DC1555A Linear Technology, DC1555A Datasheet - Page 2

• Manufacturer Part Number: DC1555A
• Description: LTC4365 High Voltage UV, OV And Reverse Supply Protection Controller
• Manufacturer: Linear Technology
• Series: -r

Specifications of DC1555A

• Design Resources: DC1555 Design Files DC1555A Schematic
• Main Purpose: Power Management, Voltage Protection, Over, Under
• Embedded: No
• Utilized Ic / Part: LTC4365
• Primary Attributes: -
• Secondary Attributes: -
• Kit Application Type: Power Management
• Application Sub Type: Overvoltage Protection
• Features: Board Intended To Demonstrate Performance Of The LTC4365 High Voltage, Undervoltage Controller
• Lead Free Status / Rohs Status: Not applicable / Not applicable

DEMO MANUAL DC1555A
OPERATING PRINCIPLES
The LTC4365 monitors the input rail voltage and discon-
nects downstream circuits when the input voltage is too
low, too high or negative. The LTC4365 provides accurate
overvoltage 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
QUICK START PROCEDURE
Demonstration circuit 1555A is easy to set up to evaluate
the performance of the LTC4365. Refer to Figures 1a and
1b for proper measurement equipment setup and follow
the procedure below.
Note that the circuit on the DC1555A is optimized for 12V
operation; The Si4230 FET limits overvoltage and reverse
voltage to 30V and –30V, respectively. Refer to the LTC4365
data sheet for applications optimized for other voltages.
Reverse Voltage Tests (Figure 1a)
1) Set JP1 to EN.
2) Set JP2 and JP3 to CONNECT LED.
3) Connect a power supply across V
4) Connect voltmeters at the input and output and ammeter
5) Ramp supply down to –30V (referenced to GND).
6) Verify output voltage is between 0V and –0.5V, all LEDs
7) Ramp supply back to 0V.
2
confi guration (connect positive rail to GND and negative
rail to V
in series with supply.
are off, and input current is <1.8mA. (FET leakage or
other board leakage paths can pull V
tive, but it will be clamped by the internal protection
diode.)
IN
).
IN
and GND in negative
OUT
slightly nega-
protection circuits automatically isolates the load from
negative input voltages.
During normal operation, a high voltage charge pump
enhances the gate of external N-channel power MOSFETs.
The LTC4365 consumes 10μA during shutdown and 125μA
while operating.
Undervoltage/Overvoltage Test (Figure 1b)
8) Reverse the polarity of power supply connection across
9) Ramp supply up to 30V and verify green V
10) Ramp supply down from 30V down to 0V and verify
11) Repeat steps 9 and 10 with 8A load connected across
Table 1
Jumper Test
12) Remove load and set supply to 9V.
13) Move jumpers and verify LEDs according to Table 2.
Table 2
6.56V to 13.51V
15.47V to 30V
V
rail to GND).
FAULT LED, green V
Table 1 within the various voltage ranges.
0V to 5.77V
IN
green V
V
V
OUT
OUT
JP1
DIS
V
EN
EN
to GND (connect positive rail to V
IN
according to Table 1.
and GND.
IN
LED, red FAULT LED, green V
CONNECT LED
CONNECT LED
= V
V
= 0V
= 0V
JP2/JP3
OUT
Open
IN
OUT
Off/Dim/On
V
LED, and V
IN
On
On
LED
VIN LED
Off
On
On
V
OUT
OUT
Off
On
Off
IN
LED
OUT
and negative
according to
IN
VOUT LED
FAULT LED
LED, and
LED, red
Off
Off
On
On
Off
On
dc1555af