ST EVAL-RHRICL1AFV1, Руководство пользователя, Страница: 17 / 27

5 Features: EVAL-RHRICL1AFV1, foldback mode
5.1 Getting started
The EVAL-RHRICL1AFV1 evaluation board is customized to allow the test of foldback operative mode of the
RHRPMICL1A integrated current limiter (ICL).
In the foldback mode, when an overcurrent event is detected, the ICL device provides a current limitation profile
whose value goes to tracking with the output voltage, reaching a small and safe value I
F
(see Figure 20. Foldback
current limiter characteristic even if a short-circuit on the load side occurs and persists.
This allows maintaining a safe power dissipation without shutting down the device, in case of failure.
The pin configuration of the ICL in this operation mode is:
•
Telecommand interface: disabled (TC_ON and TC_OFF both connected to V
CC
)
• SET_STS is connected to V
CC
(on at start-up)
• SET_FLB is connected to V
CC
(Foldback mode enabled)
• TON and TOFF are connected to GND
The external components of the board are pre-set to accomplish the following features:
•
V
CC
= 22 V with V
TH_ON
= 18 V and V
TH_OFF
= 17 V
• HYS = 1 V
• I
LIM
= 2 A
• I
F
= 100 mA
The evaluation board schematic is shown below. Please note that the capacitor Csns_3, connected in parallel to
the R
SENSE
, affects the dynamic of the reaction time and therefore the decision whether to mount it or not is up to
the application needs of the end user.
UM2605
Features: EVAL-RHRICL1AFV1, foldback mode
UM2605 - Rev 1
page 17/27