REV. 0

EVAL-ADM1070EB

–3–

1. RESIDING ON A PLUG-IN BOARD

The typical method of employing the ADM1070 is to mount

the device and its accompanying components on a plug-in

board. This board is then slotted into the live backplane

when required. When the power lines connect, the ADM1070

powers up. If the supply is stable and within tolerance, it turns

the MOSFET on in a controlled manner, applying power to

the load and powering up the rest of the board.

ADM1070

–48V

LIVE

BACKPLANE

PLUG-IN BOARD

R1

R2

FET

LOAD

0V

Figure 1. The ADM1070 Residing on a Plug-In Module

To evaluate the ADM1070 in this type of situation, the

Evaluation Board should be set up as follows.

First, the board must be set up with the preferred load. The

load can be connected to the board in many different ways.

• If a single load component will suffice it can be soldered

directly onto the Evaluation Board in Position C4.

• A load can be connected via Connector J9. The user can

custom build a board to simulate a plug-in module’s load

and plug it into edge Connector J9.

(See Figure 11 for a schematic of the J9 pinout.)

• The user may connect a load via a crocodile clip directly

to the pins of Connector J9 (although care must be taken

not to cause a short across the pins of J9).

• If a no-load condition is required then nothing should

be connected to J9 and no additional load components

soldered to the Evaluation Board.

Power must now be applied to the board via leads connected

directly to a power supply. Power is normally applied through

the red and black/blue banana connectors (J1–J4).

The higher potential (0 V) should be connected to socket J1

(red). The lower potential of the supply should be connected to

J2 or J3 (black). A diode OR-ing scheme is employed at these

terminals so that two supplies can be monitored simultaneously

if required. In this situation, the supply with the higher potential

will be used. If this supply potential drops below the voltage of

the second redundant supply, then the board will switch over to

the second supply.

The diodes can be bypassed by connecting the lower potential

power supply to the board via Socket J4 (black).

A live insertion event can be recreated by turning on the power

supply or by making the connection to the live supply. Care should

be taken when applying live voltages to the Evaluation Board.

EVALUATION BOARD

BACKPLANE

BOARD

LOAD BOARD

0V

–48V

J8

J9

HOT SWAP

Figure 2. The ADM1070 Evaluation Board

Simulating the Set-Up in Figure 1

The user can also apply power to the board via Connector J8.

A simple backplane board can be constructed that plugs into

Connector J8 and provides the –48 V supply. A live insertion

event can now be simulated by plugging the Backplane Board

(see Backplane Board section) with a live negative supply into

Connector J8. A reseating event can be simulated by discon-

necting the Evaluation Board and Backplane Boards and

reconnecting them while the supply is live. This corresponds

to a plug-in module being manually reseated. This method recreates

a board insertion/removal scenario more accurately, since the

plugging/unplugging of a board from a live supply triggers the

ADM1070’s response. Again, the proper precautions should

be taken when connecting live voltages to the Evaluation Board.

2. RESIDING ON A BACKPLANE

The ADM1070 can also perform similar undervoltage and

overvoltage protection and current limiting functions when

placed on the backplane itself.

ADM1070

R1

R2

FET

–48V

LIVE

BACKPLANE

PLUG-IN BOARD

LOAD

0V

Figure 3. The ADM1070 Residing on a Backplane

This type of setup can also be recreated with the ADM1070

Evaluation Board. Power can be applied through a backplane

board or with power leads (as described in the previous section).

The power supply and the Evaluation Board should be

connected together (by either method) and the power applied

(see Figure 4). This unit now represents the live backplane

with in-built ADM1070 circuitry in Figure 3.

A live insertion event can now be simulated by connecting the

load to the Evaluation Board (via Connector J9, as described

above). Reseating can be represented by disconnecting and

reconnecting the load to/from the Evaluation Board.