise noted.)
9
ICCA vs DATA RATE
8
INB1 and INB2
Switching
5
4
5
4
3
3
2
2
2
1
1
1
0
0.001
0
0.001
0.1
1
10
100
0.01
0.1
toc04
10
1kΩ PULLUPS ON I/OA_ AND I/OB_
0
0.001
100
0.01
0.1
toc05
toc06
6
TA = +125ºC
5
4
I/OB1 and I/OB2
Switching
3
5
5
4
4
ICCB (mA)
ICCA (mA)
6
3
3
TA = -40ºC
TA = +25ºC
2
TA = +25ºC
TA = +125ºC
2
TA = -40ºC
2
1
1
1
1kΩ PULLUPS ON I/OA_ AND I/OB_
0
0.001
0
0.01
0.1
1
10
0
3.0
3.5
4.0
DATA RATE (MHz)
ICC vs TEMPERATURE
4.5
5.0
5.5
3.0
toc07
OUTA_ VOH vs
SOURCE CURRENT
5.0
toc08
ICCB
1
0
20 35 50 65 80 95 110 125
TEMPERATURE (ºC)
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5.5
toc09
1.6
VCCA = 5V
3.5
1.4
3.0
1.2
2.5
VCCA = 3.3V
2.0
1.5
VCCA = 5V
1.0
0.8
VCCA = 3.3V
0.6
1.0
0.4
0.5
0.2
0.0
-40 -25 -10 5
5.0
OUTA_ VOL vs
SINK CURRENT
2.0
OUTA_ VOL (V)
3
OUTA_ VOH (V)
4
4.5
1.8
4.0
ICCA
2
4.0
VCCB (V)
4.5
5
3.5
VCCA (V)
6
SUPPLY CURRENT (mA)
10
ICCB vs VCCB
7
6
7
7
1
DATA RATE (MHz)
ICCA vs VCCA
7
I/OA1 and I/OA2
Switching
8
1
I/OA1 and I/OA2
Switching
DATA RATE (MHz)
ICCB vs DATA RATE
9
I/OB1 and I/OB2
Switching
6
3
0.01
toc03
7
INA1 and INA2
Switching
6
DATA RATE (MHz)
ICCB (mA)
9
8
7
4
ICCA vs DATA RATE
10
8
INA1 and INA2
Switching
5
toc02
OUTA_/OUTB_ NOT CONNECTED TO PCB
9
ICCB (mA)
6
ICCB vs DATA RATE
10
INB1 and INB2
Switching
7
ICCA (mA)
toc01
OUTA_/OUTB_ NOT CONNECTED TO PCB
ICCA (mA)
10
0.0
0
5
10
15
ISOURCE (mA)
20
25
30
0
5
10
15
20
25
30
ISINK (mA)
Maxim Integrated │ 9
MAX14851
Six-Channel Digital Isolator
Typical Operating Characteristics (continued)
(VCCA – VGNDA = 3.3V, VCCB – VGNDB = 3.3V, all inputs idle, TA = +25°C, unless otherwise noted.)
OUTB_ VOH vs
SOURCE CURRENT
5.0
toc10
4.5
OUTB_ VOL (V)
3.0
2.5
2.0
PROPAGATION DELAY (ns)
1.4
VCCB = 3.3V
1.5
1.2
VCCB = 5V
1.0
0.8
VCCB = 3.3V
0.6
1.0
0.4
0.5
0.2
0.0
15
20
25
30
5
10
ISOURCE (mA)
toc13
PROPAGATION DELAY (ns)
8
6
VGNDA-VGNDB = -100V
VCCA = VCCB
INA_ to OUTB_
HIGH TO LOW TRANSITION
2
3.5
4.0
4.5
5.0
10
8
6
HIGH TO LOW
10
20
30
40
50
60
70
80
PROPAGATION DELAY
vs. TEMPERATURE
4.5
VCCA (V)
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5.0
5.5
5.5
toc15
10
LOW TO HIGH
8
6
HIGH TO LOW
4
INA_ TO OUTB_
0
90 100
-40 -25 -10 5
20 35 50 65 80 95 110 125
TEMPERATURE (ºC)
PROPAGATION DELAY
vs. SUPPLY VOLTAGE
toc17
PROPAGATION DELAY
vs. CAPACITIVE LOAD
20
toc18
18
VGNDA-VGNDB = -100V
8
6
VGNDA-VGNDB = +100V
4
VGNDA-VGNDB = 0V
VCCA = VCCB
INB_ TO OUTA_
HIGH TO LOW TRANSITION
3.0
3.5
4.0
VCCA (V)
4.5
5.0
16
14
12
HIGH TO LOW
10
8
6
4
LOW TO HIGH
2
INB_ TO OUTA_
0
0
4.0
5.0
2
2
0
4.5
INA_ TO OUTB_
12
PROPAGATION DELAY (ns)
VCCA = VCCB
INB_ TO OUTA_
LOW TO HIGH TRANSITION
3.5
4.0
4
10
VGNDA-VGNDB = 0V
3.0
3.5
14
toc14
12
0
toc16
6
2
3.0
30
LOW TO HIGH
14
5.5
VGNDA-VGNDB = -100V
4
VCCA = VCCB
INA_ to OUTB_
LOW TO HIGH TRANSITION
12
0
VGNDA-VGNDB = +100V
8
VGNDA-VGNDB = 0V
4
CL (pF)
PROPAGATION DELAY
vs. SUPPLY VOLTAGE
10
25
16
VCCA (V)
12
6
VCCA (V)
2
0
3.0
20
18
VGNDA-VGNDB = 0V
4
15
PROPAGATION DELAY
vs. CAPACITIVE LOAD
20
VGNDA-VGNDB = +100V
10
8
ISINK (mA)
PROPAGATION DELAY vs
SUPPLY VOLTAGE
12
VGNDA-VGNDB = +100V
0
0
PROPAGATION DELAY (ns)
10
PROPAGATION DELAY (ns)
5
toc12
VGNDA-VGNDB = -100V
2
0.0
0
PROPAGATION DELAY (ns)
PROPAGATION DELAY vs
SUPPLY VOLTAGE
12
10
1.6
VCCB = 5V
3.5
PROPAGATION DELAY (ns)
toc11
1.8
4.0
OUTB_ VOH (V)
OUTB_ VOL vs
SINK CURRENT
2.0
5.5
0
10
20
30
40
50
60
70
80
90 100
CL (pF)
Maxim Integrated │ 10
MAX14851
Six-Channel Digital Isolator
Typical Operating Characteristics (continued)
(VCCA – VGNDA = 3.3V, VCCB – VGNDB = 3.3V, all inputs idle, TA = +25°C, unless otherwise noted.)
toc19
PROPAGATION DELAY
vs. SUPPLY VOLTAGE
90
PROPAGATION DELAY (ns)
PROPAGATION DELAY (ns)
80
HIGH TO LOW
9
8
7
6
LOW TO HIGH
5
4
3
2
70
VGNDA-VGNDB = 0V
40
VGNDA-VGNDB = +100V
30
1
INB_ TO OUTA_
0
-40 -25 -10 5
3.0
3.5
PROPAGATION DELAY
vs. TEMPERATURE
toc22
70
60
LOW TO HIGH
40
I/OA_ TO I/OB_
PULLUP = 1kΩ _
20
-40 -25 -10 5
20 35 50 65 80 95 110 125
PROPAGATION DELAY
vs. TEMPERATURE
5.0
VGNDA-VGNDB = 0V
50
VGNDA-VGNDB = -100V
3.0
5.5
3.5
80
60
50
30
3.5
4.0
4.5
5.0
toc25
OUTA EYE DIAGRAM
(VGNDA - VGNDB = 0V)
70
5.5
5.5
toc24
VGNDA-VGNDB = -100V
60
50
40
VGNDA-VGNDB = 0V
30
VGNDA-VGNDB = -100V
3.0
5.0
VCCA = VCCB
I/OB_ TO I/OA_
HIGH TO LOW TRANSITION
PULLUP = 1kΩ
80
VGNDA-VGNDB = 0V
40
4.5
PROPAGATION DELAY
vs. SUPPLY VOLTAGE
90
toc23
VGNDA-VGNDB = +100V
70
4.0
VCCA (V)
VCCA (V)
TEMPERATURE (ºC)
90
4.5
VCCA = VCCB
I/OB_ TO I/OA_
LOW TO HIGH TRANSITION
PULLUP = 1kΩ
90
PROPAGATION DELAY (ns)
PROPAGATION DELAY (ns)
80
30
4.0
PROPAGATION DELAY
vs. SUPPLY VOLTAGE
100
HIGH TO LOW
50
60
VCCA (V)
TEMPERATURE (ºC)
90
VGNDA-VGNDB = +100V
70
30
20
20 35 50 65 80 95 110 125
80
40
VGNDA-VGNDB = -100V
toc21
VCCA = VCCB
I/OA_ TO I/OB_
HIGH TO LOW TRANSITION
PULLUP = 1kΩ
90
60
50
PROPAGATION DELAY
vs. SUPPLY VOLTAGE
100
VCCA = VCCB
I/OA_ TO I/OB_
LOW TO HIGH TRANSITION
PULLUP = 1kΩ
11
10
toc20
PROPAGATION DELAY (ns)
PROPAGATION DELAY
vs. TEMPERATURE
PROPAGATION DELAY (ns)
12
VGNDA-VGNDB = +100V
20
3.0
3.5
4.0
4.5
5.0
5.5
VCCA (V)
OUTA EYE DIAGRAM
(VGNDA - VGNDB = ±300VAC)
toc26
toc27
PROPAGATION DELAY (ns)
80
70
60
HIGH TO LOW
OUTA
1V/div
OUTA
1V/div
0V
0V
50
40
30
GNDA - GNDB
GNDA - GNDB
I/OB_ TO I/OA_
PULLUP = 1kΩ _
20
-40 -25 -10 5
20 35 50 65 80 95 110 125
300V/div
0V
300V/div
0V
LOW TO HIGH
5ns/div
5ns/div
TEMPERATURE (ºC)
www.maximintegrated.com
Maxim Integrated │ 11
MAX14851
Six-Channel Digital Isolator
Pin Configuration
TOP VIEW
+
16 VCCB
VCCA
1
INA1
2
INA2
3
OUTA1
4
OUTA2
5
12 INB2
I/OA1
6
11 I/OB1
I/OA2
7
10 I/OB2
GNDA
8
9
15 OUTB1
MAX14851
14 OUTB2
13 INB1
GNDB
QSOP
Pin Description
PIN
NAME
1
VCCA
Supply Voltage of Logic Side A. Bypass VCCA with a 0.1µF ceramic
capacitor to GNDA.
GNDA
2
INA1
Logic Input 1 on Side A. INA1 is translated to OUTB1.
GNDA
3
INA2
Logic Input 2 on Side A. INA2 is translated to OUTB2.
GNDA
4
OUTA1
Logic Output 1 on Side A. OUTA1 is a push-pull output.
GNDA
5
OUTA2
Logic Output 2 on Side A. OUTA2 is a push-pull output.
GNDA
6
I/OA1
Bidirectional Input/Output 1 on Side A. I/OA1 is translated to/from I/OB1
and is an open-drain output.
GNDA
7
I/OA2
Bidirectional Input/Output 2 on Side A. I/OA2 is translated to/from I/OB2
and is an open-drain output.
GNDA
8
GNDA
Ground Reference for Side A
—
9
GNDB
Ground Reference for Side B
—
10
I/OB2
Bidirectional Input/Output 2 on Side B. I/OB2 is translated to/from I/OA2
and is an open-drain output.
GNDB
11
I/OB1
Bidirectional Input/Output 1 on Side B. I/OB1 is translated to/from I/OA1
and is an open-drain output.
GNDB
12
INB2
Logic Input 2 on Side B. INB2 is translated to OUTA2.
GNDB
13
INB1
Logic Input 1 on Side B. INB1 is translated to OUTA1.
GNDB
14
OUTB2
Logic Output 2 on Side B. OUTB2 is a push-pull output.
GNDB
15
OUTB1
Logic Output 1 on Side B. OUTB1 is a push-pull output.
GNDB
16
VCCB
Supply Voltage of Logic Side B. Bypass VCCB with a 0.1µF ceramic
capacitor to GNDB.
GNDB
www.maximintegrated.com
FUNCTION
REFERENCE
Maxim Integrated │ 12
MAX14851
Six-Channel Digital Isolator
Detailed Description
Unidirectional Channels
The MAX14851 is a six-channel digital isolator. The
device is rated for 600VRMS isolation voltage for 60
seconds. This digital isolator offers a low power, lowcost, and high electromagnetic interference (EMI) immunity through Maxim’s proprietary process technology.
The device uses a monolithic solution to isolate different
ground domains and block high-voltage/high-current transients from sensitive or human interface circuitry. Four of
the six channels are unidirectional, two in each direction.
All four unidirectional channels support data rates of up
to 50Mbps. The other two channels are bidirectional with
data rates up to 2Mbps.
Isolation of I2C, SPI/MICROWIRE®, and other serial
busses can be achieved with the MAX14851. The
device features two supply inputs, VCCA and VCCB, that
independently set the logic levels on either side of the
device. VCCA and VCCB are referenced to GNDA and
GNDB, respectively. The MAX14851 also features a
refresh circuit to ensure output accuracy when an input
remains in the same state indefinitely.
Digital Isolation
The MAX14851 provides galvanic isolation for digital
signals that are transmitted between two ground domains.
Up to 200VRMS of continuous isolation is supported as
well as transient differences of up to 850V.
Level Shifting
In addition to isolation, the MAX14851 can be used for
level translation. VCCA and VCCB can be independently
set to any voltage from 3.0V to 5.5V. The supply voltage
sets the logic level on the corresponding side of the isolator.
Unidirectional and Bidirectional Channels
The MAX14851 operates both as a unidirectional device
and bidirectional device simultaneously. Each unidirectional channel can only be used in the direction shown in
the functional diagram. The bidirectional channels function without requiring a direction control input.
The device features four unidirectional channels that
operate independently with guaranteed data rates from
DC to 50Mbps. The output driver of each unidirectional
channel is push-pull, eliminating the need for pullup resistors. The outputs are able to drive both TTL and CMOS
logic inputs.
Bidirectional Channels
The device features two bidirectional channels that have
open-drain outputs. The bidirectional channels do not
require a direction control input. A logic-low on one side
causes the corresponding pin on the other side to be
pulled low while avoiding data latching within the device.
The input logic-low thresholds (VIT) of I/OA1 and I/OA2
are at least 50mV lower than the output logic-low voltages
of I/OA1 and I/OA2. This prevents an output logic-low on
side A from being accepted as an input low and subsequently transmitted to side B, thus preventing a latching
action.
The I/OA1, I/OA2, I/OB1, and I/OB2 pins have open-drain
outputs, requiring pullup resistors to their respective
supplies for logic-high outputs. The output low voltages are guaranteed for sink currents of up to 35mA
for side B, and 3.5mA for side A (see the DC Electrical
Characteristics table).
Startup and Undervoltage Lockout
The VCCA and VCCB supplies are both internally
monitored for undervoltage conditions. Undervoltage
events can occur during power-up, power-down, or during
normal operation due to a slump in the supplies. When an
undervoltage event is detected on either of the supplies, all
outputs on both sides are automatically controlled, regardless of the status of the inputs (Table 1). The bidirectional
outputs become high impedance and are pulled high by the
external pullup resistor on the open-drain output. The unidirectional outputs are pulled high internally to the voltage of
the VCCA or VCCB supply during undervoltage conditions.
Table 1. Output Behavior During Undervoltage Conditions
VIN
VCCA
VCCB
VOUTA_
VOUTB_
1
Powered
Powered
1
1
0
Powered
Powered
0
0
X
Under Voltage
Powered
Follows VCCA
1
X
Powered
Under Voltage
1
Follows VCCB
www.maximintegrated.com
Maxim Integrated │ 13
MAX14851
Six-Channel Digital Isolator
Figure 3 shows an example of the behavior of the outputs during power-up and power-down. This behavior is
symmetrical for VCCA and VCCB rising/falling.
Safety Regulatory Approvals
constant high-voltage across the isolation barrier. Figure 4
shows the life expectancy of the MAX14851 vs. working
isolation voltage.
Power Supply Sequencing
Applications Information
The MAX14851 does not require special power-supply
sequencing. The logic levels are set independently on
either side by VCCA and VCCB. Each supply can be present
over the entire specified range regardless of the level or
presence of the other.
Effect of Continuous Isolation on Lifetime
Power Supply Decoupling
The MAX14851AEE+ is safety certified by UL. Per
UL1577, the MAX14851 is 100% tested at an equivalent
VISO of 720VRMS for one second (see Table 2).
High-voltage conditions cause insulation to degrade
over time. Higher voltages result in faster degradation.
Even the high-quality insulating material used in the
MAX14851 can degrade over long periods of time with a
To reduce ripple and the chance of introducing data errors,
bypass VCCA and VCCB with 0.1µF ceramic capacitors to
GNDA and GNDB, respectively. Place the bypass capacitors
as close to the power-supply input pins as possible.
Table 2. Safety Regulatory Approvals
SAFETY AGENCY
UL
STANDARD
ISOLATION NUMBER
UL1577 Recognized
5V/div
OUTA_
OUTB_
I/OA_
I/OB_
WORKING LIFE - YEARS (LOG SCALE)
VCCB
E351759
LIFE EXPECTANCY
vs. WORKING ISOLATION VOLTAGE
1000
VCCA
400µs/div
FILE NUMBER
600VRMS isolation voltage for 60 seconds
100
50
VIOWM = 200VRMS
10
1
0.1
0.001
0
100 200 300 400 500 600 700 800
WORKING ISOLATION VOLTAGE (VIOWM) - VRMS
Figure 3. Undervoltage Lockout Behavior
www.maximintegrated.com
Figure 4. Life Expectancy vs. Working Isolation Voltage
Maxim Integrated │ 14
MAX14851
Six-Channel Digital Isolator
Calculating Power Dissipation
The MAX14851 dissipates power based on the switching data rate of the input and output channels, and loads
on the channel outputs. The required current for a given
supply (VCCA or VCCB) can be estimated by summing the
current required for each channel. The supply current for
a channel depends on whether the channel is an input or
an output, the channel’s data rate, and the capacitive or
resistive load, if it is an output. The typical current for an
input or output at any data rate can be estimated from the
graphs in Figure 5 and Figure 6. Please note the data in
Figure 5 and Figure 6 are extrapolated from the supply
current measurements in a typical operating condition.
The total current for a single channel is the sum of the
“no load” current (shown in Figure 5 and Figure 6) which
is a function of Voltage and Data Rate, and the “load current” which depends upon the type of load. Current into a
capacitive load is a function of the load capacitance, the
switching frequency, and the supply voltage.
ICL = CL × fSW × VCC
where
ICL is the current required to drive the capacitive load.
CL is the load capacitance on the isolator’s output pin.
fSW is the switching frequency (bits per second / 2).
VCC is the supply voltage on the output side of the isolator.
Current into a resistive load depends on the load resistance, the supply voltage and the average duty cycle of
the data waveform. The DC load current can be conservatively estimated by assuming the output is always high.
IRL = VCC / RL
where
IRL is the current required to drive the resistive load.
VCC is the supply voltage on the output side of the isolator.
The required supply current for switching bidirectional open-drain inputs/outputs is negligible, and can be
ignored when calculating power dissipation. Some current, however, will be pulled from the supply through the
pull-up resistors on those pins. To calculate that current
under worst-case conditions, assume that the I/O is
always low and calculate the current as:
IIO = VCC / RPU
where
IIO is the current through the pull-up resistor.
VCC is the supply voltage on the side of the bidirectional
input/output.
RPU is the pull-up resistance on the input/output.
Example (shown in Figure 7): A MAX14851 is operating
with VCCA = 3.3V, VCCB = 5V.
The bidirectional channels (I/O_1 and I/O_2), in this application channel 1 (SCL) and channel 2 (SDA), implement
an isolated I2C Bus, operating at Fast Mode Plus (FM+)
with a clock rate of 1MHz. As noted previously, the power
dissipated in these channels during switching is negligible
and will be ignored for further calculations.
The other 4 channels are unidirectional;
●● INA1 is a 10MHz input driving an output OUTB1
which has a 10pF capactive load.
●● INA2 is held low and the channel is not in use and
the resistive load is negligible since the isolator is
driving a CMOS input.
●● Similarly, INB1 is held low and the channel is not in
use and the load current from OUTA1 is considered
negligible.
●● INB2 is a 5MHz input driving an output OUTA2 which
has a with a 10kΩ resistive load.
Refer to Table 3 and Table 4 for the VCCA and VCCB supply current calculation worksheets.
RL is the load resistance on the isolator’s output pin.
www.maximintegrated.com
Maxim Integrated │ 15
MAX14851
SUPPLY CURRENT PER UNIDIRECTIONAL
INPUT CHANNEL vs. DATA RATE
SUPPLY CURRENT PER UNIDIRECTIONAL
OUTPUT CHANNEL vs. DATA RATE
5.0
4.5
4.5
4.0
4.0
3.5
3.5
3.0
3.0
ICC_ (mA)
ICC_ (mA)
5.0
Six-Channel Digital Isolator
2.5
2.0
2.5
2.0
CL = 0pF
1.5
VCC_ = 3V
1.5
VCC_ = 3V
1.0
VCC_ = 3.3V
1.0
VCC_ = 3.3V
VCC_ = 5V
0.5
VCC_ = 5V
0.5
VCC_ = 5.5V
0.0
VCC_ = 5.5V
0.0
0
5
10
15
20
25
0
5
DATA RATE (MHz)
10
15
20
25
DATA RATE (MHz)
Figure 5. Supply Current per Input Channel (Estimated)
Figure 6. Supply Current per Output Channel (Estimated)
Table 3. Side A Power Dissipation Calculation Worksheet
SIDE A
VCCA = 3.3V
Channel
IN/OUT
Data Rate
(MHz)
Load Type
Load
“No Load” Current
(mA)
Load Current
(mA)
INA1
IN
10
―
INA2
IN
0
―
―
1
―
―
1.8
―
OUTA1
OUT
0
OUTA2
OUT
5
―
―
1.8
―
Resistive
10kΩ
2
0.33
6.6
0.33
TOTAL
TOTAL CURRENT
6.93
CALCULATED POWER DISSIPATION FOR SIDE A
VCCA x ICCA = 3.3V x 6.93mA = 22.9mW
Table 4. Side B Power Dissipation Calculation Worksheet
SIDE B
VCCB = 5.0V
Channel
IN/OUT
Data Rate
(MHz)
Load Type
Load
“No Load” Current
(mA)
Load Current
(mA)
OUTB1
OUT
10
Capacitive
10pF
2.8
0.5
OUTB2
OUT
0
―
―
2.1
―
INB1
IN
0
―
―
2.2
―
INB2
IN
5
―
10kΩ
2.3
0.5
TOTAL
9.4
TOTAL CURRENT
TOTAL POWER DISSIPATION FOR SIDE B
www.maximintegrated.com
1.0
10.4
VCCB x ICCB = 5V x 10.4mA = 52mW
Maxim Integrated │ 16
MAX14851
Six-Channel Digital Isolator
3.3V
5.0V
VCCA
1 Master Load on the Bus
VCCB
MAX14851
SCL
SCL
I/OA1
I/OB1
I/OA2
I/OB2
10pF
1MHz
SDA
10pF
2 Slave Loads on the Bus
10pF
10pF
20pF
20pF
SDA
10MHz
INA1
OUTB1
INA2
OUTB2
10pF
OUTA1
INB1
OUTA2
INB2
5MHz
GNDA
10KΩ
GNDB
Figure 7. Example Circuit for Supply Current Calculation
Typical Operating Circuits
3.3V
3.3V
VCCA
VCCB
MAX14851
uC
SDA
I/OA1
I/OB1
SDA
SCL
I/OA2
I/OB2
SCL
GPO1
INA1
OUTB1
GPO2
INA2
OUTB2
GPI1
GPI2
VCCB MONITOR
OUTA1
INB1
OUTA2
INB2
GNDA
MAX11259
DELTA-SIGMA
ADC
ADR1
ADR0
RDYB
GNDB
ISOLATED, I2C DELTA-SIGMA ADC
www.maximintegrated.com
Maxim Integrated │ 17
MAX14851
Six-Channel Digital Isolator
Typical Operating Circuits (continued)
3.3V
3.3V
VCCA
VCCB
MAX14851
I/OA1
I/OB1
FAULT
CS
I/OA2
I/OB2
CS
SCLK
INA1
OUTB1
SCLK
MOSI
INA2
OUTB2
SDI
MISO
OUTA1
INB1
SDO
GPI
OUTA2
INB2
DRDY
GNDA
MAX31856
THERMOCOUPLE ADC
µC
GPI
GNDB
ISOLATED, PRECISION THERMOCOUPLE TO
DIGITAL CONVERTER
Ordering Information
Chip Information
PART
TEMP RANGE
PIN-PACKAGE
MAX14851AEE+
-40°C to +125°C
16 QSOP
MAX14851AEE+T
-40°C to +125°C
16 QSOP
+Denotes lead(Pb)-free/RoHS-compliant package.
T = Tape and Reel
www.maximintegrated.com
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.com/packages. Note
that a “+”, “#”, or “-” in the package code indicates RoHS status
only. Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
16 QSOP
E16+1
21-0055
90-0167
Maxim Integrated │ 18
MAX14851
Six-Channel Digital Isolator
Revision History
REVISION
NUMBER
REVISION
DATE
0
6/17
DESCRIPTION
Initial release
PAGES
CHANGED
—
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
© 2017 Maxim Integrated Products, Inc. │ 19
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