概要

The ADuM1201 are dual-channel digital isolators based on the Analog Devices, Inc., iCoupler technology. Combining high speed CMOS and monolithic transformer technologies, these isolation components provide outstanding performance characteristics superior to alternatives, such as optocouplers. By avoiding the use of LEDs and photodiodes, iCoupler devices remove the design difficulties commonly associated with optocouplers.

The typical optocoupler concerns regarding uncertain current transfer ratios, nonlinear transfer functions, and temperature and lifetime effects are eliminated with the simple iCoupler digital interfaces and stable performance characteristics. The need for external drivers and other discrete components is eliminated with these iCoupler products. Furthermore, iCoupler devices consume one-tenth to one-sixth the power of optocouplers at comparable signal data rates.

The ADuM1201 isolators provide two independent isolation channels in a variety of channel configurations and data rates (see the Ordering Guide). Both devices operate with the supply voltage on either side ranging from 2.7 V to 5.5 V, providing compatibility with lower voltage systems as well as enabling a voltage translation functionality across the isolation barrier. In addition, the ADuM1200/ADuM1201 provide low pulse width distortion (<3 ns for CR grade) and tight channelto-channel matching (<3 ns for CR grade). Unlike other optocoupler alternatives, the ADuM1200/ADuM1201 isolators have a patented refresh feature that ensures dc correctness in the absence of input logic transitions and during powerup/power-down conditions.

The ADuM1201W is automotive grade versions qualified for 125℃ operation. See the Automotive Products section for more information.

 

特徴

Narrow body, RoHS-compliant, SOIC 8-lead package

低電力動作

5V動作

1.1 mA per channel maximum at 0 Mbps to 2 Mbps

3.7 mA per channel maximum at 10 Mbps

8.2 mA per channel maximum at 25 Mbps

3 V operation

0.8 mA per channel maximum at 0 Mbps to 2 Mbps

2.2 mA per channel maximum at 10 Mbps

4.8 mA per channel maximum at 25 Mbps

双方向通信

3 V/5 Vレベル変換

High temperature operation: 125°C

High data rate: dc to 25 Mbps (NRZ)

Precise timing characteristics

3 ns maximum pulse width distortion

3 ns maximum channel-to-channel matching

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

安全性と規制当局の承認

UL recognition

2500 V rms for 1 minute per UL 1577

CSA Component Acceptance Notice 5A

VDE Certificate of Conformity

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

VIORM = 560 V peak

自動車用途に適合

 

アプリケーション

Size-critical multichannel isolation

SPIインターフェース/データ・コンバーターの絶縁

RS-232/RS-422/RS-485 transceiver isolation

Digital field bus isolation

Hybrid electric vehicles, battery monitor, and motor drive

 

アプリケーション情報

PCB LAYOUT

The ADuM1200/ADuM1201 digital isolators require no external interface circuitry for the logic interfaces. Power supply bypassing is strongly recommended at the input and output supply pins.

The capacitor value must be between 0.01 μF and 0.1 μF.  The total lead length between both ends of the capacitor and the input power supply pin must not exceed 20 mm.

DC CORRECTNESS AND MAGNETIC FIELD IMMUNITY

Positive and negative logic transitions at the isolator input send narrow (~1 ns) pulses 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 of more than ~1 μs at the input, a periodic set of refresh pulses indicative of the correct input state is sent to ensure dc correctness at the output. If the decoder receives no internal pulses for 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.

The ADuM1201 are extremely immune to external magnetic fields. The limitation on the magnetic field immunity of the ADuM1201 is set by the condition in which induced voltage in the receiving coil of the transformer is sufficiently large enough to either falsely set or reset the decoder. The following analysis defines the conditions under which this can occur.