Features

Narrow SOIC 8 DROD package; low -power run 5V operation; the maximum 1.1 mAh per channel@0 Mbps to 2 Mbps; the maximum of each channel is 3.7 mAh@10 Mbps; the maximum per channel is 8.2 per channel 8.2 maximum 8.2 per channel. Mia@25 Mbps; 3V operation; the maximum 0.8 mAh per channel@0 Mbps to 2 Mbps; the maximum 2.2 mAh@10 Mbps per channel; the maximum of 4.8 mia per channel; two -way communication; 3 volts/5 volts Level conversion; high temperature operation: 105 ° C; high data rate: DC to 25 Mbps (NRZ); precise timing features; 3NS maximum pulse width distortion; 3NS maximum channel matching channel matching; high -common model transient rejection: gt 25 kV/microsecond; safety and regulatory approval UL recognition; 2500 V RMS, 1577 1 minute per UL; CSA component acceptance notification#5A; VDE qualification certificate; German industrial standard EN 60747-5-2 (VDE 0884 2nd 2nd No. 2 Part): 2003-01; German Industrial Standard EN 60950 (VDE 0805): 2001-12; German Industrial Standard EN 60950: 2000; VIORM 560V peak.

Application

Dimensions of critical multi-channel isolation; spi #174; interface/data converter isolation; RS-232/RS-422/RS-485 transceiver isolation; digital live bus isolation.

General description

ADM12X is a dual -channel digital isolation device based on the simulation device icoupler #174; technology. Combined with high -speed CMOS and single -chip transformers technology, these isolation elements provide excellent performance of superior to alternative devices such as optocoupled device.

By avoiding the use of LED and optoelectronics diode, the iCoupler device eliminates design difficulties related to optocoupler. The typical optocoupler problem involves an uncertain current transmission ratio, non -linear transmission function, and the effects of temperature and life. It eliminates simple digital interface and stable performance. These iCoupler eliminates demand products for external drivers and other discrete components. In addition, the I coupling device consumes one -tenth to one -sixth of the power of the optocoupler at a comparison signal data rate.

ADUM12X isolator provides two independent isolation channels with various channel configurations and data rates (see order guidelines). Both components work under the power supply voltage of 2.7 V to 5.5 V, which provides compatibility with the low -voltage system, and enables the voltage conversion function of the isolation grid. In addition, ADUM2X provides low -pulse width distortion (CR grade lt; 3NS) and tight channels to channel matching (CR level lt; 3NS). Unlike other optocouplers substitutes, ADUM12X isolates has a patented refresh function.The correctness of the DC is not in the input logic conversion and power -powered/power -off conditions.

Figure Figure

Pin configuration and function description

Typical performance features

Application information

PC board layout

ADUM120X digital isolation device does not require the external interface circuit of logical interface. It is strongly recommended to set up power bypass at the foot of the input and output power supply. The capacitance value should be between 0.01 μF and 0.1 μF. The length of the total leading lead between the two ends of the capacitor and the input power pins should not exceed 20 mm.

Communication delay related parameters

Deducting delay is the parameters describing the time required by the logic signal to spread through the component. The transmission delay to the logic low output may be different from the transmission delay to the logic high.

The pulse width distortion is the biggest difference between the two propagation delay values. It indicates the accuracy of the time maintenance of the input signal.

Channel to channel matching refers to the maximum difference between the transmission delay between the channel between the channel in a single Adum12x component.

Display delay deviation refers to the maximum difference between transmission delay between multiple Adum2x components running under the same conditions.

DC correctness and magnetic field resistance

The positive and negative logic conversion of the input terminal of the isolator inputs the narrow pulse (about 1NS) sent to the decoder through a transformer. The decoder is dual -stable, so it can be set or reset through pulse settings to indicate the input logic conversion. In the case where the input terminal does not exceed 2 μs of logical conversion, the sending indicator of the periodic refresh pulse set with the correct input state to ensure the correctness of the output end. If the decoder does not receive the internal pulse within about 5 microseconds, it is assumed that the input side is not power -on or non -function. In this case, the output of the isolationer output from the timer circuit of the door dog to the default state (see Table 8).

Adum12x is extremely immune to the external magnetic field. The restrictions on the magnetic field resistance of Adum12x are set by the incorrect settings or resetting the decoder. The following analysis defines the conditions that may occur. Check the 3V working conditions of Adum2X because it represents the most affected working mode.

The pulse amplitude of the transformer output place is greater than 1.0V. The inductive threshold of the decoder is about 0.5V, so it is established with a maximum of 0.5V, which can tolerate the induction voltage in this margin. By receiving the voltage of the coil induction:

: β is the magnetic flux density (Gauss).

N isReceive the number of coils.

RN is the radius (CM) of the nn circle of the coil.

Considering the geometric structure of receiving coils in ADUM2X, and compulsory requirements for the induction voltage at the decoder not exceeding 0.5V, the maximum allowed magnetic field is calculated, as shown in Figure 13.

For example, at a magnetic field frequency of 1 MHz, a maximum allowed magnetic field of 0.2 kgauss to generate a voltage of 0.25 V at the receiving coil. This is about 50%of the inductive threshold, which will not cause error output conversion. Similarly, if such an event occurs during the pulse period (and has the worst polarity), the receiving pulse will be reduced from gt; 1.0V to 0.75V- Essence

The previous magnetic flux density value corresponds to a specific current amplitude value at a given distance from the ADUM12X transformer. FIG. 14 represents the frequency function of the allowable current as the frequency of the selected distance. As shown in the figure, Adum12x has a strong immune, and can only be affected by the high frequency and very close to the large current of the component. For a 1 Million example, the 0.5 kA current must be placed in a place where the ADUM120 5 mm is required to affect the operation of the component.

Note that under the combination of strong magnetic fields and high -frequency, any ring circuit formed by the trajectory of the printing circuit board may generate a sufficiently large error voltage, thereby triggering the follow -up circuit The threshold. When arranging such traces, pay attention to avoid this possibility.

Power consumption

The power supply current on the given channel of the Adum12x isolator is a function of the power supply voltage, channel data rate, and channel output load.

For each input channel, the power supply current consists of:

For each output channel, the power current is:

In the formula: IDDI (D), IDDO (D) is the input and output dynamic power current (MA/Mbps) of each channel. CL is an output load capacitor (PF).

VDDO is the output power supply voltage (V). F is the input logic signal frequency (MHz, half of the input data rate, NRZ signaling).

FR is the refresh rate (MBPS) in the input stage.

IDDI (Q), IDDO (Q) is the specified input and output static power current (MA).

In order to calculate the total power supply current of IDD1 and IDD2, calculate and calculate the power supply current corresponding to each input and output channel corresponding to IDD1 and IDD2. Figure 6 and 7 provide a function of the power supply per channel as a function of the data rate under the condition of the air load. Figure 8 provides per channelThe power current is the function output condition of the 15 PF data rate.Figure 9 to 11 provides power supply currents for total IDD1 and IDD2 as ADM1200 and ADM1201 channel configuration.

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