ADuM5241ARZ_技术文档

Dual-Channel Isolators with isoPower

Integrated DC-to-DC Converter, 50 mW

Data Sheet

ADuM5240/ADuM5241/ADuM5242

FEATURES

FUNCTIONAL BLOCK DIAGRAMS

Integrated isolated dc-to-dc converter

Regulated 5 V/10 mA output

Dual dc to 1 Mbps (NRZ) signal isolation channels

Narrow-body, 8-lead SOIC package

RoHS compliant

1

2

8

7

6

V

OSC.

RECT.

REG.

V

DD

ISO

OA

OB

ENCODE

V

DECODE

IA

IB

High temperature operation: 105°C

Precise timing characteristics

3

4

V

ENCODE

3 ns maximum pulse width distortion

3 ns maximum channel-to-channel matching

70 ns maximum propagation delay

High common-mode transient immunity: >25 kV/μs

Safety and regulatory approvals

UL recognition

2500 V rms for 1 minute, per UL 1577

CSA Component Acceptance Notice #5A

VDE certificate of conformity

5

GND

ISO

Figure 1. ADuM5240

1

2

8

7

6

V

OSC.

RECT.

V

DD

ISO

IA

DECODE

ENCODE

DECODE

OA

DIN V VDE V 0884-10 (VDE V 0884-10):2006-12

3

4

V

ENCODE

IB

OB

V

_IORM= 560 V peak

5

GND

Figure 2. ADuM5241

GENERAL DESCRIPTION

The ADuM524x¹are dual-channel digital isolators with isoPower®

integrated, isolated power. Based on the Analog Devices, Inc.,

iCoupler® technology, a chip scale dc-to-dc converter provides

up to 50 mW of regulated, isolated power at 5 V, which eliminates

the need for a separate isolated dc-to-dc converter in low power

isolated designs. The Analog Devices chip scale transformer

iCoupler technology is used both for the isolation of the logic

signals as well as for the dc-to-dc converter. The result is a small

form factor, total isolation solution.

1

2

8

7

6

V

OSC.

RECT.

V

DD

ISO

IA

DECODE

ENCODE

OA

3

4

V

OB

IB

5

GND

The ADuM524x isolators provide two independent isolation

channels in a variety of channel configurations, operating from

a 5 V input supply. ADuM524x units can be used in combination

with other iCoupler products to achieve greater channel counts.

Figure 3. ADuM5242

¹Protected by U.S. Patents 5,952,849; 6,873,065; and 7,075,329.

Rev. B

Information furnished by Analog Devices is believed to be accurate and reliable. However, no

responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other

rights of third parties that may result from its use. Specifications subject to change without notice. No

license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

Trademarks and registeredtrademarks arethe property of their respective owners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781.329.4700 www.analog.com

ADuM5240/ADuM5241/ADuM5242

Data Sheet

TABLE OF CONTENTS

Features .............................................................................................. 1

ESD Caution...................................................................................7

Pin Configurations and Function Descriptions............................8

Typical Performance Characteristics ........................................... 10

Applications Information .............................................................. 11

DC-to-DC Converter................................................................. 11

Propagation Delay-Related Parameters................................... 11

DC Correctness and Magnetic Field Immunity..................... 11

Thermal Analysis ....................................................................... 12

PCB Layout ................................................................................. 12

Increasing Available Power ....................................................... 13

Insulation Lifetime..................................................................... 13

Outline Dimensions....................................................................... 14

Ordering Guide .......................................................................... 14

General Description ......................................................................... 1

Functional Block Diagrams............................................................. 1

Revision History ............................................................................... 2

Specifications..................................................................................... 3

Electrical Characteristics............................................................. 3

Package Characteristics ............................................................... 5

Regulatory Information............................................................... 5

Insulation and Safety-Related Specifications............................ 5

DIN V VDE V 0884-10 (VDE V 0884-10) Insulation

Characteristics .............................................................................. 6

Recommended Operating Conditions ...................................... 6

Absolute Maximum Ratings............................................................ 7

REVISION HISTORY

5/12—Rev. A to Rev. B

Created Hyperlink for Safety and Regulatory Approvals

Entry in Features Section................................................................. 1

Change to PCB Layout Section..................................................... 12

7/07—Rev. 0 to Rev. A

Updated VDE Certification Throughout ...................................... 1

Changes to Features.......................................................................... 1

Changes to Regulatory Information Section and Table 4 ........... 5

Changes to Table 5 and Figure 4 Caption...................................... 6

Changes to Table 7............................................................................ 7

Added Table 8; Renumbered Sequentially .................................... 7

Added Insulation Lifetime Section .............................................. 13

3/07—Revision 0: Initial Version

Rev. B | Page 2 of 16

Data Sheet

ADuM5240/ADuM5241/ADuM5242

SPECIFICATIONS

ELECTRICAL CHARACTERISTICS

All voltages are relative to their respective ground. All minimum/maximum specifications apply over the entire recommended operating

range, unless otherwise noted. All typical specifications are at T_A= 25°C, V_DD= 5.0 V, V_ISO= 5.0 V, unless otherwise noted.

Table 1.

Parameter

Symbol

Min

Typ

Max

Unit

Test Conditions

DC-TO-DC CONVERTER

DC-to-DC Converter Enabled

DC to 1 Mbps Data Rate

Setpoint

Logic signal frequency ≤ 1 MHz

I_ISO= 0 mA

V_ISO= 4.5 V

V_{ISO (SET)}

I_{ISO (max)}

4.5

10

5.2

5.5

V

mA

mV p-p

Maximum V_ISOOutput Current

Noise¹

250

Input Supply Current

At Maximum I_ISOCurrent

No Load I_ISOCurrent

DC-to-DC Converter Disabled

Primary Side Supply Input Current²

ADuM5240

ADuM5241

ADuM5242

Secondary Side Supply Input Current³

ADuM5240

I_{DD (max)}

I_{DD (Q)}

140

104

mA

I_ISO= 10 mA

I_ISO= 0 mA

I_{DD (DISABLE)}

3.3

2.7

2.2

mA

V_DD= 4.0 V

I_{ISO (DISABLE)}

V_{DD (ENABLE)}

V_{DD (DISABLE)}

2.6

2.8

3.0

4.5

mA

V

ADuM5241

ADuM5242

DC-to-DC Converter Enable Threshold⁴

DC-to-DC Converter Disable Threshold⁴

LOGIC SPECIFICATIONS

Logic Input Currents

Logic High Input Threshold

4.2

3.7

V

I_IA, I_IB

V_IH

−10

0.7 (V_DDor

+0.01

+10

µA

V

V_ISO

)

Logic Low Input Threshold

Logic High Output Voltages

V_IL

0.3 (V_DDor

V

V_ISO

)

V_OAH, V_OBH(V_DDor V_ISO

)

(V_DDor V_ISO

)

I_Ox= −20 µA, V_Ix≥ V_IH

I_Ox= −4 mA, V_Ix≥ V_IH

− 0.1

(V_DDor V_ISO

)

(V_DDor V_ISO

)

− 0.5

− 0.2

Logic Low Output Voltages

V_OAL, V_OBL

0.0

0.1

0.4

V

I_Ox= 20 µA, V_Ix≤ V_IL

I_Ox= 4 mA, V_Ix≤ V_IL

Rev. B | Page 3 of 16

ADuM5240/ADuM5241/ADuM5242

Data Sheet

Parameter

Symbol

Min

Typ

Max

Unit

Test Conditions

AC SPECIFICATIONS

Minimum Pulse Width⁵

Maximum Data Rate⁶

Propagation Delay⁷

Pulse Width Distortion, |t_PLH− t_PHL

Propagation Delay Skew⁸

PW

100

ns

Mbps

ns

C_L= 15 pF, CMOS signal levels

1

25

t_PHL, t_PLH

PWD

t_PSK

70

3

45

3

8

|

Channel-to-Channel Matching,

Codirectional Channels⁹

t_PSKCD

ns

Channel-to-Channel Matching,

t_PSKCD

15

ns

C_L= 15 pF, CMOS signal levels

Opposing-Directional Channels⁹

Output Rise/Fall Time (10% to 90%)

t_R/t_F

|CM_H|

2.5

35

ns

kV/µs

C_L= 15 pF, CMOS signal levels

V_Ix= V_DD, V_ISO, V_CM= 1000 V,

transient magnitude = 800 V

Common-Mode Transient

Immunity at Logic High Output

Common-Mode Transient

25

|CM_L|

35

kV/µs

V_Ix= 0 V, V_CM= 1000 V,

Immunity at Logic Low Output

transient magnitude = 800 V

Refresh Frequency

Switching Frequency

f_r

f_OSC

1.0

300

MHz

¹Peak noise occurs at frequency corresponding to the refresh frequency (see the PCB Layout section).

²I_{DD (DISABLE)}supply current values are specified with no load present on the digital outputs.

³I_{ISO (DISABLE)}supply current values are specified with no load present on the digital outputs and power sourced by an external supply.

⁴Enable/disable threshold is the V_DDvoltage at which the internal dc-to-dc converter is enabled/disabled.

⁵The minimum pulse width is the shortest pulse width at which the specified pulse width distortion is guaranteed.

⁶The maximum data rate is the fastest data rate at which the specified pulse width distortion and V_ISOsupply voltage is guaranteed.

⁷t_PHLpropagation delay is measured from the 50% level of the falling edge of the V_Ixsignal to the 50% level of the falling edge of the V_Oxsignal. t_PLHpropagation delay is

measured from the 50% level of the rising edge of the V_Ixsignal to the 50% level of the rising edge of the V_Oxsignal.

⁸t_PSKis the magnitude of the worst-case difference in t_PHLand/or t_PLHthat is measured between units at the same operating temperature, supply voltages, and output

load within the recommended operating conditions.

⁹Channel-to-channel matching is the absolute value of the difference in propagation delays between the two channels when operated with identical loads.

Rev. B | Page 4 of 16

Data Sheet

ADuM5240/ADuM5241/ADuM5242

PACKAGE CHARACTERISTICS

Table 2.

Parameter

Symbol

R_I-O

C_I-O

C_I

θ_JA

Min

Typ

10¹²

1.0

4.0

80

Max

Unit

Ω

pF

°C/W

Test Conditions

Resistance (Input-to-Output)

Capacitance (Input-to-Output)

Input Capacitance

f = 1 MHz

IC Junction-to-Air Thermal Resistance

REGULATORY INFORMATION

The ADuM524x are approved by the organizations listed in Table 3. Refer to Table 8 and the Insulation Lifetime section for details

regarding recommended maximum working voltages for specific cross-isolation waveforms and insulation levels.

Table 3.

UL

CSA

VDE

Recognized under 1577

Approved under CSA Component

Acceptance Notice #5A

Certified according to DIN V VDE V 0884-10

(VDE V 0884-10):2006-12²

Component Recognition Program¹

Single/basic insulation, 2500 V rms

isolation rating

Basic insulation per CSA 60950-1-03

and IEC 60950-1, 400 V rms (566 V peak)

maximum working voltage

Reinforced insulation, 560 V peak

File E214100

File 205078

File 2471900-4880-0001

¹In accordance with UL 1577, each ADuM524x is proof-tested by applying an insulation test voltage ≥ 3000 V rms for 1 second (current leakage detection limit = 5 µA).

²In accordance with DIN V VDE V 0884-10, each ADuM524x is proof-tested by applying an insulation test voltage ≥ 1050 V peak for 1 sec (partial discharge detection

limit = 5 pC). The asterisk (*) marking branded on the component designates DIN V VDE V 0884-10 approval.

INSULATION AND SAFETY-RELATED SPECIFICATIONS

Table 4.

Parameter

Symbol

Value

2500

4.90 min

Unit

V rms

mm

Conditions

Rated Dielectric Insulation Voltage

Minimum External Air Gap (Clearance)

1-minute duration

Measured from input terminals to output

terminals, shortest distance through air

Measured from input terminals to output

terminals, shortest distance path along body

L(I01)

L(I02)

Minimum External Tracking (Creepage)

4.01 min

mm

Minimum Internal Gap (Internal Clearance)

Tracking Resistance (Comparative Tracking Index)

Isolation Group

0.017 min

>175

IIIa

mm

V

Insulation distance through insulation

DIN IEC 112/VDE 0303 Part 1

Material Group (DIN VDE 0110, 1/89, Table 1)

CTI

Maximum Working Voltage Compatible with

50-Year Service Life

V_IORM

425

V peak Continuous peak voltage across the

isolation barrier

Rev. B | Page 5 of 16

ADuM5240/ADuM5241/ADuM5242

Data Sheet

DIN V VDE V 0884-10 (VDE V 0884-10) INSULATION CHARACTERISTICS

This isolator is suitable for reinforced isolation only within the safety limit data. Maintenance of the safety data is ensured by protective

circuits.

Table 5.

Description

Conditions

Symbol Characteristic Unit

Installation Classification per DIN VDE 0110

For Rated Mains Voltage ≤ 150 V rms

For Rated Mains Voltage ≤ 300 V rms

Climatic Classification

Pollution Degree (DIN VDE 0110, Table 1)

Maximum Working Insulation Voltage

Input-to-Output Test Voltage, Method b1

I to IV

I to III

40/105/21

2

424

795

V_IORM

V_PR

V peak

V_IORM× 1.875 = V_PR, 100% production

test, t_m= 1 sec, partial discharge < 5 pC

Input-to-Output Test Voltage, Method a

After Environmental Tests Subgroup 1

V_PR

V_IORM× 1.6 = V_PR, t_m= 60 sec, partial

discharge < 5 pC

V_IORM× 1.2 = V_PR, t_m= 60 sec, partial

discharge < 5 pC

Transient overvoltage, t_TR= 10 seconds

Maximum value allowed in the event of

a failure; see Figure 4

680

V peak

After Input and/or Safety Test Subgroup 2 and Subgroup 3

510

Highest Allowable Overvoltage

Safety-Limiting Values

V_TR

4000

Case Temperature

Supply Current

Insulation Resistance at T_S

T_S

I_S1

R_S

150

312

>10⁹

°C

mA

Ω

V_IO= 500 V

350

300

250

200

150

100

50

RECOMMENDED OPERATING CONDITIONS

Table 6.

Parameter

Value

Operating Temperature Range (T_A)

Supply Voltages¹

−40°C to +105°C

V_DD, DC-to-DC Converter Enabled

V_DD, DC-to-DC Converter Disabled (V_DD)

4.5 V to 5.5 V

2.7 V to 4.0 V

2.7 V to 5.5 V

1.0 ms

V_ISO, DC-to-DC Converter Disabled (V_ISO

)

Input Signal Rise/Fall Time

Input Supply Slew Rate

10 V/ms

¹All voltages are relative to their respective ground.

0

200

50

100

150

AMBIENT TEMPERATURE (°C)

Figure 4. Thermal Derating Curve, Dependence of Safety-Limiting

Values on Case Temperature, per DIN V VDE V 0884-10

Rev. B | Page 6 of 16

Data Sheet

ADuM5240/ADuM5241/ADuM5242

ABSOLUTE MAXIMUM RATINGS

Table 7.

Stresses above those listed under Absolute Maximum Ratings

may cause permanent damage to the device. This is a stress

rating only; functional operation of the device at these or any

other conditions above those indicated in the operational

section of this specification is not implied. Exposure to absolute

maximum rating conditions for extended periods may affect

device reliability.

Parameter

Rating

−55°C to +150°C

Storage Temperature Range (T_ST)

Ambient Operating Temperature Range (T_A) −40°C to +105°C

1

Supply Voltages (V_DD, V_ISO

Input Voltage (V_IA, V_IB)¹

)

−0.5 V to +7.0 V

−0.5 V to

(V_DDor V_ISO) + 0.5 V

−0.5 V to

1

Output Voltage (V_OA, V_OB

)

(V_DDor V_ISO) + 0.5 V

−18 mA to +18 mA

−100 kV/µs to

+100 kV/µs

Average Output Current per Pin (I_O)²

Common-Mode Transients (|CM|)³

ESD CAUTION

¹All voltages are relative to their respective ground.

²See Figure 4 for maximum rated current values for various temperatures.

³Refers to common-mode transients across the insulation barrier. Common-

mode transients exceeding the Absolute Maximum Ratings may cause

latch-up or permanent damage.

Table 8. Maximum Continuous Working Voltage¹

Parameter

Max

Unit

Constraint

AC Voltage, Bipolar Waveform

AC Voltage, Unipolar Waveform

Basic Insulation

Reinforced Insulation

DC Voltage

425

V peak 50-year minimum lifetime

566

560

V peak Maximum approved working voltage per IEC 60950-1

V peak Maximum approved working voltage per VDE V 0884-10

Basic Insulation

Reinforced Insulation

566

560

V peak Maximum approved working voltage per IEC 60950-1

V peak Maximum approved working voltage per VDE V 0884-10

¹Refers to continuous voltage magnitude imposed across the isolation barrier. See the Insulation Lifetime section for more details.

Rev. B | Page 7 of 16

ADuM5240/ADuM5241/ADuM5242

Data Sheet

PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS

V

1

2

3

4

8

7

6

5

V

DD

ISO

OA

OB

V

1

2

3

4

8

7

6

5

V

DD

OA

OB

ISO

ADuM5240

V

IA

IB

ADuM5242

V

IA

V

TOP VIEW

(Not to Scale)

TOP VIEW

(Not to Scale)

IB

GND

ISO

GND

ISO

Figure 5. ADuM5240 Pin Configuration

Figure 7. ADuM5242 Pin Configuration

Table 9. ADuM5240 Pin Function Descriptions

Table 11. ADuM5242 Pin Function Descriptions

No.

Mnemonic Description

1

V_DD

Supply Voltage for Isolator Primary Side,

4.5 V to 5.5 V (DC-to-DC Enabled) and

2.7 V to 4.0 V (DC-to-DC Disabled).

1

V_DD

Supply Voltage for Isolator Primary Side,

4.5 V to 5.5 V (DC-to-DC Enabled) and

2.7 V to 4.0 V (DC-to-DC Disabled).

2

3

4

V_IA

V_IB

GND

Logic Input A.

Logic Input B.

Ground. Ground reference for isolator

primary side.

2

3

4

V_OA

V_OB

GND

Logic Output A.

Logic Output B.

Ground. Ground reference for isolator

primary side.

5

GND_ISO

Isolated Ground. Ground reference for

isolator secondary side.

5

GND_ISO

Isolated Ground. Ground reference for

isolator secondary side.

6

7

8

V_OB

V_OA

V_ISO

Logic Output B.

Logic Output A.

Isolated Supply Voltage for Isolator

Secondary Side, 4.5 V to 5.5 V Output

(DC-to-DC Enabled), and 2.7 V to 5.5 V

Input (DC-to-DC Disabled).

6

7

8

V_IB

V_IA

V_ISO

Logic Input B.

Logic Input A.

Isolated Supply Voltage for Isolator

Secondary Side, 4.5 V to 5.5 V Output

(DC-to-DC Enabled), and 2.7 V to 5.5 V

Input (DC-to-DC Disabled).

V

1

2

3

4

8

7

6

5

V

DD

ISO

ADuM5241

V

OA

IA

V

TOP VIEW

(Not to Scale)

IB

OB

GND

ISO

Figure 6. ADuM5241 Pin Configuration

Table 10. ADuM5241 Pin Function Descriptions

No.

Mnemonic Description

1

V_DD

Supply Voltage for Isolator Primary Side,

4.5 V to 5.5 V (DC-to-DC Enabled) and

2.7 V to 4.0 V (DC-to-DC Disabled).

2

3

4

V_OA

V_IB

GND

Logic Output A.

Logic Input B.

Ground. Ground reference for isolator

primary side.

5

GND_ISO

Isolated Ground. Ground reference

for isolator secondary side.

6

7

8

V_OB

V_IA

V_ISO

Logic Output B.

Logic Input A.

Isolated Supply Voltage for Isolator

Secondary Side, 4.5 V to 5.5 V Output

(DC-to-DC Enabled), and 2.7 V to 5.5 V

Input (DC-to-DC Disabled).

Rev. B | Page 8 of 16

Data Sheet

ADuM5240/ADuM5241/ADuM5242

Table 12. ADuM5240 Truth Table

V_DDState

Powered

Unpowered

DC-to-DC Converter

V_ISOState

V_IAInput

V_IBInput

V_OAOutput

V_OBOutput

Enabled

Disabled

Powered (Internally)

Powered (Externally)

Unpowered

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

X

H

Z

L

X

Z

L

Z

Powered (Externally)

Unpowered

Z

Table 13. ADuM5241 Truth Table

V_DDState

Powered

Unpowered

DC-to-DC Converter

V_ISOState

V_IAInput

V_IBInput

V_OAOutput

V_OBOutput

Enabled

Disabled

Powered (Internally)

Powered (Externally)

Unpowered

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

X

H

Z

L

X

L

Z

Powered (Externally)

Unpowered

Z

Table 14. ADuM5242 Truth Table

V_DDState

Powered

Unpowered

DC-to-DC Converter

V_ISOState

V_IAInput

V_IBInput

V_OAOutput

V_OBOutput

Enabled

Disabled

Powered (Internally)

Powered (Externally)

Unpowered

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

H

L

Z

L

H

X

L

Z

Powered (Externally)

Unpowered

Rev. B | Page 9 of 16

ADuM5240/ADuM5241/ADuM5242

Data Sheet

TYPICAL PERFORMANCE CHARACTERISTICS

120

100%

0

LOAD

100

80

60

40

20

0

100

50

0

–50

0

12

0

35

2

4

6

8

10

5

10

15

20

25

30

I

OUTPUT LOAD CURRENT (mA)

TIME (µs)

ISO

Figure 8. Typical I_DDInput Current vs. I_ISOOutput Load Current

Figure 10. Typical V_ISOTransient Load Response, 5 V Output,

90% to 10% to 90% Pulsed Load, 100 nF Bypass Capacitance vs. Time

5.5

5.4

5.3

5.2

5.1

5.0

4.9

4.8

4.7

4.6

4.5

200

150

100

50

0

–50

–100

–150

–200

0

12

0

100

2

4

6

8

10

20

40

60

80

I

OUTPUT LOAD CURRENT (mA)

TIME (ns)

ISO

Figure 9. Typical Isolated V_ISOOutput Voltage vs. I_ISOOutput Load Current

Figure 11. Typical Output Voltage Noise at 100% Load,

100 nF Bypass Capacitance vs. Time

Rev. B | Page 10 of 16

Data Sheet

ADuM5240/ADuM5241/ADuM5242

APPLICATIONS INFORMATION

DC-TO-DC CONVERTER

PROPAGATION DELAY-RELATED PARAMETERS

The dc-to-dc converter section of the ADuM524x works on

principles that are common to most modern power supply

designs. V_DDpower is supplied to an oscillating circuit that

switches current into a chip scale air core transformer. Power is

transferred to the secondary side where it is rectified to a high

dc voltage. The power is then linearly regulated down to about

5.2 V and supplied to the secondary side data section and to the

Propagation delay is a parameter that describes the time it takes

a logic signal to propagate through a component. The propagation

delay to a logic low output may differ from the propagation

delay to a logic high.

INPUT (V

)

50%

Ix

t_PLH

t_PHL

V_ISOpin for external use. This design allows for a physically

OUTPUT (V

)

50%

Ox

small power section compatible with the 8-lead SOIC packaging

of this device. Active feedback was not implemented in this

version of isoPower for reasons of size and cost.

Figure 12. Propagation Delay Parameters

Pulse width distortion is the maximum difference between

these two propagation delay values and is an indication of how

accurately the timing of the input signal is preserved.

Because the oscillator runs at a constant high frequency inde-

pendent of the load, excess power is internally dissipated in the

output voltage regulation process. Limited space for transformer

coils and components also adds to internal power dissipation.

This results in low power conversion efficiency, especially at low

load currents.

Channel-to-channel matching refers to the maximum amount

the propagation delay differs between channels within a single

ADuM524x component.

Propagation delay skew refers to the maximum amount the

propagation delay differs between multiple ADuM524x

components operating under the same conditions.

The load characteristic curve in Figure 8 shows that the V_DD

current is typically 80 mA with no V_ISOload and 110 mA at full

V_ISOload at the V_DDsupply pin.

DC CORRECTNESS AND MAGNETIC FIELD

IMMUNITY

Alternate supply architectures are possible using this technology.

Addition of a digital feedback path allows regulation of power

on the primary side. Feedback would allow significantly higher

power, efficiency, and synchronization of multiple supplies at the

expense of size and cost. Future implementations of isoPower

includes feedback to achieve these performance improvements.

Positive and negative logic transitions at the isolator input cause

narrow (~1 ns) pulses to be sent to the decoder via the transformer.

The decoder is bistable and is, therefore, either set or reset by

the pulses, indicating input logic transitions. In the absence of

logic transitions at the input for more than 1 μs, a periodic set

of refresh pulses indicative of the correct input state are sent to

ensure dc correctness at the output. If the decoder receives no

internal pulses of more than about 5 μs, the input side is assumed

to be unpowered or nonfunctional, in which case the isolator

output is forced to a default state by the watchdog timer circuit

(see Table 12 through Table 14).

The ADuM524x can be operated with the internal dc-to-dc

enabled or disabled. With the internal dc-to-dc converter

enabled, the isolated supply of Pin 8 provides the output power

as well as power to the secondary-side circuitry of the part.

The internal dc-to-dc converter state of the ADuM524x is

controlled by the input V_DDvoltage, as defined in Table 6. In

normal operating mode, V_DDis set between 4.5 V and 5.5 V and

the internal dc-to-dc converter is enabled. When/if it is desired

to disable the dc-to-dc converter, V_DDis lowered to a value

between 2.7 V and 4.0 V. In this mode, V_ISOpower is supplied

externally by the user and the signal channels of the ADuM524x

continue to operate normally.

The limitation on the magnetic field immunity of the ADuM524x

is set by the condition in which induced voltage in the receiving

coil of the transformer is sufficiently large to either falsely set or

reset the decoder. The following analysis defines the conditions

under which this may occur. The 3 V operating condition of the

ADuM524x is examined because it represents the most susceptible

mode of operation.

There is hysteresis into the V_DDinput voltage detect circuit.

Once the dc-to-dc converter is active, the input voltage must be

decreased below the turn-on threshold to disable the converter.

This feature ensures that the converter does not go into

oscillation due to noisy input power.

The pulses at the transformer output have an amplitude greater

than 1.0 V. The decoder has a sensing threshold at about 0.5 V, thus

establishing a 0.5 V margin in which induced voltages can be

tolerated. The voltage induced across the receiving coil is given by

2

V = (−dβ/dt)Σπr_n; n = 1, 2, … , N

where:

β is magnetic flux density (gauss).

N is the number of turns in the receiving coil.

r_nis the radius of the n^thturn in the receiving coil (cm).

Rev. B | Page 11 of 16

ADuM5240/ADuM5241/ADuM5242

Data Sheet

Given the geometry of the receiving coil in the ADuM524x and

an imposed requirement that the induced voltage be at most

50% of the 0.5 V margin at the decoder, a maximum allowable

magnetic field is calculated, as shown in Figure 13.

100

Note that at combinations of strong magnetic field and high

frequency, any loops formed by printed circuit board (PCB)

traces could induce error voltages sufficiently large enough to

trigger the thresholds of succeeding circuitry. Care should be

taken in the layout of such traces to avoid this possibility.

THERMAL ANALYSIS

10

1

Each ADuM524x component consists of two internal die,

attached to a split-paddle lead frame. For the purposes of

thermal analysis, it is treated as a thermal unit with the highest

junction temperature reflected in the θ_JAvalue in Table 2. The

value of θ_JAis based on measurements taken with the part

mounted on a JEDEC standard 4-layer PCB with fine-width

traces in still air. Under normal operating conditions, the

ADuM524x operates at full load across the full temperature

range without derating the output current. For example, a part

with no external load drawing 80 mA and dissipating 400 mW

causes a 32°C temperature rise above ambient. It is normal for

these devices to run warm.

0.1

0.01

0.001

1k

10k

100k

1M

10M

100M

MAGNETIC FIELD FREQUENCY (Hz)

Figure 13. Maximum Allowable External Magnetic Flux Density

Following the recommendations in the PCB Layout section

decreases the thermal resistance to the PCB allowing increased

thermal margin at high ambient temperatures.

For example, at a magnetic field frequency of 1 MHz, the

maximum allowable magnetic field of 0.2 kgauss induces a

voltage of 0.25 V at the receiving coil. This is about 50% of the

sensing threshold and does not cause a faulty output transition.

Similarly, if such an event were to occur during a transmitted

pulse (and was of the worst-case polarity), it would reduce the

received pulse from >1.0 V to 0.75 V—still well above the 0.5 V

sensing threshold of the decoder.

PCB LAYOUT

The ADuM524x requires no external circuitry for its logic

interfaces. Power supply bypassing is required at the input and

output supply pins (see Figure 15).

The power supply section of the ADuM524x uses a 300 MHz

oscillator frequency to pass power through its chip scale trans-

formers. In addition, the normal operation of the data section

of the iCoupler introduces switching transients, as described in

the DC Correctness and Magnetic Field Immunity section, on

the power supply pins (see Figure 11). Low inductance capacitors

are required to bypass noise generated at the switching frequency

as well as 1 ns pulses generated by the data transfer and dc refresh

circuitry. The total lead length between both ends of the capacitor

and the input power supply pin should not exceed 20 mm.

The preceding magnetic flux density values correspond to

specific current magnitudes at given distances from the

ADuM524x transformers. Figure 14 expresses these allowable

current magnitudes as a function of frequency for selected

distances. As shown in Figure 14, the ADuM524x is extremely

immune and can only be affected by extremely large currents

operated at high frequencies very close to the component. For

the 1 MHz example noted, one would have to place a 0.5 kA

current 5 mm away from the ADuM524x to affect the operation

of the component.

In cases where EMI emission is a concern, series inductance may

be added to critical power and ground traces. Discrete inductors

should be added to the line such that the high frequency bypass

capacitors are between the inductor and the ADuM524x device

pin. Inductance can be added in the form of discrete inductors

or ferrite beads added to both power and ground traces. The

recommended value corresponds to impedance between 50 Ω

and 100 Ω at approximately 300 MHz.

1000

DISTANCE = 1m

100

10

DISTANCE = 100mm

1

If the switching speed of the data outputs is causing unacceptable

EMI, capacitance to ground can be added at output pins to slow

the rise and fall time of the output. This slew rate limits the output.

Capacitance values depend on application speed requirements.

DISTANCE = 5mm

0.1

0.01

See the AN-0971 Application Note for board layout guidelines.

1k

10k

100k

1M

10M

100M

MAGNETIC FIELD FREQUENCY (Hz)

Figure 14. Maximum Allowable Current

for Various Current-to-ADuM524x Spacings

Rev. B | Page 12 of 16

Data Sheet

ADuM5240/ADuM5241/ADuM5242

Load regulation transients are the primary source of lower

frequency power supply voltage excursions, as illustrated in

Figure 10. These should be dealt with by adding an additional

supply stiffening capacitor between V_ISOand GND_ISO. The

stiffening capacitor can be of a more highly inductive type

because the high frequency bypass is handled by the required

low inductance capacitor.

lifetime of the insulation structure within the ADuM524x.

Analog Devices performs accelerated life testing using voltage

levels higher than the rated continuous working voltage. Accel-

eration factors for several operating conditions are determined.

These factors allow calculation of the time to failure at the actual

working voltage. The values shown in Table 8 summarize the peak

voltage for 50 years of service life for a bipolar ac operating condi-

tion and the maximum CSA/VDE approved working voltages. In

many cases, the approved working voltage is higher than 50-year

service life voltage. Operation at these high working voltages

can lead to shortened insulation life in some cases.

V

DD

ISO

V

IA/OA

OA/IA

OB/IB

IB/OB

GND

The insulation lifetime of the ADuM524x depends on the voltage

waveform type imposed across the isolation barrier. The iCoupler

insulation structure degrades at different rates depending on

whether the waveform is bipolar ac, unipolar ac, or dc. Figure 16,

Figure 17, and Figure 18 illustrate these different isolation

voltage waveforms.

GND

ISO

Figure 15. Recommended Printed Circuit Board Layout

In applications involving high common-mode transients, care

should be taken to ensure that board coupling across the isolation

barrier is minimized. Furthermore, the board layout should be

designed such that any coupling that does occur equally affects

all pins on a given component side. Failure to ensure this can

cause voltage differentials between pins exceeding the absolute

maximum ratings of the device (specified in Table 7), thereby

leading to latch-up and/or permanent damage.

Bipolar ac voltage is the most stringent environment. The goal

of a 50-year operating lifetime under the ac bipolar condition

determines the recommended maximum working voltage of

Analog Devices.

In the case of unipolar ac or dc voltage, the stress on the

insulation is significantly lower, which allows operation at

higher working voltages while still achieving a 50-year service

life. The working voltages listed in Table 8 can be applied while

maintaining the 50-year minimum lifetime provided the voltage

conforms to either the unipolar ac or dc voltage cases. Any cross-

insulation voltage waveform that does not conform to Figure 17 or

Figure 18 should be treated as a bipolar ac waveform, and its

peak voltage should be limited to the 50-year lifetime voltage

value listed in Table 8.

The ADuM524x is a power device that dissipates as much as

600 mW of power when fully loaded. Because it is not possible

to apply a heat sink to an isolation device, the device primarily

depends on heat dissipation into the PCB through the GND

pins. If the device is used at high ambient temperatures, care

should be taken to provide a thermal path from the GND pins

to the PCB ground plane. The board layout in Figure 15 shows

enlarged pads for Pin 4 and Pin 5. Multiple vias should be

implemented from each of the pads to the ground plane,

which significantly reduce the temperatures inside the chip.

The dimensions of the expanded pads are left to the discretion

of the designer and the available board space.

Note that the voltage presented in Figure 17 is shown as sinusoidal

for illustration purposes only. It is meant to represent any

voltage waveform varying between 0 V and some limiting value.

The limiting value can be positive or negative, but the voltage

cannot cross 0 V.

INCREASING AVAILABLE POWER

The ADuM524x devices are not designed with the capability of

running several devices in parallel. However, if more power is

required to run multiple loads, it is possible to group loads and

run each group from an individual ADuM542x device. For

example, if a transceiver and external logic must be powered,

one ADuM524x could be dedicated to the transceiver and an

additional ADuM524x could power the external logic, which

prevents issues with load sharing because each load is dedicated

to its own supply.

RATED PEAK VOLTAGE

0V

Figure 16. Bipolar AC Waveform

RATED PEAK VOLTAGE

0V

Figure 17. Unipolar AC Waveform

INSULATION LIFETIME

All insulation structures eventually breaks down when subjected

to voltage stress over a sufficiently long period. The rate of

insulation degradation is dependent on the characteristics of the

voltage waveform applied across the insulation. In addition to

the testing performed by the regulatory agencies, Analog Devices

carries out an extensive set of evaluations to determine the

RATED PEAK VOLTAGE

0V

Figure 18. DC Waveform

Rev. B | Page 13 of 16

ADuM5240/ADuM5241/ADuM5242

OUTLINE DIMENSIONS

Data Sheet

5.00 (0.1968)

4.80 (0.1890)

8

1

5

4

6.20 (0.2441)

5.80 (0.2284)

4.00 (0.1574)

3.80 (0.1497)

0.50 (0.0196)

0.25 (0.0099)

1.27 (0.0500)

BSC

45°

1.75 (0.0688)

1.35 (0.0532)

0.25 (0.0098)

0.10 (0.0040)

8°

0°

0.51 (0.0201)

0.31 (0.0122)

COPLANARITY

0.10

1.27 (0.0500)

0.40 (0.0157)

0.25 (0.0098)

0.17 (0.0067)

SEATING

PLANE

COMPLIANT TO JEDEC STANDARDS MS-012-AA

CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS

(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR

REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.

Figure 19. 8-Lead Standard Small Outline Package [SOIC_N]

Narrow Body

(R-8)

Dimensions shown in millimeters and (inches)

ORDERING GUIDE

Number

of Inputs, of Inputs, Maximum Data

Package

Option

Model¹

V_DDSide

V_ISOSide

Rate (Mbps)

Temperature Range

−40°C to +105°C

Package Description

ADuM5240ARZ

ADuM5240ARZ-RL7

ADuM5241ARZ

ADuM5241ARZ-RL7

ADuM5242ARZ

ADuM5242ARZ-RL7

2

1

0

1

2

1

8-Lead SOIC_N

R-8

8-Lead SOIC_N, 7”Tape and Reel R-8

8-Lead SOIC_N R-8

8-Lead SOIC_N, 7”Tape and Reel R-8

8-Lead SOIC_N R-8

8-Lead SOIC_N, 7”Tape and Reel R-8

¹Z = RoHS Compliant Part.

Rev. B | Page 14 of 16

Data Sheet

NOTES

ADuM5240/ADuM5241/ADuM5242

Rev. B | Page 15 of 16

ADuM5240/ADuM5241/ADuM5242

NOTES

Data Sheet

registered trademarks are the property of their respective owners.

D06014-0-5/12(B)

Rev. B | Page 16 of 16


型号：	ADuM5241ARZ
厂家：	ADI
描述：	Dual-Channel Isolators with isoPower Integrated DC-to-DC Converter, 50 mW 双通道隔离器采用isoPower集成DC - DC转换器， 50毫瓦转换器驱动程序和接口接口集成电路光电二极管
文件：	总16页 (文件大小：304K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

ADuM5241ARZ [ADI]

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