Datasheet

Datasheet

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BD9271KUT

TSZ02201-0F1F0C100260-1-2

27.Feb.2015 Rev.004

www.rohm.com

TSZ22111・15・001

● ERROR control

There are the following four types of ERROR detection signals:

(1) LED OPEN, (2) LED SHORT, (3) REGISTER SHORT, and (4) MOS SHORT

The following section shows timing charts with the setting below:

LED OPEN

LED SHORT, REGISTER SHORT are in the same way.

(example) ERRMSK[1:0]＝10b (ERR MASK count：08d)

Zoom (A) is the operation of ERROR detection.

(1)…When the abnormal signal OPEN_ERR(internal signal) is detected, and PWM=H, the abnormal condition is detected,

ERRMSK counter starts.

(2)…When ERRMSK counter reaches to the register ERRMSK[1:0]=10b, the condition is judged to the abnormal. The internal

signal ERR_judge=H.

(3)…The external pin ERR_DET turns to ERR_DET=L within 4 clks of HSYNC.

Zoom (B) is the operation of ERROR release.

(4)…When the abnormal signal is released (OPEN_ERR=L) and PWM=H, ERRMSK counter starts.

(5)…When ERRMSK counter reaches to the register ERRMSK[1:0] =10b, the condition is judged to the normal. The internal

signal ERR_judge=H.

(6)…The external pin ERR_DET turns to ERR_DET=HiZ (High as pulled up) within 4 clks of HSYNC.

HSYNC

VSYNC

OPEN_ERR

PWM

ERRMSK[1:0]

ERRMSK counter

ERR judge

ERR_DET

zoom (A)

(1) (2) (3)

Figure 19-1. Timing Chart for Error detection 1