L6206Q データシートの表示（PDF） - STMicroelectronics

部品番号

コンポーネント説明

メーカー

L6206Q

DMOS dual full bridge driver

STMicroelectronics 

L6206Q

Circuit description

Inputs

EN

IN1

L

X(1)

H

L

H

H

H

L

H

H

1. X = Do not care.

2. High Z = high impedance output.

Table 6. Truth table

IN2

X(1)

L

L

H

H

Outputs

OUT1

High Z(2)

GND

VS

GND

VS

OUT2

High Z(2)

GND

GND

VS

VS

4.3

Non-dissipative overcurrent detection and protection

The L6206Q device integrates an overcurrent detection circuit (OCD). With this internal

overcurrent detection, the external current sense resistor normally used and its associated

power dissipation are eliminated. Figure 9 shows a simplified schematic of the overcurrent

detection circuit for bridge A. Bridge B is provided with an analogous circuit.

To implement the overcurrent detection, a sensing element that delivers a small but precise

fraction of the output current is implemented with each high side Power MOSFET. Since this

current is a small fraction of the output current there is very little additional power

dissipation. This current is compared with an internal reference current IREF. When the

output current reaches the detection threshold Isover, the OCD comparator signals a fault

condition. When a fault condition is detected, an internal open-drain MOSFET with a pull-

down capability of 4 mA connected to the OCD pin is turned on. Figure 10 shows the OCD

operation.

This signal can be used to regulate the output current simply by connecting the OCD pin to

the EN pin and adding an external R-C, as shown in Figure 9. The off-time before

recovering normal operation can be easily programmed by means of the accurate

thresholds of the logic inputs.

IREF and, therefore, the output current detection threshold, are selectable by the RCL value,

following Equation 1 and Equation 2:

Equation 1

Isover = 5.6 A ± 30% at -25 °C < Tj < 125 °C if RCL = 0  (PROGCL connected to GND)

Equation 2

Isover = 2---R-2---1-C---0-L--0-- ± 10% at -25 °C < Tj < 125 °C if 5 k < RCL < 40 k

Figure 11 shows the output current protection threshold versus RCL value in the range 5 k

to 40 k.

DocID022028 Rev 3

11/27

27

Share Link: