AP3987CT

Document number: DS41644 Rev. 2 - 2

12 of 15

www.diodes.com

June 2019

© Diodes Incorporated

AP3987CT

Operation Description (continued)

11.4 Internal Over Temperature Protection (Internal OTP)

If the IC junction temperature exceeds the threshold TOTP, the AP3987CT shuts down immediately and enters the hold mode. If the junction

temperature decreases by hysteresis temperature THYS, the AP3987CT can recover to normal operation. If not, the power system keeps the hold

mode.

11.5 External Over Temperature Protection (External OTP)

The AP3987CT provides external Over Temperature Protection (OTP) by connecting a Negative Temperature Coefficient (NTC) resistor from OTP

pin to GND. Internally, a current source IOTP is injected to the OTP pin, which generates a voltage proportional to the NTC resistance. At high

ambient temperature, the NTC resistance gets lower and results in the OTP pin voltage decreasing. If the OTP pin voltage drops below an

internally-set threshold VOTP, then the OTP is triggered, and the AP3987CT shuts down immediately and enters the fast auto recovery mode. The

power system will keep fast auto recovery mode until the ambient temperature decreases and OTP pin voltage increases over the voltage

VOTP_REC, which the AP3987CT can recover to normal operation.

If the OTP pin is not connected to the NTC resistor, the external OTP function will not work and the IC can still work normally with internal OTP.

Ordering Information

AP3987CT X - X

Packing

Package

13 : 13" Tape & Reel

S7 : SO-7

Product Name

Package

Temperature Range

Part Number

Marking ID

13

”Tape and Reel

Quantity

Part Number Suffix

SO-7

-40°C to +85°C

AP3987CTS7-13

AP3987CT

4000/Tape and Reel

-13

Marking Information

AP3987CT

(Top View)

YY WW X X

Logo

WW : Week : 01~52; 52

YY : Year : 18,19, 20 ~

X X : Assembly Code

represents 52 and 53 week

Marking ID

1

2

3

4

5

6

7