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dc2417af

DEMO MANUAL DC2417A

OPERATING PRINCIPLES

QUICK START PROCEDURE

The LTC4367 monitors the input voltage and disconnects

downstream circuits when the input voltage is too low, too

highornegative.TheLTC4367providesaccurateovervolt-

age and undervoltage comparators to ensure that power

is applied to the system only if the input supply is within

the allowable voltage window. Reverse supply protection

circuits automatically isolate the load from negative input

voltages.

DC2417A is easy to set up to evaluate the performance of

the LTC4367. Refer to Figure 1 for proper measurement

equipment setup and follow the procedure below.

Reverse Voltage Tests

1 Set JP1 to EN.

2 Set JP2 and JP3 to CONNECT LED.

3 Connect a power supply across VIN and GND in nega-

tive configuration (connect positive terminal to GND

and negative terminal to VIN).

4 Connect voltmeters at the input and output and an

ammeter in series with the supply.

5 Ramp VIN down to –30V (referenced to GND).

6 Verify output voltage is 0V and all LEDs are off.

7 Set JP2 and JP3 to OPEN position and measure the

input current. It should be ≤2.4mA.

8 Ramp VIN back to 0V and set JP2 and JP3 to CONNECT

LED position.

Undervoltage/Overvoltage Test

9 Correct the polarity of the power supply connection

across VIN to GND (connect positive terminal to VIN

and negative terminal to GND).

During normal operation, a high voltage charge pump en-

hancesthegateoftheexternalN-channelpowerMOSFETs.

The LTC4367 consumes 5μA during shutdown and 70μA

while operating.

10 Ramp supply up to 60V and verify that the green VIN

LED and the red FAULT LED light up, but the green

VOUT LED, does not light up.

11 Ramp supply down from 60V to 0V and verify the green

VIN LED, red FAULT LED, green VOUT LED, and VOUT

voltage according to Table 1 below.

12 Repeat steps 10 and 11 with a 3 A resistive load con-

nected between VOUT and GND.

Table 1

VIN

VOUT

VIN LED

VOUT LED

FAULT LED

0V to 5.97V

0V

Off/Dim/On

Off

On

5.97V to 14.95V

On

On

Off

14.95V to 60V

0V

On

Off

On

13 Remove load and set supply to 9V.

14 Move jumpers and verify LEDs according to Table 2

below.

Table 2

JP1

JP2/JP3

VIN LED

VOUT LED

EN

CONNECT LED

On

On

DIS

CONNECT LED

On

Off

EN

OPEN

Off

Off